12-years surveillance of poliomyelitis and acute flaccid paralysis in Fars Province, Southern Iran

ABSTRACT

Following the widespread use of poliovirus vaccine in the mid-1950s, the incidence of poliomyelitis declined rapidly in many industrialized countries. The aim of this study was to determine the surveillance of poliomyelitis and acute flaccid paralysis [AFP] in Fars Province, southern Iran to detect poliovirus wherever it may circulate. From 1995 to 2006, in a cross-sectional study, all patients over 15 years of age with flaccid paralysis in Fars Province of Iran were enrolled. The surveillance medical officers visited every AFP case, took clinical histories, and performed clinical examinations. Two stool samples were collected from each reported case within 14 days of the onset of paralysis and sent to WHO-accredited laboratories for poliovirus isolation and intra-typic differentiation. AFP cases from which stool sample of wild poliovirus was isolated were classified as confirmed poliomyelitis. Those AFP cases whose cultures for poliovirus were negative were referred to an expert panel. Whenever possible, nerve conduction velocity tests, electromyography, and other diagnostic modalities such as brain and vertebral MRI were performed along with a detailed neurological examination at least three weeks after the onset of paralysis. The non-polio AFP rate was 227 [mean 18.91 per year]. Only one case of poliomyelitis was reported in the first year of surveillance. Other 226 cases had non-polio AFP. The most common cause of paralysis among these patients was Guillain-Barre syndrome [66%]. The non-polio AFP rate is almost in agreement with the estimated incidence of AFP in the population aged 0-15 years worldwide. Routine coverage with three doses of OPV with supplementary immunization activities has reportedly reached over 95% of all target children. The existing system must be closely monitored and actively supported to maintain and constantly improve performance