Indoor Residual Spraying Research Articles

Sibling Species Composition and Susceptibility Status of Anopheles gambiae s.l. to Insecticides Used for Indoor Residual Spraying in Eastern Uganda.

Malaria remains one of the most critical disease causing morbidity and mortality in Uganda. Indoor residual spraying (IRS) and the use of insecticide-treated bed nets are currently the predominant malaria vector control interventions. However, the emergence and spread of insecticide resistance among malaria vectors threaten the continued effectiveness of these interventions to control the disease, particularly in high transmission areas. To inform decisions on vector control, the current study evaluated the Anopheles malaria vector species and their susceptibility levels to 0.1% bendiocarb and 0.25% pirimiphos-methyl insecticides used in IRS intervention program in Namutumba district, Eastern Uganda. Anopheles larvae were collected between March and May 2017 from different breeding sites in the parishes of Nsinze and Nawaikona in Nsinze sub-county and reared to adults to assess the susceptibility status of populations in the study area. Mosquitoes were identified using morphological keys and species-specific polymerase chain reaction (PCR) assays. Susceptibility tests were conducted on 2- to 5-day-old non-blood-fed adult female Anopheles that emerged using insecticide-impregnated papers with 0.1% bendiocarb and 0.25% pirimiphos-methyl following standard World Health Organization (WHO) insecticide susceptibility bioassays. A Log-probit regression model was used to derive the knock-down rates for 50% and 95% of exposed mosquitoes. A total of 700 mosquito larvae were collected from different breeding sites. Morphological identification showed that 500 individuals that emerged belonged to Anopheles gambiae sensu lato (s.l.), the main malaria vector. The PCR results showed that the dominant sibling species under the A. gambiae complex was Anopheles arabiensis 99.5% (395/397). WHO bioassay tests revealed that the population of mosquitoes exhibited high levels of susceptibility (24-hour post-exposure mortality 98-100%) to both insecticides tested. The median knock-down time, KDT50, ranged from 6.6 to 81.4 minutes, while the KDT95 ranged from 21.6 to 118.9 minutes for 0.25% pirimiphos-methyl. The KDT50 for 0.1% bendiocarb ranged from 2.8 to 62.9 minutes, whereas the KDT95 ranged from 36.0 to 88.5 minutes. These findings indicate that bendiocarb and pirimiphos-methyl are still effective against the major malaria vector, A. arabiensis in Nsinze sub-county, Namutumba district, Uganda and can be effectively used for IRS. The study has provided baseline information on the insecticide susceptibility status on malaria vectors in the study area. However, routine continuous monitoring program of insecticide susceptibility and malaria vector composition is required so as to guide future decisions on insecticide use for IRS intervention toward malaria elimination and to track future changes in vector population.

Effectiveness of Indoor Residual Spraying as A Method of Controlling Dengue Fever in Communities: A systematic review

Background: Dengue remains a significant public health issue in the Western Pacific Region. In the absence of a vaccine, vector control is the mainstay for dengue prevention and control. This study aimed to explore the effectiveness of Indoor Residual Spraying as A Method of Controlling Dengue Fever in Communities. Subjects and Method: A systematic review was conducted by searching articles from PubMed, ResearchGate, Science Direct, Google Scholar, and EBSCO is an article published from 2013 to 2023. The keywords were “dengue hemorrhagic fever” OR “DHF” AND “community” OR “family” AND “disaster” AND “IRS” OR “indoor residual spraying”. The inclusion criteria were a Cross-sectional study. The articles were selected by PRISMA flow diagram method. Results: A total of 9 studies were included in this review. All of the studies stated that IRS can have both an immediate and sustained effect on reducing adult and immature A. aegypti populations and should be considered as an adult mosquito control strategy by dengue vector control programs also IRS led to 86-96% reduction in dengue cases in sprayed premises, compared to unsprayed controls. Conclusion: IRS significantly reduces the malaria burden in high-transmission settings. Keywords: dengue hemorrhagic fever, DHF, family, community. Correspondence: Titik Anggraeni. School of Health Sciences Estu Utomo Boyolali, Central Java, Indonesia. Jl. Tentara Pelajar 7, Mudal, Boyolali, Central Java, Indonesia. Email: titik.anggraeni146@gmail.com. Mobile: +62 858-6729-2673.

Baseline characterization of entomological drivers of malaria transmission in Namibia: a targeted operational entomological surveillance strategy

BackgroundNamibia’s focus on the elimination of malaria requires an evidence-based strategy directed at understanding and targeting the entomological drivers of malaria transmission. In 2018 and 2019, the Namibia National Vector-borne Diseases Control Program (NVDCP) implemented baseline entomological surveillance based on a question-based approach outlined in the Entomological Surveillance Planning Tool (ESPT). In the present study, we report on the findings of the ESPT-based NVDCP on baseline vector species composition and bionomic traits in malaria endemic regions in northern Namibia, which has the aim of generating an evidence base for programmatic decision-making.MethodsNine representative sentinel sites were included in the 2018 entomological surveillance program (Kunene, Omusati, Oshana, Ohangwena, Oshikoto, Otjozondjupa, Kavango West, Kavango East and Zambezi); the number was reduced to four sites in 2019 due to limited funding (Ohangwena, Kavango West, Kavango East, and Zambezi). In the 2018 baseline collections, multiple sampling methods (human landing catches, pyrethroid spray catches, U.S. Centers for Disease Control and Prevention light traps [CDC-LTs], resting boxes [RBs] and larval sampling) were utilized to evaluate indoor/outdoor human biting rates, resting behaviors and insecticide resistance (IR). CDC-LTs and RBs were not used in 2019 due to low and non-representative sampling efficacies.ResultsOverall, molecular evidence demonstrated the presence of three primary mosquito vectors, namely Anopheles arabiensis, rediscovered Anopheles gambiae sensu stricto and Anopheles funestus sensu stricto, alongside Anopheles squamosus and members of the Anopheles coustani complex. Vectors were found to bite throughout the night (1800 hours 0600 hours) both indoors and outdoors, with An. arabiensis having the highest biting rates outdoors. Low numbers of indoor resting Anopheles point to possible low indoor residual spraying (IRS) efficacy—with An. arabiensis found to be the major vector species resting indoors. The IR tests demonstrated varying country-wide resistance levels to the insecticide deltamethrin, with the resistance levels confirmed to have increased in 2019, evidence that impacts national programmatic decision-making. Vectors demonstrated susceptibility to the insecticides dichlorodiphenyltrichloroethane, bendiocarb and Actellic 300CS in 2018, with mosquitoes from only one site (Kavango West) demonstrating possible resistance to DDT. Targeted and question-based entomological surveillance enabled a rapid and focused evidence base to be built, showing where and when humans were being bitten and providing entomological data on long-lasting insecticidal nets, IRS efficacy and insecticide resistance, which the Ministry of Health and Social Services-Namibia can use to further build a monitoring and evaluation framework for understanding the drivers of transmission.ConclusionIdentification and characterization of species-specific bionomic traits allows for an understanding of where and when vector human contact may occur as well as the potential impact of interventions. Low indoor resting rates as well as the presence of insecticide resistance (and the increase in its frequency) point to the need for mosquito-behavior-directed and appropriate interventions as well as the requirement for a resistance mitigation strategy. The ESPT-based question- and minimal essential indicator-based operational research strategy provides programs with directed and focused data for facilitating decision-making while requiring limited funding and capacity.Graphical

Mapping Aedes aegypti indoor resting behavior reveals a preference vulnerable to householder-led vector control.

Many mosquito vectors rest inside human habitations, a behavioral trait that is exploited for vector control by indoor residual spraying (IRS) of interior walls with insecticide. Although IRS and its refined version targeted IRS are very effective against Aedes aegypti, they are expensive and logistically challenging to deliver in densely populated urban areas where outbreaks of dengue and other arboviruses are the greatest challenge. In experiments in Recife, Brazil, we set out to quantify the indoor resting behavior of Ae. aegypti at a level beyond that previously reported. We found that significantly more Ae. aegypti males, unfed and fed females visited the base of walls (height 0-20 cm, corresponding to 12.3% of the total wall surface) more frequently than upper wall areas, with the difference more pronounced at higher temperatures. When the lowest 20 cm of the walls was treated with an appropriate insecticide and colored black, we recorded up to 85% cumulative mortality after 24-h exposure in the experimental room. The findings are significant because feasibly, householders could treat this small and accessible target zone manually, without the need for visits by costly IRS teams or equipment, reducing insecticide use and enabling communities to actively protect their own indoor environment.

SUSCEPTIBILITY OF TWO STRAINS OF BEDBUGS TO DELTAMETHRIN AND LABORATORY EVALUATION OF PESGUARD FG161 EFFICACY AGAINST CIMEX LECTULARIUS

The aim of the study conducted from April to December 2022 was to assess theeffectiveness of Pesguard FG161, a commercial insecticide formulation from SumitomoChemical Co., Ltd, against field bed bugs. This emulsifiable concentrate (EC) formulationcombines two active ingredients, D-Tetramethrin and Cyphenothrin, and is recommendedfor indoor residual spraying. Populations of the bed bug Cimex lectularius collected inTrung Van commune, Nam Tu Liem district (Trung Van strain), Ha Noi, and in ThinhLang commune, Hoa Binh district, Hoa Binh province (Thinh Lang strain) were evaluatedusing the surface contact method. Exposure time was 4 hours, and the mortality of bedbugs in contact with the treated panel was recorded on a daily basis for up to 4 days, andthe residual bioefficacy of the product was evaluated after one day, seven days, and thirtydays of spraying. According to the study, Pesguard FG161 can effectively control fieldbed bugs, as evidenced by its high success rate in killing them (mortality were 100%)

Using routine health data to evaluate the impact of indoor residual spraying on malaria transmission in Madagascar

IntroductionIndoor residual spraying (IRS) and insecticide-treated bed nets (ITNs) are cornerstone malaria prevention methods in Madagascar. This retrospective observational study uses routine data to evaluate the impacts of IRS overall,...

Assessment of Use of Indoor Residual Spraying (IRS) Among Medical Students in Abia State University, Uturu (ABSU) Nigeria

Authors: Prince Ezenwa Ndubueze Onyemachi, Akwuruoha, Emmanuel Maduabuchi, Okeh Happiness Emmanuel, Ibeh-Raymond Shalom, Odinakachi Agwu Umah Kalu, Ogbu Uchechwukwu Oji, Ndu-Agomuo Ihuoma Lois. Background: Malaria has remained one of the life-threatening diseases affecting Nigeria as a nation especially those living in malaria endemic region. The causative organism of malaria ii plasmodium and transmitted to man by infected female anopheles’ mosquito. The clinical features of malaria vary from mild to severe and complicated according to species of parasite present and the patient’s state of immunity. Students in this region are also prone to contracting the disease. Objective: To determine the use of indoor residual spraying (IRS) among medical students in Abia State University, Uturu, Nigeria. Methods and Materials: This descriptive cross-sectional study was carried out to assess the use of Indoor Residual Spraying (IRS) among medical students of ABSU. The study involved both preclinical and clinical students. A Simple random sampling was used in selecting participants and data was obtained using self-administered questionnaires, analyzed with Statistical Package for Social Sciences (SPSS), version 26.0 and presented in form of tables. Association between the sociodemographic variables and level of usage of IRS were determined and statistical significance was set at P<0.05. Result: A total number 407 students and out which of 389 participated in this study with a response rate of 95.6% and mean age of 21.98±3.52 years, more students were in the range of 20-24, and the dominant tribe was Igbo (94.3%), more of males (50.6%) participated in this study and practice of was poor (31.9%). A high proportion of students (99.7%) had a good knowledge of malaria transmission and IRS. Conclusion: The study reported a high level of knowledge of malaria preventive measures but a poor practice to its utilization, thus a need for proper health education to improve usage of Indoor residual spraying.

Ivermectin as a novel malaria control tool: Getting ahead of the resistance curse

Reduction in malaria clinical cases is strongly dependent on the ability to prevent Anopheles infectious bites. Vector control strategies using long-lasting insecticidal nets and indoor residual spraying with insecticides have contributed to significantly reduce the incidence of malaria in many endemic countries, especially in the Sub-Saharan region. However, global progress in reducing malaria cases has plateaued since 2015 mostly due to the increased insecticide resistance and behavioral changes in Anopheles vectors. Additional control strategies are thus required to further reduce the burden of malaria and contain the spread of resistant and invasive Anopheles vectors. The use of endectocides such as ivermectin as an additional malaria control tool is now receiving increased attention, driven by its different mode of action compared to insecticides used so far and its excellent safety record for humans. In this opinion article, we discuss the advantages and disadvantages of using ivermectin for malaria control with a focus on the risk of selecting ivermectin resistance in malaria vectors. We also highlight the importance of understanding how ivermectin resistance could develop in mosquitoes and what its underlying mechanisms and associated molecular markers are, and propose a research agenda to manage this phenomenon.

Health care cost of floods: Evidence from Typhoon Morakot in Taiwan

Using the difference-in-difference (DID) method, this study uses Typhoon Morakot, which occurred in August 2009, as an example to estimate the effect of flooding on health care cost burden. The main data source is the medical claims records of a cohort of three million patients in Taiwan’s National Health Insurance system. By examining flood-related physiological diseases and disaster-related mental illnesses, our results indicate that the increase in outpatient health care costs resulting from the flood caused by the typhoon is approximately NTD 8.95 billion (USD 280 million), equivalent to approximately 69% of the annual special budget for flooding prevention during the period 2006–2019 in Taiwan. Moreover, the increase in outpatient expenditure for mental illnesses is nearly 10 times that of physiological diseases. An important implication of our findings is that the cost of preventing natural disasters, such as floods, can be offset by saving health care costs, particularly for mental illnesses. Our results also suggest that in addition to providing safe drinking water and indoor residual spraying, offering continuous post-disaster mental health services can further save health care expenditures caused by natural disasters.

Estimating malaria transmission risk through surveillance of human–vector interactions in northern Ghana

BackgroundVector bionomics are important aspects of vector-borne disease control programs. Mosquito-biting risks are affected by environmental, mosquito behavior and human factors, which are important for assessing exposure risk and intervention impacts. This study estimated malaria transmission risk based on vector–human interactions in northern Ghana, where indoor residual spraying (IRS) and insecticide-treated nets (ITNs) have been deployed.MethodsIndoor and outdoor human biting rates (HBRs) were measured using monthly human landing catches (HLCs) from June 2017 to April 2019. Mosquitoes collected were identified to species level, and Anopheles gambiae sensu lato (An. gambiae s.l.) samples were examined for parity and infectivity. The HBRs were adjusted using mosquito parity and human behavioral observations.ResultsAnopheles gambiae was the main vector species in the IRS (81%) and control (83%) communities. Indoor and outdoor HBRs were similar in both the IRS intervention (10.6 vs. 11.3 bites per person per night [b/p/n]; z = −0.33, P = 0.745) and control communities (18.8 vs. 16.4 b/p/n; z = 1.57, P = 0.115). The mean proportion of parous An. gambiae s.l. was lower in IRS communities (44.6%) than in control communities (71.7%). After adjusting for human behavior observations and parity, the combined effect of IRS and ITN utilization (IRS: 37.8%; control: 57.3%) on reducing malaria transmission risk was 58% in IRS + ITN communities and 27% in control communities with ITNs alone (z = −4.07, P < 0.001). However, this also revealed that about 41% and 31% of outdoor adjusted bites in IRS and control communities respectively, occurred before bed time (10:00 pm). The mean directly measured annual entomologic inoculation rates (EIRs) during the study were 6.1 infective bites per person per year (ib/p/yr) for IRS communities and 16.3 ib/p/yr for control communities. After considering vector survival and observed human behavior, the estimated EIR for IRS communities was 1.8 ib/p/yr, which represents about a 70% overestimation of risk compared to the directly measured EIR; for control communities, it was 13.6 ib/p/yr (16% overestimation).ConclusionIndoor residual spraying significantly impacted entomological indicators of malaria transmission. The results of this study indicate that vector bionomics alone do not provide an accurate assessment of malaria transmission exposure risk. By accounting for human behavior parameters, we found that high coverage of ITNs alone had less impact on malaria transmission indices than combining ITNs with IRS, likely due to observed low net use. Reinforcing effective communication for behavioral change in net use and IRS could further reduce malaria transmission.Graphical

Effectiveness of Intermittent Preventive Treatment with Sulfadoxine-Pyrimethamine in Pregnancy: Low Coverage and High Prevalence of Plasmodium falciparum dhfr-dhps Quintuple Mutants as Major Challenges in Douala, an Urban Setting in Cameroon.

Intermittent preventive treatment in pregnancy with sulfadoxine and pyrimethamine (IPTp-SP) is a key component in the malaria control strategy implemented in Africa. The aim of this study was to determine IPTp-SP adherence and coverage, and the impact on maternal infection and birth outcomes in the context of widespread SP resistance in the city of Douala, Cameroon. Clinical and demographic information were documented among 888 pregnant women attending 3 health facilities, from the antenatal care visit to delivery. Positive samples were genotyped for P. falciparum gene (dhfr, dhps, and k13) mutations. The overall IPTp-SP coverage (≥three doses) was 17.5%, and 5.1% received no dose. P. falciparum prevalence was 16%, with a predominance of submicroscopic infections (89.3%). Malaria infection was significantly associated with locality and history of malaria, and it was reduced among women using indoor residual spraying. Optimal doses of IPTp-SP were significantly associated with reduced infection among newborns and women (secundiparous and multiparous), but there was no impact of IPTp-SP on the newborn bodyweight. Pfdhfr-Pfdhps quintuple mutants were over-represented (IRNI-FGKAA, IRNI-AGKAA), and sextuple mutants (IRNI-AGKAS, IRNI-FGEAA, IRNI-AGKGS) were also reported. The Pfk13 gene mutations associated with artemisinin resistance were not detected. This study highlights the role of ANC in achieving optimal SP coverage in pregnant women, the mitigated impact of IPTp-SP on malaria outcomes, and the high prevalence of multiple SP-resistant P. falciparum parasites in the city of Douala that could compromise the efficacy of IPTp-SP.

Towards malaria elimination: analysis of travel history and case forecasting using the SARIMA model in Limpopo Province

Despite various efforts and policy implementation aimed at controlling and eliminating malaria, imported malaria remains a major factor posing challenges in places that have made progress in malaria elimination. The persistence of malaria in Limpopo Province has largely been attributed to imported cases, thus reducing the pace of achieving the malaria-free target by 2025. Data from the Limpopo Malaria Surveillance Database System (2010–2020) was analyzed, and a seasonal auto-regressive integrated moving average (SARIMA) model was developed to forecast malaria incidence based on the incidence data’s temporal autocorrelation. The study found that out of 57,288 people that were tested, 51,819 (90.5%) cases were local while 5469 (9.5%) cases were imported. Mozambique (44.9%), Zimbabwe (35.7%), and Ethiopia (8.5%) were the highest contributors of imported cases. The month of January recorded the highest incidence of cases while the least was in August. Analysis of the yearly figures showed an increasing trend and seasonal variation of recorded malaria cases. The SARIMA (3,1,1) X (3,1,0) [12] model used in predicting expected malaria case incidences for three consecutive years showed a decline in malaria incidences. The study demonstrated that imported malaria accounted for 9.5% of all cases. There is a need to re-focus on health education campaigns on malaria prevention methods and strengthening of indoor residual spray programs. Bodies collaborating toward malaria elimination in the Southern Africa region need to ensure a practical delivery of the objectives.

Acceptability, Feasibility, Drug Safety, and Effectiveness of a Pilot Mass Drug Administration with a Single Round of Sulfadoxine-Pyrimethamine Plus Primaquine and Indoor Residual Spraying in Communities with Malaria Transmission in Haiti, 2018.

For a malaria elimination strategy, Haiti's National Malaria Control Program piloted a mass drug administration (MDA) with indoor residual spraying (IRS) in 12 high-transmission areas across five communes after implementing community case management and strengthened surveillance. The MDA distributed sulfadoxine-pyrimethamine and single low-dose primaquine to eligible residents during house visits. The IRS campaign applied pirimiphos-methyl insecticide on walls of eligible houses. Pre- and post-campaign cross-sectional surveys were conducted to assess acceptability, feasibility, drug safety, and effectiveness of the combined interventions. Stated acceptability for MDA before the campaign was 99.2%; MDA coverage estimated at 10 weeks post-campaign was 89.6%. Similarly, stated acceptability of IRS at baseline was 99.9%; however, household IRS coverage was 48.9% because of the high number of ineligible houses. Effectiveness measured by Plasmodium falciparum prevalence at baseline and 10 weeks post-campaign were similar: 1.31% versus 1.43%, respectively. Prevalence of serological markers were similar at 10 weeks post-campaign compared with baseline, and increased at 6 months. No severe adverse events associated with the MDA were identified in the pilot; there were severe adverse events in a separate, subsequent campaign. Both MDA and IRS are acceptable and feasible interventions in Haiti. Although a significant impact of a single round of MDA/IRS on malaria transmission was not found using a standard pre- and post-intervention comparison, it is possible there was blunting of the peak transmission. Seasonal malaria transmission patterns, suboptimal IRS coverage, and low baseline parasitemia may have limited the effectiveness or the ability to measure effectiveness.

BOHEMIA a cluster randomized trial to assess the impact of an endectocide-based one health approach to malaria in Mozambique: baseline demographics and key malaria indicators

BackgroundMany geographical areas of sub-Saharan Africa, especially in rural settings, lack complete and up-to-date demographic data, posing a challenge for implementation and evaluation of public health interventions and carrying out large-scale health research. A demographic survey was completed in Mopeia district, located in the Zambezia province in Mozambique, to inform the Broad One Health Endectocide-based Malaria Intervention in Africa (BOHEMIA) cluster randomized clinical trial, which tested ivermectin mass drug administration to humans and/or livestock as a potential novel strategy to decrease malaria transmission.MethodsThe demographic survey was a prospective descriptive study, which collected data of all the households in the district that accepted to participate. Households were mapped through geolocation and identified with a unique identification number. Basic demographic data of the household members was collected and each person received a permanent identification number for the study.Results25,550 households were mapped and underwent the demographic survey, and 131,818 individuals were registered in the district. The average household size was 5 members and 76.9% of households identified a male household head. Housing conditions are often substandard with low access to improved water systems and electricity. The reported coverage of malaria interventions was 71.1% for indoor residual spraying and 54.1% for universal coverage of long-lasting insecticidal nets. The median age of the population was 15 years old. There were 910 deaths in the previous 12 months reported, and 43.9% were of children less than 5 years of age.ConclusionsThe study showed that the district had good coverage of vector control tools against malaria but sub-optimal living conditions and poor access to basic services. The majority of households are led by males and Mopeia Sede/Cuacua is the most populated locality in the district. The population of Mopeia is young (< 15 years) and there is a high childhood mortality. The results of this survey were crucial as they provided the household and population profiles and allowed the design and implementation of the cluster randomized clinical trial.Trial registration NCT04966702.

Residual insecticide surface treatment for preventing malaria: a systematic review protocol

IntroductionMalaria presents a significant global public health burden, although substantial progress has been made, with vector control initiatives such as indoor residual surface spraying with insecticides and insecticide-treated nets. There now exists many different approaches to apply residual insecticide to indoor and outdoor surfaces in malaria-endemic settings, although no comprehensive systematic reviews exist evaluating these interventions. This manuscript outlines the protocol for a systematic review which aims to synthesise the best available evidence regarding full or partial indoor or outdoor residual insecticide surface treatment for preventing malaria.Methods and analysisThis review will comprehensively search the literature (both published and unpublished) for any studies investigating the effectiveness of residual insecticide surface treatment for malaria. Studies will be screened to meet the inclusion criteria by a minimum of two authors, followed by assessment of risk of bias (using appropriate risk-of-bias tools for randomised and non-randomised studies) and extraction of relevant information using structured forms by two independent authors. Meta-analysis will be carried out where possible for epidemiological outcomes such as malaria, anaemia, malaria-related mortality, all-cause mortality and adverse effects. Certainty in the evidence will be established with GRADE assessments.Ethics and disseminationA full review report will be submitted to the Vector Control & Insecticide Resistance Unit, Global Malaria Program, WHO. A version of this report will be submitted for publication in an open access peer-reviewed journal. The report will inform the development of WHO recommendations regarding residual insecticide treatment for malaria. This systematic review does not require ethics approval as it is a review of primary studies.Systematic review registrationPROSPERO 293194.

MALARIA CONTROLSTRATEGY ON INDONESIAN ARMY IN BORDER ENDEMIC MALARIA PAPUA AND PAPUA NEW GUINEA (CASE ON BORDER SECURITY TASK FORCE INFANTRY YONIF 713/ST, YONIT 300/R DAN YONIF 509 KOSTRAD IN AUGUST 2019-APRIL 2020)

Every year, 1350 TNI personnel are sent as a Security Task Force to the north sector of RI-PNG Border which is a malaria endemic area. The nine-month assignment allowed the soldiers to become infected with malaria, despite effective control measures being implemented.The aim of control is to prevent death and reduce the incidence of malaria. There are three control strategies according to the TNI technical guidelines: i) Anopheles vector control. ii) Vector mapping in postal environment. iii) Early case management and treatment.Rapid diagnosis test (RDT), Primaquine and Dihydroartemisinin-Piperaquine (DHP) treatment were performed as the first line in case management.The research method is qualitative with observation, FGD, in-depth interviews and retrospective analysis used in the study.The results of the observation there are gaps in the implementation of control strategies by the three task force battalions in border area, namely there is no extension media, still using fogging, undisciplined using refellan and mosquito nets. Prophylaxis and Indoor Residual Spraying (IRS) have not been used. From FGDs and in-depth interviews with related parties, the sub-optimality occurred due to conflicts with local culture (HakUlayat) and poor environmental management. From a retrospective analysis of health data, 1350 troops, 855 were malaria positive (incidence = 63.33%), 2 died (CFR = 0.23%) and 259 (incidence = 19.19%) relapsed. From the type of plasmodium, P. Vivax= 506, P. Falciparum= 322 and Mix= 43 .The conclusion is that there is a need for self-discipline from each personnel and a multidisciplinary approach with field practitioners, infectiologists, microbiologists, epidemiologists, entomologists, sociologists, anthropologists, in controlling malaria.

Semi-field evaluation of a volatile transfluthrin-based intervention reveals efficacy as a spatial repellent and evidence of other modes of action.

Presently, the most common malaria control tools-i.e., long lasting insecticide-treated nets (LLINs) and indoor residual spraying (IRS)-are limited to targeting indoor biting and resting behaviors of Anopheles mosquito species. Few interventions are targeted towards malaria control in areas where transmission is driven or persists due to outdoor biting behaviors. This study investigated a volatile pyrethroid-based spatial repellent (VPSR) designed to bridge this gap and provide protection from mosquito bites in outdoor spaces. Southern Province, Zambia, is one such environment where outdoor biting is suspected to contribute to malaria transmission, where people are active in the evening in open-walled outdoor kitchens. This study assessed the VPSR in replica kitchens within a controlled semi-field environment. Endpoints included effects on mosquito host seeking, immediate and delayed mortality, deterrence, blood feeding inhibition, and fertility. Host-seeking was reduced by approximately 40% over the course of nightly releases in chambers containing VPSR devices. Mosquito behavior was not uniform throughout the night, and the modeled effect of the intervention was considerably higher when hourly catch rates were considered. These two observations highlight a limitation of this overnight semi-field design and consideration of mosquito circadian rhythms is recommended for future semi-field studies. Additionally, deterrence and immediate mortality were both observed in treatment chambers, with evidence of delayed mortality and a dose related response. These results demonstrate a primarily personal protective mode of action with possible positive and negative community effects. Further investigation into this primary mode of action will be conducted through a field trial of the same product in nearby communities.

Investigating insecticide susceptibility status of adult mosquitoes against some class of insecticides in Osogbo metropolis, Osun State, Nigeria.

The study evaluates the resistance and susceptibility of adult female Anopheles gambiae s. l., Aedes aegypti and Culex quinquefasciatus mosquitoes sourced within Osogbo metropolis, Osun State, Nigeria to four groups of insecticides [Permethrin, Deltamethrin, Pirimiphos-methyl and DDT (Dichlorodiphenyltrichloroethane)] and the distribution of their larval habitat within the metropolis. Mosquito larvae of the three genera were collected during the wet season and reared to adult stage in the laboratory. Emerged adult female mosquitoes were exposed to insecticide impregnated papers of the four insecticide groups for 60mins using WHO kits to determine the knock down rate (kdr). Thereafter, they were transferred into holding tubes and left for 24hrs to assess their resistance and susceptibility according to the WHO protocol. Four types of larval habitats were identified (tires, ground pools, gutters and plastic containers). Anopheles gambiae s. l. showed the highest resistance to Permethrin (49%) (p = 0.04, p<0.05) while the highest susceptibility was recorded with Pirimiphos-methyl (69%) with the lowest against Permethrin (16%) (P = 0.002; p<0.05). The highest resistance of A. aegypti was against OC-Control (45%) (p = 0.031; p<0.05). Permethrin had the highest susceptibility (60%) against A. aegypti while OC-control had the lowest (11%) (p = 0.005; p< 0.05). Culex quinquefasciatus had a lower resistance to OC-control (38%) as compared with Aedes aegypti (45%). However, it was least susceptible to Pirimiphos-methyl (52%) and DDT (17%) respectively (p = 0.013; p<0.05). The susceptibility of A. gambiae s. l. and C. quinquefasciatus to Pirimiphos-methyl and A. aegypti to Permethrin is an indication of the possibility of success if employed for vector control of A. gambiae s. l., C. quinquefasciatus and A. aegypti respectively. This could be through their inclusion as active ingredients in insecticide treated nets (ITNs) and indoor residual spray (IRS) with a view to abating malaria and other life-threatening mosquito-borne diseases constituting global public health scourge.

Altering of the sprayed wall after indoor residual spraying and associated factors among households in Boricha district, Sidama regional state, Ethiopia, 2019: community-based cross-sectional study

BackgroundIndoor residual spraying (IRS) has been the main tool used to control malaria. Reducing the life span and the density of the vector mosquitoes are direct effects of IRS towards restricting malaria transmission. Residents must not wash or re-plaster walls after the spray application for at least 6 months to fight against malaria with IRS. This study sought to assess the alteration of the sprayed wall after the IRS operation and associated factors among households in the Boricha district.MethodsCommunity-based cross-sectional study was conducted among 608 households selected using multi-stage sampling. A structured interviewer-administered questionnaire was used to collect data. Data were analysed by SPSS version 25. Both bivariable and multivariable logistic regression analysis was done. Finally, the strength of the association was measured based on AOR with 95% CI and statistical significance was declared at a p-value less than 0.05.ResultFrom the total of 608 sprayed houses included in the study, 37.3% (95% CI: 33.41% – 41.15%) were found to have altered sprayed walls. The highest class of wealth index category (AOR = 2.50; 95% CI: 1.19, 5.16), low level of comprehensive knowledge about IRS (AOR = 6.08; 95% CI: 3.37, 10.94), did not get information within 2 weeks before spray (AOR = 2.09; 95% CI: 1.43, 3.05), absence of supervision after the spray operation (AOR = 1.77; 95% CI: 1.27, 2.73) and walking distance to nearest health facility (AOR = 2.39; 95% CI: 1.63, 3.35) remained significant factors of altering of the sprayed wall after IRS.ConclusionThe prevalence of alteration was relatively high. The highest socio-economic status, poor knowledge about indoor residual spraying, lack of information about IRS within two weeks before spray, absence of supervision after IRS, and walking distance of more than 30 min to reach the nearest health post were the factors affecting the alteration status of the sprayed wall. Future efforts to focus on successive awareness creation activities should be done before and after IRS operation to the community by concerned bodies.

Mapping malaria incidence using routine health facility surveillance data in Uganda

IntroductionMaps of malaria risk are important tools for allocating resources and tracking progress. Most maps rely on cross-sectional surveys of parasite prevalence, but health facilities represent an underused and powerful...