Preventing Bolivian Hemorrhagic Fever: A Guide To Safety

Bolivian Hemorrhagic Fever (BHF) is a severe febrile illness with a mortality rate of 5-30%. The disease is caused by the Machupo virus, which was first identified in 1963 and is transmitted to humans by infected vesper mice. While there is currently no cure or vaccine for BHF, several measures can be taken to prevent infection. These include reducing contact with vesper mice, practising good hygiene, and avoiding exposure to contaminated food or surfaces. In addition, measures such as rodent control and mosquito extermination can help to limit the spread of the disease.

Avoid areas with rodent infestations

Bolivian Hemorrhagic Fever (BHF) is a severe and potentially fatal disease caused by the Machupo virus, with a mortality rate of 25-35%. The virus is transmitted to humans through exposure to the excreta and secretions of infected wild rodents in Bolivia, primarily the large vesper mouse (Calomys callosus). As there are currently no vaccines or specific treatments available for BHF, prevention is crucial. One essential strategy to prevent infection is to avoid areas with rodent infestations.

Rodent infestations pose a significant risk of BHF transmission to humans. The large vesper mouse, which carries the Machupo virus, thrives in villages and near human habitations. Therefore, it is essential to be cautious when visiting or living in areas where rodent infestations are prevalent. This includes both rural and urban settings, as the Calomys callosus can be found in both environments.

When travelling or living in areas where rodent infestations may occur, it is crucial to take preventive measures. These measures include ensuring proper waste management, maintaining good hygiene practices, and avoiding contact with rodents and their excreta. It is also important to be vigilant for signs of rodents, such as droppings or nesting materials, and to report any sightings to the appropriate authorities.

In addition to avoiding areas with rodent infestations, it is important to practice general pest control measures. This includes sealing any gaps or holes in buildings that may allow rodents to enter, keeping food in sealed containers, and removing potential sources of water, such as standing water or water-filled containers. By reducing the presence of rodents, the risk of BHF transmission can be significantly decreased.

Furthermore, it is important to be aware of the symptoms of BHF, especially if you have been in an area with a rodent infestation. The initial symptoms of BHF include fever, malaise, headache, and myalgia, which can progress to more severe symptoms such as bleeding from the nose and gums, tremors, delirium, and convulsions. If you experience any of these symptoms, seek medical attention immediately, as early diagnosis and supportive care are crucial for managing BHF.

Avoid contact with body fluids of infected people

Bolivian Hemorrhagic Fever (BHF), or black typhus, is a hemorrhagic fever and zoonotic infectious disease originating in Bolivia. It is caused by the Machupo mammarenavirus, which is transmitted to humans by infected vesper mice (Calomys callosus), a rodent indigenous to northern Bolivia. While person-to-person transmission of BHF is rare, it is important to take precautions to avoid contact with the body fluids of infected individuals. Here are some detailed instructions to avoid such contact:

Understand the Risks of Body Fluid Exposure

Recognize that body fluids such as blood, saliva, semen, and vaginal fluid can contain viruses like HIV, hepatitis B or C, and other blood-borne illnesses. While the risk is lower for other body fluids like sweat, tears, vomit, and urine, they can still transmit these viruses if they contain traces of blood.

Respond to Accidental Contact

If you come into contact with the body fluids of an infected person, always treat the situation as potentially infectious. If you have an open wound, sore, or scratch and come into contact with body fluids, immediately wash the area thoroughly with soap and water. If the body fluids come into contact with your eyes, nose, or mouth, rinse the affected area with water.

Seek Medical Attention

If you are sexually assaulted or bitten by an infected person, go to a hospital emergency department as soon as possible. Reporting the incident promptly will help ensure that evidence is obtained and that you receive the necessary medical treatment.

Get Tested and Treated

After exposure to blood or body fluids, seek medical attention as soon as possible. You may need immediate treatment, such as a vaccine or medication, to protect against infection. Your treatment will depend on the type of exposure and the results of tests for infectious diseases like HIV, hepatitis B, and hepatitis C.

Prevent the Spread of Infection

If you have been exposed to blood or body fluids, take steps to prevent the spread of infection to others. Avoid sexual activities or use protection during sexual intercourse. Do not share personal items like toothbrushes, razors, or smoking equipment. Cover any open wounds or scratches, and properly dispose of any materials contaminated with blood, such as needles, syringes, or bandages.

Practice Safe Handling and Cleaning

When handling body fluids or cleaning wounds, always wear clean disposable gloves. Wash your hands carefully with soap and warm water for at least 15 to 20 seconds after removing gloves and disposing of them in a plastic bag. When cleaning spills, use absorbent materials like paper towels, then disinfect the area with a solution of one part bleach to nine parts water, allowing it to remain in contact for at least 10 minutes.

Use standard, contact and droplet precautions when managing suspected cases

Standard, contact, and droplet precautions are essential when managing suspected cases of Bolivian Hemorrhagic Fever (BHF) to prevent the spread of infection and ensure the safety of healthcare workers and other patients. Here are the detailed instructions for implementing these precautions:

Standard Precautions:

• Hand hygiene: Wash hands thoroughly with soap and water before and after any patient contact.
• Personal Protective Equipment (PPE): Wear appropriate PPE, including gloves, before any patient contact.
• Respiratory hygiene: Cover your mouth and nose when coughing or sneezing, and instruct patients to do the same.
• Injection and sharp object safety: Handle and dispose of sharp objects properly.
• Waste disposal: Dispose of all waste generated by the patient or their environment safely and separately.

Contact Precautions:

• Gloves and gown: Always wear gloves and a fluid-resistant, non-sterile gown when entering the room of a patient on contact precautions.
• Eye and face protection: Wear eye protection, such as goggles or a face shield, if there is a possibility of contact with bodily fluids.
• Patient placement: Place the patient in a private room, if possible, or cohort them with patients infected with similar organisms.
• Patient transport: If a patient must be transported outside their room, instruct them to wear a facemask and maintain a distance of at least 3 feet from others.
• Environmental cleaning: Regularly clean and disinfect the patient's environment, including any equipment or surfaces they may have come into contact with.

Droplet Precautions:

• Masks: Wear a surgical mask when interacting with a patient on droplet precautions or entering their room.
• Patient placement: Ideally, place patients in individual rooms. If not possible, ensure spatial separation of more than 3 feet and use curtains for privacy.
• Respiratory hygiene: Instruct patients on droplet precautions to wear a facemask when outside their room and to practice good respiratory hygiene, including covering their mouth and nose when coughing or sneezing.

By following these standard, contact, and droplet precautions, healthcare workers can effectively reduce the risk of BHF transmission and protect themselves and others from this potentially deadly disease.

Use airborne precautions when performing aerosol-generating procedures

Aerosol-generating procedures (AGPs) are medical procedures that produce minute particles that become suspended in the air (known as aerosols). They are of concern as they potentially increase the transmission risk for pathogens that can spread via aerosols. Aerosol generation occurs when tiny droplets of liquid are suspended in the air. Aerosols can be generated during many medical procedures. Some medical procedures might produce more aerosols than others, and particles of different sizes, although there remains considerable uncertainty about the risks of aerosol-generating procedures leading to airborne disease transmission.

The concept and classification of AGPs is controversial. Some argue that the real issue is one of "aerosol-generating patients" rather than "aerosol-generating procedures" and that the concept of AGPs should be discarded. Evidence supporting the aerosolising nature of many of the procedures was also lacking, and often based on the precautionary principle and low-quality mechanistic studies.

Aerosols can provide the mechanism of transfer for a number of important pathogens. Hence, AGPs are an infectious risk when performed on patients infected with these pathogens. Pathogens that may be spread by AGPs are generally those considered to spread by the "airborne route". They include coronaviruses (SARS, MERS, COVID-19), influenza, and varicella zoster (chickenpox).

The WHO lists the following clinical procedures as AGPs:

• Cardiopulmonary resuscitation (including chest compressions)
• Dentistry procedures
• Manual ventilation (before intubation)
• Non-invasive ventilation
• Sputum induction using nebulised hypertonic saline

However, there is no universal consensus as to what constitutes an aerosol-generating procedure. Other procedures identified as AGPs include:

• Breaking closed ventilation systems (intentionally or unintentionally)
• High-flow oxygen therapy
• High-frequency oscillatory ventilation
• Nasopharyngeal aspirate
• Nasopharyngoscopy or laryngoscopy
• Nebulised or aerosol therapy
• Tracheostomy procedures

Mitigation strategies for AGPs include:

• Risk-assess each patient
• Minimal number of personnel
• Doors closed for a set period of time after the procedure
• High rate of air exchanges in the room
• Airborne PPE (in addition to Contact PPE)
• Face mask (FFP3 or N95)
• Water-resistant gown
• Eye protection (face shield/visor/goggles)
• Performed by the most qualified operator available
• Consider alternatives to performing the procedure
• Consider procedure modifications to decrease risk (e.g. video laryngoscopy instead of direct laryngoscopy)

Monitor bodily fluids of recovering patients for the virus

Monitoring Bodily Fluids of Recovering Patients for the Virus

Bolivian Hemorrhagic Fever (BHF) is a severe, often fatal illness with no known cure or vaccine. The disease is caused by the Machupo virus, an arenavirus transmitted to humans by the excreta of infected wild native rodents. While person-to-person transmission is possible, it is believed to be rare.

Due to the high pathogenicity of the Machupo virus, it is crucial to monitor the bodily fluids of recovering patients for the virus to prevent further outbreaks and ensure the safety of the surrounding community. Here are some key considerations and protocols for this process:

• Timing of Monitoring: The incubation period for BHF varies depending on host factors, viral pathogenicity, and disease severity. The disease has three phases: prodromal, hemorrhagic, and convalescent. The slow convalescent phase is experienced by patients who survive the illness. Even after recovering from BHF, patients may continue to shed the virus in their bodily fluids for months. Therefore, monitoring should continue for an extended period after the patient's recovery.
• Bodily Fluids to Monitor: Patients' blood, saliva, urine, and semen should be monitored for the presence of the Machupo virus. These fluids have the potential to transmit the disease to others, especially through close contact or sexual intercourse.
• Testing and Diagnosis: Blood tests, such as polymerase chain reaction (PCR) tests, can be used to detect the presence of the virus in the blood. However, there is a lack of antibody tests to determine previous infections. Viral agents of BHF are highly pathogenic and require reference laboratories for handling, which may not be available in endemic areas.
• Infection Control Measures: Healthcare providers should take appropriate precautions when dealing with suspected or confirmed BHF cases. Standard, contact, and droplet precautions, including eye protection, are recommended. Airborne precautions are necessary when performing procedures that may aerosolize the virus.
• Patient Management: Recovering patients should be advised to avoid close contact with others, especially sexual partners and household members, until they have tested negative for the virus. This precaution will help prevent the potential spread of the disease to those in close proximity.
• Surveillance and Reporting: Clinicians and healthcare providers should maintain vigilance and report any suspected or confirmed BHF cases to local or national health authorities. This reporting is crucial for monitoring the disease's spread and implementing necessary control measures.

By diligently monitoring the bodily fluids of recovering patients for the Machupo virus, healthcare providers can contribute to the early detection of potential new cases and help prevent the spread of this severe and often fatal disease.

Frequently asked questions