Spread of polio in Syria due to vaccine derived strain

A second outbreak of polio involving 17 children is due to a strain of the virus derived from the polio vaccine. This viral strain can occur when there is an inability of health workers to immunize all children and sanitation is poor. Sixteen of the paralyzed children were from Mayadin, south of Deir al-Zour, and one was from farther north in Raqqa.

Advice

The regular oral polio vaccine contains a weakened form of the polio virus that activates the immune system’s response and creates immunity to polio infection. The live polio vaccine is secreted in the waste of vaccinated children, and over time, it can mutate into an infectious strain that may afflict the unvaccinated. The risks are especially high in areas where not all children have received the vaccine and where the mutated virus can spread from contaminated sewage or water.

Travellers in any country that reports cases of polio can reduce their risk of exposure to poliovirus by ensuring that their childhood vaccinations, including polio, are up-to-date prior to travelling. Residents (and visitors for more than 4 weeks) from infected areas should receive an additional dose of oral polio vaccine or inactivated polio vaccine within 4 weeks to 12 months before travelling.

French:

Les voyageurs dans tout pays qui signale des cas de polio peuvent réduire leur risque d’exposition au virus de la poliomyélite en veillant à ce que leurs vaccinations, y compris la polio, soient à jour avant le voyage. Les résidents (et les visiteurs pendant plus de 4 semaines) des zones infectées devraient recevoir une dose supplémentaire de vaccin antipoliomyélitique oral ou de vaccin antipoliomyélitique inactivé dans les 4 semaines à 12 mois avant le voyage.