Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, re...Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, relies on the efficacy and residual activity of the insecticides applied, which to a certain extent are influenced by the nature of the sprayed surfaces. The bioefficacy of indoor residual-sprayed deltamethrin wettable granule (WG) formulation for the control of malaria was compared with the current dose of deltamethrin wettable powder (WP) in malaria endemic areas in Balai Ringin, Sarawak. Doses of 20 mg/m2 WP (control), 20 mg/m2 WG, 30 mg/m2 WG and 40 mg/m2 WG were sprayed separately on different surfaces namely, wooden, rough-bamboo, smooth-bamboo and brick surfaces. Residual activity of WP and WG formulations was tested against lab-bred Anopheles maculatus using WHO standard procedure. Deltamethrin at 30 mg/m2 WG exhibited the highest sustainable level of effectiveness against An. maculatus (An. maculatus mortality was between 95% - 100%) up to week 60 post-spraying when sprayed on smooth- bamboo surface. These results indicated that 30 mg/m2 WG could be an ideal concentration for controlling malaria vector effectively up to 15 months of which long-lasting residual spraying was envisaged. The usual two spraying cycles per year with 20 mg/m2 deltamethrin WP could be replaced with 30 mg/m2 deltamethrin WG since the long residual activity was achieved by employing a single spraying only.展开更多
Knowledge of the composition and biting habits of mosquito associated with endemic areas is important in establishing sound vector control programmes and understanding the epidemiology of vector borne diseases. The bi...Knowledge of the composition and biting habits of mosquito associated with endemic areas is important in establishing sound vector control programmes and understanding the epidemiology of vector borne diseases. The biting activity cycle of several mosquito species in Serian, Sarawak was observed and described. Collections were carried out indoors and outdoors for 12 hours from 6.00 pm to 6.00 am using human landing catch techniques. A total of 7271 mosquitoes comprising 27 species belonging to sixgenera were collected. Mansonia bonneae (23.6%) was the predominant species caught in the study areas followed by Culex vishnui (22.3%), Culex pseudovishnui (19.6%) and Culex tritaenorhynchus (13.7%). A high rate of human biting activity by Ma. bonneae was detected during November but the activity was low during January.The biting activity of Ma.bonneae was found higher outdoor compared to indoorand peaked at 7.00 pm-8.00 pm.Cx.vishnui also exhibited similar biting activity peak while Anopheles letiferex-hibited biting activity peaked at 12.00 am-1.00 am.Cx.pseudovishnui showed biting patterns which were almost similar between indoor and outdoor activity and could be considered active throughout the 12 hour period.展开更多
文摘Malaria control programme utilizing indoor residual spraying of chemical insecticide is only effective if a high coverage of targeted area is achieved. The effectiveness of the residual spraying, on the other hand, relies on the efficacy and residual activity of the insecticides applied, which to a certain extent are influenced by the nature of the sprayed surfaces. The bioefficacy of indoor residual-sprayed deltamethrin wettable granule (WG) formulation for the control of malaria was compared with the current dose of deltamethrin wettable powder (WP) in malaria endemic areas in Balai Ringin, Sarawak. Doses of 20 mg/m2 WP (control), 20 mg/m2 WG, 30 mg/m2 WG and 40 mg/m2 WG were sprayed separately on different surfaces namely, wooden, rough-bamboo, smooth-bamboo and brick surfaces. Residual activity of WP and WG formulations was tested against lab-bred Anopheles maculatus using WHO standard procedure. Deltamethrin at 30 mg/m2 WG exhibited the highest sustainable level of effectiveness against An. maculatus (An. maculatus mortality was between 95% - 100%) up to week 60 post-spraying when sprayed on smooth- bamboo surface. These results indicated that 30 mg/m2 WG could be an ideal concentration for controlling malaria vector effectively up to 15 months of which long-lasting residual spraying was envisaged. The usual two spraying cycles per year with 20 mg/m2 deltamethrin WP could be replaced with 30 mg/m2 deltamethrin WG since the long residual activity was achieved by employing a single spraying only.
文摘Knowledge of the composition and biting habits of mosquito associated with endemic areas is important in establishing sound vector control programmes and understanding the epidemiology of vector borne diseases. The biting activity cycle of several mosquito species in Serian, Sarawak was observed and described. Collections were carried out indoors and outdoors for 12 hours from 6.00 pm to 6.00 am using human landing catch techniques. A total of 7271 mosquitoes comprising 27 species belonging to sixgenera were collected. Mansonia bonneae (23.6%) was the predominant species caught in the study areas followed by Culex vishnui (22.3%), Culex pseudovishnui (19.6%) and Culex tritaenorhynchus (13.7%). A high rate of human biting activity by Ma. bonneae was detected during November but the activity was low during January.The biting activity of Ma.bonneae was found higher outdoor compared to indoorand peaked at 7.00 pm-8.00 pm.Cx.vishnui also exhibited similar biting activity peak while Anopheles letiferex-hibited biting activity peaked at 12.00 am-1.00 am.Cx.pseudovishnui showed biting patterns which were almost similar between indoor and outdoor activity and could be considered active throughout the 12 hour period.
