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Lingala M.A.L.,National Institute of Malaria Research ICMR
Journal of Infection and Public Health | Year: 2017

Background: Malaria is a public health problem caused by Plasmodium parasite and transmitted by anopheline mosquitoes. Arid and semi-arid regions of western India are prone to malaria outbreaks. Malaria outbreak prone districts viz. Bikaner, Barmer and Jodhpur were selected to study the effect of meteorological variables on Plasmodium vivax and Plasmodium falciparum malaria outbreaks for the period of 2009-2012. Method: The data of monthly malaria cases and meteorological variables was analysed using SPSS 20v. Spearman correlation analysis was conducted to examine the strength of the relationship between meteorological variables, P. vivax and P. falciparum malaria cases. Pearson's correlation analysis was carried out among the meteorological variables to observe the independent effect of each independent variable on the outcome. Results: Results indicate that malaria outbreaks have occurred in Bikaner and Barmer due to continuous rains for more than two months. Rainfall has shown to be an important predictor of malaria outbreaks in Rajasthan. P. vivax is more significantly correlated with rainfall, minimum temperature (P. <. 0.01) and less significantly with relative humidity (P. <. 0.05); whereas P. falciparum is significantly correlated with rainfall, relative humidity (P. <. 0.01) and less significantly with temperature (P. <. 0.05). The determination of the lag period for P. vivax is relative humidity and for P. falciparum is temperature. The lag period between malaria cases and rainfall is shorter for P. vivax than P. falciparum. Conclusion: In conclusion, the knowledge generated is not only useful to take prompt malaria control interventions but also helpful to develop better forecasting model in outbreak prone regions. © 2017 The Author.

Dhiman R.C.,National Institute of Malaria Research ICMR | Sarkar S.,National Institute of Malaria Research ICMR
Malaria Journal | Year: 2017

Background: Risks of malaria epidemics in relation to El Niño and Southern Oscillation (ENSO) events have been mapped and studied at global level. In India, where malaria is a major public health problem, no such effort has been undertaken that inter-relates El Niño, Indian Summer Monsoon Rainfall (ISMR) and malaria. The present study has been undertaken to find out the relationship between ENSO events, ISMR and intra-annual variability in malaria cases in India, which in turn could help mitigate the malaria outbreaks. Methods: Correlation coefficients among ‘rainfall index’ (ISMR), ‘+ winter ONI’ (NDJF) and ‘malaria case index’ were calculated using annual state-level data for the last 22 years. The ‘malaria case index’ representing ‘relative change from mean’ was correlated to the 4 month (November-February) average positive Oceanic Niño Index (ONI). The resultant correlations between ‘+ winter ONI’ and ‘malaria case index’ were further analysed on geographical information system platform to generate spatial correlation map. Results: The correlation between ‘+ winter ONI’ and ‘rainfall index’ shows that there is great disparity in effect of ENSO over ISMR distribution across the country. Correlation between ‘rainfall index’ and ‘malaria case index’ shows that malaria transmission in all geographical regions of India are not equally affected by the ISMR deficit or excess. Correlation between ‘+ winter ONI’ and ‘malaria case index’ was found ranging from −0.5 to + 0.7 (p < 0.05). A positive correlation indicates that increase in El Niño intensity (+ winter ONI) will lead to rise in total malaria cases in the concurrent year in the states of Orissa, Chhattisgarh, Jharkhand, Bihar, Goa, eastern parts of Madhya Pradesh, part of Andhra Pradesh, Uttarakhand and Meghalaya. Whereas, negative correlations were found in the states of Rajasthan, Haryana, Gujarat, part of Tamil Nadu, Manipur, Mizoram and Sikkim indicating the likelihood of outbreaks in La Nina condition. Conclusions: The generated map, representing spatial correlation between ‘ + winter ONI’ and ‘malaria case index’, indicates positive correlations in eastern part, while negative correlations in western part of India. This study provides plausible guidelines to national programme for planning intervention measures in view of ENSO events. For better resolution, district level study with inclusion of IOD and ‘epochal variation of monsoon rainfall’ factors at micro-level is desired for better forecast of malaria outbreaks in the regions with ‘no correlation’. © 2017 The Author(s).

Srividya G.,Safdarjung Hospital Campus | Kulshrestha A.,Safdarjung Hospital Campus | Singh R.,National Institute of Malaria Research ICMR | Salotra P.,Safdarjung Hospital Campus
Parasitology Research | Year: 2012

Diagnostic parameters for visceral leishmaniasis (VL), a potentially fatal parasitic disease caused by Leishmania donovani, have been redefined in the last decade with the development of serological and molecular tests, though a definitive diagnosis still banks on the century-old parasitological methods in many areas. Recombinant antigens have improved performance of serodiagnostic methods. Serology-based tests, rk39 antigen dipstick, and direct agglutination test commonly employed in the field are highly sensitive methods, however, fail to distinguish past infections. Molecular approaches have become increasingly relevant due to remarkable sensitivity, specificity, and flexibility in choice of samples. Quantitative polymerase chain reaction is a highly sensitive and specific tool used in referral labs for detection/assessment of parasite load in VL patients and subsequently in monitoring treatment response to antileishmanial agents. The method displays potential to provide threshold for distinguishing asymptomatics in endemic areas. Currently, improvement in VL diagnostics is required for successful decentralized (point-of-care) testing in field conditions and to detect VL-HIV co-infection. Techniques such as loop-mediated isothermal amplification offer a reliable molecular diagnostic method for field application. The diagnosis based on bioanalytics/biosensors promise frontiers for point-of-care VL detection after adequate standardization. This review summarizes the recent developments in VL diagnostics, drawing attention towards the need for standardization of the diagnostics across the affected regions. © Springer-Verlag 2011.

Dev V.,National Institute of Malaria Research Field Station | Sangma B.M.,National Vector Borne Disease Control Programme | Dash A.P.,National Institute of Malaria Research ICMR
Malaria Journal | Year: 2010

Background: Malaria is endemic in Garo hills of Meghalaya, and death cases are reported annually. Plasmodium falciparum is the major parasite, and is solely responsible for each malaria-attributable death case. Garo hills are categorized high-risk for drug-resistant malaria; however, there exists no data on malaria transmitting mosquitoes prevalent in the region. Included in this report are entomological observations with particular reference to vector biology characteristics for devising situation specific intervention strategies for disease transmission reduction. Methods: The epidemiological data of the West Garo hills have been reviewed retrospectively for 2001-2009 to ascertain the disease transmission profile given the existing interventions. Point prevalence study was conducted in Dalu Community Health Centre that lies in close proximity to international border with Bangladesh to ascertain the true prevalence of malaria, and parasite species. Mosquito collections were made in human dwellings of malaria endemic villages aiming at vector incrimination, and to study relative abundance, resting and feeding preferences, and their present susceptibility status to DDT. Results: Investigations revealed that the West Garo hill district is co-endemic for Plasmodium falciparum and Plasmodium vivax, but P. falciparum was the predominant infection (> 82%). Malaria transmission was perennial and persistent with seasonal peak during May-July corresponding to months of high rainfall. Entomological collections revealed that Anopheles minimus was the predominant species that was incriminated by detection of sporozoites in salivary glands (infection rate 2.27%), and was ascertained to be fully susceptible to DDT. Conclusion: For the control of malaria, improved diagnosis and sustained supply of drugs for artemisinin-based combination therapy are strongly advocated, which should be enforced for treatment of every single case of P. falciparum. Greater political commitment is called for organized vector control operations along border/high-risk areas to contain the spread of drug-resistant malaria, and averting impending disease outbreaks. © 2010 Dev et al; licensee BioMed Central Ltd.

Liu M.,Morehouse School of Medicine | Guo S.,Morehouse School of Medicine | Hibbert J.M.,Morehouse School of Medicine | Jain V.,National Institute of Malaria Research ICMR | And 3 more authors.
Cytokine and Growth Factor Reviews | Year: 2011

C-X-C motif chemokine 10 (CXCL10) also known as interferon γ-induced protein 10. kDa (IP-10) or small-inducible cytokine B10 is a cytokine belonging to the CXC chemokine family. CXCL10 binds CXCR3 receptor to induce chemotaxis, apoptosis, cell growth and angiostasis. Alterations in CXCL10 expression levels have been associated with inflammatory diseases including infectious diseases, immune dysfunction and tumor development. CXCL10 is also recognized as a biomarker that predicts severity of various diseases. A review of the emerging role of CXCL10 in pathogenesis of infectious diseases revealed diverse roles of CXCL10 in disease initiation and progression. The potential utilization of CXCL10 as a therapeutic target for infectious diseases is discussed. © 2011.

Dua V.K.,National Institute of Malaria Research ICMR | Pandey A.C.,National Institute of Malaria Research ICMR | Dash A.P.,National Institute of Malaria Research ICMR
Indian Journal of Medical Research | Year: 2010

Background & objectives: Development of insect resistance to synthetic pesticides, high operational cost and environmental pollution have created the need for developing alternative approaches to control vector-borne diseases. In the present study we have investigated the insecticidal activity of essential oil isolated from the leaves of Lantana camara against mosquito vectors. Methods: Essential oil was isolated from the leaves of L. camara using hydro-distillation method. Bioassay test was carried out by WHO method for determination of adulticidal activity against mosquitoes. Different compounds were identified by gas chromatography-mass spectrometry analysis. Results: LD50 values of the oil were 0.06, 0.05, 0.05, 0.05 and 0.06 mg/cm2 while LD90 values were 0.10, 0.10, 0.09, 0.09 and 0.10 mg/cm2 against Ae. aegypti, Cx. quinquefasciatus, An. culicifacies, An. fluvialitis and An. stephensi respectively. KDT50 of the oil were 20, 18, 15, 12, and 14 min and KDT90 values were 35, 28 25, 18, 23 min against Ae. aegypti, Cx. quinquefasciatus, An. culicifacies, An. fluviatilis and An. stephensi, respectively on 0.208 mg/cm2 impregnated paper. Studies on persistence of essential oil of L. camara on impregnated paper revealed that it has more adulticidal activity for longer period at low storage temperature. Gas chromatographic-mass spectrometric analysis of essential oil showed 45 peaks. Caryophyllene (16.37%), eucalyptol (10.75%), α-humelene (8.22%) and germacrene (7.41%) were present in major amounts and contributed 42.75 per cent of the total constituents. Interpretation &conclusion: Essential oil from the leaves of L. camara possesses adulticidal activity against different mosquito species that could be utilized for development of oil-based insecticide as supplementary to synthetic insecticides.

Tennyson S.,Madras Christian College | Ravindran K.J.,National Institute of Malaria Research ICMR | Arivoli S.,P.A. College
Asian Pacific Journal of Tropical Biomedicine | Year: 2012

Objective: To determine the larvicidal activity of twenty five plant extracts against Culex quinquefasciatus (Cx. quinquefasciatus). Methods: The larvicidal activity was determined against the third instar larvae of Cx. quinquefasciatus at 1 000 ppm concentration. Larval mortality was assessed after 24 and 48 h. Results: The hexane extracts of Cleistanthus collinus (C. collinus) and Murraya koeingii (M. koeingii) plants showed 100 percent mortality at 24 h bioassay followed by diethyl ether, dichloromethane and ethyl acetate extracts of C. collinus, Leucas aspera (L. aspera), Hydrocotyle javanica (H. javanica), M. koeingii, Sphaeranthus indicus (S. indicus) and Zanthoxylum limonella (Z. limonella) after 48 h exposure. Conclusions: The results indicate larvicidal activity against Cx. quinquefasciatus and further investigations are needed to elucidate this activity against a wide range of all stages of mosquito species and also the active ingredients of the extract responsible for larvicidal activity should be identified. © 2012 Asian Pacific Tropical Biomedical Magazine.

Dhiman R.C.,National Institute of Malaria Research ICMR | Pahwa S.,National Institute of Malaria Research ICMR | Dhillon G.P.S.,National Vector Borne Disease Control Programme | Dash A.P.,National Institute of Malaria Research ICMR
Parasitology Research | Year: 2010

It is unequivocal that climate change is happening and is likely to expand the geographical distribution of several vector-borne diseases, including malaria and dengue etc. to higher altitudes and latitudes. India is endemic for six major vector-borne diseases (VBD) namely malaria, dengue, chikungunya, filariasis, Japanese encephalitis and visceral leishmaniasis. Over the years, there has been reduction in the incidence of almost all the diseases except chikungunya which has re-emerged since 2005. The upcoming issue of climate change has surfaced as a new threat and challenge for ongoing efforts to contain vectorborne diseases. There is greater awareness about the potential impacts of climate change on VBDs in India and research institutions and national authorities have initiated actions to assess the impacts. Studies undertaken in India on malaria in the context of climate change impact reveal that transmission windows in Punjab, Haryana, Jammu and Kashmir and north-eastern states are likely to extend temporally by 2-3 months and in Orissa, Andhra Pradesh and Tamil Nadu there may be reduction in transmission windows. Using PRECIS model (driven by HadRM2) at the resolution of 50×50 Km for daily temperature and relative humidity for year 2050, it was found that Orissa, West Bengal and southern parts of Assam will still remain malarious and transmission windows will open up in Himachal Pradesh and north-eastern states etc. Impact of climate change on dengue also reveals increase in transmission with 2 C rise in temperature in northern India. Reemergence of kala-azar in northern parts of India and reappearance of chikungunya mainly in southern states of India has also been discussed. The possible need to address the threat and efforts made in India have also been highlighted. The paper concludes with a positive lead that with better preparedness threat of climate change on vectorborne diseases may be negated. © Springer-Verlag 2010.

Singh P.K.,World Health Organization | Dhiman R.C.,National Institute of Malaria Research ICMR
Journal of Vector Borne Diseases | Year: 2012

The article reviews the issue of climate change and health in the Indian context. The importance of climate change leading to estimated loss of above 2.5 million DALYs in southeast Asia, mortality due to heat waves, and the importance of air quality related respiratory diseases, disasters due to excessive floods, malnutrition due to reduction in rice, maize and sorghum crops etc. Latest work undertaken in India, vis-a-vis current scenario and need for further work has been discussed. There is felt need of further studies on assessing the impact on dengue and chikungunya as the transmission dynamics of these diseases involve water availability, storage and life style, etc. Uncertainties and knowledge gaps identified in the studies undertaken so far have also been highlighted. As regards to vector borne diseases, there is a need to concentrate in the areas which are presently free from malaria and with use of best available tools of interventions in already disease endemic areas like northeastern states, the risk of climate change impacts can be minimized.

Barik T.K.,National Institute of Malaria Research ICMR | Barik T.K.,Berhampur University | Kamaraju R.,National Institute of Malaria Research ICMR | Gowswami A.,Indian Statistical Institute
Parasitology Research | Year: 2012

Presently, there is a need for increased efforts to develop newer and effective methods to control mosquito vectors as the existing chemical and biological methods are not as effective as in earlier period owing to different technical and operational reasons. The use of nanomaterial products in various sectors of science including health increased during the last decade. We tested three types of nanosilica, namely lipophilic, hydrophilic and hydrophobic, to assess their larvicidal, pupicidal and growth inhibitor properties and also their influence on oviposition behaviour (attraction/deterrence) of mosquito species that transmit human diseases, namely malaria (Anopheles), yellow fever, chickungunya and dengue (Aedes), lymphatic filariasis and encephalitis (Culex and Aedes). Application of hydrophobic nanosilica at 112.5 ppm was found effective against mosquito species tested. The larvicidal effect of hydrophobic nanosilica on mosquito species tested was in the order of Anopheles stephensi>Aedes aegypti>Culex quinquefasciatus, and the pupicidal effect was in the order of A. stephensi >C. quinquefasciatus>Ae. aegypti. Results of combined treatment of hydrophobic nanosilica with temephos in larvicidal test indicated independent toxic action without any additive effect. This is probably the first report that demonstrated that nanoparticles particularly nanosilica could be used in mosquito vector control. ©Springer-Verlag 2012.

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