Wild poliovirus in China
WPV update 4
30 SEPTEMBER 2011 - The Ministry of Health (MOH), China, informed WHO on 26 August 2011 that wild poliovirus type 1 (WPV1) has been isolated from four young children, aged between four months and two years, with onset of paralysis between 3 and 19 July 2011. WHO has since been informed of seven more cases, including four adults. The Chinese Ministry of Health has therefore alerted WHO of a total of nine cases of polio (all WPV1), from three prefectures (Hotan, Kasghar and Bayingolin Mongol Autonomous Prefectures in southern Xinjiang Uygur Autonomous Region in western China). Genetic sequencing has determined that the WPV1 cases found in China are most closely related to virus circulating in Pakistan. The last WPV case in China was reported in 1999 and was due to an importation from India. The last indigenous polio case occurred in China in 1994. The MOH conducted an initial province-wide response vaccination campaign from 8 to 12 September, targeting 3.8 million children. Six of the 14 prefectures in the province, including the provincial capital of Urumqi, targeted children under 15 years of age, while the other prefectures targeted children under 5 years of age. An additional vaccination round, targeting those aged between 15 and 40, was conducted in Hotan Prefecture from 13 to 17 September.