Vaccine–derived Poliovirus, Thailand, 2003

摘要

To the Editor: The PolioEradication Campaign was started inThailand in 1990, and the last poliocase was reported in April 1997.Although no new cases have beenreported, the Polio EradicationCampaign continues with 4 preven-tion strategies: high coverage with 3doses of oral polio in children <1 yearof age, acute flaccid paralysis surveil-lance, acute flaccid paralysis caseinvestigation and response, andNational Immunization Day. Also, theMinistry of Public Health is preparedfor a national emergency response topolio importation and circulated vac-cine–derived poliovirus (1).In April 2003, a case of acute flac-cid paralysis was reported fromPhakhao district, Loei province. Thepatient was an 18-month-old boy withnormal physical development andnutritional status. He had a history ofmild asthma and had received bron-chodilator drugs occasionally duringupper respiratory tract infections inthe past. The patient had been fullyvaccinated. He had received a total of5 doses of oral polio vaccine: a dose at2, 4, and 6 months of age, and 2 doseson National Immunization Day inDecember 2002 and January 2003