Taenia/Taeniasis

General Characteristics and Epidemiology

General features of Taenia

Taenia is a genus of parasitic cestodes (tapeworms). 

Eggs: 

• Spherical
• Thick, striated wall
• Contains a 6-hooked (hexacanth) embryo Embryo The entity of a developing mammal, generally from the cleavage of a zygote to the end of embryonic differentiation of basic structures. For the human embryo, this represents the first two months of intrauterine development preceding the stages of the fetus. Fertilization and First Week

Adults:

• Size:
  • T. saginata: < 5 m in length
  • T. solium: approximately  2–7 m in length
• Ribbon-like, segmented body:
  • Scolex:
    • Rostellum with 2 rings of hooks in T. solium
    • 4 muscular suckers
  • Strobila with approximately 1000 proglottids:
    • Segmented
    • Contains sets of reproductive organs

Clinically relevant species

Taenia tapeworms cause the following diseases:

• Taeniasis:
  • T. saginata (beef tapeworm)
  • T. solium (pork tapeworm)
  • T. asiatica (Asian tapeworm)
• Cysticercosis: T. solium

Epidemiology

Geographic distribution of species:

• T. solium and T. saginata: worldwide
• T. asiatica: Asia ASIA Spinal Cord Injuries

Taeniasis:

• Affects approximately 50 million people worldwide
• Rare in the United States
• Highest incidence Incidence The 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 occurs in areas where:
  • There is poor access to clean water
  • Ingestion of raw or undercooked meat is common 

Cysticercosis:

• Approximately 1000 cases diagnosed each year in the United States
• More common in immigrants

Pathogenesis

Hosts

• Definitive host: humans
• Intermediate hosts:
  • T. saginata: cattle
  • T. solium and T. asiatica: pigs

Risk factors for hosts

• Eating raw or undercooked beef or pork
• Those living in:
  • Rural areas
  • Developing countries 
• Poor sanitation Sanitation The development and establishment of environmental conditions favorable to the health of the public. Hepatitis E Virus
• Close contact with infected animals Animals Unicellular 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

Transmission

• Taeniasis: ingestion of larval stages in meat
• Cysticercosis: ingestion of T. solium eggs through:
  • Contaminated food or water
  • Fecal–oral transmission

Life cycle and pathophysiology

Taeniasis:

1. Pigs or cattle ingest vegetation that is contaminated with eggs or gravid proglottids.
2. Eggs hatch in the intestine → oncospheres
3. Invasion into the intestinal wall → bloodstream → migration to striated muscle Striated muscle One of two types of muscle in the body, characterized by the array of bands observed under microscope. Striated muscles can be divided into two subtypes: the cardiac muscle and the skeletal muscle. Muscle Tissue: Histology → develop into cysticerci ( larvae Larvae Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals. Ascaris/Ascariasis within a fluid-filled sac)
4. Humans ingest raw or undercooked beef or pork → develop into an adult tapeworm in the intestine and attach to the intestinal wall with the scolex
5. Adults produce proglottids → mature and become gravid → detach from the tapeworm
6. Gravid proglottids and eggs are excreted in the feces → cycle continues

Cysticercosis:

1. Humans consume food or water contaminated with T. solium eggs or gravid proglottids.
2. Eggs hatch in the intestine → oncospheres
3. Invasion into the intestinal wall → bloodstream → migration to tissues and organs → develop into cysticerci → cysticercosis
4. Cysticerci can migrate to the CNS → neurocysticercosis

Clinical Presentation

Taeniasis

Most patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship (particularly adults) are asymptomatic. 

• Common symptoms include:
  • Passing proglottids in the stool (most common)
  • Nausea Nausea An 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
  • Anorexia Anorexia The 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 
  • Abdominal pain Abdominal Pain Acute Abdomen
  • Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) ani
• Less common:
  • Constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation or diarrhea Diarrhea Diarrhea 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
  • Headache Headache The 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
  • Dizziness Dizziness An imprecise term which may refer to a sense of spatial disorientation, motion of the environment, or lightheadedness. Lateral Medullary Syndrome (Wallenberg Syndrome)
  • Anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder
• Complications due to obstruction from tapeworm segments:
  • Biliary obstruction:
    • Cholecystitis Cholecystitis Cholecystitis is the inflammation of the gallbladder (GB) usually caused by the obstruction of the cystic duct (acute cholecystitis). Mechanical irritation by gallstones can also produce chronic GB inflammation. Cholecystitis is one of the most common complications of cholelithiasis but inflammation without gallstones can occur in a minority of patients. Cholecystitis
    • Pancreatitis Pancreatitis Inflammation of the pancreas. Pancreatitis is classified as acute unless there are computed tomographic or endoscopic retrograde cholangiopancreatographic findings of chronic pancreatitis. The two most common forms of acute pancreatitis are alcoholic pancreatitis and gallstone pancreatitis. Acute Pancreatitis
  • Intestinal obstruction Intestinal obstruction Any impairment, arrest, or reversal of the normal flow of intestinal contents toward the anal canal. Ascaris/Ascariasis
  • Appendicitis Appendicitis Appendicitis is the acute inflammation of the vermiform appendix and the most common abdominal surgical emergency globally. The condition has a lifetime risk of 8%. Characteristic features include periumbilical abdominal pain that migrates to the right lower quadrant, fever, anorexia, nausea, and vomiting. Appendicitis

Cysticercosis

Signs and symptoms depend on the tissues involved.

Muscular and dermatologic cysticercosis:

• Most are asymptomatic
• Cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change may be palpated under the skin Skin The 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
• Myalgia Myalgia Painful sensation in the muscles. Ion Channel Myopathy
• Myositis

Ocular cysticercosis:

• Foreign body Foreign Body Foreign Body Aspiration sensation
• Ocular pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Floaters Floaters Chorioretinitis
• Impaired vision Vision Ophthalmic Exam
• Sensation of movement in the eye
• Redness Redness Inflammation
• Photophobia Photophobia Abnormal sensitivity to light. This may occur as a manifestation of eye diseases; migraine; subarachnoid hemorrhage; meningitis; and other disorders. Photophobia may also occur in association with depression and other mental disorders. Migraine Headache

Neurocysticercosis:

• Seizures Seizures A 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
• Focal neurologic deficits Neurologic Deficits High-Risk Headaches
• Intracranial hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension:
  • Headache Headache The 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
  • Nausea Nausea An 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
  • Vertigo Vertigo Vertigo is defined as the perceived sensation of rotational motion while remaining still. A very common complaint in primary care and the ER, vertigo is more frequently experienced by women and its prevalence increases with age. Vertigo is classified into peripheral or central based on its etiology. Vertigo
  • Papilledema Papilledema Swelling of the optic disk, usually in association with increased intracranial pressure, characterized by hyperemia, blurring of the disk margins, microhemorrhages, blind spot enlargement, and engorgement of retinal veins. Chronic papilledema may cause optic atrophy and visual loss. Idiopathic Intracranial Hypertension
• Psychiatric disturbances:
  • Altered mental status Altered Mental Status Sepsis in Children
  • Changes in personality
  • Learning disabilities Learning disabilities Conditions characterized by a significant discrepancy between an individual’s perceived level of intellect and their ability to acquire new language and other cognitive skills. These may result from organic or psychological conditions. Relatively common subtypes include dyslexia, dyscalculia, and dysgraphia. DiGeorge Syndrome

Diagnosis and Management

Diagnosis

• Nonspecific laboratory findings:
  • Anemia Anemia Anemia 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
  • Eosinophilia Eosinophilia Abnormal increase of eosinophils in the blood, tissues or organs. Autosomal Dominant Hyperimmunoglobulin E Syndrome
• Stool studies:
  • Identifying eggs or proglottids will establish the diagnosis of taeniasis.
  • ELISA ELISA An 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 for Taenia antigens
  • PCR PCR Polymerase 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 identify DNA DNA A 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
• Serology Serology The study of serum, especially of antigen-antibody reactions in vitro. Yellow Fever Virus for cysticercosis: enzyme-linked immunoelectrotransfer blot
• CT or MRI may be used in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with suspected neurocysticercosis.
  • “Swiss cheese” appearance
  • Lesions can be:
    • Cystic Cystic Fibrocystic Change
    • Calcified
    • Ring-enhancing
  • Other potential findings:
    • Hydrocephalus Hydrocephalus Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, intracranial. Subarachnoid Hemorrhage with ventricular enlargement
    • Leptomeningeal enhancement

Taeniasis management

Taeniasis can be treated with anthelmintic therapy Anthelmintic therapy Agents that kill parasitic worms. They are used therapeutically in the treatment of helminthiasis in man and animal. Toxocariasis:

• Praziquantel Praziquantel An anthelmintic used in most schistosome and many cestode infestations. Anthelmintic Drugs (preferred)
• Niclosamide Niclosamide An antihelmintic that is active against most tapeworms. Anthelmintic Drugs

Cysticercosis management

• General: Asymptomatic disease does not require treatment.
• Ocular cysticercosis: ophthalmologic evaluation
• Neurocysticercosis:
  • Anthelmintic therapy Anthelmintic therapy Agents that kill parasitic worms. They are used therapeutically in the treatment of helminthiasis in man and animal. Toxocariasis
    • Albendazole Albendazole A benzimidazole broad-spectrum anthelmintic structurally related to mebendazole that is effective against many diseases. Anthelmintic Drugs
    • Praziquantel Praziquantel An anthelmintic used in most schistosome and many cestode infestations. Anthelmintic Drugs may be added.
  • Corticosteroids Corticosteroids Chorioretinitis
    • Prednisone Prednisone A synthetic anti-inflammatory glucocorticoid derived from cortisone. It is biologically inert and converted to prednisolone in the liver. Immunosuppressants or dexamethasone Dexamethasone An anti-inflammatory 9-fluoro-glucocorticoid. Antiemetics
    • Given prior to and during anthelmintic therapy Anthelmintic therapy Agents that kill parasitic worms. They are used therapeutically in the treatment of helminthiasis in man and animal. Toxocariasis
    • Reduce inflammation Inflammation Inflammation 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 dying cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change
  • Antiepileptic medications
  • Neurosurgical consultation for:
    • ↑ Intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension 
    • Intraventricular cysticerci

Prevention

• Properly cook meat.
• Identify and treat infected patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship.
• Perform proper hygiene.
• Avoid potentially contaminated food and water.

Comparison of Tapeworm Species

Differential Diagnosis

• Ascariasis Ascariasis Ascariasis is most often caused by A. lumbricoides. If symptomatic, characteristics typically follow 2 phases, which correlate with the migration of the parasite through the body. The early phase may include cough, dyspnea, and wheezing. The late phase typically includes abdominal discomfort, bloating, nausea, and intermittent diarrhea. Ascaris/Ascariasis: infection caused by the parasitic roundworm, Ascaris Ascaris Ascaris is a genus of parasitic nematodes. The infection, ascariasis, is most often caused by A. lumbricoides. Transmission occurs primarily via ingestion of water or food contaminated with Ascaris eggs. Most patients with ascariasis are asymptomatic. Ascaris/Ascariasis lumbricoides: Transmission of the worm occurs from ingestion of water or food that is contaminated with Ascaris Ascaris Ascaris is a genus of parasitic nematodes. The infection, ascariasis, is most often caused by A. lumbricoides. Transmission occurs primarily via ingestion of water or food contaminated with Ascaris eggs. Most patients with ascariasis are asymptomatic. Ascaris/Ascariasis eggs. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may be asymptomatic or experience cough and hemoptysis Hemoptysis Hemoptysis is defined as the expectoration of blood originating in the lower respiratory tract. Hemoptysis is a consequence of another disease process and can be classified as either life threatening or non-life threatening. Hemoptysis can result in significant morbidity and mortality due to both drowning (reduced gas exchange as the lungs fill with blood) and hemorrhagic shock. Hemoptysis. A large worm burden can cause intestinal obstruction Intestinal obstruction Any impairment, arrest, or reversal of the normal flow of intestinal contents toward the anal canal. Ascaris/Ascariasis and impair growth in children. Examination of the stool may show the presence of worms or eggs. Management is with anthelmintic therapy Anthelmintic therapy Agents that kill parasitic worms. They are used therapeutically in the treatment of helminthiasis in man and animal. Toxocariasis.
• Gastroenteritis Gastroenteritis Gastroenteritis is inflammation of the stomach and intestines, commonly caused by infections from bacteria, viruses, or parasites. Transmission may be foodborne, fecal-oral, or through animal contact. Common clinical features include abdominal pain, diarrhea, vomiting, fever, and dehydration. Gastroenteritis: inflammation Inflammation Inflammation 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 of the stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy and intestines, commonly caused by infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease from bacteria Bacteria Bacteria 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, viruses Viruses Minute infectious agents whose genomes are composed of DNA or RNA, but not both. They are characterized by a lack of independent metabolism and the inability to replicate outside living host cells. Virology, or parasites: Common clinical features include abdominal pain Abdominal Pain Acute Abdomen, diarrhea Diarrhea Diarrhea 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, vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, fever Fever Fever 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, and dehydration Dehydration The condition that results from excessive loss of water from a living organism. Volume Depletion and Dehydration. Diagnostic testing with stool analysis or culture is not always required but can help determine the etiology in certain circumstances. Most cases are self-limited; therefore, the only required treatment is supportive therapy (fluids). 
• Inflammatory bowel disease (IBD): includes Crohn’s disease and ulcerative colitis Colitis Inflammation of the colon section of the large intestine, usually with symptoms such as diarrhea (often with blood and mucus), abdominal pain, and fever. Pseudomembranous Colitis and is characterized by chronic inflammation Chronic Inflammation Inflammation of the GI tract owing to a cell-mediated immune response to the GI mucosa. Symptoms include diarrhea Diarrhea Diarrhea 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, abdominal pain Abdominal Pain Acute Abdomen, weight loss Weight loss Decrease in existing body weight. Bariatric Surgery, and extraintestinal manifestations. Diagnosis includes imaging, endoscopy Endoscopy Procedures of applying endoscopes for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. Transluminal, to examine or perform surgery on the interior parts of the body. Gastroesophageal Reflux Disease (GERD), and biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Management involves steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors, aminosalicylates, immunomodulators, and biologic agents Biologic Agents Immunosuppressants.
• Pernicious anemia Pernicious anemia A megaloblastic anemia occurring in children but more commonly in later life, characterized by histamine-fast achlorhydria, in which the laboratory and clinical manifestations are based on malabsorption of vitamin B12 due to a failure of the gastric mucosa to secrete adequate and potent intrinsic factor. Megaloblastic Anemia: causes vitamin B₁₂ deficiency and megaloblastic anemia Megaloblastic anemia Megaloblastic anemia is a subset of macrocytic anemias that arises because of impaired nucleic acid synthesis in erythroid precursors. This impairment leads to ineffective RBC production and intramedullary hemolysis that is characterized by large cells with arrested nuclear maturation. The most common causes are vitamin B12 and folic acid deficiencies. Megaloblastic Anemia due to a deficiency of intrinsic factor Intrinsic factor A glycoprotein secreted by the cells of the gastric glands that is required for the absorption of vitamin B 12 (cyanocobalamin). Deficiency of intrinsic factor leads to vitamin B12 deficiency and anemia, pernicious. Gastritis, which is required for vitamin B₁₂ absorption Absorption Absorption involves the uptake of nutrient molecules and their transfer from the lumen of the GI tract across the enterocytes and into the interstitial space, where they can be taken up in the venous or lymphatic circulation. Digestion and Absorption: Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may have fatigue Fatigue The 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, cognitive decline, neuropathy Neuropathy Leprosy, ataxia Ataxia Impairment of the ability to perform smoothly coordinated voluntary movements. This condition may affect the limbs, trunk, eyes, pharynx, larynx, and other structures. Ataxia may result from impaired sensory or motor function. Sensory ataxia may result from posterior column injury or peripheral nerve diseases. Motor ataxia may be associated with cerebellar diseases; cerebral cortex diseases; thalamic diseases; basal ganglia diseases; injury to the red nucleus; and other conditions. Ataxia-telangiectasia, and glossitis. Low vitamin B₁₂ levels, anti-intrinsic factor antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions, and the Schilling test can be used for diagnosis. Management includes vitamin B₁₂ replacement.
• Bacterial meningitis Bacterial meningitis Bacterial infections of the leptomeninges and subarachnoid space, frequently involving the cerebral cortex, cranial nerves, cerebral blood vessels, spinal cord, and nerve roots. Meningitis: life-threatening bacterial infection of the meninges Meninges The brain and the spinal cord are enveloped by 3 overlapping layers of connective tissue called the meninges. The layers are, from the most external layer to the most internal layer, the dura mater, arachnoid mater, and pia mater. Between these layers are 3 potential spaces called the epidural, subdural, and subarachnoid spaces. Meninges: Anatomy: Bacterial meningitis Bacterial meningitis Bacterial infections of the leptomeninges and subarachnoid space, frequently involving the cerebral cortex, cranial nerves, cerebral blood vessels, spinal cord, and nerve roots. Meningitis can present with fever Fever Fever 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, headache Headache The 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, meningeal signs, and seizures Seizures A 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.  The diagnosis is made by clinical examination and confirmed by finding bacteria Bacteria Bacteria 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 in the CSF, which is obtained by lumbar puncture Lumbar Puncture Febrile Infant. Management involves corticosteroids Corticosteroids Chorioretinitis and IV antibiotics directed against the identified bacteria Bacteria Bacteria 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.
• Intracranial tumors: benign Benign Fibroadenoma or malignant growth of cells in the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification: Intracranial tumors present as headache Headache The 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, unexplained nausea Nausea An 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 or vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, blurred vision Blurred Vision Retinal Detachment, and difficulty in speech or hearing. The diagnosis is made with a neurologic examination, imaging (MRI or CT), and sometimes biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Management includes radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma, chemotherapy Chemotherapy Osteosarcoma, and/or surgery.
• Brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease: a collection of pus in the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification parenchyma due to an infection: Brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease presents with fever Fever Fever 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, headache Headache The 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, seizures Seizures A 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, nausea Nausea An 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, and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia. The diagnosis is based mainly on imaging, as it is difficult to arrive at a definitive diagnosis on the basis of clinical presentation alone. Management includes antibiotic therapy and surgery to drain the abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease.