Twelve laboratory-confirmed cases of circulating vaccine-derived poliovirus type 1 have been diagnosed since late April in Port Moresby (1 case) and in the provinces of Eastern Highlands (4 cases), Enga (2 cases), Madang (2 cases), and Morobe (3 cases). The most recent was on August 2. One clinical case of polio often represents hundreds of infections in the population with out symptoms. Risk to travelers is negligible but an adult booster of inactivated polio vaccine for all travelers going there is recommended (in addition to a past a primary series).
Papua New Guinea has not had a case of wild poliovirus since 1996, and the country was certified as polio-free in 2000. In response to the cases 4 rounds of large scale immunisations campaigns have been started to vaccinate children under 5 years.