POLIOMYELITIS IN OMAN - ACUTE FLACCID PARALYSIS SURVEILLANCE LEADING TO EARLY DETECTION AND RAPID RESPONSE TO A TYPE-3 OUTBREAK

Countries are increasingly requesting guidance on carrying out acute f laccid paralysis (AFP) surveillance, aimed at detecting and confirming all cases of acute paralytic poliomyelitis. The experience of Oman pr ovides many lessons in this respect. AFP surveillance in Oman was esta blished systematically. First, an epidemiologist was assigned to coord inate surveillance, and a laboratory for performing poliovirus isolati on was identified. Next, operational guidelines for AFP surveillance w ere developed and widely promoted among health staff. The qualify of t he system has been monitored for more than 3 years with selected perfo rmance indicators. From January 1990 to April 1993, 49 AFP cases were reported, corresponding to an average annual rate of 2.1 AFP cases per 100 000 children aged less than 15 years. A total of 98% of the AFP c ases were investigated within 48 hours of being reported; two stool sa mples were obtained from 94% of the cases. Following complete investig ation, nearly a third of the reported AFP cases were classified as bei ng clinically compatible with Guillain-Barre syndrome. Four AFP cases, all reported in 1991, were confirmed to be due to wild type 3 poliovi rus. Because AFP surveillance detected these cases rapidly, Oman was a ble to carry out outbreak control measures promptly and more than 350 000 extra doses of oral poliovirus vaccine were delivered to children under 6 years of age.