Poliomyelitis in China

Key facts

  • Polio (poliomyelitis) mainly affects children under five years of age.
  • In 2012, only three countries in the world (Afghanistan, Nigeria and Pakistan) remain polio-endemic, down from more than 125 countries in 1988, when the World Health Assembly committed to eradicate polio globally.
  • As long as a single child remains infected, children in all countries are at risk of contracting polio. In 2010-2012, more than 30 separate importations into previously polio-free countries occurred.

Polio in China

  • China had its last indigenous polio case in 1994
  • In 2000, the Regional Commission for the Certification of Poliomyelitis Eradication (RCC) in WHO Western Pacific Region declared China polio-free.
  • China, therefore, has successfully maintained elimination of polio for over 11 years.
  • In July to October 2011, China experienced an outbreak caused by imported wild poliovirus type 1 from Pakistan. The outbreak affected 10 young children and 11 adults, and resulted in 2 deaths. The last polio case in this outbreak had onset of symptoms on 9 October 2011
  • China neighbours two of the three countries that remain polio-endemic, Pakistan and Afghanistan. This means China remains especially vigilant in efforts to maintain a polio-free status.

Polio Vaccine in China

  • Currently, China’s Ministry of Health continues to recommend the use of live oral poliovirus vaccine (OPV) in its national immunization programme.
  • China produces enough OPV to vaccinate all children born in the country every year.
  • At present, no inactivated poliovirus vaccine (IPV) is produced by manufacturers in China. Imported IPV became available in September 2009, but the supply is limited and the vaccine has to be paid for out of pocket by the recipient.

Progress

  • Poliomyelitis has been historically endemic in China, with periodic epidemics having been documented since the early 1950s. Control of this devastating disease was an early public-health priority for the newly formed People’s Republic of China.
  • By 1963, oral polio vaccine (OPV) was being administered in annual mass campaigns during winter.
  • In 1978, OPV was included in the schedule of the newly established Expanded Programme on Immunization. Cases of poliomyelitis declined dramatically with increasing vaccine use through nation-wide campaigns and routine immunization immunisation services.
  • The last indigenous wild poliovirus (WPV) was isolated in September 1994; in October 2000, China was certified as being polio free.
  • In 1995 and 1996, four paralysis cases caused by WPVs from Myanmar were detected in the border area of Yunnan Province.
  • In 1999, one paralysis case caused by WPVs from the Sub-Indian Continent identified in Qinghai Province.
  • In 2011, the imported WPV from Pakistan caused polio outbreak in southern part in Xinjiang and resulted in 21 polio paralysis cases.
  • Until polio is eradicated globally, increasing international and domestic population movements pose a significant risk for importation of WPVs to China.

Strategies

China adopted four core strategies to achieve and sustain polio-free status:

  • high routine immunization coverage with three doses of poliovirus vaccine in the infant period and fourth dose of poliovirus vaccine in the four year of life;
  • supplementary doses of OPV to all children mainly under five years of age during SIAs, with some SIAs in expanded age-groups according to epidemiological evidences;
  • surveillance for wild poliovirus through reporting and laboratory testing of all acute flaccid paralysis (AFP) cases among children under fifteen years of age;
  • targeted “mop-up” campaigns once wild poliovirus transmission is limited to a specific focal area.
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