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Background: After the decades of Dichlorodiphenyltrichloroethane (DDT) use, Phlebotomus argentipes reportedly developed resistance against it affecting every aspect of vector control at grass-root level. Although DDT based Indoor Residual Spray (IRS) has been replaced with Alphacypermethrine-a Synthetic Pyrethroid (SP) based insecticide, since 2016 but its successful implementation at the Visceral Leishmaniasis (VL) endemic regime of Bihar doesn’t cause much effect upon VL vector density. Furthermore, the outcomes of existing operational research works, it had been observed that VL vectors are continuously changing its behavior under the pressure of insecticides.
Methods: For validating the hypothesis, present study has been carried out at Vaishali and Patna being highly and semi-endemic sites respectively for quantifying the oriental behavior among VL vectors persuaded by the IRS and enforce them to remain alive and get trapped in light trap even after changed chemical composition of IRS i.e., SP-IRS from routine DDT-IRS.
Results: Following results, a significant reduction in sand fly density (i.e., 33.09% and 29.16%) was observed for outdoor and indoor caught sand flies, collected with light trap and aspirator respectively. Significant higher no. of sand fly collection in terms of per light traps per night was recorded from the outdoor sites than those from indoor habitat for each village of Vaishali and Saran district of Bihar. Higher no. of male sand flies than to that of female ones were collected from outdoor sites and only unfed female sand flies (i.e., 100%) were caught following SP-IRS from each study villages of Vaishali and Saran districts of Bihar.
Conclusions: The results of higher no. of sand flies collection from the outdoor sites as compared with the indoor habitat validate the hypothesis of gradual shifting of habitat of VL vectors from endophilic to exophilic which is undoubtedly followed due to the fact of developed resistance among them against chemical constituent of IRS. Results provide very useful information about the sand fly dynamics under the impact of IRS and accordingly, advocates the combined approach of IRS along with insecticidal fogging together at a same time that could be an effective dividend for maximum VL vector control along for negotiating VL cases at par for longer duration during the maintenance phase at the VL foci.
Malaviya P, Hasker E, Picado A, Mishra M, Van Geertruyden JP, Das ML, et al. Exposure to Phlebotomus argentipes (Diptera, Psychodidae, Phlebotominae) sand flies in rural areas of Bihar, India: the role of housing conditions. PLOS one. 2014;9(9):e106771. Available:https://doi.org/10.1371/journal.pone.0106771
Swaminath CS, Shortt HE, Anderson LAP. Transmission of Indian kala-azar to man by the bite of P. argentipes Annadale and Brunetti. Indian J Med Res. 1942;30:473-477.
Kumar V, Bimal S, Kesari S, Kumar AJ, Bagchi AK, Akbar MA, et al. Evaluation of a dot-immunoblot assay for detecting leishmanial antigen in naturally infected Phlebotomus argentipes (Diptera: psychodidae). Ann Trop Med Parasit. 2005;99(4):371-376.
Sharma U, Singh S. Insect vectors of Leishmania: Distribution, physiology and their control. J Vector Borne Dis. 2008; 45:255–272.
Ghosh KK, Das S, Hati AK. Studies on seasonal man sandfly (Phlebotomus argentipes) contact at night. Journal of Indian Association of Communicable Diseases. 1982;5:14-18.
Dinesh DS, Ranjan A, Palit A, Kishore K, Kar SK. Seasonal and nocturnal landing/biting behaviour of Phlebotomus argentipes (Diptera: Psychodidae). Ann Trop Med Parasitol. 2001;95(2):197-202.
Kishore K, Kumar V, Kesari S, Bhattacharya SK, Das P. Susceptibility of Phlebotomus argentipes against DDT in endemic districts of North Bihar, India. J Comm Dis. 2004;36(1):41-44.
Kumar V, Kesari S, Kumar AJ, Dinesh DS, Ranjan A, Prasad M, et al. Vector density and the control of kala-azar in Bihar, India. Mem Inst Oswaldo Cruz 2009;104:1019-1022.
Joshi A, Narain JP, Prasittisuk C, Bhatia R, Hashim G, Jorge A, et al. Can Visceral leishmaniasis be eliminated from Asia? J Vector Borne Dis. 2008;45:105-111.
Muniaraj M. The lost hope of elimination of Kala-azar (visceral leishmaniasis) by 2010 and cyclic occurrence of its outbreak in India, blame falls on vector control practices or co-infection with human immunodeficiency virus or therapeutic modalities? Trop Parasitol. 2014;4:10-19.
Mukhopadhyay AK, Sexena NBLK, Narasimhan MVVL. Susceptibility status of Phlebotomus argentipes to DDT in some Kala-azar endemic districts of Bihar, India. Indian J Med Res. 1990;91:458-460.
Singh R, Das RK, Sharma SK. Resistance of sandflies to DDT in Kalaazar endemic district of Bihar, India. Bull. World Health Organ. 2001;79:793.
Coleman M, Foster GM, Deb R, Singh RP, Ismail HM, Shivam P, et al. DDT-based indoor residual spraying suboptimal for Visceral leishmaniasis elimination in India. Proc Natl Acad Sci. 2015;112:8573-8578.
Kumar V, Shankar L, Kesari S, Bhunia GS, Dinesh DS, Mandal R, et al. Insecticide susceptibility of Phlebotomus argentipes & assessment of vector control in two districts of West Bengal, India. Indian J Med Res. 2015;142(2):211-215.
Rama A, Kumar V, Kesari S, Singh VP, Das P. Monitoring susceptibility status of Phlebotomus argentipes (Diptera: Psychodidae) at Bihar (India) for the procurement of homozygous DDT resistant colony. J Trop Dis. 2015;3(4):170.
Rama A, Kesari S, Das P, Kumar V. Studying DDT susceptibility at discriminating time interval focusing maximum limit of exposure time survived by DDT resistant Phlebotomus argentipes (Diptera: Psychodidae): An investigative report. Jpn J Infect Dis. 2017;70(4):437-441.
Kumar V, Shankar L, Rama A, Kesari S, Dinesh DS, Bhunia GS, et al. Analysing host preference behavior of Phlebotomus argentipes (Diptera: Psychodidae) under the impact of indoor residual spray. International Journal of Tropical Disease & Health. 2015;7(2):69-79.
Chowdhury R, Huda MM, Kumar V, Das P, Joshi AB, Banjara MR, et al. The Indian and Nepalese programmes of indoor residual spraying for the elimination of Visceral leishmaniasis: performance and effectiveness. Ann Trop Med Parasitol. 2011;105:31-35.
Huda MM, Mondal D, Kumar V, Das P, Sharma SN, Das ML, et al. Toolkit for monitoring and evaluation of indoor residual spraying for Visceral leishmaniasis control in the India subcontinent: application and results. J Trop Med. 2011; 876742.
Desjeux P. Leishmaniasis: Current situation and new perspectives. Comparative Imm Micro Infect Dis. 2004; 27:305–318.
Kishore K, Kumar V, Kesari S, Dinesh DS, Kumar AJ, Das P, et al. Vector control in leishmaniasis. Indian J Med Res. 2006; 123(3):467-472.
Kumar V, Rama A, Mishra PS, Siddiqui NA, Singh RP, Dasgupta RK, et al. Investigating associative impact of indoor residual spray and insecticide treated nets for minimizing visceral leishmaniasis vector population in Bihar (India). International Journal of Tropical Disease and Health. 2017;23(4):1-15.
National Vector Borne Disease Control Programme (NVBDCP). Accelerated plan for kala-azar elimination. 2017. Directorate National Vector Borne Disease Control Programme. NVBDCP; 2017.
Dhiman RC, Raghavendra K, Kumar V, Kesari S, Kishore K. Susceptibility status of Phlebotomus argentipes to insecticides in districts Vaishaii and Patna (Bihar). J Comm Dis. 2003;35(1):49-51.
Gomes B, Purkait B, Deb RM, Rama A, Singh RP, Foster GM, et al. Knockdown resistance mutations predict DDT resistance and pyrethroid tolerance in the visceral leishmaniasis vector Phlebotomus argentipes. PLoS Negl Trop Dis. 2017; 11(4):e0005504.
Mukhopadhyay AK, Chakravarty AK, Kureel VR. Resurgence of Phlebotomus argentipes & Ph. papatasi in parts of Bihar (India) after DDT spraying. Indian J Med Res. 1987;85:158-160.
Roberts DR, Alecrim WD, Hshieh P, Grieco JP, Bangs M, Andre RG, et al. A probability model of vector behavior: effects of DDT repellency, irritancy, and toxicity in malaria control. J Vector Ecol. Journal of the Society for Vector Ecology. 2001;25(1):48-61.