The document discusses the epidemiology of poliomyelitis (polio). It notes that polio mainly affects children under 5 and can cause paralysis or death in a small percentage of cases. Through global vaccination efforts, polio cases have declined over 99% since 1988. Currently only 4 countries remain endemic for polio. Surveillance of acute flaccid paralysis is a key strategy used by the Global Polio Eradication Initiative to detect poliovirus transmission and target vaccination campaigns.

1. Epidemiology of Poliomyelitis Joint Program for Family and Community Medicine Oct. 17, 09 Ghaiath M. A. Hussein MBBS, MHSc. (Bioethics)

7. Global Status 1988

8. GLOBAL STATUS 2004

13. The virion consists of a single strand of RNA containing genetic information and a protein coat. Humans are its only natural host. - The poliovirus is a member of a larger family known as Picornaviruses, which also includes rhinoviruses (such as influenza) and the hepatitis A virus. - Polio belongs to the enterovirus subgroup, made up of over 70 viruses that infect the intestines. - It is one of the smallest RNA viruses, measuring around 25 nm in diameter. AGENT: POLIO VIRUS

14. Group: Group IV ( (+)ssRNA ) Family: Picornaviridae Genus: Enterovirus Species: Poliovirus

16. Left: Picture of poliovirus. The poliovirus is extremely small, about 50 nm (nanometer = one-billionth of a meter) Courtesy of David Belnap and James Hogle Right: Cross-section of the poliovirus showing the RNA, capsid, and nerve cell receptors Illustration courtesy of Link Studio

19. The Global Polio Eradication Initiative

22. Before a WHO region can be certified polio-free, three conditions must be satisfied: ( A) at least three years of zero polio cases due to wild poliovirus ( B) excellent certification standard surveillance ( c) each country must illustrate the capacity to detect, report and respond to “imported” polio cases. Laboratory stocks must be contained and safe management of the wild virus in inactivated polio vaccine (IPV) manufacturing sites must be assured before the world can be certified polio-free.

24. Case Definition: In the Global Polio Eradication Initiative (PEI), acute flaccid paralysis is defined as: Any case of AFP in a child aged <15 years, or any case of paralytic illness in a person of any age when polio is suspected. Acute: rapid progression of paralysis from onset to maximum paralysis Flaccid: loss of muscle tone, “floppy” – as opposed to spastic or rigid Paralysis: weakness, loss of voluntary movement Any case meeting this definition undergoes a thorough investigation to determine if the paralysis is caused by polio.

26. Components of AFP surveillance 1.The AFP surveillance network and case notification 2.Case and laboratory investigation 3.Outbreak response and active case search in the community 4.60-day follow-up, cross-notification and tracking of cases 5.Data management and case classification 6.Virologic case classification scheme 7. Surveillance performance indicators