Prevalence of Lymphatic Filariasis in the Northeastern States of India, with Particular Reference to Assam and Prospects of Elimination
India is committed for the elimination of lymphatic filariasis (ELF) by 2020. Efforts were made to achieve this goal across the country during the last 10 years or so, and data thus generated reflect both the success and weaknesses of the ELF programme. India is contributing highest load of Lymphatic Filariasis (LF) infection to the global scenario, thus facing a massive challenge to make ELF programme a success. In this endeavour, the implementation of single annual dose of diethylcarbamazine citrate (DEC) and albendazole (Alb), in more than 250 endemic districts of the country for 8–10 years in a row, speaks volumes about the daunting commitment of the Government of India towards this programme. Apart from ensuring consistency in delivery of drugs for LF, the mapping of the areas which are still not covered under mass drug administration (MDA) is also a challenge for the programme managers. Data on endemicity of the LF are lacking specially from northeastern states of India.
In the northeastern region, which comprises eight states, only Assam is known as the endemic state for Lymphatic Filariasis (Anonymous, 1991) and, therefore, mass drug administration for ELF is being implemented only in this state. Of the 35 districts of Assam state, at least seven are endemic for LF and received MDA. Though, after several rounds of MDA, declining trend of microfilaria (mf) rate had been noticed in many districts of Assam, however, few districts still continued to report mf rate higher than the cutoff level of 1%. Unlike many parts of the country, LF is not uniformly distributed in the endemic districts of Assam. The tea garden worker population reports high microfilaria carriers, while the non-tea garden population records significantly low mf rate. As a result a district may report mf rate less than 1% and not qualify for MDA, whereas the population concentrated in the tea garden areas of the same district, which is sizeable in number, depicts mf rate as high as 5% even after several rounds of MDA (Khan et al. 2015). Therefore, ELF programme in northeast India needs a special attention to cover this vulnerable population with MDA for the success of the ELF.
We sincerely thanks to the director general of Indian Council of Medical Research, New Delhi, and director of ICMR-RMRC, Dibrugarh, for permission, encouragement and financial support for carrying out this study. We also acknowledge support and encouragement received from the director and programme managers, National Vector Borne Disease Control Programme, Delhi. This study would not have been possible without active and consistent support from the staff of the Division of Entomology and Filariasis, ICMR-Regional Medical Research Centre Dibrugarh, and we sincerely acknowledge contribution of my colleagues and supporting staff who have played pivotal role such as, Mr. CK Sarmah, technical officer; Mr. NK Baruah, laboratory technician; Mr. P. Doloi, laboratory technician; Mr. R. Doloi, laboratory technician; and the staff vehicle drivers who took the team to some of the most difficult and almost inaccessible survey areas endemic to lymphatic filariasis. We are also thankful to the director of Vector Control Research Centre, Puducherry, for sharing certain information and valuable suggestions. Support extended by district officials/PHCs/tea estate managers/doctors is also gratefully acknowledged.
- Anonymous (1991) In health information of India –Population exposed to the risk of filariasis, Ministry of Health and Family Welfare, Govt. of India. pp 147–148Google Scholar
- Anonymous (2004) Statistical hand book of Assam. Directorate of Economics and statistics, Govt. of Assam, Guwahati, India), p 116Google Scholar
- Bockarie MJ, Ibam E, Alexander ND, Hyun P, Dimber Z, Bockarie F, Alpers MP, Kazura JW (2000) Toward eliminating lymphatic filariasis in Papua New Guinea: impact of annual single-dose mass treatment on transmission of Wuchereriabancrofti in East Sepik Province. P N G Med J 43(3–4):172–182 PubMed PMID: 11939298 PubMedGoogle Scholar
- Das PK, Ramaiah KD, Vanamail P, Pani SP, Yuvaraj J, Balarajan K, Bundy DAP (2001b) Placebo–controlled community trial of four cycles of single-dose diethylcarbamazine or ivermectin against Wuchereriabancrofti infection and transmission in India. Trans R Soc Trop Med Hyg 95:336–341CrossRefGoogle Scholar
- Khan AM, Dutta P, Sarmah CK, Baruah NK, Das S, Pathak AK, Sarmah P, Hussain ME, Mahanta J. Prevalence of lymphatic filariasis in a tea garden worker population of Dibrugarh (Assam), India after six rounds of mass drug administration. J Vector Borne Dis 2015 Dec;52(4):314–320. PubMed PMID: 26714512Google Scholar
- Khan AM, Mahanta J (2005) Lymphatic Filariasis eradication programme. Curr Sci 88(9):1359–1360Google Scholar
- Raina VK, Tripathi VC, Das PB, Kumar A (1993) Declining trend of Brugiamalayi in district Cachar, Assam state, India. J Commun Dis 25:107–111Google Scholar
- Ramaiah KD, Das PK, Appavoo NC, Ramu K, Augustin DJ, Vinay Kumar KN, Chandrakala AV (2000) Aprogramme to eliminate lymphatic filariasis in tamil nadu state, India: compliance with annual single-dose DEC mass treatment and some related operational aspects. Trop Med Int Health 5:842–847CrossRefGoogle Scholar
- Ramaiah KD, Das PK, Vanamail P, Pani SP (2003) The impact of six rounds of single-dose mass administration diethylcarbamazine or ivermectin on transmission of Wuchereria bancrofti by Culex quinquefasciatus and its implications for lymphatic filariasis elimination programme. Trop Med Int Health 8:1082–1092CrossRefGoogle Scholar
- Rao SS (1942) Observations on Filariasis in Lakhipur and Binakandy tea-gardens (Cachar District, Lower Assam). Indian J Med Res 30:345–350Google Scholar
- Sasa M (1976) Human filariasis, a global survey of epidemiology and control. Tokyo, University of Tokyo Press, p 819Google Scholar
- Singh S, Bora D, Lal S. (2010) Lymphatic filariasis in East District, Sikkim. J Commun Dis 42(1):33–37. PubMed PMID: 22468549Google Scholar
- Vanamail P, Ramaiah KD, Subramanian S, Pani SP, Yuvaraj J, Das PK (2005) Pattern of community compliance with spaced, single, mass administrations of diethylcarbamazine or ivermectin, for the elimination of lymphatic filariasis from rural areas of southern India. Ann Trop Med Parasitol 99:237–242CrossRefGoogle Scholar
- WHO (2005) Global programme to eliminate lymphatic Filariasis. Wkly Epidemiol Rec 23(80):201–212Google Scholar