Description of Medical Condition An acute infectious disease caused by Vibrio cholerae (El Tor type is responsible for current epidemic, the other type, classic, is found only in Bangladesh). (New serotype now in Bangladesh, India (0139). Important because of lack of efficacy of standard vaccine.) Characteristics include severe diarrhea with extreme fluid and electrolyte depletion, and vomiting, muscle cramps and prostration. Usual course: acute; chronic; relapsing. Clinical course is 3-5 days, and in the early stages a severely affected patient can lose one liter of fluid per hour Endemic areas: India; Southeast Asia; Africa; Middle East; Southern Europe; Oceania; South and Central America System(s) affected: Gastrointestinal Genetics: N/A Incidence/Prevalence in USA: […]


Description of Medical Condition Systemic bacterial infection caused by Brucella species in infected animal products, or vaccine. Incubation period usually 5-60 days, but highly variable and may be several months. Characterized by intermittent or irregular fevers, with symptoms ranging from subclinical disease to infection of almost any organ system. Bone and joint involvement common. May be chronic or recurrent. Case fatality untreated less than 2%. System(s) affected: Endocrine/Metabolic, Gastrointestinal, Renal/Urologic, Pulmonary, Nervous, Skin/Exocrine, Musculoskeletal, Cardiovascular Genetics: None; some evidence for intrauterine transmission Incidence/Prevalence in USA: About 100/year (105 cases in 1992; 0.34/100,000), but probably underreported Common in developing countries; consider in immigrants Highest rates in Hispanic population, along US-Mexico border Considered […]

Brain Abscess

Description of Medical Condition Single or multiple abscesses within the brain, usually occurring secondary to a focus of infection outside the central nervous system. May mimic brain tumor but evolves more rapidly (days to a few weeks). It starts as a cerebritis, becomes necrotic, and subsequently becomes encapsulated. System(s) affected: Nervous Genetics: No known genetic pattern Incidence/Prevalence in USA: Infrequent Predominant age: Median age 30-40 Predominant sex: Male > Female (2:1) Medical Symptoms and Signs of Disease Recent onset of headache becoming severe Nausea and vomiting Mental changes progressing to stupor and coma Afebrile or low-grade fever Neck stiffness Seizures Papilledema Focal neurological signs depending on location What Causes Disease? Direct […]


Description of Medical Condition An intoxication producing paralytic disease caused by neurotoxins of Clostridium botulism and is the most toxic substances known to science. The toxin prevents acetylcholine release at presynaptic membranes, blocking neuromuscular transmission in cholinergic nerve fibers. Four forms exist: Foodborne botulism Infantile botulism Wound botulism Classification undetermined System(s) affected: Endocrine/Metabolic, Gastrointestinal, Nervous Genetics: N/A Incidence/Prevalence in USA: Rare 0.34/100,000 with 75% the infantile form Foodborne — 24 cases/year Infantile-71 cases/year Wound botulism — less than 100 cases in literature Indeterminate — very rare but incidence unknown Predominant age: Foodborne — all ages Infantile — 2 to 4 months (rare after 6 months) Wound- usually younger adult Undetermined-older than […]

Management of Bacterial Meningitis

Central nervous system infections, especially bacterial meningitis, are frequently life-threatening and usually constitute medical emergencies that require accurate and prompt treatment. (Portions of this section about meningitis have previously been published [Swartz and O'Hanley 1987] and are reproduced with permission of the publisher, Scientific American Medicine, New York. [Send permission to section editor.]) Fortunately, advances in methods of diagnosis and treatment developed during the past 15 years have significantly improved the prognosis associated with many of these illnesses. New diagnostic methods (such as latex agglutination and polymerase chain reaction) supplement rather than supplant cerebrospinal fluid studies. The cerebrospinal fluid studies frequently provide important initial information needed for clinical and microbiologic diagnosis; […]

Pelvic inflammatory disease (PID)

Description of Medical Condition PID is a clinical syndrome caused by the ascent of microorganisms from the vagina and endocervix to the endometrium, fallopian tubes, ovaries, and contiguous structures. PID is a broad term that includes a variety of upper genital tract infections, unrelated to pregnancy or surgical procedures, such as salpingitis, salpingo-oophoritis, endometritis, tubo-ovarian inflammatory masses, and pelvic or diffuse peritonitis. Pathogenesis The precise mechanism by which microorganisms ascend from the lower genital tract is not known. One possibility is that chlamydial or gono-coccal endocervicitis alters the defense mechanisms of the cervix allowing ascent of the vaginal flora with or without the original pathogen. Other possibilities suggest that polymicrobial infection […]


Description of Medical Condition Osteomyelitis is an acute or chronic infection of the bone and its structures caused most commonly by bacteria and rarely by other microorganisms. This infection may be acquired either by hematogenous, contiguous, or direct inoculation such as trauma or surgery. System(s) affected: Musculoskeletal Genetics: There is no genetic predisposition known in this disease Incidence/Prevalence in USA: Uncommon Predominant age: This infection is commonly seen in older adults; hematogenous is bimodal, also seen in infants and children Predominant sex: Males > Females Medical Symptoms and Signs of Disease Hematogenous long bone infection in children Abrupt onset of high fever Irritability Malaise Restriction of movement of the involved extremity […]

Pneumonia, bacterial

Description of Medical Condition An acute, bacterial infection of the lung parenchyma. Infection may be community-acquired or nosocomial (hospital acquired by an inpatient for at least 48 hours or inpatient in the previous 90 days). Most commonly, community-acquired disease is caused by Streptococcus pneumoniae or Mycoplasma pneumoniae. Hospital-acquired pneumonia is usually due to gram negative rods (60%, such as Pseudomonas) or Staphylococcus (30%). System(s) affected: Pulmonary Genetics: No known genetic pattern Incidence/Prevalence in USA: Incidence-community-acquired: 1200 cases/100,000 population per year Incidence — nosocomial: 800 cases/100,000 admissions per year Predominant age: Age extremes Predominant sex: Male > Female Medical Symptoms and Signs of Disease Cardinal signs and symptoms Cough and fever Chest […]

Arthritis, infectious

Description of Medical Condition Invasion of joints by live microorganisms or their fragments. One of the few curable causes of arthritis. May allow early recognition of systemic infection/disease. System(s) affected: Musculoskeletal Genetics: N/A Incidence/Prevalence in USA: Neisserial: Responsible for 50% of infectious arthritis Arthritis occurs in 0.6% of the 3% of women with gonorrhea Arthritis occurs in 0.1% of the 0.7% of men with gonorrhea Arthritis occurs in 7% of individuals with N. meningitidis Non-Neisserial: – Half as frequent as Neisserial Predominant age: Neisserial: Especially 15-40, can occur at any age Non-Neisserial: Prior to age 2:27% Staphylococcus, 20% Streptococcus, 33% Haemophilus, and 13% other gram negative rods, 7% miscellaneous Age 2-14: […]