Center for Medical Entomology and Vector Management

Delhi, India

Center for Medical Entomology and Vector Management

Delhi, India
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Kumar K.,Center for Medical Entomology and Vector Management | Balakrishnan N.,NCDC Bangalore Branch | Sharma A.K.,Center for Medical Entomology and Vector Management
International Journal of Zoology | Year: 2014

The Nilgiri hills and adjoining downhill areas provide favourable ecological conditions for the propagation of haematophagous arthropods owing to richness in vegetation and animal activities. A study has been undertaken during 2008-2010 on the distribution and abundance of ticks of domestic animals in seven different biotopes. A total of 3,008 domestic animals were examined in areas ranging from an altitude of 300 to 2200 meters above mean sea level (MSL) of which 1,335 (44.5%) animals were having tick infestation. A total of 6,012 adult and immature ticks belonging to 12 species (11 ixodid and one argasid) were collected. Eleven tick species were collected from Kallar area situated downhill eastern slopes of the Nilgiris followed by Burliar area (7 species) located at higher altitudes. From Masinagudi area near to dense forests and scrub jungles, five species were recorded. However, at higher elevations on the hills, Udhagamandalam area, only one species was recorded. Among various tick species recorded in the study, Boophilus microplus was distributed in almost all areas surveyed followed by Haemaphysalis spinigera and Rhipicephalus sanguineus. The factors governing their distribution and epidemiological significance in the transmission of various tick-borne diseases of public health importance are discussed. © 2014 Kaushal Kumar et al.


Sharma P.,National Center for Disease Control | Mittal V.,National Center for Disease Control | Chhabra M.,National Center for Disease Control | Kumari R.,Center for Medical Entomology and Vector Management | And 5 more authors.
Virologica Sinica | Year: 2015

[Figure not available: see fulltext.] © 2015, Wuhan Institute of Virology, CAS and Springer Science+Business Media Singapore Pte Ltd.


Sharma P.,National Center for Disease Control | Mittal V.,National Center for Disease Control | Chhabra M.,National Center for Disease Control | Kumari R.,Center for Medical Entomology and Vector Management | And 3 more authors.
VirusDisease | Year: 2016

Dengue virus type 2 (DENV-2) has been associated with severe dengue outbreaks in many countries including India. Its predominance was recorded nearly after a decade in the capital city, Delhi in 2013. The present study characterizes DENV-2 circulated during 2013–2014. Analysis based on envelope (E) gene showed the presence of two clades (I and II) of DENV-2, within the Cosmopolitan genotype. Analysis of time of most recent common ancestor revealed the existence of clade I for more than a decade (95 % HPD 13–16 years) however, clade II showed comparatively recent emergence (95 % HPD 5–13 years). Presence of different clades is of high significance as this may result in increased virus transmission and major outbreaks. Further, the presence of a unique amino acid substitution, Q325H was also observed in an isolate; 14/D2/Del/2013 (KT717981). This substitution falls in immune epitope (epitope id: 150268) and may have important role in host immune response. © 2016 Indian Virological Society


PubMed | Center for Medical Entomology and Vector Management and National Center for Disease Control
Type: Journal Article | Journal: Virusdisease | Year: 2016

Dengue virus type 2 (DENV-2) has been associated with severe dengue outbreaks in many countries including India. Its predominance was recorded nearly after a decade in the capital city, Delhi in 2013. The present study characterizes DENV-2 circulated during 2013-2014. Analysis based on envelope (E) gene showed the presence of two clades (I and II) of DENV-2, within the Cosmopolitan genotype. Analysis of time of most recent common ancestor revealed the existence of clade I for more than a decade (95% HPD 13-16years) however, clade II showed comparatively recent emergence (95% HPD 5-13years). Presence of different clades is of high significance as this may result in increased virus transmission and major outbreaks. Further, the presence of a unique amino acid substitution, Q325H was also observed in an isolate; 14/D2/Del/2013 (KT717981). This substitution falls in immune epitope (epitope id: 150268) and may have important role in host immune response.


Saxena V.K.,Center for Medical Entomology and Vector Management
Journal of Communicable Diseases | Year: 2014

Japanese encephalitis (JE) is a serious public health problem in several parts of India, because of its threatening morbidity and mortality outcome, particularly among children. In India, there are 3 known mosquito vector species widely present in all the endemic areas. The ecology of JE is a multidimensional issue involving several macro- to- micro level factors influencing the spatio- temporal dynamics of transmission. There is a need to understand the ecological linkage and the interface of the reservoir (bird)- amplifier (pig)- the vector (mosquito) as a crucial aspect of the biologic route in the maintenance of the JEV in nature. The type of association of domestic and peridomestic biotopes as drivers of JEV also needs to be understood at the local scale. Risk factor identification based on micro analysis of diverse factors ranging from local ecology to socio- economic well being of people living in endemic areas, is of utmost importance for JE prevention and control. The scarcity of specific information and importance of socioeconomic and cultural aspects in relation to JE epidemiology has been emphasized and reviewed in the article. All these aspects of JE ecosystem have been grossly reviewed highlighting specific areas of interest for disease prevention/ control programme in order to provoke ecological thinking among various specialists like epidemiologists, medical entomologists, molecular epidemiologists and public health decision makers.


Sharma G.,University of Delhi | Kumar K.,Center for Medical Entomology and Vector Management | Sharma A.,Center for Medical Entomology and Vector Management | Agrawal V.,University of Delhi
Journal of the American Mosquito Control Association | Year: 2012

Using in vitro bioassays, we evaluated the crude methanol, ethanol, chloroform, and acetone leaf extracts of Artemisia annua as well as pure artemisinin against late 3rd and early 4th instars of Culex quinquefasciatus and Cx. tritaeniorhynchus. Based on the lethal concentration for 50% mortality (LC50) and lethal concentration for 90% mortality (LC90) values, the chloroform leaf extract was the most toxic, followed by methanol, ethanol, and acetone. The LC50 and LC90 values for chloroform extract were 0.18 and 9.65 ppm against Cx. quinquefasciatus and 0.91 and 8.73 ppm against Cx. tritaeniorhynchus, respectively. The LC50 and LC90 values for artemisinin, dissolved in chloroform, were significantly higher, 14.31 and 296.39 ppm for Cx. quinquefasciatus and 4.13 and 50.36 ppm for Cx. tritaeniorhynchus, respectively. © 2012 by The American Mosquito Control Association, Inc.


Kaur S.,Indian Defence Research And Development Laboratory | Kaur S.,National University of Ireland | Sarkar M.,Indian Defence Research And Development Laboratory | Sarkar M.,Center for Medical Entomology and Vector Management | And 3 more authors.
New Biotechnology | Year: 2012

We determined the fatty acid compositions of six species of freshwater microalgae belonging to the Chlorophyta, which were isolated from freshwater bodies in Assam, India. All six microalgae Desmodesmus sp. DRLMA7,. Desmodesmus elegans DRLMA13,. Scenedesmus sp. DRLMA5,. Scenedesmus sp. DRLMA9. Chlorella sp. DRLMA3 and. Chlorococcum macrostigmatum DRLMA12-showed similar fatty acid profiles 16:0, 16:4, 18:1, 18:2, and 18:3 as major components. We also compared fatty acid compositions during the late exponential and stationary growth phases of. D. elegans DRLMA13 and. Scenedesmus sp. DRLMA9 in BG11 medium. We observed enhanced percentages of total saturated and monounsaturated fatty acids with a concomitant decrease in polyunsaturated fatty acid content upon the prolonged cultivation of both microalgae. Distinct morphological features of microalgal isolates were determined by scanning electron microscopic (SEM) studies. An ornamented cell wall was found in D. elegans DRLMA13, which is characteristic of small spineless species of. Desmodesmus. The isolated microalgae were further distinguished through analysis of internal transcribed spacer 2 (ITS2) secondary structures and compensatory base changes (CBCs). Analysis of CBCs showed the relatedness of. Chlorella sp. DRLMA3 with other Chlorella-like organisms, but it does not belong to the clade comprising. Chlorella sensu stricto, which includes. Chlorella vulgaris. The CBC count between. Scenedesmus sp. DRLMA9 and other species of. Scenedesmus provides evidence that this isolate represents a new species. © 2011 Elsevier B.V.


Kumari R.,Center for Medical Entomology and Vector Management | Kumar K.,Center for Medical Entomology and Vector Management | Chauhan L.S.,Center for Medical Entomology and Vector Management
Tropical Medicine and International Health | Year: 2011

Objective To report dengue virus and its disease transmission in Aedes albopictus in the National Capital Territory of Delhi, India. Methods Monthly Aedes surveys were carried out in 126 urban localities of Delhi in 2008 and 2009. Pools of all three species of Aedes mosquitoes were tested for Dengue virus (DENV) using an antigen-capture enzyme-linked immunosorbent assay. Results Aedes aegypti was the most prevalent species, breeding throughout the year. Aedes albopictus was found in 9.52% of surveyed localities including the central urban part of Delhi, in March and from August to October. Aedes albopictus and Aedes vittatus are adapting to breed in manmade containers in the urban areas of Delhi in addition to their natural habitats of bamboo bushes and rock pits. Of the 229 pools of Ae. aegypti and 34 pools of Ae. albopictus tested, 10.5% and 11.76% were positive for dengue virus, respectively. No dengue virus infection was recorded in Ae. vittatus. Conclusion This is the first report of dengue virus in Ae. albopictus from north India. Because DENV was detected in Ae. albopictus, which adapted to manmade containers, both its spread and transmission dynamics should be checked. © 2011 Blackwell Publishing Ltd.


Kumar K.,Center for Medical Entomology and Vector Management | Sharma A.K.,Center for Medical Entomology and Vector Management | Kumar S.,Center for Medical Entomology and Vector Management | Patel S.,Regional Filariasis Training and Research Center | And 2 more authors.
Asian Pacific Journal of Tropical Medicine | Year: 2011

Objective: To understand the insecticide resistance status of Culex quinquefasciatus Say (Diptera: Culicidae) (Cx. Quinquefasciatus) to deltamethrin, cyfluthrin, permethrin, lambdacyhalothrin, DDT and malathion in filarial endemic areas of Uttar Pradesh, India. Methods: Insecticide susceptibility assays were performed on wild-caught adult female Cx. quinquefasciatus mosquitoes to deltamethrin (0.05%), cyfluthrin (0.15%), permethrin (0.75%), lambdacyhalothrin (0.05%), malathion (5.0%) and DDT (4.0%), the discriminating doses recommended by the World Health Organisation (WHO). Results: The data showed that Cx. quinquefasciatus is highly resistant to DDT and malathion; the mortality was 28.33% and 27.5%, respectively and incipient resistance to synthetic pyrethroids (deltamethrin, cyfluthrin, permethrin, and lambdacyhalothrin), where mortality ranged from 95.83% in permethrin to 98.33% in cyfluthrin and lambdacyhalothrin. Knockdown times (KDT 50) in response to synthetic pyrethroids varied significantly between different insecticides (P<0.01) from 31.480 min for permethrin to 21.650 for cyfluthrin. Conclusions: The results presents here provide the status report of the insecticide resistance/susceptibility of Cx. quinquefasciatus in major filaria endemic areas of northern India. © 2011 Hainan Medical College.


PubMed | Center for Medical Entomology and Vector Management
Type: Journal Article | Journal: Asian Pacific journal of tropical medicine | Year: 2011

To understand the insecticide resistance status of Culex quinquefasciatus Say (Diptera: Culicidae) (Cx. Quinquefasciatus) to deltamethrin, cyfluthrin, permethrin, lambdacyhalothrin, DDT and malathion in filarial endemic areas of Uttar Pradesh, India.Insecticide susceptibility assays were performed on wild-caught adult female Cx. quinquefasciatus mosquitoes to deltamethrin (0.05%), cyfluthrin (0.15%), permethrin (0.75%), lambdacyhalothrin (0.05%), malathion (5.0%) and DDT (4.0%), the discriminating doses recommended by the World Health Organisation (WHO).The data showed that Cx. quinquefasciatus is highly resistant to DDT and malathion; the mortality was 28.33% and 27.5%, respectively and incipient resistance to synthetic pyrethroids (deltamethrin, cyfluthrin, permethrin, and lambdacyhalothrin), where mortality ranged from 95.83% in permethrin to 98.33% in cyfluthrin and lambdacyhalothrin. Knockdown times (KDT(50)) in response to synthetic pyrethroids varied significantly between different insecticides (P<0.01) from 31.480 min for permethrin to 21.650 for cyfluthrin.The results presents here provide the status report of the insecticide resistance/susceptibility of Cx. quinquefasciatus in major filaria endemic areas of northern India.

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