Ehrlichiosis and anaplasmosis are tick-borne bacterial infections. The most common causative species include Ehrlichia chaffeensis and Anaplasma phagocytophilum, which infect and multiply within monocytes and granulocytes, respectively. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. A maculopapular or petechial rash occurs in some patients. Gastrointestinal, neurologic, and respiratory symptoms are also possible. The diagnosis is based on clinical suspicion and confirmed PCR or antibody testing. Management is with doxycycline.
Obligate intracellular bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology
Coccobacilli
Grow in membrane-bound vacuoles in leukocytesLeukocytesWhite blood cells. These include granular leukocytes (basophils; eosinophils; and neutrophils) as well as non-granular leukocytes (lymphocytes and monocytes).White Myeloid Cells: Histology, particularly:
MonocytesMonocytesLarge, phagocytic mononuclear leukocytes produced in the vertebrate bone marrow and released into the blood; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.Innate Immunity: Phagocytes and Antigen Presentation
GranulocytesGranulocytesLeukocytes with abundant granules in the cytoplasm. They are divided into three groups according to the staining properties of the granules: neutrophilic, eosinophilic, and basophilic. Mature granulocytes are the neutrophils; eosinophils; and basophils.White Myeloid Cells: Histology
Light microscopy:
Individual organisms are difficult to appreciate.
Frequently visualized as morulae (microcolony of organisms within a vacuole)
Stains:
Wright
Giemsa
Microscopic images of Giemsa-stained cells infected with anaplasmosis: Cell nuclei are labeled “N” and the arrows point to Anaplasma morulae.
Image: “Giemsa stained cells infected with Ap.” by University of Minnesota, Department of Entomology, Saint Paul, Minnesota 55108, USA. License: CC BY 2.0
Rare causes of ehrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis in humans:
IncidenceIncidenceThe number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time.Measures of Disease Frequency in the United States:
IncidenceIncidenceThe number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time.Measures of Disease Frequency is higher in men than women.
Commonly occurs between April and September
Risk factors[11,13,14]
For ehrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis/anaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis:
Travel to or living in an endemic area
Owning pets
Participating in outdoor activities in wooded areas:
E. chaffeensis is transmitted by AmblyommaAmblyommaA genus of hardbacked ticks, in the family Ixodidae. It includes the lone star tick, Amblyomma americanum, and the Gulf Coast tick, Amblyomma maculatum, in the Americas. Amblyomma americanum is the primary vector of Ehrlichia chaffeensis and Ehrlichia ewingii which cause Ehrlichiosis. Other Amblyomma-associated diseases include tularemia and rickettsiosis.Rickettsia americanum (Lone Star tickLone Star TickRocky Mountain Spotted Fever).
A. phagocytophilum is transmitted by Ixodes ticksTicksBlood-sucking acarid parasites of the order ixodida comprising two families: the softbacked ticks (argasidae) and hardbacked ticks (ixodidae). Ticks are larger than their relatives, the mites. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many tick-borne diseases, including the transmission of rocky mountain spotted fever; tularemia; babesiosis; african swine fever; and relapsing fever.Coxiella/Q Fever.
IatrogenicIatrogenicAny adverse condition in a patient occurring as the result of treatment by a physician, surgeon, or other health professional, especially infections acquired by a patient during the course of treatment.Anterior Cord Syndrome (rare):
Blood transfusion
Solid organ transplantationOrgan TransplantationTransplantation is a procedure that involves the removal of an organ or living tissue and placing it into a different part of the body or into a different person. Organ transplantations have become the therapeutic option of choice for many individuals with end-stage organ failure. Organ Transplantation
A Lone Star tick, which can transmit E. chaffeensis
Image: “Amblyomma americanum tick” by James Gathany. License: Public Domain
Transmission electron microscopy analysis of E. chaffeensis infected ticks: E. chaffeensis organisms appear in cytoplasmic vacuoles of a tick’s midgut cell.
Image: “Transmission electron microscopy (TEM) analysis of E. chaffeensis infected ticks” by Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America. License: CC BY 4.0
Reservoirs[5,9,14]
A wide range of wild and domestic animalsAnimalsUnicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, animalia was one of the kingdoms. Under the modern three domain model, animalia represents one of the many groups in the domain eukaryota.Cell Types: Eukaryotic versus Prokaryotic can serve as reservoirs. The most notable are:
White-tailed deer (E. chaffeensis)
White-footed mice (A. phagocytophilum)
Virulence factorsVirulence factorsThose components of an organism that determine its capacity to cause disease but are not required for its viability per se. Two classes have been characterized: toxins, biological and surface adhesion molecules that affect the ability of the microorganism to invade and colonize a host.Haemophilus[10,15]
Surface proteinsProteinsLinear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.Energy Homeostasis:
Allow binding to host cells for entry
Antigenic variation helps with evading a host’s immune systemImmune systemThe body’s defense mechanism against foreign organisms or substances and deviant native cells. It includes the humoral immune response and the cell-mediated response and consists of a complex of interrelated cellular, molecular, and genetic components.Primary Lymphatic Organs.
Bacterial effector proteinsProteinsLinear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein.Energy Homeostasis:
Translocate into a host cell
Modify the cell’s cytoskeletonCytoskeletonThe network of filaments, tubules, and interconnecting filamentous bridges which give shape, structure, and organization to the cytoplasm.The Cell: Cytosol and Cytoskeleton to allow bacterial entry
Allow bacteria-containing vacuoles to avoid lysosome fusion
Alter geneGeneA category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.Basic Terms of Genetics expression in the host cell nucleusNucleusWithin a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (cell nucleolus). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the endoplasmic reticulum. A cell may contain more than one nucleus.The Cell: Organelles
E. chaffeensis is introduced into the skinSkinThe skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue.Skin: Structure and Functions during a tick bite.
Infects monocytesMonocytesLarge, phagocytic mononuclear leukocytes produced in the vertebrate bone marrow and released into the blood; contain a large, oval or somewhat indented nucleus surrounded by voluminous cytoplasm and numerous organelles.Innate Immunity: Phagocytes and Antigen Presentation and macrophagesMacrophagesThe relatively long-lived phagocytic cell of mammalian tissues that are derived from blood monocytes. Main types are peritoneal macrophages; alveolar macrophages; histiocytes; kupffer cells of the liver; and osteoclasts. They may further differentiate within chronic inflammatory lesions to epithelioid cells or may fuse to form foreign body giant cells or langhans giant cells.Innate Immunity: Phagocytes and Antigen Presentation
Spreads through the lymphatics or bloodto:
Bone marrowBone marrowThe soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.Bone Marrow: Composition and Hematopoiesis
LiverLiverThe liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy
SpleenSpleenThe spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen: Anatomy
The clinical presentation is due to the effects of the host’s inflammatory response.
A. phagocytophilum is introduced into the skinSkinThe skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue.Skin: Structure and Functions during a tick bite → neutrophil recruitmentRecruitmentSkeletal Muscle Contraction
A. phagocytophilum enters neutrophilsNeutrophilsGranular leukocytes having a nucleus with three to five lobes connected by slender threads of chromatin, and cytoplasm containing fine inconspicuous granules and stainable by neutral dyes.Innate Immunity: Phagocytes and Antigen Presentation:
Alters intracellular killing
Induces neutrophil activationNeutrophil activationThe process in which the neutrophil is stimulated by diverse substances, resulting in degranulation and/or generation of reactive oxygen products, and culminating in the destruction of invading pathogens. The stimulatory substances, including opsonized particles, immune complexes, and chemotactic factors, bind to specific cell-surface receptors on the neutrophil.Ehrlichiosis and Anaplasmosis and cytokine release → contributes to tissue injury and clinical manifestations
Infection spreads hematogenously.
Clinical Presentation
Signs and symptoms[11–15]
The incubationIncubationThe amount time between exposure to an infectious agent and becoming symptomatic.Rabies Virus period is typically 1–2 weeks, and the clinical presentation can vary greatly.
FeverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
HeadacheHeadacheThe symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders.Brain Abscess
NauseaNauseaAn unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses.Antiemetics
VomitingVomitingThe forcible expulsion of the contents of the stomach through the mouth.Hypokalemia
DiarrheaDiarrheaDiarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea
Respiratory symptoms:
Cough
Shortness of breathShortness of breathDyspnea is the subjective sensation of breathing discomfort. Dyspnea is a normal manifestation of heavy physical or psychological exertion, but also may be caused by underlying conditions (both pulmonary and extrapulmonary).Dyspnea
AnaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis with erythemaErythemaRedness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes.Chalazion migrans rashRashRocky Mountain Spotted Fever → suspect co-infection with Borrelia burgdorferiBorrelia burgdorferiA specific species of bacteria, part of the borrelia burgdorferi group, whose common name is lyme disease spirochete.Borrelia
Neurologic symptoms (rare in anaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis but seen in 20% of cases of ehrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis):
About half of infected individuals require hospitalizationHospitalizationThe confinement of a patient in a hospital.Delirium, with up to a 2.7% and a 0.3% mortalityMortalityAll deaths reported in a given population.Measures of Health Status rate associated with HMEHMEEhrlichiosis and Anaplasmosis and HGAHGAEhrlichiosis and Anaplasmosis, respectively. The risk of severe disease and complications is increased in immunocompromisedimmunocompromisedA human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation.Gastroenteritis individuals, those with extremes of age, and those with delayed treatment.
SeizuresSeizuresA seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
ARDS
MyocarditisMyocarditisMyocarditis is an inflammatory disease of the myocardium, which may occur alone or in association with a systemic process. There are numerous etiologies of myocarditis, but all lead to inflammation and myocyte injury, most often leading to signs and symptoms of heart failure. Myocarditis and heart failureHeart FailureA heterogeneous condition in which the heart is unable to pump out sufficient blood to meet the metabolic need of the body. Heart failure can be caused by structural defects, functional abnormalities (ventricular dysfunction), or a sudden overload beyond its capacity. Chronic heart failure is more common than acute heart failure which results from sudden insult to cardiac function, such as myocardial infarction.Total Anomalous Pulmonary Venous Return (TAPVR)
Pericardial effusionPericardial effusionFluid accumulation within the pericardium. Serous effusions are associated with pericardial diseases. Hemopericardium is associated with trauma. Lipid-containing effusion (chylopericardium) results from leakage of thoracic duct. Severe cases can lead to cardiac tamponade.Pericardial Effusion and Cardiac Tamponade and tamponadeTamponadePericardial effusion, usually of rapid onset, exceeding ventricular filling pressures and causing collapse of the heart with a markedly reduced cardiac output.Pericarditis
Renal failureRenal failureConditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate.Crush Syndrome
Coagulopathy
Septic shockSeptic shockSepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status.Sepsis and Septic Shock
Opportunistic infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease
Diagnosis and Management
Differences in diagnostic and management approaches are seen based on practice location. The following information is based on US (ehrlichiosis and anaplasmosis) and European literature and guidelines.
Diagnosis
Diagnostic principles:[5,6,9,11,13]
Consider clinical presentation and epidemiologic exposures (travel history, tick bite, location of exposure, and timing/season).
Obtain diagnostic testsDiagnostic testsDiagnostic tests are important aspects in making a diagnosis. Some of the most important epidemiological values of diagnostic tests include sensitivity and specificity, false positives and false negatives, positive and negative predictive values, likelihood ratios, and pre-test and post-test probabilities. Epidemiological Values of Diagnostic Tests when infection is suspected, but do not delay initiating treatment, as illness can progress rapidly.
Definitive studies:
Indirect fluorescent antibodyIndirect fluorescent antibodyA form of fluorescent antibody technique commonly used to detect serum antibodies and immune complexes in tissues and microorganisms in specimens from patients with infectious diseases. The technique involves formation of an antigen-antibody complex which is labeled with fluorescein-conjugated anti-immunoglobulin antibody.Chikungunya Virus (IFA) testing[3,6,9,11–14]
Obtain a sample (acute sample) on presentation, then 2–4 weeks later (convalescent sample).
Reference: IFA for IgGIgGThe major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b.Hypersensitivity Pneumonitis (as IgMIgMA class of immunoglobulin bearing mu chains (immunoglobulin mu-chains). Igm can fix complement. The name comes from its high molecular weight and originally being called a macroglobulin.Immunoglobulins: Types and Functions is less specific and does not necessarily indicate acute infection)
Positive test: 4-fold seroconversionSeroconversionThe appearance of antibodies against causative agents in the blood of individuals during the course of an infection or following immunization.HIV Infection and AIDS (with IgGIgGThe major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b.Hypersensitivity Pneumonitis at least 1:64–1:80)
Often negative in the 1st week
If antibiotics are taken during testing, antibody production against the infection does not rise as expected.
ELISAELISAAn immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.St. Louis Encephalitis Virus antibody testing: another form of serologySerologyThe study of serum, especially of antigen-antibody reactions in vitro.Yellow Fever Virus testing[12]
PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR) to detect organism DNADNAA deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).DNA Types and Structure:[2,5,9,11–14]
Sensitive even during the 1st week of infection
Requires PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR) testing per species
If antibiotics are received within 48 hours, the sensitivity decreases (potentially producing false negativeFalse negativeAn FN test result indicates a person does not have the disease when, in fact, they do.Epidemiological Values of Diagnostic Tests results).
If clinical suspicion is high, treatment is recommended even with a negative PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR).
Culture isolation and immunohistochemical (IHC) assays:[11,12,13]
Performed only in specialized laboratories (routine blood cultures are not useful)
When bone marrowBone marrowThe soft tissue filling the cavities of bones. Bone marrow exists in two types, yellow and red. Yellow marrow is found in the large cavities of large bones and consists mostly of fat cells and a few primitive blood cells. Red marrow is a hematopoietic tissue and is the site of production of erythrocytes and granular leukocytes. Bone marrow is made up of a framework of connective tissue containing branching fibers with the frame being filled with marrow cells.Bone Marrow: Composition and HematopoiesisbiopsyBiopsyRemoval and pathologic examination of specimens from the living body.Ewing Sarcoma is performed (often for workup of cytopeniasCytopeniasIPEX Syndrome), immunostaining of the specimen provides the diagnosis of anaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis or ehrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis.
Supporting laboratory studies:[11–14]
ThrombocytopeniaThrombocytopeniaThrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia
Leukopenia
AnemiaAnemiaAnemia is a condition in which individuals have low Hb levels, which can arise from various causes. Anemia is accompanied by a reduced number of RBCs and may manifest with fatigue, shortness of breath, pallor, and weakness. Subtypes are classified by the size of RBCs, chronicity, and etiology. Anemia: Overview and Types
↑ ASTASTEnzymes of the transferase class that catalyze the conversion of l-aspartate and 2-ketoglutarate to oxaloacetate and l-glutamate.Liver Function Tests and ALTALTAn enzyme that catalyzes the conversion of l-alanine and 2-oxoglutarate to pyruvate and l-glutamate.Liver Function Tests
↑ Alkaline phosphataseAlkaline PhosphataseAn enzyme that catalyzes the conversion of an orthophosphoric monoester and water to an alcohol and orthophosphate.Osteosarcoma
Peripheral blood smear evaluations for ehrlichiosis and anaplasmosis: These blood smears show intracellular morulae of A. phagocytophilum (1) and E. chaffeensis (2).
Image: “Etiologic agents of ehrlichioses” by CDC/NCID. License: Public Domain
If patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship do not improve with therapy, they should be evaluated for a concurrent BabesiaBabesiaBabesiosis is an infection caused by a protozoa belonging to the genus, Babesia. The most common Babesia seen in the United States is B. microti, which is transmitted by the Ixodes tick. The protozoa thrive and replicate within host erythrocytes. Lysis of erythrocytes and the body’s immune response result in clinical symptoms. Babesia/Babesiosisinfection.
Treatment details and considerations[5,6,9,11,13,14]
Antibiotics:
Doxycycline:
1st-line therapy
Given to all ages (risk of dental staining in the pediatric group is low if course is short)
Adult dose: 100 mg (oral or IV) twice daily for 10 days or up to 3–5 days after feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever resolves (whichever is longer)
Pediatric dose: 2.2 mg/kg/dose (oral or IV) twice daily up to 3–5 days after feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever resolves; maximum dose: 100 mg/dose
RifampinRifampinA semisynthetic antibiotic produced from streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits dna-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms.Epiglottitis:
Alternative therapy
Adult dose: 300 mg twice daily for 7–10 days
Pediatric dose: 20 mg/kg/day in 2 divided doses; maximum dose: 300 mg for 7–10 days
Co-infections are possible because Ixodes is the vector for Borrelia burgdorferiBorrelia burgdorferiA specific species of bacteria, part of the borrelia burgdorferi group, whose common name is lyme disease spirochete.Borreliaand BabesiaBabesiaBabesiosis is an infection caused by a protozoa belonging to the genus, Babesia. The most common Babesia seen in the United States is B. microti, which is transmitted by the Ixodes tick. The protozoa thrive and replicate within host erythrocytes. Lysis of erythrocytes and the body’s immune response result in clinical symptoms. Babesia/Babesiosis.
Treatment:
Borrelia burgdorferiBorrelia burgdorferiA specific species of bacteria, part of the borrelia burgdorferi group, whose common name is lyme disease spirochete.Borrelia (Lyme diseaseLyme diseaseLyme disease is a tick-borne infection caused by the gram-negative spirochete Borrelia burgdorferi. Lyme disease is transmitted by the black-legged Ixodes tick (known as a deer tick), which is only found in specific geographic regions. Patient presentation can vary depending on the stage of the disease and may include a characteristic erythema migrans rash. Lyme Disease) and other BorreliaBorreliaBorrelia are gram-negative microaerophilic spirochetes. Owing to their small size, they are not easily seen on Gram stain but can be visualized using dark-field microscopy, Giemsa, or Wright stain. Spirochetes are motile and move in a characteristic spinning fashion due to axial filaments in the periplasmic space. Borrelia spp. infectionsInfectionsInvasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases.Chronic Granulomatous Disease respond to doxycycline (10 days).
BabesiaBabesiaBabesiosis is an infection caused by a protozoa belonging to the genus, Babesia. The most common Babesia seen in the United States is B. microti, which is transmitted by the Ixodes tick. The protozoa thrive and replicate within host erythrocytes. Lysis of erythrocytes and the body’s immune response result in clinical symptoms. Babesia/Babesiosis microti requires a different antibiotic regimen (1st-line therapy: azithromycinAzithromycinA semi-synthetic macrolide antibiotic structurally related to erythromycin. It has been used in the treatment of Mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis.Macrolides and Ketolides + atovaquoneAtovaquoneA hydroxynaphthoquinone that has antimicrobial activity and is being used in antimalarial protocols.Antimalarial Drugs).
Prevention[11–14]
Avoiding tick bites is key to preventing these diseases.
Inspecting for ticksTicksBlood-sucking acarid parasites of the order ixodida comprising two families: the softbacked ticks (argasidae) and hardbacked ticks (ixodidae). Ticks are larger than their relatives, the mites. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many tick-borne diseases, including the transmission of rocky mountain spotted fever; tularemia; babesiosis; african swine fever; and relapsing fever.Coxiella/Q Fever after outdoor activity
Removing any attached ticksTicksBlood-sucking acarid parasites of the order ixodida comprising two families: the softbacked ticks (argasidae) and hardbacked ticks (ixodidae). Ticks are larger than their relatives, the mites. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many tick-borne diseases, including the transmission of rocky mountain spotted fever; tularemia; babesiosis; african swine fever; and relapsing fever.Coxiella/Q Fever to reduce the risk of infection
Tick control on domestic animalsAnimalsUnicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, animalia was one of the kingdoms. Under the modern three domain model, animalia represents one of the many groups in the domain eukaryota.Cell Types: Eukaryotic versus Prokaryotic
Table: Comparison of several clinically relevant gram-negative tick-borne bacteriaBacteriaBacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology
Organism
Ehrlichia chaffeensisEhrlichia chaffeensisA species of gram-negative bacteria that is the causative agent of human ehrlichiosis. This organism was first discovered at fort chaffee, arkansas, when blood samples from suspected human ehrlichiosis patients were studied.Ehrlichiosis and Anaplasmosis
Anaplasma phagocytophilumAnaplasma phagocytophilumA species of gram-negative bacteria in the genus anaplasma, family anaplasmataceae, formerly called ehrlichia phagocytophila or ehrlichia equi. This organism is tick-borne (ixodes) and causes disease in horses and sheep. In humans, it causes human granulocytic ehrlichiosis.Ehrlichiosis and Anaplasmosis
Rickettsia rickettsiiRickettsia rickettsiiA species of gram-negative, aerobic bacteria that is the etiologic agent of rocky mountain spotted fever. Its cells are slightly smaller and more uniform in size than those of rickettsia prowazekii.Rickettsia
Borrelia burgdorferiBorrelia burgdorferiA specific species of bacteria, part of the borrelia burgdorferi group, whose common name is lyme disease spirochete.Borrelia
Rocky Mountain spotted feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
Lyme diseaseLyme diseaseLyme disease is a tick-borne infection caused by the gram-negative spirochete Borrelia burgdorferi. Lyme disease is transmitted by the black-legged Ixodes tick (known as a deer tick), which is only found in specific geographic regions. Patient presentation can vary depending on the stage of the disease and may include a characteristic erythema migrans rash. Lyme Disease
SpirocheteSpirocheteTreponema is a gram-negative, microaerophilic spirochete. Owing to its very thin structure, it is not easily seen on Gram stain, but can be visualized using dark-field microscopy. This spirochete contains endoflagella, which allow for a characteristic corkscrew movement.Treponema
DermacentorDermacentorA widely distributed genus of ticks, in the family ixodidae, including a number that infest humans and other mammals. Several are vectors of diseases such as tularemia; rocky mountain spotted fever; colorado tick fever; and anaplasmosis.Rickettsia tick
Ixodes tick
ReservoirReservoirAnimate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers.Escherichia coli
White-tailed deer
White-footed mouse
DermacentorDermacentorA widely distributed genus of ticks, in the family ixodidae, including a number that infest humans and other mammals. Several are vectors of diseases such as tularemia; rocky mountain spotted fever; colorado tick fever; and anaplasmosis.Rickettsia tick
Rodents
Deer
Geographical distribution in the United States
Southeast and South Central states
Northeast and upper Midwest states
Southeast and South Central states
Northeast and Midwest states
Diagnosis
PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR)
ELISAELISAAn immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.St. Louis Encephalitis Virus
PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR)
ELISAELISAAn immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.St. Louis Encephalitis Virus
PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR)
Clinical
ELISAELISAAn immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.St. Louis Encephalitis Virus
Western blot
Management
Doxycycline
Doxycycline
AmoxicillinAmoxicillinA broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration.Penicillins
CeftriaxoneCeftriaxoneA broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears.Cephalosporins
IFA: immunofluorescent antibody
Differential Diagnosis
BabesiosisBabesiosisBabesiosis is an infection caused by a protozoa belonging to the genus, Babesia. The most common Babesia seen in the United States is B. microti, which is transmitted by the Ixodes tick. The protozoa thrive and replicate within host erythrocytes. Lysis of erythrocytes and the body’s immune response result in clinical symptoms. Babesia/Babesiosis: a tick-borne infection caused by BabesiaBabesiaBabesiosis is an infection caused by a protozoa belonging to the genus, Babesia. The most common Babesia seen in the United States is B. microti, which is transmitted by the Ixodes tick. The protozoa thrive and replicate within host erythrocytes. Lysis of erythrocytes and the body’s immune response result in clinical symptoms. Babesia/Babesiosis. PatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship can be asymptomatic or develop feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, fatigueFatigueThe state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli.Fibromyalgia, malaiseMalaiseTick-borne Encephalitis Virus, and arthralgias. Asplenic, immunocompromisedimmunocompromisedA human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation.Gastroenteritis, and elderly patientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship are at risk for severe disease, causing hemolytic anemiaHemolytic AnemiaHemolytic anemia (HA) is the term given to a large group of anemias that are caused by the premature destruction/hemolysis of circulating red blood cells (RBCs). Hemolysis can occur within (intravascular hemolysis) or outside the blood vessels (extravascular hemolysis). Hemolytic Anemia, thrombocytopeniaThrombocytopeniaThrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia, hepatosplenomegalyHepatosplenomegalyCytomegalovirus, renal failureRenal failureConditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate.Crush Syndrome, and death. Diagnosis is confirmed with a peripheral blood smearPeripheral Blood SmearAnemia: Overview and Types, serologic testing, and PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR). Management includes antimicrobials such as atovaquoneAtovaquoneA hydroxynaphthoquinone that has antimicrobial activity and is being used in antimalarial protocols.Antimalarial Drugs plus azithromycinAzithromycinA semi-synthetic macrolide antibiotic structurally related to erythromycin. It has been used in the treatment of Mycobacterium avium intracellulare infections, toxoplasmosis, and cryptosporidiosis.Macrolides and Ketolides.
Rocky Mountain spotted feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever: a disease caused by Rickettsia rickettsiiRickettsia rickettsiiA species of gram-negative, aerobic bacteria that is the etiologic agent of rocky mountain spotted fever. Its cells are slightly smaller and more uniform in size than those of rickettsia prowazekii.Rickettsia that presents with feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, fatigueFatigueThe state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli.Fibromyalgia, headacheHeadacheThe symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders.Brain Abscess, and a rashRashRocky Mountain Spotted Fever following a tick bite. However, this disease is associated with the DermacentorDermacentorA widely distributed genus of ticks, in the family ixodidae, including a number that infest humans and other mammals. Several are vectors of diseases such as tularemia; rocky mountain spotted fever; colorado tick fever; and anaplasmosis.Rickettsia tick, and the rashRashRocky Mountain Spotted Fever presents more frequently than in HMEHMEEhrlichiosis and Anaplasmosis or HGAHGAEhrlichiosis and Anaplasmosis. Diagnosis is made based on the clinical features, biopsyBiopsyRemoval and pathologic examination of specimens from the living body.Ewing Sarcoma of the rashRashRocky Mountain Spotted Fever, and serologic testing. Management involves antibiotics, including doxycycline.
Viral hepatitis:liverLiverThe liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: AnatomyinflammationInflammationInflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation caused by an infection with the hepatitis virusVirusViruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology. PatientsPatientsIndividuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures.Clinician–Patient Relationship may present with a viral prodromeProdromeSymptoms that appear 24–48 hours prior to migraine onset.Migraine Headache of feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, anorexiaAnorexiaThe lack or loss of appetite accompanied by an aversion to food and the inability to eat. It is the defining characteristic of the disorder anorexia nervosa.Anorexia Nervosa, and nauseaNauseaAn unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses.Antiemetics. Right upper quadrantRight upper quadrantAnterior Abdominal Wall: Anatomyabdominal painAbdominal PainAcute Abdomen, jaundiceJaundiceJaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice, and transaminitisTransaminitisTick-borne Encephalitis Virus also occur. The diagnosis is made with viral serologic testing and will differentiate hepatitis from HMEHMEEhrlichiosis and Anaplasmosis or HGAHGAEhrlichiosis and Anaplasmosis. Management of acute hepatitisAcute HepatitisAutoimmune Hepatitis is supportive.
MononucleosisMononucleosisInfectious mononucleosis (IM), also known as “the kissing disease,” is a highly contagious viral infection caused by the Epstein-Barr virus. Its common name is derived from its main method of transmission: the spread of infected saliva via kissing. Clinical manifestations of IM include fever, tonsillar pharyngitis, and lymphadenopathy. Mononucleosis: a disease caused by the Epstein-Barr virusEpstein-Barr VirusEpstein-Barr virus (EBV) is a linear, double-stranded DNA virus belonging to the Herpesviridae family. This highly prevalent virus is mostly transmitted through contact with oropharyngeal secretions from an infected individual. The virus can infect epithelial cells and B lymphocytes, where it can undergo lytic replication or latency. Epstein-Barr Virus that is characterized by feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, fatigueFatigueThe state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli.Fibromyalgia, lymphadenopathyLymphadenopathyLymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy, and pharyngitisPharyngitisPharyngitis is an inflammation of the back of the throat (pharynx). Pharyngitis is usually caused by an upper respiratory tract infection, which is viral in most cases. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, and hoarseness. Pharyngitis. These latter 2 features are less commonly seen in HMEHMEEhrlichiosis and Anaplasmosis or HGAHGAEhrlichiosis and Anaplasmosis. Diagnosis is based on clinical features and testing, such as a heterophile antibody test or serologySerologyThe study of serum, especially of antigen-antibody reactions in vitro.Yellow Fever Virus. Management is supportive.
Lyme diseaseLyme diseaseLyme disease is a tick-borne infection caused by the gram-negative spirochete Borrelia burgdorferi. Lyme disease is transmitted by the black-legged Ixodes tick (known as a deer tick), which is only found in specific geographic regions. Patient presentation can vary depending on the stage of the disease and may include a characteristic erythema migrans rash. Lyme Disease: an infection caused by B. burgdorferi, which is transmitted by the Ixodes tick. Presentation depends on the stage of the disease and may include a characteristic erythemaErythemaRedness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes.Chalazion migrans rashRashRocky Mountain Spotted Fever. Neurological, cardiac, ocular, and joint manifestations are also common in later stages. Diagnosis relies on clinical findings and tick exposure and is supported by serological testing. Antibiotics are used for treatment.
BrucellosisBrucellosisBrucellosis (also known as undulant fever, Mediterranean fever, or Malta fever) is a zoonotic infection that spreads predominantly through ingestion of unpasteurized dairy products or direct contact with infected animal products. Clinical manifestations include fever, arthralgias, malaise, lymphadenopathy, and hepatosplenomegaly. Brucella/Brucellosis: an infection caused by BrucellaBrucellaBrucellosis (also known as undulant fever, Mediterranean fever, or Malta fever) is a zoonotic infection that spreads predominantly through ingestion of unpasteurized dairy products or direct contact with infected animal products. Clinical manifestations include fever, arthralgias, malaise, lymphadenopathy, and hepatosplenomegaly. Brucella/Brucellosis, which spreads predominantly after the ingestion of unpasteurized dairy products or direct contact with infected animal products. Clinical manifestations include feverFeverFever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever, arthralgias, malaiseMalaiseTick-borne Encephalitis Virus, lymphadenopathyLymphadenopathyLymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy, and hepatosplenomegalyHepatosplenomegalyCytomegalovirus. Diagnosis is based on clinical manifestations, exposure history, serologySerologyThe study of serum, especially of antigen-antibody reactions in vitro.Yellow Fever Virus, and culture studies. Management involves a combination of antibiotics, including doxycycline, rifampinRifampinA semisynthetic antibiotic produced from streptomyces mediterranei. It has a broad antibacterial spectrum, including activity against several forms of Mycobacterium. In susceptible organisms it inhibits dna-dependent RNA polymerase activity by forming a stable complex with the enzyme. It thus suppresses the initiation of RNA synthesis. Rifampin is bactericidal, and acts on both intracellular and extracellular organisms.Epiglottitis, and aminoglycosidesAminoglycosidesAminoglycosides are a class of antibiotics including gentamicin, tobramycin, amikacin, neomycin, plazomicin, and streptomycin. The class binds the 30S ribosomal subunit to inhibit bacterial protein synthesis. Unlike other medications with a similar mechanism of action, aminoglycosides are bactericidal. Aminoglycosides.
Billing and Coding
Diagnosis Codes:
These codes are used to formally document a diagnosis of EhrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis or AnaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis, specific tick-borne bacterial illnesses, for patient records, billing, and reporting to public health authorities.
Domain
Code
Description
ICD-10-CM
A79.81
AnaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis
ICD-10-CM
A79.82
EhrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis
SNOMED CT
40993009
AnaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis (disorder)
SNOMED CT
24050000
EhrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis (disorder)
Evaluation & Workup:
These laboratory codes are used to order tests that support a diagnosis, such as a complete blood count (CBC), which often shows characteristic low platelet and white blood cell counts, and PCRPCRPolymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules.Polymerase Chain Reaction (PCR) tests, which directly detect the bacterial DNADNAA deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).DNA Types and Structure.
Domain
Code
Description
CPT
87798
Infectious agent detection by nucleic acid (DNADNAA deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).DNA Types and Structure or RNARNAA polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity.RNA Types and Structure), not otherwise specified
CPT
85027
Complete (CBC), automated (Hgb, Hct, RBC, WBC and platelet count)
LeukocytesLeukocytesWhite blood cells. These include granular leukocytes (basophils; eosinophils; and neutrophils) as well as non-granular leukocytes (lymphocytes and monocytes).White Myeloid Cells: Histology
LOINC
777-3
PlateletsPlateletsPlatelets are small cell fragments involved in hemostasis. Thrombopoiesis takes place primarily in the bone marrow through a series of cell differentiation and is influenced by several cytokines. Platelets are formed after fragmentation of the megakaryocyte cytoplasm. Platelets: Histology
Medications:
These codes are used in pharmacy and hospital systems to prescribe and track the administration of doxycycline, the essential first-line antibiotic treatment for both EhrlichiosisEhrlichiosisEhrlichiosis is a tick-borne bacterial infection. The most common causative species include Ehrlichia chaffeensis, which infect and multiply within monocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis and AnaplasmosisAnaplasmosisAnaplasmosis is a tick-borne bacterial infection. The most common causative species include Anaplasma phagocytophilum, which infect and multiply within granulocytes. The clinical presentation can vary widely, but often includes fever, malaise, headache, myalgia, and arthralgias. Ehrlichiosis and Anaplasmosis in adults and children.
Domain
Code
Description
RxNorm
3640
doxycycline (ingredient)
ATC
J01AA02
doxycycline
Complications & Supportive Procedures:
These ICD-10 codesICD-10 CodesEhrlichiosis and Anaplasmosis (Clinical) are used to document severe, life-threatening complications that can arise from delayed treatment, such as acute respiratory failureRespiratory failureRespiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure, septic shockSeptic shockSepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status.Sepsis and Septic Shock, and acute kidney injuryAcute Kidney InjuryAcute kidney injury refers to sudden and often reversible loss of renal function, which develops over days or weeks. Azotemia refers to elevated levels of nitrogen-containing substances in the blood that accompany AKI, which include BUN and creatinine. Acute Kidney Injury.
Domain
Code
Description
ICD-10-CM
J96.00
Acute respiratory failureRespiratory failureRespiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure, unspecified whether with hypoxiaHypoxiaSub-optimal oxygen levels in the ambient air of living organisms.Ischemic Cell Damage or hypercapniaHypercapniaA clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood.Neonatal Respiratory Distress Syndrome
ICD-10-CM
R65.21
Severe sepsisSevere SepsisSepsis in Children with septic shockSeptic shockSepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status.Sepsis and Septic Shock
ICD-10-CM
N17.9
Acute kidney failure, unspecified
ICD-10-CM
G04.90
EncephalitisEncephalitisEncephalitis is inflammation of the brain parenchyma caused by an infection, usually viral. Encephalitis may present with mild symptoms such as headache, fever, fatigue, and muscle and joint pain or with severe symptoms such as seizures, altered consciousness, and paralysis.Encephalitis and encephalomyelitis, unspecified
References
Summary of notifiable diseases–United States, 2010. (2012). Centers for Disease Control and Prevention (CDC). MMWR Morb Mortal Wkly Rep. 2012;59(53):1. https://pubmed.ncbi.nlm.nih.gov/22647710/
Everett ED, Evans KA, Henry RB, McDonald G. Human ehrlichiosis in adults after tick exposure. Diagnosis using polymerase chain reaction. (1994). Ann Intern Med. https://pubmed.ncbi.nlm.nih.gov/8147545/
Dawson JE, Fishbein DB, Eng TR, Redus MA, Green NR. Diagnosis of human ehrlichiosis with the indirect fluorescent antibody test: kinetics and specificity. (1990). https://pubmed.ncbi.nlm.nih.gov/2192013/
Dumler JS, Dawson JE, Walker DH. Human ehrlichiosis: hematopathology and immunohistologic detection of Ehrli Humchia chaffeensis. (1993). Hum Pathol. https://pubmed.ncbi.nlm.nih.gov/8491479/
Brouqui, P., Bacellar, F., Baranton, G.,et al. (2004). Guidelines for the diagnosis of tick-borne bacterial diseases in Europe. Clin Microbiol Infect. 10(12):1108–1132. https://pubmed.ncbi.nlm.nih.gov/15606643/