Chapare hemorrhagic fever (CHHF) is a viral hemorrhagic fever caused by infection with Chapare virus. The Chapare virus is in the arenavirus family. Arenaviruses are usually spread to people through direct contact with infected rodents or indirectly through the urine or feces (droppings) of an infected rodent.

There have been two documented outbreaks of CHHF to date. The first occurred in 2003 in Chapare Province, Bolivia, which resulted in one fatal case. The second outbreak occurred in 2019 in Caranavi Province, Bolivia and resulted in five confirmed cases— three of which were fatal.

Transmission

Though the rodent reservoir of Chapare virus is unknown, similar arenaviruses are typically transmitted either through direct or indirect contact with the saliva, urine, and droppings of infected rodents. Examples of direct contact include bites and scratches by infected rodents. Examples of indirect contact include breathing in the virus when it is stirred into the air or ingestion of food contaminated with the urine, salvia, or droppings of infected rodents.

Signs and Symptoms

The symptoms of CHHF resemble those of other South American hemorrhagic fevers, such as Argentine hemorrhagic fever (AHF) or Bolivian hemorrhagic fever (BHF).

Due to the low number of documented cases of CHHF, there is limited information about the progression of signs and symptoms of this illness and the incubation period. The incubation period, or the time between initial exposure to the development of symptoms, is variable and ranges from 4 – 21 days for arenaviruses.

The documented signs and symptoms of CHHF from the first and second outbreaks included some or all of the following:

• fever
• headache
• joint and muscle pain
• pain behind the eyes
• stomach pain
• vomiting
• diarrhea
• bleeding gums
• rash
• irritability

Diagnosis

Because infection with Chapare virus infection can produce hemorrhagic symptoms in humans, often with a fatal outcome, work with suspected samples should be conducted using the highest biosecurity standards available (CDC advises a Biosafety Level 4 laboratory), strictly following all protocols for personal protection, sample inactivation and waste disposal. In the United States, Chapare virus is classified as a Select Agent.

Treatment

There is currently no treatment for CHHF. Supportive therapy is important for recovery from and survival of CHHF. This includes:

• maintenance of hydration
• management of shock (eg, fluid resuscitation, administration of vasopressin stocks)
• sedation
• pain relief
• transfusions (when necessary)