ABSTRACT
Background: Malaria is the most important tropical and parasitic disease in the world. Endophagy of many malaria vectors advocates that impeding their entry into houses and preventing their contact with the occupants from infective bites could protect them against malaria. Methods: The study was carried out in Jaisalmer District, India and three villages were selected as test villages and three as control. Cross-sectional malaria prevalence surveys and mosquito collections were conducted in all the study villages. Insecticide-treated nets (ITNs) were tied below the beds for personal protection against the mosquito bite. Door and window curtains along with partition curtains were treated with insecticide for baring the entry of mosquito vectors. Results: Plasmodium vivax and P. falciparum were reported from the study villages. Higher malaria cases were detected in the control villages than the insecticide-treated bed net-distributed villages. The percentages of reduction of mosquito density in the houses of the ITNs distributed villages were significantly higher than the control villages. The insecticide activity was decreased slowly, and the knockdown time (KD50) values were found to be increased with the duration of usage of net. The KD50 of Anopheles subpictus s.l. was found to be more than the An. stephensi. Rooms where the ITNs were found to be significantly lower per man-hour density of mosquitoes. Conclusion: The use of alternative forms of ITNs shows a potential for preventing malaria and are making a significant contribution to the mosquito control. Effective use of ITNs could be helpful in the malaria elimination in India by 2030.
ABSTRACT
BACKGROUND: Transmission of malaria and dengue in the desert part of India is mainly caused by Anopheles stephensi and Aedes aegypti respectively. The maintenance and transmission of the pathogens that cause malaria and dengue are dependent on the physiology of the mosquito vectors. We aimed to measure the energy contents in the mosquitoes transmitting malaria and dengue in the desert part of the country. METHODS: Immature stages of mosquitoes were collected from six different larval habitats situated in Jodhpur City of Rajasthan state, India. The immature stages of both the mosquitoes were collected once in fortnightly from each location. Quantitative estimations of the lipid, glucose, and glycogen of the laboratory-reared and field collected An. stephensi and Ae. aegypti were made by spectrophotometric method. The energy contents of the larvae, pupae, females, and males were estimated in triplicates on six different occasions. RESULTS: The lipid content of laboratory-reared larvae, pupae and female mosquitoes of An. stephensi and Ae. aegypti was found to be lower than their conspecific field-collected specimens. Whereas, the glycogen content in the laboratory-reared larvae, pupae and female mosquitoes of An. stephensi and Ae. aegypti was higher than that of their conspecific field-collected specimens. The glucose content in all the stages of the laboratory-reared An. stephensi was lower than their conspecific field-collected specimens except in few cases. CONCLUSION: The higher amount of lipid in field-collected mosquitoes may be because of the availability of food in the natural habitat and adaptation of mosquitoes. Mosquitoes living in desert climate are physiologically better equipped to survive in the desert environment.
