Definition: Chapare hemorrhagic fever (CHHF) is caused by Chapare virus, a single-strand RNA virus of the Arenaviridae family. Chapare virus is certainly zoonotic, or animal-borne. The limited clinical information about CHHF comes from a small, poorly described cluster of hemorrhagic fever cases in rural Bolivia. A single fatal case yielded the only clinical description and blood specimen to date.
Symptoms and Treatment: The symptoms of CHHF, as reported in the only described patient, resemble those of other South American hemorrhagic fevers, such as Argentine HF or Bolivian HF. The incubation period is unknown, but for Argentine hemorrhagic fever (AHF) is 6 to 16 days. The CHHF clinical course included: Fever, headache, articulation and muscle pain, vomiting. These symptoms were followed by deterioration with multiple hemorrhagic signs. The only described CHHF patient died 14 days after onset of symptoms. Supportive therapy is important in CHHF. This includes: maintenance of hydration, management of shock, sedation, pain relief, usual precautions for patients with bleeding disorders, transfusions. Use of convalescent plasma therapy for treatment of AHF reduces mortality significantly and anecdotal evidence shows that the antiviral drug ribavirin may also hold promise for treating AHF. Ribavirin has also been considered for preventing development of disease in people exposed to other arenaviruses.
Statistics: In the first two to three years of the 1959 outbreak, most of the cases were in male adults in the rural areas around San Joaquin. The reason for the high male case rate is suspected to be due to the ratio of male-to-female working in the fields. In 1962 an increase in the number of urban cases was correlated to a decrease in the domestic feline population [and an increase in the rodent populations within the town. The drop in feline population is suspected to have been caused by an over exposure to DDT and not due to infection from MACV. Control of the outbreak was accomplished by 1965 following identification of the rodent reservoir and initiation of a systematic trapping of rodents including the importation of a feline population.