Bolivian Hemorrhagic Fever Outbreak

Bolivian Hemorrhagic Fever Caused by Chapare Virus
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Researchers have found that a deadly virus that caused an outbreak of hemorrhagic fever in Bolivia, is capable of human-to-human transmission.

In 2019, an outbreak of Bolivian hemorrhagic fever affected the capital city of La Paz and resulted in three deaths. Initially, researchers assumed it was just a case of hemorrhagic fever, similar to Ebola. Therefore, scientists began testing samples for Dengue and Yellow fever virus. 

However, it soon became clear the culprit was really something else. They then sought help from the U.S. Centers for Disease Control and Prevention (CDC).

Bolivian Hemorrhagic Fever Confirmed as Chapare Virus Infection

CDC used genome sequencing technology to analyze the samples. Thus, confirming it as Chapare virus. Prior to this, Bolivia had only ever reported one such case of Chapare virus infection, back in 2004. 

We isolated the virus, and we were expecting to find a more common disease, but the sequence data pointed to Chapare virus. We were really surprised because the 2019 outbreak in La Paz occurred long after the first case was identified in 2004.

Dr. Maria Morales-Betoulle, PhD

Furthermore, A report at the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH), confirmed the virus is capable of human-to-human transmission. The outbreak caused infections in a total of five people, including three healthcare workers.

What is the Chapare Virus?

The 2019 Chapare virus outbreak infected five people. Two of which were agricultural workers and the rest were healthcare workers.

The Chapare virus belongs to the arenavirus family. Infection results in hemorrhagic fevers. Infected rodents are responsible for spreading the disease in humans. Transmission occurs as a result of coming in contact with saliva from infected rodents or inhaling aerosols from droppings or saliva. 

Signs and symptoms include fever, headache, pain behind the eye, abdominal pain, and skin rash. As there is no specific treatment for the disease, supportive care remains the recommended management.

Viral RNA was identified in the pigmy rice rats found near one of the patient’s home and nearby farmlands. This specific rodent species is commonly found across Bolivia. Thus, suggesting that the two agricultural workers likely got infected while working in the rice fields.

Infection in a healthcare setting usually occurs as a result of coming in contact with the blood and body fluids of an infected person. Similar to the case of the three healthcare workers affected in the 2019 outbreak.

Furthermore, over five months after infection, the viral RNA was identified in the semen of one of the survivors. Thus, raising concerns about the risk of sexual transmission of the disease.

Healthcare Workers at Risk

According to the report, those working in healthcare settings should practice adequate safety measures when handling samples of suspected individuals. Furthermore, the report raises concern for a future outbreak. Which is as a result of the virus transmitting from human-to-human.

While there is still much that remains unknown about Chapare virus, it’s commendable how quickly this team was able to develop a diagnostic test, confirm human-to-human transmission and uncover preliminary evidence of the virus in rodents

Joel Breman, ASTMH President

Since the outbreak, Bolivian scientists have identified three more suspected cases. Sources report that all three are alive.


Morales-Betoulle, Maria, et al. “Detection & Characterization of a Novel Strain of Chapare Virus During an Outbreak of Viral Hemorrhagic Fever in Bolivia, 2019.” American Society of Tropical Medicine and Hygiene , 16 Nov. 2020,!/9181/presentation/3040

Pan American Health Organization /World Health Organization. Epidemiological Alert: Hemorrhagic fever due to Arenavirus in Bolivia18 July 2019. Washington, D.C. PAHO / WHO. 2019 


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