Publications (34)25.19 Total impact
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Article: Predictive habitat modeling for forest malaria vector species An. dirus in India–a GIS-based approach
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ABSTRACT: Anopheles dirus is found in deep-forested areas where manual surveys are very difficult because of inacces-sibility. Geographic Information System (GIS) and a Boolean operator have been used to map areas where the species is likely to be found. Being a forest-based species, thematic maps of forest cover, altitude, rain-fall and temperature were prepared. Overlaying and integration of thematic maps were done using Arc/Info NT and analysis by Arc/view 3.1 (GIS ESRI) software. The results were validated through reported distri-bution and were found correct. The technique can cover vast and inaccessible areas, fast and easily dupli-cable in other parts of the world. Once the vector distribution is known, species-specific control measures can be formulated. GLOBALLY malaria clinical cases are reported as 300–500 million and 1.5–2.7 million deaths annually. The increasing trend of environmental change is dramatically changing malaria distribution pattern at local and as well as global scales. Malaria situation is worsening with large-scale epidemics and increasing mortality. There have been immense efforts to correlate malaria and the environment as the latter influences development of both parasite and vector (http://www.who.ch/). In spite of several reports of vector distribution from India, large areas still remain unexplored, specifically deep-forested areas where manual surveys are very tedious due to difficult accessibility 1–3 . The distribution of vector is mainly governed by suitable environmental conditions for breeding, survival and longe-vity. Many parameters associated with environmental change can now be remotely-sensed using remote sensing technologies and combined with geographic information system (GIS) can describe local and landscape-level fea-tures influencing disease and vector distribution. Recently, using GIS distribution of Anopheles sundaicus, we have described a coastal malaria vector species and the results were found to be very encouraging 4 . In the present study an attempt has been made to map the distribution of Anopheles dirus (Peyton Harrison, 1979) using GIS. Thematic maps of ecological parameters, namely forest cover, altitude, rainfall and temperature toposheets pub-lished by Survey of India were digitized. Using GIS favourable range of each ecological parameter for An. dirus was identified and extracted out from the digital maps. Boolean operator was used to integrate the maps of favourable range of each ecological parameter to depict areas where the species is likely to be found. The study revealed many new areas besides the reported distribution. An. dirus is one of the most efficient vectors of malaria in north-eastern India. It breeds in pools, disused wells, borrow pits, hoof prints and drains covered with foliage in deep-forested areas 3 . It enters houses or cattle sheds for feeding, but leaves soon thereafter. This species maintains a high man–mosquito contact. In Arunachal Pradesh, perennial malaria transmission was maintained in spite of DDT spraying and there was an increase in transmission between 1964 and 1969. Similar situations also prevail in other forested areas 5 . In India an estimated 50 million people living mainly in deep-forested and forest fringe areas are exposed to this species along with An. minimus and An. fluviatilis 6 . The species is highly anthropophilic and endophagic, occurs in high numbers and may con-stitute up to 60% of catches, effective flight range is about 1.5 km. It usually feeds late at night with peak biting activity from midnight till 03.00 h (ref. 7). The GIS predicted distribution of An. dirus in different parts of India is presented here.; 80. -
Article: A spatial statistical approach to analyze malaria situation at micro level for priority control in Ranchi district, Jharkhand.
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ABSTRACT: Background & objectives: The presence of efficient malaria vectors namely Anopeles culicifacies, An. fluviatilis and An. annularis (Diptera: Culicidae), rapid industrialization causing large influx of population and poor health infrastructure are some of the factors that make malaria an important public health problem in Ranchi, the capital of Jharkhand State, India. A geographical information system (GIS) based retrospective study using spatial statistical tools was initiated in 328 subcentres of 14 primary health centres (PHCs) of the district using malaria epidemiological data of three years (2007-2009) to identify spatial distribution pattern of Plasmodium vivax (Pv) and Plasmodium falciparum (Pf) occurrence, delineation of hot spots and to map directional distribution trend of Pf spread to help formulate evidence-based policy and to prioritize control during 2011. Methods: Spatial statistics tools like Global Moran's I index, Getis-Ord GiFNx01 and Standard Deviational Ellipse were used in GIS domain for analysis. Results: Spatial distribution pattern of Pv occurrence was found random while Pf distribution was significantly clustered. During 2007-2009, the number of subcentres under Pf hot spot category exhibited downward trend while high Pf risk subcentres exhibited upward trend. One consistent Pf hot spot consisting of five subcentres was identified in Silli PHC. During 2009, one Pf hot spot consisting of 20 subcentres and 18 subcentres under high Pf risk category were identified in Angara, Silli, Burmu and Kanke PHCs. A shifting trend in Pf spread was noticed from north-west to western direction from 2008 onwards. Interpretation & conclusions: The study recommended priority control in 20 Pf hot spot and 18 high Pf risk reporting subcentres including five consistent Pf hot spot subcentres in Angara, Silli, Burmu and Kanke PHCs during 2011 to address grave malaria situation in the district in a cost-effective manner.The Indian journal of medical research 11/2012; 136(5):776-82. · 1.84 Impact Factor -
Article: Retrospective study of chikungunya outbreak in urban areas of India.
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ABSTRACT: A retrospective study on chikungunya outbreak in India in five States viz. Delhi, Madhya Pradesh, Orissa, Maharashtra and Kerala was conducted in 2007-2008 to know the distribution and determinants of chikungunya fever outbreak in India. On the basis of high and low incidence of chikungunya fever, two districts from each State and two wards from the selected district were taken for random selection of 1000 households from 10 districts and 5 States. Semi-structured questionnaires were administered to individuals, patients, qualified health professionals and to stakeholders for collecting information. The educational background and occupation of the respondents showed variations across the study States. Only in high incidence ward of Maharashtra, water storage period for 3-6 days and emptying, drying of water containers on weekly basis was noted. The study through knowledge, attitude, belief, practice (KABP) obtained individual's perception of chikungunya fever, its prevention and control. Patients' expenditure on treatment was mainly recorded less than Rs 500 across study States. Health facility survey obtained an overview of the capacity of local health facilities. Stakeholders' perception regarding chikungunya fever was also noted. The study revealed differences in awareness of chikungunya, cause of the disease, vector responsible, mode of transmission, biting time and elimination of breeding of mosquitoes statistically significant among high and low incidence wards of all the States. Expenditure on treatment was independent of economically active status and loss of man-days across all the States. Education and occupation did not have any relation with emptying/drying of water containers in high incidence wards. Strengthening of surveillance, information, education and communication (IEC) activities along with case management facilities may be provided by the State health department for prevention of chikungunya outbreaks in future. Stakeholders should be more involved in outbreak management and future planning.The Indian journal of medical research 03/2012; 135:351-8. · 1.84 Impact Factor -
Article: Application of spatial technology in malaria research & control: some new insights.
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ABSTRACT: Geographical information System (GIS) has emerged as the core of the spatial technology which integrates wide range of dataset available from different sources including Remote Sensing (RS) and Global Positioning System (GPS). Literature published during the decade (1998-2007) has been compiled and grouped into six categories according to the usage of the technology in malaria epidemiology. Different GIS modules like spatial data sources, mapping and geo-processing tools, distance calculation, digital elevation model (DEM), buffer zone and geo-statistical analysis have been investigated in detail, illustrated with examples as per the derived results. These GIS tools have contributed immensely in understanding the epidemiological processes of malaria and examples drawn have shown that GIS is now widely used for research and decision making in malaria control. Statistical data analysis currently is the most consistent and established set of tools to analyze spatial datasets. The desired future development of GIS is in line with the utilization of geo-statistical tools which combined with high quality data has capability to provide new insight into malaria epidemiology and the complexity of its transmission potential in endemic areas.The Indian journal of medical research 08/2009; 130(2):125-32. · 1.84 Impact Factor -
Article: Low efficacy of chloroquine: time to switchover to artemisinin-based combination therapy for falciparum malaria in India.
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ABSTRACT: Drug resistance in Plasmodium falciparum poses a major threat to malaria control globally; including India. Chloroquine is still the most widely used drug in the country because of its safety and cost effectiveness. Although chloroquine resistance was first reported in 1973 in North Eastern India, the extent of the problem was realized only after the more intensive 28-day drug efficacy studies were used to monitor drug resistance. In the present study, efficacy of chloroquine in treatment of uncomplicated falciparum malaria was investigated using standard World Health Organization (WHO) procedures in three distinct epidemiological settings. The prevalence of molecular markers of drug resistance, Pfcrt K76T, Pfmdr1 N86Y, was also studied. A total of 374 children and adults with uncomplicated P. falciparum malaria were enrolled at six sites in four states, treated with chloroquine and follow-up was done for 28 days. The cumulative incidence of success of chloroquine at Day 28 by the Kaplan Meier analysis in the state of Orissa (District Sundargarh, CHC Bisra and Kuarmunda) was 57 (95% CI 43-68) and 54 (95% CI 40-66); in the state of Jharkhand (District Ranchi, PHC Angara and District Simdega, PHC Jaldega) it was 72 (95% CI 59-81) and 65 (95% CI 50-76); in the state of Goa (District North-Goa, Panaji Town), it was 20 (95% CI 10-2) and in the state of Rajasthan (District Udaipur, PHC Rishabdev), it was 96 (95% CI 85-99). Treatment failure was related to Pfcrt mutations but not Pfmdr mutations. Early treatment failure was observed only in 15.8% out of total failures, probably due to the semi-immune nature of the population. This type of response may give false perception about efficacy of the failing drug to patients, clinicians and National Authorities. In a large country like India it is not feasible to conduct in vivo studies in all districts and lack of direct correlation between molecular markers, in vitro studies and treatment outcome makes it difficult to predict the areas requiring change of policy. In this scenario, it is a challenge for National Programmes to make evidence-based revisions in the drug policy. However, considering the global, especially Southeast Asian, scenario and interpretation of available in vivo data, trends of mutations, availability of effective drugs and support of international donors, India should consider changing the first line treatment, at least for all diagnosed P. falciparum cases.Acta tropica 08/2009; 111(1):21-8. · 2.22 Impact Factor -
Article: Molecular characterization of chikungunya virus from Andhra Pradesh, India.
The Indian journal of medical research 04/2009; 129(3):335-7; author reply 337. · 1.84 Impact Factor -
Article: Geographical information system (GIS) in decision support to control malaria--a case study of Koraput district in Orissa, India.
Journal of vector borne diseases 04/2009; 46(1):72-4. · 1.18 Impact Factor -
Article: Operational feasibility of rapid diagnostic kits & blister packs use for malaria control in high transmission areas of Orissa & Chhattisgarh.
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ABSTRACT: Early diagnosis and prompt treatment of cases with malaria are two important components of malaria control strategy. The independent assessment of the operational feasibility of rapid diagnostic kits and blister packs for malaria in some selected high transmission areas of Orissa and Chhattisgarh was done with the objectives to assess the knowledge and skills of the paramedical personnel and their acceptability by the paramedical personnel and the community, and to assess improvement in patients' health seeking behaviour. The basic information regarding malaria situation, epidemiological divisions, distribution data of rapid diagnostic kits and blister packs, etc., was collected from State and district headquarters. The subcentres from the primary health centres/community health centres were selected on the basis of supply of rapid diagnostic kits and blister packs. The subcentres were visited and health personnel interviewed about their knowledge and skills on the use of rapid diagnostic kits and blister packs. A cross-sectional survey was conducted to assess the public opinion about rapid diagnostic kits and blister packs. We found that the paramedicals were well trained in the use of rapid diagnostic kits and blister pack administration and the acceptance was good by both paramedicals and general public. The compliance rate of radical treatment with blister packs was 100 per cent and no adverse events were reported. Our findings showed that rapid diagnostic kits and blister packs under remote and inaccessible highly malarious areas can be introduced that will have significant impact in reducing malaria morbidity and mortality.The Indian journal of medical research 01/2007; 125(1):65-72. · 1.84 Impact Factor -
Article: Prediction of Anopheles minimus habitat in India - a tool for malaria management.
International Journal of Geographical Information Science. 01/2005; 19:91-98. -
Article: Spiracular indices in Anopheles stephensi: a taxonomic tool to identify ecological variants.
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ABSTRACT: Thoracic spiracle length and its index was examined for their ability to discriminate two ecological variants, type form and mysorensis, of Anopheles stephensi in the adult stage. The type form is exclusively domestic in all seasons, whereas the mysorensis variant occupies the outdoor niche during monsoon and postmonsoon seasons, with spillover into domestic sites during summer ecological stress periods. A statistically significant co-relation was established between the ridge count of the egg and two adult measurements, the thoracic spiracle length, and the spiracular index. In An. stephensi type form, average spiracle length was 0.11-0.12 mm and average spiracular index was 8.09-9.23, whereas in mysorensis, the corresponding figures were 0.09-0.10 mm and 6.82-7.60. These parameters showed consistent variations in population of mosquitoes that emerged during monsoon and summer season. The thoracic lengths in both variants remained constant, and only spiracular lengths showed fluctuations in three seasonal populations. These measures provide discrimination of adult variants--identifications that are essential in malaria control programs.Journal of Medical Entomology 12/2003; 40(6):747-9. · 1.76 Impact Factor -
Article: GIS based malaria information management system for urban malaria scheme in India.
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ABSTRACT: A GIS based information management system has been developed to help Urban Malaria Control in India. The basic objective is to develop a model to assist planning and implementation of a suitable control measure. The system can help in: (i) identifying high receptive areas in time and space domain; (ii) identifying risk factors for high receptivity; (iii) monitoring and evaluating control measures. To demonstrate this system, information on 33 parameters and malaria cases has been attached to a digitised map of Dindigul, an urban town in Tamil Nadu. Functionalities of the system and its utility are described in this paper. A GIS based information management system ensures that if a localised spurt of the disease occurs, it can be associated rapidly with a likely cause, a specific vector, and a probable human source, so that appropriate preventive action can be taken to arrest any rising trend.Computer Methods and Programs in Biomedicine 06/2003; 71(1):63-75. · 1.52 Impact Factor -
Article: Cytotaxonomic evidence for the presence of Anopheles nivipes in India.
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ABSTRACT: Anopheles philippinensis mosquitoes were collected from 5 states in India: Assam, Meghalaya, Arunachal Pradesh, Manipur, and Nagaland. Half-gravid females were examined for variations in wing venation using the presector dark mark on vein I and polytene chromosomes derived from ovarian nurse cells. Polytene chromosomes were examined for diagnostic inversions, t on chromosome arm 2 and I on arm 5. Based on wing characteristics, both An. philippinensis and An. nivipes were identified. Polytene chromosome examinations revealed that all specimens from these 2 populations had 2t; 51 inversion genotype, a diagnostic character for An. nivipes. The wing character was not diagnostic; therefore, it was concluded that all the specimens examined were actually An. nivipes and not An. philippinensis. Further, the X chromosome was of x+b type, that is, the standard arrangement with reference to the inversion b, reported in the An. nivipes population in Thailand. This is the 1st report that unequivocally establishes the occurrence of An. nivipes in India and also shows that the adult wing character is not reliable in distinguishing An. philippinensis from An. nivipes, as has been observed in Thailand.Journal of the American Mosquito Control Association 07/2000; 16(2):71-4. · 0.91 Impact Factor -
Article: Geographic information system as a tool to study malaria receptivity in Nadiad Taluka, Kheda district, Gujarat, India.
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ABSTRACT: Nadiad taluka, Kheda district, Gujarat State, India, comprising of 100 villages with unstable malaria and periodic epidemics, was selected for the study. Using topo sheets and satellite imageries thematic maps on water table, water quality, hydro-geomorphology, soil type, relief, irrigation channels, were prepared, overlaid and integrated sequentially using Arclnfo software. The composite map resulted in 13 stratification classes. Stratification classes 1-12 fell in non-irrigated tracts and exhibited 95% matching of areas of high receptivity as revealed by geographical information systems (GIS) and annual malaria parasite incidence (API). Stratification class 13, an irrigated area, showed poor matching but the ground verification established low receptivity of the area. Thus the study resulted in complete reconciliation of cause and effect relationship as established as per GIS in explaining malaria epidemiology. In general, the study revealed that high malaria in villages of Nadiad is mainly due to high water table, soil type, irrigation and water quality. Based on local malaria transmission determinants, a revised malaria control strategy has been suggested.The Southeast Asian journal of tropical medicine and public health 01/2000; 30(4):650-6. · 0.60 Impact Factor -
Article: Mosquito fauna and breeding habitats of anophelines in Car Nicobar Island, India.
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ABSTRACT: A total of 31 species of mosquitoes belonging to 10 genera, i.e. Anopheles, Aedes, Armigeres, Culex, Harpagomyia, Hodgesia, Mansonia, Orthopodomyia, Toxorhynchites and Uranotaenia were collected from Car Nicobar Island. Four Anopheles species, An. barbumbrosus, An. insulaeflorum, An. kochi and An. roperi were recorded for the first time from this Island. An. sundaicus was the most predominant species encountered. The results of the study on anophelines with emphasis on species-specific breeding preference in various aquatic habitats have been recorded.Indian journal of malariology 01/1999; 35(4):197-205. -
Article: Estimation of larval production in Sanjay Lake and its surrounding ponds in Delhi, India using remote sensing technology.
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ABSTRACT: A feasibility study to use remote sensing techniques for estimation of mosquito production in Sanjay lake in east Delhi was carried out. Besides the Sanjay lake, larval production for 12 surrounding remote sensing identifiable ponds was also estimated. Inspite of some limitations the technique is very useful for rapid mapping of major breeding sites, recording temporal changes and estimation of larval production in a cost effective manner in terms of survey cost and time.The Southeast Asian journal of tropical medicine and public health 01/1997; 27(4):834-40. · 0.60 Impact Factor -
Article: Study on the feasibility of delineating mosquitogenic conditions in and around Delhi using Indian Remote Sensing Satellite data.
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ABSTRACT: A feasibility study to identify mosquitogenic conditions in six study sites in and around Delhi (Bhalaswa lake, Nazafgarh drain, Seelampur lake, Sanjay lake, Okhla barrage and Hindon barrage) using Indian Remote Sensing Satellites was carried out. The water bodies with marshy areas, vegetation and human settlements were considered as environmental variables responsible for mosquitogenic conditions. Multidate IRS 1A and B, LISS-II satellite data were collected and analysed on Vax 11/780 computers. False colour composite (FCC) images were generated and land cover assessed using supervised classification based on ground truth training sets. Ground truth validation of satellite data was done on satellite pass dates. Concurrent monitoring of larval and adult mosquito density was performed by selecting sub-sites in each study site. The results indicate that mosquitogenic conditions can be identified (with limitation of resolution, i.e. 36.5 m) using FCC images and these images can be used as base maps of study sites. Characterization of study sites based on land cover was done from the view point of mosquitogenic conditions. Spatial changes in mosquito density vis-a-vis changes in environmental variables revealed positive correlation with water bodies and vegetation in some study sites.Indian journal of malariology 10/1996; 33(3):107-25. -
Article: Control of mosquito breeding using wood scrapings treated with neem oil.
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ABSTRACT: Wood scrapings were given shape of a ball and soaked in 5, 10 and 20% neem (Azadirachta indica) oil diluted in acetone. Control of Anopheles stephensi and Aedes aegypti breeding in water storage overhead tanks (OHTs) with the application of these balls was achieved for 45 days. Two balls soaked in 5% neem oil produced the best results among other concentrations tested.Indian journal of malariology 07/1995; 32(2):64-9. -
Article: Repellent action of neem cream against mosquitoes.
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ABSTRACT: Neem cream was used as mosquito repellent to provide protection against Aedes albopictus, Ae. aegypti, Culex quinquefasciatus, Anopheles culicifacies and An. subpictus mosquitoes. The application of neem cream on exposed body parts @2.0 gm/person showed 78 (range 65-95), 89 (range 66-100) and 94.4 (range 66-100) per cent protection against Aedes, Culex and Anopheles mosquitoes respectively. Significant difference was observed between neem cream treated and untreated group of population for Aedes mosquitoes (p < 0.001). Application of neem cream was found to be a safe and suitable alternative to insecticide impregnated coils for personal protection against mosquitoes and one application was 68% effective for four hours.Indian journal of malariology 07/1995; 32(2):47-53. -
Article: A study of the relationship of rice cultivation and annual parasite incidence of malaria in India.
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ABSTRACT: Twenty one year data (1963-1983) of 25 states/UTs of India on area under rice cultivation and annual parasite incidence was analysed using correlation and regression analysis to evaluate the relationship of irrigated area under rice cultivation and the statewise annual parasite incidence of malaria. In 23 states either the correlation is negative or non-significant whereas in Punjab and Nagaland significant positive correlation is observed. Study showed that in India at the macro level (i.e. data pooled at the state level both for rice cultivation and (API) rice cultivation by and large had poor relationship to API.Social Science [?] Medicine 02/1994; 38(1):165-78. · 2.70 Impact Factor -
Article: A study of the relationship of rice cultivation and annual parasite incidence of malaria in India
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ABSTRACT: Twenty one year data (1963-1983) of 25 states/UTs of India on area under rice cultivation and annual parasite incidence was analysed using correlation and regression analysis to evaluate the relationship of irrigated area under rice cultivation and the statewise annual parasite incidence of malaria. In 23 states either the correlation is negative or non-significant whereas in Punjab and Nagaland significant positive correlation is observed. Study showed that in India at the macro level (i.e. data pooled at the state level both for rice cultivation and (API) rice cultivation by and large had poor relationship to API.Social Science & Medicine. 01/1994; 38(1):165-178.
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2007–2009
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National Institute of Malaria Research
Delhi, NCT, India
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