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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. Source

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. Source

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. Source

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. Source

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. Source

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