What are the other Names for this Condition? (Also known as/Synonyms)

• Black Typhus
• Ordog Fever 
• South American Hemorrhagic Fever

What is Bolivian Hemorrhagic Fever? (Definition/Background Information)

• Bolivian Hemorrhagic Fever is a severe and deadly disease found in humans. It is an emerging viral illness which is endemic to certain regions in Bolivia in South America. Rodents are the asymptomatic carriers of infection and transmit the virus to humans
• Machupo virus (MACV) and Chapare virus (CHAPV) are the two recognized causative viruses of Bolivian Hemorrhagic Fever. The disease can be transmitted in a variety of ways - from contact with infected rodents and their excreta, bodily fluids from infected individuals, and via contaminated medical equipment
• The signs and symptoms of the disease appear between 4-21 days after exposure to infection. In most of the individuals, the infection improves after 1-2 weeks of a self-limiting flu-like illness, but approximately one-third of the untreated cases develop severe hemorrhagic illness that can be life-threatening
• The best diagnostic test to detect Bolivian Hemorrhagic Fever infection is polymerase chain reaction (PCR) test which detects the genetic material present in the virus. Currently, there are no antiviral treatments available, and only symptomatic treatment is administered
• The prognosis of Bolivian Hemorrhagic Fever is generally poor (25-35% fatality rates) in the absence of early treatment. Also, presently, There are no approved vaccines available to prevent this infection

Who gets Bolivian Hemorrhagic Fever? (Age and Sex Distribution)

• The exact burden of Bolivian Hemorrhagic Fever is not known due to insufficient population studies in Bolivia. However, it is reported that the condition is frequently misdiagnosed or may remain underdiagnosed
• Both male and female genders of any age group can be affected

What are the Risk Factors for Bolivian Hemorrhagic Fever? (Predisposing Factors)

The risk factors for Bolivian Hemorrhagic Fever may include:

• Living in or traveling to Bolivia - almost all cases of Bolivian Hemorrhagic Fever have been reported from Bolivia
• Agricultural work - as the agricultural harvest takes place in rainy months in Bolivia when rodent migration is at its highest
• Providing care for individuals with the disease - thus placing medical professionals and family members at risk for infection
• Medical procedures that may disperse (spray) particles of the infected person’s body fluids, such as during chest compressions, cardiopulmonary resuscitation (CPR), intubation, mechanical ventilation, and endoscopies
• Performing research on contaminated samples

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Bolivian Hemorrhagic Fever? (Etiology)

• There are two recognized causative agents of Bolivian Hemorrhagic Fever, which belong to Arenaviridae family and clade B of South American hemorrhagic fever arenaviruses:
  • Machupo virus (MACV)
  • Chapare virus (CHAPV) 
• These are RNA viruses, which means that they have ribonucleic acid (RNA) as their genetic material
• The animal reservoir for Machupo virus is a rodent called Calomys callosus, or the large Vesper mouse, which is found in northern Bolivia in South America. However, the rodent reservoirs of Chapare virus are not yet known
• The rodents develop asymptomatic infection and excrete virus in bodily fluids such as saliva, urine, and feces
• The transmission to humans occurs through animal-human contact or human-human contact. Transmission from rodents to humans may occur through:
  • Inhalation of rodent excreta stirred in air
  • Consumption of food contaminated with rodent excreta
  • Contact with rodent excreta through cuts/breaks in skin or mucous membranes
  • Bites and scratches by infected rodents
• Human to human transmission may take place through contact with body fluids of infected individuals

What are the Signs and Symptoms of Bolivian Hemorrhagic Fever?

The signs and symptoms of Bolivian Hemorrhagic Fever vary depending on the length of infection. There are three clinical phases of the illness:

• Prodromal phase (1-5 days)
• Hemorrhagic phase (2-10 days)
• Convalescent phase (weeks to months)

The prodromal phase produces flu-like signs and symptoms which may include:

• Fever
• Fatigue and malaise
• Headache
• Pain behind the eyes
• Muscle and joint pain
• Low-back pain
• Stomach pain
• Anorexia
• Nausea/vomiting
• Diarrhea and dehydration
• Dizziness
• Irritability
• Decrease in blood cell counts

Prodromal phase progresses to hemorrhagic phase in one-third of the cases. It is characterized by the most severe symptoms, including bleeding manifestations in various organs such as:

• Bleeding in skin, eyes, gums, or nose
• Blood in vomitus, cough, urine, or stools
• Bleeding from sites of skin or vein puncture
• Fluid in lungs
• Low blood pressure
• Liver damage
• Neurological signs such as tremors, muscle spasms, seizures, delirium, and coma

If prompt treatment is not received, around one-third of the individuals with hemorrhagic phase succumb to the condition from complications including pulmonary edema, massive internal bleeding, and hypovolemic shock, usually seven to twelve days after the onset of symptoms.

Individuals who survive the hemorrhagic phase progress to a convalescent phase that can last several weeks or even months until full recovery. The following can occur during this phase:

• Fatigue
• Dizziness
• Beau lines in nails (horizontal depressions in the nail plate)
• Hair loss 

How is Bolivian Hemorrhagic Fever Diagnosed?

To make the diagnosis of Bolivian Hemorrhagic Fever, it is important to collect information about the following:

• Clinical data including signs and symptoms, physical examination, and course of the illness including changes in blood chemistry
• Travel to endemic areas in Bolivia
• History of exposure to rodents in the endemic areas
• History of contact with individuals with suggestive symptomatology

The following tests, although performed at only designated centers (e.g., Centers for Disease Control and Prevention/CDC), can be used to confirm the diagnosis:

• Molecular tests, e.g., polymerase chain reaction (PCR) which is a highly specific test
• Virus isolation in cell culture
• Serological tests are not specific and may include:
  • Enzyme-linked immunosorbent assay (ELISA)
  • Indirect immunofluorescence
  • Complement fixation test
  • Neutralizing antibody test

Differential diagnosis - other conditions which may present with similar signs and symptoms include:

• Argentine hemorrhagic fever 
• Malaria
• Dengue
• Yellow fever
• Leptospirosis
• Hantavirus

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Bolivian Hemorrhagic Fever?

As Bolivian Hemorrhagic Fever symptoms worsen, life-threatening complications may occur, such as:

• Multiple organ failure
• Severe bleeding
• Hypovolemic shock

In general, not much information is available about the long-term complications of the disease.

How is Bolivian Hemorrhagic Fever Treated?

Currently, there are no antiviral treatments approved for individuals with Bolivian Hemorrhagic Fever. Only supportive therapy is provided to individuals to help them cope with the disease and its symptoms. These include:

• Fever control
• Fluid and electrolytes maintenance
• Oxygen and blood pressure checks
• Pain relief
• Transfusions for bleeding disorders 

Immune serum collected from convalescent individuals can be helpful in increasing the survival if administered in the early phase of disease.

How can Bolivian Hemorrhagic Fever be Prevented?

Preventive measures for Bolivian Hemorrhagic Fever may include:

• Public health measures for public education and vigilance
• Avoiding exposure to rodents and their body fluids and droppings
• Rodent control using rodenticide and rodent traps in and around homes
• Avoiding contact with body fluids (e.g., saliva, blood, respiratory secretions, semen, urine, etc.) of affected individuals (both sick and recovering), until their tests are negative for the virus
• Strictly isolating the suspected or confirmed cases
• Following all infection-control procedures in healthcare and other settings. Use of protective clothing, masks, and gloves
• Being careful while handling rodents and patient samples, especially during research

Other preventative measures include:

• Frequent hand washing
• Ensuring proper disposal of contaminated materials
• Avoiding or limiting travel to the endemic regions in Bolivia, especially if there are reports of an outbreak

What is the Prognosis of Bolivian Hemorrhagic Fever? (Outcomes/Resolutions)

• Bolivian Hemorrhagic Fever is a severe disease with an average mortality rate of 25-35% in the absence of early diagnosis and treatment
• Mortality can be decreased with prompt supportive treatment, if the condition is suspected in the early phases of the illness
• Survivors are known to recover fully without any long-term complications

Additional and Relevant Useful Information for Bolivian Hemorrhagic Fever:

Machupo virus is named after a tributary of Amazon River that flows through the region where the first outbreak occurred. Chapare virus is named after the geographic region where it was discovered in Bolivia.