South Sudan: Polio virus transmission continues in northwestern states as of December 2020. /update 1

Event

Health authorities in South Sudan reported 10 additional cases of circulating vaccine-derived poliovirus (cVDPV) Oct. 29-Dec. 8, bringing the total for the year to 22 cases. These recently reported cases are the first reported cVDPV cases in the country since 2014. Western Bahr El Ghazal (six cases) is the most affected area, followed by Warrap (five cases) and Northern Bahr El Ghazal (one case) states. This represents the most complete data available as of Dec. 17.

Context

These are the first known cases of cVDPV in South Sudan since 2014. Cases of cVDPV are a rare result of widespread vaccination using oral polio vaccine (OPV), which contains a live but weakened strain of poliovirus. When a child is immunized with OPV, the weakened vaccine-virus replicates in the intestine for a limited time, leading to the development of antibodies. In areas of inadequate sanitation, vaccine-virus excreted by these children can spread in the community infecting susceptible individuals.

Polio is highly infectious and can spread rapidly through contact with infected fecal material, such as in 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.

Advice

Visit a doctor to receive polio vaccination before traveling to South Sudan, as even mildly symptomatic or asymptomatic people are infectious. Additionally, fully vaccinated adults should consider receiving a single lifetime booster dose of polio vaccine. Practice basic food and water precautions: Drink only boiled, bottled, or purified water, and ensure that food is properly prepared and served hot. Wash hands regularly with soap and water or use alcohol-based hand sanitizer when soap and water are unavailable.