Ebola virus disease and hantavirus have attracted renewed attention in recent weeks because of the serious risks they pose to public health. Although they are very different diseases, both can begin with similar symptoms and require strict infection prevention and control (IPAC) measures to limit the risk of transmission.
Recent articles published in CMAJ (Canadian Medical Association Journal) highlight key information about these diseases for healthcare professionals.
Hantavirus Cases and Risks
Hantavirus is a nationally reportable disease in Canada. Each year, approximately 4 to 5 cases are confirmed and reported to public health authorities. Most infections occur after exposure to rodents in agricultural areas of Manitoba, Saskatchewan, Alberta, and British Columbia.
One strain, known as the Andes virus, is unusual because it can spread from one person to another.
Symptoms and Diagnosis of Hantavirus
Different hantavirus strains can cause different forms of illness. In North and South America, including the Andes virus that has recently been in the news, infections can lead to hantavirus cardiopulmonary syndrome. In Europe and Asia, hantaviruses are more commonly associated with hemorrhagic fever and kidney dysfunction.
The incubation period for both forms is generally 2 to 4 weeks. Common symptoms include fever, headache, muscle aches, and abdominal pain.
Diagnosis is made through serology and polymerase chain reaction (PCR) testing. These tests are performed by the National Microbiology Laboratory in Winnipeg.
Hantavirus Treatment and Infection Control
There is currently no approved antiviral medication or vaccine specifically for hantavirus. As a result, treatment focuses on supportive care to help manage symptoms and complications.
Because of the potential for transmission, suspected Andes virus infections require strict infection prevention and control measures. Patients should be isolated using airborne, droplet, and contact precautions. Infectious disease specialists should be involved in patient management, and public health authorities must be notified.
Ebola Virus Disease and Ongoing Outbreaks
Ebola outbreaks have occurred periodically in Central and West Africa since the disease was first identified in 1976. Three major Ebola viruses are known to infect humans, and researchers believe fruit bats are the natural source.
The virus spreads through direct contact with bodily fluids such as blood, vomit, diarrhea, and sperm. People can also become infected by touching contaminated objects or surfaces.
The current outbreak in the Democratic Republic of Congo involves Bundibugyo ebolavirus, which has a reported fatality rate of 30% to 50%.
Ebola Symptoms and Testing
Although Ebola is often associated with bleeding, fewer than half of patients develop hemorrhagic symptoms.
Typical symptoms include a fever of 38°C or higher, fatigue, muscle pain, and gastrointestinal problems. The incubation period ranges from 2 to 21 days.
Diagnosis is confirmed using PCR testing.
People who develop symptoms and have possible exposure risks should be evaluated and tested. This includes travelers who have recently visited countries experiencing Ebola virus disease outbreaks, as well as people who have had close contact with infected individuals or with bats, primates, or game animals from affected regions.
Advances and Limitations in Ebola Treatment
Suspected Ebola cases require rigorous infection prevention and control procedures. Health Canada recommends detailed screening and assessment protocols along with extensive protective equipment, including a fit-tested N95 respirator, face shield, gloves, and fluid-impermeable clothing.
Significant progress has been made in preventing and treating some forms of Ebola. Vaccines targeting Zaire ebolavirus have proven highly effective, and two antiviral treatments have reduced mortality rates from 50% to 35%.
However, no approved vaccines or medications currently exist to prevent or treat Bundibugyo ebolavirus. For patients infected with this strain, supportive care remains the primary treatment option.