Viral Diseases - HEPATITIS A

(Infectious hepatitis, Epidemic hepatitis, Epidemic jaundice)

AGENT:

Family Picornaviridae, Genus enterovirus

RESERVOIR AND INCIDENCE:

More than 200 cases of hepatitis A virus infection in humans have been associated with nonhuman primates, principally chimpanzees but also woolly and patas monkeys, Celebes apes, siamangs, and gorillas. Man, and rarely captive chimpanzees, are the reservoir host; less frequently, certain other nonhuman primates. An enzootic focus has been identified in Malaysia, but there is no suggestion of transmission to man.

TRANSMISSION:

Although transmission of the virus may occur by contaminated needles, it is usually by the fecal-oral route. Nonhuman primates acquire the disease from man.

DISEASE IN NONHUMAN PRIMATES:

Usually do not show clinical signs, although malaise, vomiting, and jaundice have been reported. Disease is detected by elevated liver enzymes or diagnostic liver biopsies. Usually a self-limiting disease.

DISEASE IN MAN:

Fever, malaise, anorexia, headache, muscle pain, abdominal discomfort, and jaundice. Liver enzymes are elevated along with LDH, bilirubin, and alkaline phosphatase. Morbidity is variable and mortality is 0.6% Development of antibody confers lifelong immunity.

DIAGNOSIS:

RIA or ELISA

TREATMENT:

Bed rest, IV fluids if dehydrated.

PREVENTION/CONTROL:

Strictly quarantine newly arrived chimps and allow only limited human contact for at least 45-60 days. Protective clothing (gown, gloves, & mask) Routine disinfection of equipment and personal hygiene. Administer immune serum to handlers of newly imported chimpanzees (0.02ml/kg) every 3 mos. or 0.06 ml/kg every 4 months. Vaccine developed.