Viral Hemorrhagic Fevers
GENERAL PRINCIPLES
• This syndrome is caused by many different RNA viruses, including filoviruses (Ebola and Marburg), Aaviviruses (dengue, yellow fever), bunyaviruses (Hantaviruses, Congo-Crimean hemorrhagic fever [CCHF], Rift Valley fever [RVF]), and arenaviruses (South American hemorrhagic fevers, Lassa fever) (Table 14-14).
• The 2014-16 West African Ebola virus disease (EVD) epidemic and subsequent outbreaks in Central Africa demonstrate that sustained human-to-human transmission of EVD is possible in vulnerable populations.
• Case fatality rates are variable but can be as high as 90% for EVD in resource-limited settings.
DIAGNOSIS
Clinical Presentation
• Early symptoms include fevers, myalgias, and malaise, with varying severity and symptomatology depending on the virus, but all can severely disrupt vascular permeability and cause DIC. Thrombocytopenia, leukopenia, and hepatitis are common.
• Vbmiting and severe diarrhea leading to significant dehydration and mortality, as evidenced by the West African EVD epidemic, can also be a prominent feature.61
Diagnostic Testing
• Diagnosis requires consideration of epidemiology and patient risk factors, especially travel to endemic areas.
• Serology performed by reference laboratories can confirm diagnosis. Notify local infection control and public health departments immediately.
TREATMENT
• Treatment is primarily supportive with attention to infection control.
• A recombinant vesicular stomatitis virus-Zaire Ebola virus vaccine offered protection against EVD after exposure during the West African EVD epidemic. Preexposure vaccination is recommended for adults who are at high risk for occupational exposure.62
• Monoclonal antibodies have been approved for the treatment of EVD.
• Exposed contacts should monitor temperature twice daily for 3 weeks. Postexposure prophylaxis with oral ribavirin can be administered to febrile CCHF, Lassa, and RVF contacts.