Neurologic Infections in Travelers

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


Semin Neurol. 2019;39(3):399-414. 

In This Article



Poliomyelitis belongs to the Enterovirus genus and is transmitted via fecal–oral or oral route. After the initiation of the Global Polio Eradication Initiative (GPEI) in 1988, polio was eradicated from the Americas by 1991. Two countries that have not reached eradication status are Pakistan and Afghanistan. There were outbreaks of wild poliovirus in Africa and the Middle East, with subsequent control as of 2015.[72] Threat of transmission among travelers is still present despite this global campaign, mainly in South Asia and West Africa.[2]

Life Cycle, Ecology, and Species

Poliovirus is a nonenveloped, single-stranded RNA virus with three types (1, 2, and 3). The virus typically infects the oropharynx and replicates in lymphatic tissue. In a very small percentage, the virus will invade the CNS.[72]

Clinical Manifestations

Most infections are asymptomatic. Symptomatic patients will have a mild febrile illness followed by acute flaccid paralysis of one or more limbs or meningitis. Respiratory failure can occur.[2,70] Post-polio syndrome is believed to be an exacerbation of existing muscle weakness, fatigue, and pain, for which other etiologies have been ruled out. This entity, the causation of which is controversial, occurs in 20 to 85% and can occur decades after initial infection.[73]


Poliovirus can be identified from throat secretions 1 week after symptom onset, or in stool specimens up to 4 weeks after onset of symptoms.[72] CSF studies are rarely positive for viral isolation or PCR identification.[72]


There is no specific treatment for poliomyelitis. Supportive management is the mainstay of treatment. There is no specific treatment for post-polio syndrome either, but physical therapy may improve outcomes.[73] Two effective vaccines are available: the inactivated polio vaccine (IPV) was introduced in 1955 and the live oral polio vaccine (OPV) introduced in the 1960s. The OPV has been linked to vaccine-associated paralytic poliomyelitis. The OPV is still used in countries with wild poliovirus in an effort to eradicate polio.[72]