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 Italy disease statistics of Chapare Hemorrhagic Fever were given as The ability of a virus to bind to different cellular receptors via its glycoprotein makes GP an important pathogenic factor. OW and NW clade C arenaviruses use alpha-dystroglycan (αDG) as their receptor for cell entry. The differences in affinity of GP binding to αDG may contribute to differences in the disease outcome. Two strains of LCMV, clone 13 (Cl 13) and Armstrong (ARM), can induce different disease outcomes in mouse models. The Cl 13 strain causes chronic infection, whereas the ARM strain causes acute infection. Studies showed that LCMV with high affinity for αDG, such as the Cl 13 strain, is able to infiltrate the white pulp of the spleen and abolish the cytotoxic T lymphocytes, therefore inducing a persistent infection.