SummaryThis paper reports on DEC distribution and compliance with treatment in a large-scale annual single-dose mass treatment programme to eliminate lymphatic filariasis in the south Indian state of Tamil Nadu. 76.9% of households (82.5% in rural areas and 58.0% in urban areas) were aware of drug distribution for control of filariasis. DEC was given to 70% (= distribution rate) (range 0-92%) of the population and 53.5% (range 12-89%) complied with treatment. The distribution rate was more than 75% in 74% of the villages and compliance was in the range of 51-75% in 76% of the villages. About 5% of the treated population reported side-effects. Distribution and compliance were higher in rural than urban areas and similar between males and females. Qualitative data showed that some socio-economic factors, logistic and drug-related problems and people's poor knowledge and perceived benefits of treatment played a role in a proportion of the population not receiving or taking the drug. The Tamil Nadu programme showed that large-scale repeated annual DEC mass treatment is feasible and that existing health services are capable of delivering the drug to all communities. While even poor to moderate compliance rates can reduce the vector transmission of infection to some extent, improved drug distribution and compliance with treatment are necessary to consolidate the gains of earlier rounds of treatment and achieve the goal of filariasis elimination within a reasonable time frame.

SummaryLymphatic ®lariasis (LF) is targeted for global elimination. Repeated annual single-dose mass treatment with anti®larials has been recommended as the principal strategy to achieve LF elimination. This requires an effective and sustainable strategy to deliver the drug, diethylcarbamazine (DEC), to communities. In this study, a new drug delivery strategy ± community-directed treatment (comDT) ± was developed and implemented and its effectiveness compared with that of the traditional health servicesorganized drug delivery, in rural areas of Tamil Nadu, India. Qualitative and quantitative data showed that the communities and health services were able to distribute the drug in almost all villages. The drug distribution rate and treatment compliance rate of comDT and health services treatment were statistically compared after adjusting them for clustering. Under the comDT 68% (n 20 villages; range: 0±97%) of the population received DEC, compared with 74% (n 20 villages; range: 48±95%) with the health services treatment strategy (P > 0.05). However, only about 53% (range: 0±91%) of comDT recipients and 59% (range: 32±79%) of those who received DEC from the health services consumed the drug (P > 0.05). Although statistically not signi®cant, the distribution and compliance rates were lower under the comDT strategy. Also, the strategy's operationalization appears to be dif®cult because of some social factors, and the tradition of communities' dependence on health services for treatment, whereas health services-organized distribution was much less cumbersome and found to be more acceptable to people. However, the distribution (74%) and compliance rates (59%) achieved by health services were also only moderate and may not be adequate to eliminate LF in a reasonable time frame. Health services manpower alone may not be suf®cient to distribute the drug. We conclude that drug distribution by health services is the best option for India and participation of the community volunteers and village level government staffs in the programme is necessary to effectively distribute the drug and attain the desirable levels of treatment compliance to eliminate LF.keywords lymphatic ®lariasis, drug delivery, elimination, rural areas, India correspondence K. D. Ramaiah, Vector