Infants infected with vaccine-derived polio in Myanmar
Two children have contracted circulating vaccine-derived poliovirus type 2 with accompanying acute flaccid paralysis in Myanmar, according to WHO.
“The Ministry of Health, supported by WHO and partners of the Global Polio Eradication Initiative, is engaging in implementing an urgent outbreak response plan,” WHO officials wrote in a news release. “The Ministry of Health plans to conduct at least three more large-scale [supplementary immunization activities] in Rakhine and neighboring provinces as well as other identified ‘high risk’ areas of the country, between now and the end of February 2016.”
The children, aged 16 months and 28 months, experienced the onset of paralysis, a common indicator of polio infection, on October 5 and April 16, respectively. Both are from the same township in Rakhine, which borders Bangladesh. The Myanmar Ministry of Health has begun a detailed investigation in the affected area. Officials collected stool samples from 28 households and community contacts of the infected children for laboratory investigation. WHO officials identified three additional acute flaccid paralysis cases, and their cause is under investigation.
WHO officials noted that the genetic diversion between the polio isolates collected in April and October suggest that vaccine-derived polio may have been circulating for more than 1 year.
According to the news release, polio vaccination coverage in Myanmar is approximately 76%, with lower coverage among those with special risks. Worldwide withdrawal of type 2 oral polio vaccine (OPV) is scheduled for April, when bivalent OPV will replace trivalent OPV.
WHO officials recommend that travelers to the area be fully vaccinated against polio before arriving.
“It is important that all countries, in particular those with frequent travel and contacts with polio-affected countries and areas, strengthen surveillance for cases of acute flaccid paralysis in order to rapidly detect any new virus importation and to facilitate a rapid response,” WHO officials wrote.