ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the insecticidal effect of diatomaceous earth (DE) against adults and nymphs of Blattella germanica.</p><p><b>METHODS</b>This cross sectional study has been done on the laboratory strain of German cockroaches. Two stages, nymph and adult, were exposed to six dose rates of the DE, 2.5, 5, 10, 15, 20 and 25 g/m(2), at 24, 48 and 72 h exposure period. Mortality (number of dead cockroaches) was assessed after 24 h. Other exposed specimens were transferred to the beakers contained food and water for counting the retard mortality rate after 1 week.</p><p><b>RESULTS</b>Increasing in dose rates of DE increased mortality rate, so that the lowest and highest mortality rates were observed in 2.5 and 25 g/m(2), respectively. The results of the statistical analysis showed no significant difference in the lethality of 50% of DE plus water on the German cockroach nymphs.</p><p><b>CONCLUSIONS</b>Due to the resistance of German cockroach against organochloride, organophosphorus, carbamate and pyrethriodes insecticides, it is suggested to use DE for insect's control.</p>
ABSTRACT
Long-lasting insecticidal nets [LLINs] have been advocated as an effective tool against malaria transmission. However, success of this community based intervention largely depends on the knowledge and practice regarding malaria and its prevention. According to the national strategy plan on evaluation of LLINs [Olyset nets], this study was conducted to determine the perceptions and practices about malaria and to improve use of LLINs in Bashagard district, one of the important foci of malaria in Southeast Iran. The study area comprised 14 villages that were randomized in two clusters and designated as LLINs and untreated nets. Each of households in both clusters received two bed nets by the free distribution and delivery. After one month quantitative data collection method was used to collect information regarding the objectives of the study. On the basis of this information, an educational program was carried out in both areas to increase motivation for use of bed nets. Community knowledge and practice regarding malaria and LLIN use assessed pre- and post-educational program. The data were analyzed using SPSS ver.16 software. At baseline, 77.5% of respondents in intervention and 69.4% in control area mentioned mosquito bite as the cause of malaria, this awareness increased significantly in intervention [90.3%] and control areas [87.9%], following the educational program. A significant increase also was seen in the proportion of households who used LLINs the previous night [92.5%] compared with untreated nets [87.1%]. Educational status was an important predictor of LLINs use. Regular use of LLIN was considerably higher than the targeted coverage [80%] which recommended by World Heaths Organization. About 81.1% and 85.3% of respondents from LLIN and control areas reported that mosquito nuisance and subsequent malaria transmission were the main determinants of bed net use. These findings highlight a need for educational intervention in implementation of long-lasting insecticidal nets; this should be considered in planning and decision-making in the national malaria control program during the next campaigns of LLINs in Iran