Challenges in Elimination of Filariasis: New Foci of B. Malayi Infection in Odisha, India

Abstract

Background: Odisha was endemic for B. malayi along with W. bancrofti for Lymphatic Filariasis, but since 2004, there was no evidence of B. malayi in Elimination of Lymphatic Filariasis (ELF) program. We conducted the present study to reconfirm the presence of B malayi in Baleswar and Bhadrak districts of Odisha. Methods: We conducted a night blood survey in 12 villages of Baleswar and 11 villages of Bhadrak district of Odisha in June 2017. Villages were selected purposively based on highest morbidity of reported lymphatic filariasis. A total of 6230 and 5606 blood slides were collected in Baleswar and Bhadrak districts respectively. Data was analyzed by using Microsoft Excel, 2007. Results were presented in the form of rates & ratios appropriately. Chi square, students‘t’ test & SEP was used as test of significance and p≤0.05 was considered statistically significant. Results: In Baleswar and Bhadrak district 0.99% and 0.43% of the slides were positive for microfilariasis (Mf). In Baleswar district Mf was detected in 83.3% of villages and in 5 villages the Mf infection rate was more than 1 percent. In Bhadrak district Mf was detected in 72.7% of villages and in 2 villages the Mf infection rate was more than 1 percent. In Baleshwar and Bhadrak district 98.4% and 33.3% of positive slides were due to B malayi infection and the difference was statistically significant (p<0.001). The difference in the age and sex wise distribution was statistically insignificant. Conclusion: Present study confirms the presence of B malayi infection in Baleshwar and Bhadrak districts of Odisha.