RESUMO
Our study rationale was to establish contemporary epidemiological data on malaria and schistosomiasis among school-going children in Chikwawa District before future environmental changes associated with the Shire Valley Transformation Programme occurred. Our cross-sectional surveys tested 1134 children from 21 government-owned primary schools (approximately 50 children per school); rapid diagnostic tests for malaria (Humasis Pf/PAN) and intestinal schistosomiasis (urine-Circulating Cathodic Antigen) were used, with urine reagents strips and egg-filtration with microscopy for urogenital schistosomiasis. All infected children were treated with an appropriate dose of Lonart® (for malaria) and/or Cesol® (for schistosomiasis). Across 21 schools the overall prevalence was 9.7% (95% CI: 8.8-10.6%) for malaria, 1.9% (95% CI: 1.4-2.3%) for intestinal schistosomiasis, and 35.0% (95% CI: 33.6-36.5%) for egg-patent urogenital schistosomiasis. The prevalence of co-infection of malaria with urogenital schistosomiasis was 5.5% (95% CI: 4.8-6.2%). In a third of the schools, the prevalence of malaria and urogenital schistosomiasis was above national averages of 10.5% and 40-50%, respectively, with two schools having maxima of 36.8% and 84.5%, respectively. Set against a background of ongoing control, our study has revealed an alarming burden of malaria and schistosomiasis in southern Malawi. These findings call for an immediate mitigating response that significantly bolsters current control interventions to better safeguard children's future health.
RESUMO
The use of a metofluthrin-impregnated spatial repellent device (MSRD) is a new and effective method for preventing mosquito blood feeding. Indoor environmental factors such as room temperature and ventilation rate are thought to be important for MSRD activity. Measurements of room temperature and vaporization of metofluthrin from MSRD in typical rural metal-roof and thatched-roof houses in southeastern Malawi were conducted. The relationship between house structure and the number of collected Anopheline mosquitoes with and without MSRD treatment was also investigated. The difference between daytime and nighttime room temperature was significantly higher in metal-roof houses than in thatched-roof houses. The vaporization of metofluthrin from the MSRD was not accelerated by the high room temperature, but by the high indoor air flow by ventilation. The number of mosquito collections was significantly higher in thatched-roof houses than in metal-roof houses. MSRD-treated thatched-roof houses have a higher probability of mosquito infestation, but the vaporization of metofluthrin is also higher because of indoor air flow, resulting in a reduction in mosquito numbers. Metal-roof houses with closed eaves reduce the probability of mosquito invasion, and a longer predicted effectiveness occurs with MSRD because of the controlled release of metofluthrin through lower indoor air flow.
Assuntos
Anopheles , Repelentes de Insetos , Malária , Animais , Habitação , Humanos , Malária/prevenção & controle , Malaui , Controle de Mosquitos/métodos , VolatilizaçãoRESUMO
Long-lasting insecticidal nets (LLINs) experience some operational problems that reduce their effectiveness, such as limited spaces for hanging, biting of mosquitoes outdoors, a shift of key biting time from midnight to dawn or dusk, and development of pyrethroid resistance in mosquitoes. The concept of spatial repellency may be a countermeasure to overcome the above issues. The effect of the combined use of metofluthrin-impregnated spatial repellent devices (MSRDs) and LLINs (Olyset® Plus) on malaria prevalence and vector mosquitoes were examined in malaria endemic villages in south-eastern Malawi. The intervention reduced the infection rate in children as well as the number of pyrethroid-resistant vector mosquitoes. To achieve effective malaria control, continued intervention using MSRDs with 2 strips per 10 m2 at 3-month intervals to reduce the density of malaria mosquitoes is recommended.
