CONSOLIDATING AND SURVEILLANCE MEASURES AFTER MALAYAN FILARIASIS BASICALLY ELIMINATED IN SICHUAN PROVINCE

Objective To master the distribution pattern of residual microfilaremia and endemic dynamics of filariasis, so as to speed up the elimination of malayan filariasis in Sichuan. Methods During the first 3 years after filariasis basically eliminated, consolidating measures such as complete case screen and treatment, and mosquito control by pyrethroid were carried out. Then surveillance activities on etiology, serology and mosquito vector were conducted. Results From 1982 to 1996, a total of 265 116 and 20 457 persons were screened in cross-sectional and key population etiological surveillance and 34 and 24 residual microfilaremia were detected out in 1982-1988 respectively. 28 287 mosquitoes in human rooms were examined in cross-sectional surveillance and only 1 mosquito infected with one Ⅱ-stage larva was detected out in 1984. From 1987 to 1995, 6 372 persons (21 338 person-times) and 37 134 mosquitoes in human rooms were examined in longitudinal surveillance but neither microfilaremia nor infected mosquito were found. From 1989 to 2000, no microfilaremia and infected mosquito were detected out again in surveillance activities and besides, there were no significant differences in antibody level between persons living in endemic or non-endemic areas ( P 0.05). Conclusion Consolidating measures taken in Sichuan after filariasis basically eliminated for eliminating the disease led to good control effectiveness. Surveillance on etiology and mosquito showed that long term control effectiveness was achieved.