Tajikistan: Vaccine-derived polio activity reported in Khatlon Province during September /update 2

Event

Health authorities reported nine additional cases of circulating vaccine-derived poliovirus type 2 (cVDPV2) in Tajikistan Aug. 4-Sept. 2, bringing the total to 32 confirmed cases in Tajikistan since Jan. 1. Khatlon Province remains the most affected. This represents the most complete data available as of Sept. 7.

Context

Authorities reported the first known case of cVDPV2 in Tajikistan in mid-February. The country had a significant outbreak of wild poliovirus (WPV) in 2010, when officials reported 463 WPV cases. Cases of cVDPV are a rare result of widespread vaccination using oral polio vaccine (OPV), which contains a live but weakened poliovirus strain. When a child is immunized with OPV, the weakened vaccine-virus replicates in the intestine for a limited time, leading to antibodies' development. In areas of inadequate sanitation, vaccine-virus excreted by these children can spread in the community.

Polio is highly infectious and can spread rapidly through contact with infected fecal material, such as contaminated food and water. Infections are generally mild, but one in 200 cases leads to irreversible paralysis. Among those victims, 5-10 percent die when respiratory muscles become affected. The risk of paralysis increases with age. There is no specific treatment for polio.

The risk of healthy individuals contracting polio from contaminated food or water remains negligible. Still, individuals with compromised immune systems or those suffering from long-term illness may be more susceptible.

Advice

Visit a doctor to receive a precautionary polio booster before traveling to Tajikistan, as even mildly symptomatic or asymptomatic people are infectious. Practice basic food and water precautions: drink only boiled, bottled, or purified water, and ensure that food is properly prepared and served hot.

Resources

US CDC Travel Health Notice for Polio in Asia