Neurologic Infections in Travelers

Malveeka Sharma, MD, MPH; Joseph R. Zunt, MD, MPH

Disclosures

Semin Neurol. 2019;39(3):399-414. 

In This Article

Viral Hemorrhagic Fever

Epidemiology/Life Cycle, Ecology, and Species

Viral hemorrhagic fevers (VHFs) are caused by several families of RNA viruses, including Filovirus (Ebola and Marburg), arenavirus (Lassa fever, lymphocytic choriomeningitis virus, Lujo, Guanarito, Machupo, Junin, Sabia, and Chapare viruses), bunyavirus (Rift Valley fever, Crimean–Congo hemorrhagic fever, and hantavirus), and flavivirus (dengue, yellow fever, Omsk hemorrhagic fever, Kyasanur Forest disease, and Alkhurma virus). Transmission varies but can be person-to-person through direct contact with bodily fluids from cadavers of infected patients, direct interaction with infected livestock, inhalation of material contaminated by infected rodent excreta, or vector-borne. These viruses are distributed across the globe and each has an endemic region. The risk of transmission is low in international travelers unless travel includes exposure to urban areas, spelunking, monkeys, rat urine, or epidemic regions.[62]

Clinical Manifestations

Most VHFs present with nonspecific symptoms of fever, myalgia, and prostration within 3 weeks of exposure. This is usually followed by severe coagulopathy. The CNS manifestations of VHF are typically underreported. Table 5 lists the CNS manifestations of important VHF viruses and potential mechanisms.[63–67]

Diagnosis

All VHFs are reportable to local health authorities and the CDC. Whole blood or serum may be tested for virologic (RT-PCR, antigen detection, virus isolation) or serologic (IgM, IgG) evidence of infection. Appropriate personal protective equipment should be used.[62] In the United States, specimens should be sent to biosafety level 4 facilities.[2]

Treatment

Suspected or confirmed cases should be managed in isolation facilities. There is no specific antiviral treatment. Supportive management includes fluid and electrolyte replacement and blood transfusions.[62] Ribavirin has been shown to have varying efficacy for Lassa virus, Junin virus, Hantavirus, and Crimean–Congo hemorrhagic fever. Human monoclonal antibodies and novel experimental drugs have shown some promise for treatment of Ebola. Convalescent serum has been shown to be useful in Argentine VHF.[64] For the majority of VHF, no vaccine is available. The risk of acquiring VHF is very low in international travelers. Prevention should focus on personal protective equipment, avoiding regions with outbreaks or endemic infection, and avoiding contact with rodents and livestock.[62] Rift Valley fever has multiple inactivated and live vaccines available, however none are licensed for use.[68]

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