Don’t ‘pooh-pooh’ stool cultures for surveillance of acute flaccid paralysis

With the continuing risk of poliovirus importation into Canada, active surveillance of acute flaccid paralysis (AFP) in children younger than 15 years of age for potential cases of paralytic poliomyelitis continues to be the focus of surveillance activities. The single most important laboratory investigation to confirm or rule out a diagnosis of paralytic poliomyelitis, which is recommended by the national Working Group on Polio Eradication, is a stool specimen collected within two weeks of the onset of paralysis for isolation of wild or vaccine strains of poliovirus. In 1999, stool specimens were taken for 25 (40.9%) of 61 confirmed cases. Sixteen of the 25 cases were reported as negative for the poliovirus and other enteroviruses; however, laboratory results were unknown for nine cases. The 1999 rate remains significantly lower than the World Health Organization’s target of an adequate stool investigation in 80% of AFP cases. A protocol for the investigation of AFP and suspected cases of paralytic poliomyelitis has been published (1) and may be accessed electronically via the Internet at http://www.hc-sc.gc.ca/hpb/lcdc/bid/di/polio_e.html.