[The role of epidemiologic surveillance of migrants in the system of poliomyelitis control].

AIM: Analysis of results of virological study of material from children of migrants and evaluation of intensity of immunity against polioviruses in these children. MATERIALS AND METHODS: 1668 feces samples from patients with acute flaccid paralysis and contact individuals and 479 feces samples from healthy children from families of migrants, as well as 1012 blood sera of children aged 3 - 4 and 14 - 15 years living in the same territory of Russia, and 169 blood sera of children of migrants were studied. Polioviruses and non-polio enteroviruses were isolated by standard procedures recommended by WHO in 3 cell cultures - RD, L20B and Hep-2. Virus identification was carried out by microneutralization test with rabbit antisera against poliomyelitisvirus, RIVM (Bilthoven, Netherlands). For intra-type differentiation EIA and PCRwere used. Antibody titers were determined in microneutralization reaction with reference poliovirus vaccines strains in Hep-2 cell culture. RESULTS: The frequency of detection of polioviruses in children of migrants was significantly higher than in patients with acute flaccid paralysis. In a larger percent of cases children of migrants did not have protective antibody titers against polioviruses of all the 3 serotypes. CONCLUSION: Migrants as a significant source of poliovirus detection may be an indicator group for detection of signs of unfavorable epidemic situation. Based on the results of epidemiologic surveillance of migrants the fact of import of wild poliovirus into North-West of Russia with the absence of poliomyelitis was proven, which confirms an important role of this form of monitoring in the system of poliomyelitis control.