A campaign of "communication for behavioural impact" to improve mass drug administrations against lymphatic filariasis: structure, implementation and impact on people's knowledge and treatment coverage.

In the mass drug administrations (MDA) that form the principal strategy of the Global Programme to Eliminate Lymphatic Filariasis, treatment coverages of at least 65%-80% will be needed if the programme is to be successful. In the Indian state of Tamil Nadu, where treatment coverages were typically <65%, a comprehensive strategy of advocacy and communication, called the "communication for behavioural impact" (COMBI) campaign, has been developed and implemented, in an attempt to improve treatment coverage. This strategy combined advocacy, aimed at state-, district- and village-level administrations, with communication activities targeted at individual communities. The main aim was to alter the behaviour of many of those included in the rounds of MDA, so that they would be more likely to accept and consume the diethylcarbamazine tablets offered to them. The COMBI campaign had two variants, COMBI(+) and the more intensive COMBI(+ +), each of which has been implemented in six districts. Both the variants included the "personal selling" of treatment, via door-to-door visiting by a total of 113,500 filaria-prevention assistants. These assistants were able to visit 34%-49% of the households in each target community. In the COMBI(+ +) districts, up to 44% and 38% of households received information on lymphatic filariasis and its elimination via television commercials and posters, respectively. Overall, 78% of the villages in the COMBI(+ +) districts and 33% of those in the COMBI(+) districts were considered to have had good exposure to the communication campaign. At the end of this campaign about 30% more people (than pre-campaign) believed that lymphatic filariasis could be eliminated and many of those targeted considered lymphatic filariasis to be a dreadful disease, knew that a particular day had been designated "Filaria Day", and thought that the tablets offered in MDA should be consumed to prevent or eliminate the disease. Apparently as the result of the COMBI campaign, drug consumption increased, from 33% of those living in endemic communities, to 37% in the COMBI(+) districts and to 49% in the COMBI(+ +). Coverages as high as 65%-73% were recorded among those who had had the maximum exposure to the communication campaign. These results indicate that the COMBI campaign favourably changed the perception and behaviour of the people towards the elimination of lymphatic filariasis. The costs of the COMBI(+) and COMBI(+ +) strategies were only U.S.$0.002 and U.S.$0.009 per capita, respectively.