Community practices of using bed nets & acceptance & prospects of scaling up insecticide treated nets in north-east India.

Background & objectives: The National Vector Borne Disease Control Programme (NVBDCP), India has been promoting and scaling up the use of insecticide-treated nets (ITNs) in the tribal dominated malarious areas of north-east India. But, information on sleeping habits, bed net ownership and use practices, and feedback of communities in ITN - targeted areas is needed for formulating a strategic framework for upscaling the coverage of ITNs. We carried out a community-based cross-sectional survey in select areas of Nagaland and Mizoram (where ITNs were introduced) along with Assam (where ITNs were not introduced) to know the response of community. Methods: Following large scale introduction of ITNs during 2001-2002 in the north-eastern States of Nagaland and Mizoram by NVBDCP, India, a cross-sectional community-based survey was undertaken in April-May, 2003 covering 435 households of Nagaland and 464 households in Mizoram, using a structured questionnaire, to assess the demographic variables relevant to bed net use, bed net washing practices and acceptability of ITNs etc., for upscaling the coverage of ITNs in the surveyed communities. A total of 448 households in 8 villages in a non-ITN PHC area of Assam were served as the control area. Results: The average bet net usage per family (2.01 to 2.65). Bed net use was mostly seasonal in Nagaland where a majority (65.1-78.7%) used bed nets only during summers and monsoon as compared to the year round use in Mizoram (83.5%) and Assam (78.9%). Frequent washing of nets was most common in Assamese communities with 77 per cent households washing their nets at least once in a month. More than two third users favoured use of ITNs over the conventional indoor residual spray of DDT for malaria control. Interpretation & conclusion: ITNs are widely acceptable in the user communities and a demand for ITNs is evident in the non-user communities of north-east India. Approach of treating community owned nets through an efficient service delivery mechanism will be a viable option for upscaling the ITN coverage.

Community practices of using bed nets & acceptance & prospects of scaling up insecticide treated nets in north-east India.

BACKGROUND & OBJECTIVE: The National Vector Borne Disease Control Programme (NVBDCP), India has been promoting and scaling up the use of insecticide-treated nets (ITNs) in the tribal dominated malarious areas of north-east India. But, information on sleeping habits, bed net ownership and use practices, and feedback of communities in ITN--targeted areas is needed for formulating a strategic framework for upscaling the coverage of ITNs. We carried out a community-based cross-sectional survey in select areas of Nagaland and Mizoram (where ITNs were introduced) along with Assam (where ITNs were not introduced) to know the response of community. METHODS: Following large scale introduction of ITNs during 2001-2002 in the north-eastern States of Nagaland and Mizoram by NVBDCP, India, a cross-sectional community-based survey was undertaken in April-May, 2003 covering 435 households of Nagaland and 464 households in Mizoram, using a structured questionnaire, to assess the demographic variables relevant to bed net use, bed net washing practices and acceptability of ITNs etc., for upscaling the coverage of ITNs in the surveyed communities. A total of 448 households in 8 villages in a non-ITN PHC area of Assam were served as the control area. RESULTS: The average bet net usage per family (2.01 to 2.65). Bed net use was mostly seasonal in Nagaland where a majority (65.1-78.7%) used bed nets only during summers and monsoon as compared to the year round use in Mizoram (83.5%) and Assam (78.9%). Frequent washing of nets was most common in Assamese communities with 77 per cent households washing their nets at least once in a month. More than two third users favoured use of ITNs over the conventional indoor residual spray of DDT for malaria control. INTERPRETATION & CONCLUSION: ITNs are widely acceptable in the user communities and a demand for ITNs is evident in the non-user communities of north-east India. Approach of treating community owned nets through an efficient service delivery mechanism will be a viable option for upscaling the ITN coverage.

Detection & molecular confirmation of a focus of Plasmodium malariae in Arunachal Pradesh, India.

BACKGROUND & OBJECTIVE: During a malaria epidemiological study in Arunachal Pradesh, Plasmodium malariae like human malaria parasites were seen in blood smears from fever cases. The study was undertaken to detect the presence of P. malariae and to confirm its identity through DNA based polymerase chain reaction approach. METHODS: Fever survey was carried out in 22 villages in Indo-Myanmar bordering district of Lohit, Arunachal Pradesh in 2005. Morphologically suspected P. malariae cases were confirmed using nested PCR based on 18S small subunit ribosomal DNA gene sequence. RESULTS: Screening of 1,995 fever cases resulted in 9 probable cases of P. malariae based on morphological identification in Chakma tribe people residing in 2 villages. Nested PCR confirmed the identity of all probable cases of P. malariae by producing diagnostic band of 144 bp. PCR method was able to detect mixed infection of P. malariae with P. vivax and with P. falciparum. INTERPRETATION & CONCLUSION: P. malariae may have been present in Arunachal Pradesh but most probably is being misdiagnosed due to its close resemblance with P. vivax, especially in ring forms. Estimation of actual case load of P. malariae in north-east India is, therefore, important with accurate species identification using molecular methods.

Therapeutic efficacy of anti-malarials in Plasmodium falciparum malaria in an Indo-Myanmar border area of Arunachal Pradesh.

BACKGROUND & OBJECTIVES: Malaria is one of the major public health problems in the north eastern region of India. Antimalarial drug resistance is widespread and one of the important causes of recent resurgence of falciparum malaria in this region. Antimalarial drugs are seen to be used sequentially one after another in many areas of the region, when therapeutic failure is observed with a drug. In view of this, the present study was undertaken to assess the therapeutic efficacy of common antimalarial drugs viz., chloroquine, sulfadoxine+pyrimethamine (S-P) and quinine, administered sequentially to the patients with Plasmodium falciparum infection in a Myanmar bordering area of Arunachal Pradesh. METHODS: A hospital based in vivo study was carried out with 53 patients with uncomplicated falciparum malaria. All patients were first treated with chloroquine and therapeutic efficacy assessed. In case of therapeutic failure of chloroquine combination drug (S-P) was given and those showing failure with S-P combination, oral quinine was administered and followed up for 28 days to assess both clinical and parasitological responses. RESULTS: Therapeutic failure was observed with chloroquine in 83.1 per cent (44 of 53) and to both chloroquine and S-P combination drug in 44.1 per cent (19/43) patients. Further, 15.8 per cent patients (3 of 19) failed to respond even to quinine. Overall, 5.7 per cent patients (3 of 53) showed unresponsiveness to all the three drugs i.e., chloroquine, S-P combination and quinine. Asexual parasite clearance and also fever clearance was slowest with chloroquine and fastest with quinine. INTERPRETATION & CONCLUSION: The findings of this study show the presence of multi drug failure P. falciparum in Jairampur-Nampong, a western Myanmar bordering area of Arunachal Pradesh. Anti malarial drug resistance is increasing in Indo-Myanmar border areas and systematic studies need to be done to review the situation.

Epidemiology of malaria outbreak (April/May, 1999) in Titabor Primary Health Centre, district Jorhat (Assam).

An investigation was undertaken of a malaria outbreak in the Primary Health Centre Titabor, district Jorhat, Assam during May/June 1999. The fever rate in the community since March 1999, was 44.4 per cent with an average case load of 2.5 per family. The fever cases peaked in the third week of May. Slide positive and slide falciparum rates in mass blood survey, in the study village were 16.1 and 14.5 per cent respectively with 90 per cent infection of Plasmodium falciparum. Males (SPR 17.5%) suffered relatively more than females (SPR 14.7%). Malaria prevalence was significantly less in individuals above 15 yr of age (SPR 11.0%) as compared to those below 15 yr (SPR 22.9%). Prevalence of malaria as well as mosquito densities in different clusters of the village were inversely related to the distance from the forested Naga hills. Anopheles minimus and A. dirus were collected in good numbers with comparatively higher densities of the former. Several factors like unusual climatic conditions, inadequate surveillance, unsatisfactory laboratory services and inadequate indoor residual insecticide spray were instrumental for the outbreak.

Filariasis in the labour population of a tea estate in Upper Assam.

Preliminary random and mass blood surveys undertaken between 2000-0100 h in a tea garden of Upper Assam revealed more than 8 per cent positivity for microfilaria (mf) of Wuchereria bancrofti. The mf carriers were considerably high among males (73) as compared to females (48). Culex quinquefasciatus was incriminated as a vector with man hour density of 68.5 in human dwellings (indoors). The detection of mf in children who had never moved from the area and filaria larvae in vector mosquitoes collected from human dwellings indicate that indigenous transmission is going on in the garden and that filariasis has become a local health problem.

Biting cycles of some potential vector mosquitos of Japanese encephalitis of Assam, India.

Biting activities of five potential vector species of Japanese encephalitis (JE) were observed in a JE affected district of Assam, India. Most of the species exhibited two peak periods of biting activity, one in early hours and other around midnight. However, in case of Culex fuscocephala several peaks were observed throughout the night.

Host feeding patterns of Culex vishnui sub group of mosquitoes in Dibrugarh district of Assam.

The host feeding patterns of three species of mosquitoes belonging to vishnui sub group, Culex tritaeniorhynchus, Culex vishnui and Culex pseudovishnui, the most prevalent species in Dibrugarh district were determined by analysing their blood meals. All 3 species were found be essentially zoophilic. High percentage of pig feeding was observed in Culex tritaeniorhynchus (40 per cent) and Culex vishnui (35.3 per cent) in comparison to other prevalent species in this area. In contrast Culex pseudovishnui another member of this group was not attracted to pigs (0.4 per cent). Few human feeds were recorded for Culex tritaeniorhynchus (0.4 per cent), Culex vishnui (0.4 per cent) and Culex pseudovishnui (0.8 per cent), indicating their occasional contact with human hosts. Considering the importance of this group as proven vectors of Japanese encephalitis the relevance of these results to JE transmission in this area are discussed.