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: Approximately one third of patients develop severe neurological or hemorrhagic symptoms within a week of the prodromal phase. Symptoms include flushing of the head and torso, petechiae, hypotension, blood in vomit and stool, delirium, convulsions, tremors, bleeding gums, coma, and death. The mortality rate varies between outbreaks of BHF but is estimated to be around 25%. The convalescent phase can last up to eight weeks and can include fatigue, dizziness and hair loss. The cause of these neurological issues is currently unknown. The effectiveness of immune serum treatment with non-human primates following exposure to MACV implies clearance is mediated through a humoral immune response.