Role of health extension workers in the relationship between vector control interventions and malaria in Ethiopia

Background Despite a tremendous decline in the burden of malaria through public health interventions, it is yet remains a critical parasitic health problem in Ethiopia. Insecticide-treated nets and indoor residual spray are considered as the most effective preventive interventions against malaria. This study intended to determine the role of health extension workers in influencing the relationship between vector control strategies and malaria prevalence in Ethiopia. Methods The study adopted a descriptive study based on panel data collected from 10 regions of Ethiopia from 2010 to 2018. The data collected were analyzed using STATA version 13.0. Structural equation modelling was used to assess the mediating effect of health extension workers in the relationship. Further, the random effect model was employed to investigate the direct relationship among the study variables. Results We observed a strong mediating role of health extension workers to the relationship between strategic interventions and malaria prevalence, where the direct path is (β = 0.64, p < 0.05), and the indirect path (β = 0.72, p < 0.001) and (β = 0.98, p < 0.001) confirming the mediation condition to appear. Our analysis revealed that, insecticide-treated nets and indoor residual spray significantly impacts the malaria prevalence (β = 0.20, p < 0.05) and (β = 0.70, p < 0.001) respectively. Further, our analysis suggests that the cumulative effect of indoor residual spray and insecticide-treated mosquito nets have helped better avert malaria prevalence (β = 81.3%, P < 0.05). Moreover, the finding demonstrates the incremental rate of 30.2%, which is the indirect effect of the research [(β = 0.813) - (β1 = 0.511)]. Conclusion The findings are potentially useful for the health sector in charge of infectious disease prevention and control, particularly in developing countries explaining how these group provided support to reduce malaria ensuring the provision of proper health message about the program.

Effect of Different Wall Surface Coverage With Deltamethrin-Treated Netting on the Reduction of Indoor-Biting Anopheles Mosquitoes (Diptera: Culicidae)

Indoor residual spray with deltamethrin remains the most common tool for reducing malaria transmission in Thailand. Deltamethrin is commonly used to spray the entire inner surfaces of the walls to prevent mosquitoes from resting. This study compared the mosquito landing responses on humans inside three experimental huts treated with deltamethrin at three different extents of wall coverage (25%, 50%, and full coverage), with one clean/untreated hut serving as a control. There were no significant differences between the numbers of Anopheles mosquitoes landing in the 50% and full coverage huts, whereas, in comparison to both of these, there was a significantly greater number landing in the 25% coverage hut. This study demonstrates that varying the percent coverage of indoor surfaces with deltamethrin-treated netting influences the blood-feeding success of wild Anopheles, and our findings suggest that it may be possible to reduce the extent of insecticide surface treatment while maintaining equivalent mosquito avoidance action to that seen in fully treated structures.

UTILIZATION AND EFFECTIVENESS OF MALARIA PREVENTION METHODS AMONG PREGNANT WOMEN IN TERTIARY HOSPITAL SITUATED IN RURAL COMMUNITY OF EKITI STATE, NIGERIA

Background: National surveys indicate that among countries in Africa where malaria is endemic, Nigeria alone accounts for 21% of pregnancies that are unprotected from malaria. This study aimed to ascertain the extent of utilization and effectiveness of malaria prevention methods, found out the existing relationship between maternal parasitaemia and the effectiveness of these methods at (p<0.05) level of signicance.Methods: The study was a cross sectional survey involving 264 consenting pregnant women who were recruited at booking clinic at Federal Teaching Hospital, Ido -Ekiti, Ekiti State, Nigeria. Interviewer administered questionnaire was used to elicit information on their socio-demographic characteristics, mode and extent of utilization of malaria prevention methods and their effectiveness. Venous blood samples were collected and analyzed for malaria parasitaemia using the microscopy. Data was analyzed using SPSS version 20.0 Results:The malaria prevention methods most commonly reported as being effective were the Insecticide Treated Nets (ITNs), Indoor Residual Spray (IRS) or both, which were utilized by 97(36.5%), 79 (30.0%) and 88 (33.4%) participants respectively. Eight (8.3%), 9 (10.8%), and 7 (7.9%) of the participants that used ITNs, IRS or both combination respectively tested positive for malaria parasitaemia. There was a statistically signicant association between maternal parasitaemia and malaria prevention methods using ITNs (p=0.001), IRS (p = 0.001) or both (p = 0.001).Conclusion: The most commonly adopted malaria prevention methods were ITNs, Indoor Residual Spray or both. Despite their protective effectiveness, their utilizations are still poor. Information and communication strategies by the stakeholders are suggested to improve the utilization of these methods as adopted by other countries.

Performance of Indoor Residual Spray on entomological parameters of malaria transmission using pirimiphos-methyl in the context of pyrethroids resistance in Koulikoro region, Mali.

Background: Following vectors resistance to both pyrethroid and carbamates, organophosphate (pirimiphos-methyl) was used in the Indoor Residual Spray campaigns of 2015 to 2016 in the district of Koulikoro. In this context, we assessed the effect of IRS on malaria transmission by comparing entomological indices in two localities: Koulikoro (LLINs+IRS), and Banamba (LLINs -only) districts. Methods: The study was conducted in two villages of each of Koulikoro and Banamba in 2016. Pyrethroid spray catch and entry window trapping where used to collect mosquitoes monthly WHO bioassay test was used to assess mosquito’s susceptibility to insecticides. Mosquitoes were identified into species by PCR and the infection rate using ELISA. Results: An. coluzii was by far the most frequent species. Its density was rainfall dependent in no-IRS area, and almost independent in IRS area. The IR in the no-IRS area was 1.24%, while in the IRS area, we could not detect infection. In the no-IRS area, the EIR was 0.21 infective bites /person month with the peak in September. High resistance to pyrethroids and carbamates and susceptibility to organophosphates was observed in all sites. Conclusion: A big randomized study is needed to better estimate the added value of the IRS in an integrated malaria control strategy. Key words: Mali, IRS, Long-lasting insecticidal nets, insecticide resistance, transmission.