Usage of personal-protection measures against mosquitoes and the low prevalences of Wuchereria bancrofti microfilaraemia in the Indian city of Chennai.

The usage of personal-protection measures against mosquitoes and the prevalence of Wuchereria bancrofti microfilaraemia were assessed in different areas of the city of Chennai, a large urban area in southern India. Most of the households investigated (75% to 92%, depending on socio-economic status) used some form of personal protection (such as mosquito coils, vaporizing mats and liquids and mosquito nets). The study households spent a mean (S.D.) of 109.45 (141.65) Indian rupees/month on personal protection, such expenditure increasing significantly with increasing household income (F=2.95; P=0.03). Over the last three decades the prevalence of W. bancrofti microfilaraemia has been slowly declining in Chennai. Most of the 'moderate-income' areas of the city investigated in the present study appeared free of such microfilaraemia, and the prevalences recorded in about half of the low- and very-low-income study areas did not exceed 1.0%. The mean prevalences recorded in the moderate-, low- and very-low-income areas were 0.51%, 1.15% and 1.30%, respectively. Given their very low prevalences of microfilaraemia, relatively good housing, sanitation and health care and extensive use of personal-protection measures, the 100 million Indians living in (mostly urban) moderate- and high-income areas may not require active mass drug administrations (MDA) against lymphatic filariasis. The need to develop simple methods to stratify urban areas, into those that require and those that do not require active MDA, remains. If lymphatic filariasis is to be eliminated from India in a reasonable time-frame, at least as a public-health problem, MDA should now be focused on the poorer localities.

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.

Situation analysis in a large urban area of India, prior to launching a programme of mass drug administrations to eliminate lymphatic filariasis.

The main strategy now adopted for the elimination of lymphatic filariasis (LF) is based on mass drug administrations (MDA). Annual administration of antifilarial drugs to 65%-80% of the population at risk of the disease is believed to be necessary if LF is to be eliminated, at least as a public-health problem, within a reasonable time-frame. To facilitate the development of drug-delivery strategies that are sufficient to ensure such high treatment coverages in large urban areas, a situation analysis was undertaken in the Indian city of Chennai. The subjects interviewed came from households with high, moderate, low or very low incomes. A lack of information on the prevalence and socio-economic impact of the disease meant that LF was not viewed as a major pubic-health problem in the study area, even though cases of elephantiasis and hydrocele were detected in 2%-8% and 7%-20% of the households investigated. Overall, 40% of the interviewees from very-low-income households and 78% of those from middle-income households knew that (the parasite causing) elephantiasis was transmitted by mosquitoes. Only 4% of the subjects from high-income areas and 1% of those from low-income areas were aware that filarial infection was a major cause of hydrocele. Most of the subjects (>55% of each of the four socio- economic groups considered) felt that they were not at risk of developing elephantiasis. When specifically asked, only 35% of the subjects from high-income households but 84% of those from low-income households said that they would be willing to consume tablets of an antifilarial drug (diethylcarbamazine) in MDA to eliminate LF. It is therefore unclear whether high-income households in urban areas should be included in MDA programmes. The interviewees felt that an intensive campaign of information, education, communication and advocacy would be necessary if an effective MDA-based programme were to be implemented. Drug distribution through the health services was the most preferred option.Clearly, factors such as a lack of appreciation of the socio-economic impact of LF, a general belief that the risk of elephantiasis is low, doubts about the need to include all sectors of the eligible population in MDA, and a common dependence on private practitioners make successful MDA against LF in urban areas a challenging task. On the positive side, however, an urban population is often covered by a huge network of colleges, private practitioners, non-governmental organizations and residents' associations, and such networks provide new opportunities in the development of effective drug-delivery strategies.

The mosquito problem and type and costs of personal protection measures used in rural and urban communities in Pondicherry region, South India.

Personal protection measures have become an important tool against mosquito nuisance. The severity of mosquito nuisance and the type and costs of personal protection measures in the Pondicherry region in South India have been investigated, using a structured questionnaire. The number of respondents sampled was 300 in the urban area and 100 in rural areas. 87 and 63% of the urban and rural respondents, respectively, felt that mosquito nuisance was severe in their locality. 83% of the urban and 27% of the rural respondents are aware that mosquitoes transmit diseases and were able to name at least one mosquito-borne disease. All the neighbourhood shops in urban and a majority in rural areas stocked personal protection products. As many as 99.3 and 73% of the urban and rural respondents, respectively, were found to use personal-protection measures during some or all seasons of the year. Mosquito coils were the most widely used measure in both urban and rural areas, followed by vaporising mats in the former and electric fans in the latter areas. 48 and 40% in urban and rural areas, respectively, used personal-protection measures daily. In urban areas 46% used the measures in more than one room. Only a small proportion (3-14%) used bed nets. The average monthly expenditure on the measures was Rupees (Rs.) 62.17 (US$ 1.30) (range: Rs. 0.00-500.00) in urban areas and Rs. 8.03 (US$ 0.17) (range Rs. 0.00-45.00) in rural areas. Annual expenditure on personal protection measures in urban areas amounted to 0.63% of the per capita income. 73.7% of the respondents in urban areas expressed satisfaction with the protective effect of the measures used by them. However, 46.3% of the urban and 15% of the rural respondents felt that the personal-protection measures are harmful to health. Some of the perceived harmful effects are allergy, breathing problems, cough and head ache.

Effectiveness of community and health services-organized drug delivery strategies for elimination of lymphatic filariasis in rural areas of Tamil Nadu, India.

Lymphatic filariasis (LF) is targeted for global elimination. Repeated annual single-dose mass treatment with antifilarials 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 services-organized 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 significant, the distribution and compliance rates were lower under the comDT strategy. Also, the strategy's operationalization appears to be difficult 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 sufficient 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.