Filariasis In India Research Articles

Increasing Compliance with Mass Drug Administration Programs for Lymphatic Filariasis in India through Education and Lymphedema Management Programs

BackgroundNearly 45% of people living at risk for lymphatic filariasis (LF) worldwide live in India. India has faced challenges obtaining the needed levels of compliance with its mass drug administration (MDA) program to interrupt LF transmission, which utilizes diethylcarbamazine (DEC) or DEC plus albendazole. Previously identified predictors of and barriers to compliance with the MDA program were used to refine a pre-MDA educational campaign. The objectives of this study were to assess the impact of these refinements and of a lymphedema morbidity management program on MDA compliance.Methods/Principal FindingsA randomized, 30-cluster survey was performed in each of 3 areas: the community-based pre-MDA education plus community-based lymphedema management education (Com-MDA+LM) area, the community-based pre-MDA education (Com-MDA) area, and the Indian standard pre-MDA education (MDA-only) area. Compliance with the MDA program was 90.2% in Com-MDA+LM, 75.0% in Com-MDA, and 52.9% in the MDA-only areas (p<0.0001). Identified barriers to adherence included: 1) fear of side effects and 2) lack of recognition of one's personal benefit from adherence. Multivariable predictors of adherence amenable to educational intervention were: 1) knowing about the MDA in advance of its occurrence, 2) knowing everyone is at risk for LF, 3) knowing that the MDA was for LF, and 4) knowing at least one component of the lymphedema management techniques taught in the lymphedema management program.Conclusions/SignificanceThis study confirmed previously identified predictors of and barriers to compliance with India's MDA program for LF. More importantly, it showed that targeting these predictors and barriers in a timely and clear pre-MDA educational campaign can increase compliance with MDA programs, and it demonstrated, for the first time, that lymphedema management programs may also increase compliance with MDA programs.

Possible relationship among socio-economic determinants, knowledge and practices on lymphatic filariasis and implication for disease elimination in India

To assess the socio-economic determinants, knowledge and practices on lymphatic filariasis in India and discuss the implications for elimination. A case-control study was undertaken to obtain knowledge and practice measures on various dimensions of the Wuchereria bancroftian filarial disease using a structured questionnaire. A structural equation model, a statistical technique for testing and estimating causal relationships using a combination of statistical data and qualitative causal assumptions, was developed. Among the affected individuals, the model was able to explain more than 90% of the variance in awareness about the lymphatic filariasis, 58% of the variance in prevention aspects of the disease and 24% of the variance in people's knowledge about mosquitoes. The corresponding values in non-infected individuals were 49, 24 and 34%, respectively. A significant positive effect of education on awareness and prevention aspects of the disease was noted among the non-infected individuals. However, among the affected individuals, the awareness on various aspects of the disease was completely absent. The present analysis highlights the crucial role played by formal education on creating awareness about lymphatic filariasis and how to prevent this vector-borne disease. The importance of education on intervention measures against mosquito breeding and biting is also dealt with in the analysis for planning an effective and sustainable control program.

Lymphatic filariasis in India

Lymphatic filariasis caused by Wuchereria bancrofti and Brugia malayi is an important public health problem in India. Both parasites produce essentially similar clinical presentations in man, related mainly to the pathology of the lymphatic system. Filariasis is endemic in 17 States and six Union Territories, with about 553 million people at risk of infection. The Government of India has accorded a high priority for elimination of this infection through mass chemotherapy programme (annual, single dose of Diethylcarbamazine citrate, i.e. DEC - 6 mg/kg of bodyweight, plus Albendazole repeated four to six times). This campaign has become a part of the National Vector-Borne Disease Control Programme in 2003 under the National Health Policy 2002 and aims to eliminate filariasis by 2015. We discuss here the epidemiology and current control strategy for filariasis; highlighting key issues, challenges and options in the implementation of the programme, and suggesting measures for mid-course corrections in the elimination strategy.

Mass drug administration against filariasis in India: perceptions and practices in a rural community in Kerala

In India, annual rounds of mass drug administration (MDA) based on diethylcarbamazine and albendazole are used to control filariasis, which is a major public-health problem. In December 2007/January 2008, a few weeks after one such MDA, a household survey was conducted in the Ernakulam district of Kerala to evaluate coverage and compliance. After one member aged >14 years from each of 599 households was interviewed, coverage of the last MDA was estimated to be 77.0% and compliance only 39.6%. Most (67.4%) of the interviewees were not aware of the term 'mass drug administration' but 20.9% of the others thought that MDA prevented the occurrence of filariasis. Most (62.3%) of those interviewed said that they obtained information about MDA from television or radio programmes and/or newspapers and most (66.3%) considered MDA to be useful (only 5.0% said that MDA were not useful, the other interviewees saying that they did not know whether MDA were useful or not). Those who had not ingested the tablets given to them in the last MDA said that they were fearful of the drugs (39.4% of the non-compliers), were too ill to take the drugs (22.5%) or had misconceptions about the aims of the MDA (12.5%). Only 2.7% of the interviewees who had ingested the distributed tablets reported adverse effects and these were mild (fever, drowsiness, swelling/oedema and/or vomiting) and only occurred within 24 h of tablet ingestion. In a univariate analysis, individual compliance in the last MDA was found to be positively associated with perceived benefits to the individual (P<0.001), the perceived usefulness of MDA (P=0.001) and certain study wards within the panchayat (P=0.032). It therefore appears that communication exercises targeted at the areas with relatively low compliance and designed to improve perceptions of the benefits and usefulness of MDA against filariasis could be the key to a successful control programme.

Development of physiological resistance and its stage specificity in Culex quinquefasciatus after selection with deltamethrin in Assam, India

The study investigated the development and stage specificity of physiological resistance to insecticides in a colony of Culex quinquefasciatus Say (Diptera: Culicidae) mosquitoes, which are vectors of bancroftian filariasis in India, after selection with deltamethrin. Resistance was selected by exposing the larvae to the concentration of deltamethrin that caused 50% mortality in the tested population (i.e., LC50). Under continuous selection pressure, the LC50 increased steadily in subsequent generations. The estimated LC50 for the F0 generation was 0.409 microg/L; the LC50 first displayed a substantial increase in the F5 generation (5.616 microg/L) and reached 121.902 microg/L in the F10 generation. The objective of this study was to establish a deltamethrin-resistant colony to develop a research programme that will study the evolution of physiological resistance patterns and stage-specific resistance responses in Cx. quinquefasciatus larvae and adults under laboratory conditions. An approximately 298-fold increase in resistance was recorded after 10 generations, as evidenced by the resistance ratio (RR50). The progress and effect of the selection pressure in the adult stage was monitored with the World Health Organisation (WHO) diagnostic test. The mortality, as observed using the WHO diagnostic test, declined significantly from the F5 generation (85%) onwards and the highest rate of survival (65%) was observed in the F10 generation.

Management of filariasis using prediction rules derived from data mining.

The present paper demonstrates the application of CART (classification and regression trees) to control a mosquito vector (Culex quinquefasciatus) for bancroftian filariasis in India. The database on filariasis and a commercially available software CART (Salford systems Inc. USA) were used in this study. Baseline entomological data related to bancroftian filariasis was utilized for deriving prediction rules. The data was categorized into three different aspects, namely (1) mosquito abundance, (2) meteorological and (3) socio-economic details. This data was taken from a database developed for a project entitled "Database management system for the control of bancroftian filariasis" sponsored by Ministry of Communication and Information Technology (MC&IT), Government of India, New Delhi. Predictor variables (maximum temperature, minimum temperature, rain fall, relative humidity, wind speed, house type) were ranked by CART according to their influence on the target variable (month). The approach is useful for forecasting vector (mosquito) densities in forthcoming seasons.

Mass drug administration to eliminate lymphatic filariasis in India.

Mass drug administration (MDA) to eliminate lymphatic filariasis is already in place in 32 out of 83 endemic countries. Expansion of the MDA programme to other countries and within large countries such as India is necessary to achieve the goal of lymphatic filariasis elimination. However, expansion and sustenance of the global campaign to eliminate lymphatic filariasis requires commitment and allocation of funds by governments and donor agencies. This could be achieved, at least to some extent, by highlighting the benefits of the programme in relation to costs. On the basis of various studies in south India, this article assesses the costs, effectiveness and economic and social benefits of the MDA programmes aimed at eliminating lymphatic filariasis.

Safety, tolerability, efficacy and plasma concentrations of diethylcarbamazine and albendazole co-administration in a field study in an area endemic for lymphatic filariasis in India

Filariasis control programmes are moving towards a strategy of repeated single-dose mass treatment of endemic populations. Using a combination, such as albendazole (ALB) to diethylcarbamazine (DEC) gives both macrofilaricidal and antihelmintic activity. However, the safety of the combination versus DEC alone should be established in field studies in large populations prior to incorporation into national programmes. The present study compared the safety, tolerability, and efficacy of single doses of DEC 6 mg/kg + ALB placebo with DEC 6 mg/kg + ALB 400 mg in populations living in two filariasis endemic villages in the district of Wardha in western India. The study was double blind, parallel group, and randomized. Safety and tolerability study were studied in males and females older than 5 years. Safety was assessed by monitoring if adverse events (AEs) over 5 days affected daily acivities. Subjects in the 2 treatment groups experienced insignificantly different effects on daily activities and the combination was shown to be safe. Efficacy was evaluated by microfilaraemia (Mf), immunochromatographic test (ICT) and ultrasonography (USG) at 0, 3, 6, and 12 months of follow up. The efficacy study enrolled 103 male patients (aged 18–50 years) in microfilariae positive, clinical disease and asymptomatic, amicrofilaremic groups. There was no significant difference in efficacy between groups at 12 months. Within the Mf positive group, significant differences were seen in microfilaraemia ( P<0.001) with both treatments, and in USG ( P<0.001 and P<0.004 respectively), at 12 months. The present field study has shown the combination of DEC+ALB to be as safe as the single drug DEC and thus the combination can be put in use in the national filariasis control programmes. Both drugs were adequately absorbed. The study at present does not provide evidence for the greater efficacy of the combination at 12 months follow up. While the safety of the combination has been ascertained, the incorporation or otherwise of ALB into national programmes for greater efficacy must await results of studies with longer follow up.

Towards elimination of lymphatic filariasis in India.

The global initiatives to eliminate lymphatic filariasis as a public health problem by the year 2020 have generated a great deal of debate in India, the largest endemic country. This has led to a shift in the focus from control to elimination of the disease. Although the campaign to eliminate filariasis has begun, much more needs to be done. Several recent research studies have provided an insight into various operational issues and prospects of elimination of lymphatic filariasis. In this article, the current scenario, recent research results, logistics and the prospects of eliminating lymphatic filariasis in India will be discussed.

Resistance to Malathion in Culex quinquefasciatus Say (Diptera: Culicidae) from Madurai, South India

Organophosphorus-derived pesticides are commonly used to control Culex quinquefasciatus, the principal vector of filariasis in India. This paper reports on the susceptibility of C. quinquefasciatus from Madurai city, Tamil Nadu and its environs, to the organophosphate Malathion. It was observed that both larval and adult mosquitoes had low levels of resistance to the pesticide, with resistance ratios at LC50, LC90, and LC95 varying from 0.94 to 3.07 in larvae, and 0.93 to 34.68 in adults. This observation indicates the possibility of higher resistance developing in C. quinquefasciatus populations, the limitation of organophosphorus compounds as larvicides in mosquito breeding sites as a measure to control filariasis, and the importance of research into alternative measures for managing C. quinquefasciatus.

Mapping of lymphatic filariasis in India.

The derivation of detailed epidemiological maps, at the relevant spatial resolution, is being increasingly recognized as vital to the effective design and implementation of successful programmes for the control of parasites and their vectors. Geographical information systems (GIS) and a recently complied database on the distribution of lymphatic filariasis in India have now been used to develop the first maps at district-level (i.e. the level at which control against this parasite will be enacted in India) of filariasis endemicity in this country. The derived maps indicate both the substantial extent as well as the marked variability in the geographical distribution of this disease in India. The causative infection and/or the symptomatic disease were detected in most (257) of the 289 districts surveyed up to 1995. Currently there may be up to 27.09 million microfilaraemics, 20.83 million cases of symptomatic filariasis, and about 429.32 million individuals potentially at risk of infection in the country. Probability mapping, based on data quantiles, clearly indicates that the risk of filarial infection in India is not constant throughout the country but exhibits strong regional trends. Filariasis in general may be a particular problem of the eastern half of the country. The results indicate the potentially vital role that GIS-based mapping approaches can play in the development of filariasis-control campaigns in India and elsewhere.

Filariasis in India.

Filariasis is one of the major problems of public health in India, because of the many millions of people who are infected and because practical measures for its control have proved so difficult. The extent of the infection and the difficulties of control have been well shown in the excellent studies carried out under the National Filaria Control Programme, directed from the National Institute for Communicable Diseases at Delhi. This Programme was launched in 1955 and it has constituted the biggest and best sustained antifilarial organization in the world. Most of the statistics quoted in this paper are derived from its reports. It may seem rash for an outsider like the author to speak or write on filariasis in India when there are already many experts in the country who have a more intimate and deeper knowledge of the subject. Nevertheless this rashness has been ventured because filarial infection seems so important for India that attention ought to be drawn to it, on such an occasion as the Jubilee Celebration of the Haffkine Institute when the medical problems of the country are passed, as it were, under review.