Use Of Bed Nets Research Articles

Caregiver exposure to malaria social and behaviour change messages can improve bed net use among children in an endemic country: secondary analysis of the 2015 Nigeria Malaria Indicator Survey

BackgroundTo reduce the malaria burden in Nigeria, the National Malaria Strategic Plan (NMSP) 2014‒2020 calls for the scale-up of prevention and treatment interventions, including social and behaviour change (SBC). SBC interventions can increase awareness and improve the demand for and uptake of malaria interventions. However, there is limited evidence supporting the implementation of SBC interventions to improve key malaria behaviours, such as insecticide-treated bed net (ITN) use, among children in Nigeria.MethodsUsing data from 2015 Nigeria Malaria Indicator Survey, this study used multiple logistic regression to assess the relationship between caregiver exposure to malaria messages and ITN use among children under five.ResultsCaregiver exposure to ITN-related messages was significantly associated with ITN use among children under five (odds ratio [OR] = 1.63, p < 0.001).ConclusionsThe results suggest that caregiver exposure to topic-specific SBC messages improves the use of ITNs among children. Given these results, Nigeria should strive to scale up SBC interventions to help increase ITN use among children in line with the objectives of the NMSP. Further evidence is needed to determine which SBC interventions are the most effective and scalable in Nigeria.

A population-based study of the prevalence and risk factors of low-grade Plasmodium falciparum malaria infection in children aged 0-15years old in northern Tanzania.

Northern Tanzania experiences significant malaria-related morbidity and mortality, but accurate data are scarce. We update the data on patterns of low-grade Plasmodium falciparum malaria infection among children in northern Tanzania. Plasmodium falciparum malaria prevalence (pfPR) was assessed in a representative sample of 819 children enrolled in 94 villages in northern Tanzania between October 2015 and August 2016, using a complex survey design. Individual- and household-level risk factors for pfPR were elicited using structured questionnaires. pfPR was assessed using rapid diagnostic tests (RDTs) and thick film microscopy (TFM). Associations with pfPR, based on RDT, were assessed using adjusted odds ratios (aOR) and confidence intervals (CI) from weighted survey logistic regression models. Plasmodium falciparum malaria prevalence (pfPR) was 39.5% (95% CI: 31.5, 47.5) by RDT and 33.4% (26.0, 40.6) by TFM. pfPR by RDT was inversely associated with higher-education parents, especially mothers (5-7years of education: aOR 0.55; 95% CI: 0.31, 0.96, senior secondary education: aOR 0.10; 95% CI: 0.02, 0.55), living in a house near the main road (aOR 0.34; 95% CI: 0.15, 0.76), in a larger household (two rooms: aOR 0.40; 95% CI: 0.21, 0.79, more than two rooms OR 0.35; 95% CI: 0.20, 0.62). Keeping a dog near or inside the house was positively associated with pfPR (aOR 2.01; 95% CI: 1.26, 3.21). pfPR was not associated with bed-net use or indoor residual spraying. Nearly 40% of children in northern Tanzania had low-grade malaria antigenaemia. Higher parental education and household metrics but not mosquito bed-net use were inversely associated with pfPR.

Comparison of Malaria Control Interventions in Angola

Background: There is lack of evidence on which of the two highly recommended malaria prevention methods, mosquito bednets and indoor residual spraying, is more effective than the other. Objective: To compare the effectiveness of mosquito bednets and indoor residual spraying in the prevention of malaria. Based on the Health Belief Model, the research questions tested whether there is any relationship between the use of mosquito bednet or the use of indoor residual spraying and contracting malaria. Materials and Methods: Using a quantitative research design, secondary data from the 2011 Angola malaria indicator survey were analyzed using IBM/SPSS version 24. Chi-square for association, logistic regression, and multinomial logistic regression tests were conducted with significance level set at p value of ≤ .05. Results: From 578 children who slept under mosquito bednet the night before data collection 9.2% (n = 28) had malaria compared to 5.7% (n = 31) of 331 children who did not sleep under mosquito bednet. However, there was no statistically significant association between the use of mosquito bednet and having malaria x2 (1) = 3.324, p = .068, odds = .613, 95% CI [.361, 1.042]. From 2139 children who lived in dwellings that were not sprayed against mosquito 13.2% (n = 250) had malaria compared to 5.6% (n = 7) of 133 children who lived in sprayed dwellings. Furthermore, there was a statistically significant association between the use of indoor residual spraying and having malaria, x2 (1) = 5.152, p = .023, odds = 2.382, 95% CI [1.100, 5.158]. Conclusion: The malaria prevention programs in Angola should focus on indoor residual spraying. It is recommended that all households in Angola malaria prone areas should be regularly sprayed.

Global Sensitivity Analysis to Study the Impacts of Bed-Nets, Drug Treatment, and Their Efficacies on a Two-Strain Malaria Model

Malaria is a deadly infectious disease, which is transmitted to humans via the bites of infected female mosquitoes. Antimalarial drug resistance has been identified as one of the characteristics of malaria that complicates control efforts. Typically, the use of insecticide-treated bed-nets (ITNs) and drug treatment are some of the recommended control strategies against malaria. Here, the use of ITNs, drug treatment, and their efficacies and evolution of antimalarial drug resistance are considered to be the major driving forces in the dynamics of malaria transmissions. We formulate a mathematical model of two-strain malaria to assess the impacts of ITNs, drug treatment, and their efficacies on the transmission dynamics of the disease in a human population. We propose a simple mosquito biting rate function that depends on both the proportion of ITN usage and its efficacy. We show that both disease-free and co-existence equilibrium points are globally-asymptotically stable where they exist. The global uncertainty and sensitivity analysis conducted show that if about 95% of malaria cases can be treated with fewer than 5% treatment failure in a population with 95% ITN usage that remains 95% effective, malaria can be controlled. We find that the order in which numerous intervention measures are taken is important.

Determinants of bed net use conditional on access in population surveys in Ghana

BackgroundInsecticide-treated nets (ITNs) are one of the most effective and widely available methods for preventing malaria, and there is interest in understanding the complexities of behavioural drivers of non-use among those with access. This analysis evaluated net use behaviour in Ghana by exploring how several household and environmental variables relate to use among Ghanaians with access to a net.MethodsSurvey data from the Ghana 2014 Demographic and Health Survey and the 2016 Malaria Indicator Survey were used to calculate household members’ access to space under a net as well as the proportion of net use conditional on access (NUCA). Geospatial information on cluster location was obtained, as well as average humidex, a measure of how hot it feels, for the month each cluster was surveyed. The relationship between independent variables and net use was assessed via beta-binomial regression models that controlled for spatially correlated random effects using non-Gaussian kriging.ResultsIn both surveys, increasing wealth was associated with decreased net use among those with access in households when compared to the poorest category. In 2014, exposure to messages about bed net use for malaria prevention was associated with increased net use (OR 2.5, 95% CrI 1.5–4.2), as was living in a rural area in both 2014 (OR 2.5, 95% CrI 1.5–4.3) and 2016 (OR 1.6, 95% CrI 1.1–2.3). The number of nets per person was not associated with net use in either survey. Model fit was improved for both surveys by including a spatial random effect for cluster, demonstrating some spatial autocorrelation in the proportion of people using a net. Humidex, electricity in the household and IRS were not associated with NUCA.ConclusionNet use conditional on access is affected by household characteristics and is also spatially-dependent in Ghana. Setting (whether the household was urban or rural) plays a role, with wealthier and more urban households less likely to use nets when they are available. It will likely be necessary in the future to focus on rural settings, urban settings, and wealth status independently, both to better understand predictors of household net use in these areas and to design more targeted interventions to ensure consistent use of vector control interventions that meet specific needs of the population.

Suppression of malaria vector densities and human infection prevalence associated with scale-up of mosquito-proofed housing in Dar es Salaam, Tanzania: re-analysis of an observational series of parasitological and entomological surveys

In the city of Dar es Salaam, Tanzania, rapid and spontaneous scale-up of window screening occurred through purely horizontal commercial distribution systems without any public subsidies or promotion. Scale-up of window screening coincided with a planned evaluation of programmatic, vertically managed scale-up of regular larvicide application as an intervention against malaria vectors and transmission. We aimed to establish whether scale-up of window screening was associated with suppression of mosquito populations, especially for malaria vectors that strongly prefer humans as their source of blood. This study was a re-analysis of a previous observational series of epidemiological data plus new analyses of previously partly reported complementary entomological data, from Dar es Salaam. Between 2004 and 2008, six rounds of cluster-sampled, rolling, cross-sectional parasitological and questionnaire surveys were done in urban Dar es Salaam to assess the effect of larviciding and other determinants of malaria risk, such as use of bed nets and antimalarial drugs, socioeconomic status, age, sex, travel history, mosquito-proofed housing, and spending time outdoors. The effects of scaled-up larvicide application and window screening were estimated by fitting generalised linear mixed models that allowed for both spatial variation between survey locations and temporal autocorrelation within locations. We also conducted continuous longitudinal entomological surveys of outdoor human biting rates by mosquitoes and experimental measurements of mosquito host preferences. Best-fit models of Plasmodium falciparum malaria infection prevalence among humans were largely consistent with the results of the previous analyses. Re-analysis of previously reported epidemiological data revealed that most of the empirically fitted downward time trend in P falciparum malaria prevalence over the course of the study (odds ratio [OR] 0·04; 95% CI 0·03-0·06; p<0·0001), which was not previously reported numerically or attributed to any explanatory factor, could be plausibly explained by association with an upward trend in city-wide window screening coverage (OR 0·07; 0·05-0·09; p<0·0001) and progressive rollout of larviciding (OR 0·50; 0·41-0·60; p<0·0001). Increasing coverage of complete window screening was also associated with reduced biting densities of all taxonomic groups of mosquitoes (all p<0·0001), especially the Anopheles gambiae complex (relative rate [RR] 0·23; 95% CI 0·16-0·33) and Anopheles funestus group (RR 0·08; 0·04-0·16), which were confirmed as the most efficient vectors of malaria with strong preferences for humans over cattle. Larviciding was also associated with reduced biting densities of all mosquito taxa (p<0·0001), to an extent that varied consistently with the larvicide targeting scheme and known larval ecology of each taxon. Community-wide mosquito proofing of houses might deliver greater impacts on vector populations and malaria transmission than previously thought. The spontaneous nature of the scale-up observed here is also encouraging with regards to practicality, acceptability, and affordability in low-income settings. United States Agency for International Development, Bill & Melinda Gates Foundation, Wellcome Trust, and Valent BioSciences LLC.

Potential factors influencing lymphatic filariasis transmission in \u201chotspot\u201d and \u201ccontrol\u201d areas in Ghana: the importance of vectors

BackgroundMass drug administration (MDA) programmes for the control of lymphatic filariasis in Ghana, have been ongoing in some endemic districts for 16 years. The current study aimed to assess factors that govern the success of MDA programmes for breaking transmission of lymphatic filariasis in Ghana.MethodsThe study was undertaken in two “hotspot” districts (Ahanta West and Kassena Nankana West) and two control districts (Mpohor and Bongo) in Ghana. Mosquitoes were collected and identified using morphological and molecular tools. A proportion of the cibarial armatures of each species was examined. Dissections were performed on Anopheles gambiae for filarial worm detection. A questionnaire was administered to obtain information on MDA compliance and vector control activities. Data were compared between districts to determine factors that might explain persistent transmission of lymphatic filariasis.ResultsHigh numbers of mosquitoes were sampled in Ahanta West district compared to Mpohor district (F = 16.09, P = 0.002). There was no significant difference between the numbers of mosquitoes collected in Kassena Nankana West and Bongo districts (F = 2.16, P = 0.185). Mansonia species were predominant in Ahanta West district. An. coluzzii mosquitoes were prevalent in all districts. An. melas with infected and infective filarial worms was found only in Ahanta West district. No differences were found in cibarial teeth numbers and shape for mosquito species in the surveyed districts. Reported MDA coverage was high in all districts. The average use of bednet and indoor residual spraying was 82.4 and 66.2%, respectively. There was high compliance in the five preceding MDA rounds in Ahanta West and Kassena Nankana West districts, both considered hotspots of lymphatic filariasis transmission.ConclusionsThe study on persistent transmission of lymphatic filariasis in the two areas in Ghana present information that shows the importance of local understanding of factors affecting control and elimination of lymphatic filariasis. Unlike Kassena Nankana West district where transmission dynamics could be explained by initial infection prevalence and low vector densities, ongoing lymphatic filariasis transmission in Ahanta West district might be explained by high biting rates of An. gambiae and initial infection prevalence, coupled with high densities of An. melas and Mansonia vector species that have low or no teeth and exhibiting limitation.

Socio-economic and demographic disparities in ownership and use of insecticide-treated bed nets for preventing malaria among rural reproductive-aged women in northern Ghana.

BackgroundMalaria continues to be a leading cause of morbidity and mortality in most countries in Sub-Saharan Africa. Insecticide-treated bed nets (ITNs) is one of the cost-effective interventions for preventing malaria in endemic settings. Ghana has made tremendous efforts to ensure widespread ownership and use of ITNs. However, national coverage statistics can mask important inequities that demand targeted attention. This study assesses the disparities in ownership and utilization of ITNs among reproductive-aged women in a rural impoverished setting of Ghana.MethodsPopulation-based cross-sectional data of 3,993 women between the age of 15 and 49 years were collected in seven districts of the Upper East region of Ghana using a two-stage cluster sampling approach. Bivariate and multivariate regression models were used to assess the social, economic and demographic disparities in ownership and utilization of ITN and to compare utilization rates among women in households owning at least one ITN.ResultsAs high as 79% of respondents were found to own ITN while 62% of ITN owners used them the night preceding the survey. We identified disparities in both ownership and utilization of ITNs in wealth index, occupational status, religion, and district of residence. Respondents in the relative richest wealth quintile were 74% more likely to own ITNs compared to those in the poorest quintile (p-value< 0.001, CI = 1.29–2.34) however, they were 33% less likely to use ITNs compared to the poorest (p-value = 0.01, CI = 0.50–0.91).ConclusionInterventions aimed at preventing and controlling malaria through the use of bed nets in rural Ghana and other similar settings should give more attention to disadvantage populations such as the poor and unemployed. Tailored massages and educational campaigns are required to ensure consistent use of treated bed nets.

A Review on Major Risk Factors and Current Status of Visceral Leishmaniasis in North India

In India, more than 1,00,000 people are affected every year by Visceral Leishmaniasis (VL). VL is a chronic and fatal disease caused by Leishmania donovani parasites which are transmitted by infected female sand flies, Phlebotomus argentipes. Ninety percent of total cases of the world are reported from India, Bangladesh and Sudan. Several districts of the state Bihar show the occurrence of VL. This is 40-50% of the world cases and 90% of the cases in India. Conversely, information on epidemiology of kala-azar in India remains scanty due to inadequate studies about the various risk factors associated with VL. The present review contributes to the study of the number of cases, deaths, prevalence and incidence caused by VL, spatial distribution, basic epidemiologic features, the vector biology, transmission of the parasite, hosts and most importantly the major risk factors viz. climatic, the physical and biotic factors, the socio-economic conditions, the environmental factors, deforestation due to urbanization, domestic animals and the living standard. For this study we chose five states in India; Bihar, Uttarakhand, Uttar Pradesh, Jharkhand and West Bengal. The study period was from 2010-2017. A decreasing trend was observed in the number of incidences, cases and deaths. But on the contrary, the Post Kala Azar Dermal Leishmaniasis cases (PKDL) showed an increasing trend. The Gram Pradhans (Heads of Villages) and the villagers were also questioned regarding the associated risk factors viz. housing conditions- kaccha (mud) houses, poverty, use of bed nets, cleanliness, damp floors, cooking fuel, vegetation, the rearing of the domestic animals etc. The study suggests that the control measures have been effective in suppressing/eradicating VL but seeing the PKDL trend it also leaves a suspicion that apart from P. argentipus some other flies may also be playing the role as vectors in the transmission of VL. To decrease the transmission of Leishmania donovani and to achieve the goal of total eradication of VL from India in near future, a better understanding of the biology underlying transmission and disease with the major risk factors is the pressing need.

Anemia among Schoolchildren with Malaria and Soil-Transmitted Helminth Coinfections after Repeated Rounds of Mass Drug Administration in Muheza District, Tanzania.

Coinfections with malaria and soil-transmitted helminths (STHs) has been common among school-aged children in Tanzania. However, after a countrywide scaling up of interventions for malaria and STHs, there are limited data on the prevalence of malaria-STH coinfections and its effect on anemia in schoolchildren in Tanzania. We assessed the distribution and risk factors for malaria, STHs, and malaria-STH coinfections, and its relation to anemia among 445 primary schoolchildren in Muheza district. A semi-structured questionnaire was used to collect demographic characteristics of the children. Malaria rapid diagnostic test (mRDT) was used to diagnose malaria infection. Soil-transmitted helminths were diagnosed using the Kato-Katz technique. Primary outcome was anemia, defined as hemoglobin concentration < 11 g/dL. Chi-square (χ2) or Fisher's exact tests, Kruskal-Wallis or t-test, and logistic models were used as appropriate. Overall, the prevalence of malaria, STHs, malaria-STH coinfection, and anemia were 18.4%, 6.1%, 1.6%, and 19.8%, respectively. Anemic children were more likely to have malaria (adjusted odds ratio [aOR] = 4.538, 95% CI: 2.189-9.409), whereas frequent use of bed nets was associated with reduced risk of malaria (aOR = 0.234, 95% CI: 0.130-0.42). On the other hand, not always using latrines and eating raw uncooked food increased the risk of STH infection. The prevalence of anemia was high and was associated with both malaria and malaria-STH infections, therefore calling for more integrated malaria-STH control approaches to target school-aged children.

Presentation and Treatment Outcomes of Liberian Children Age 5 Years and Under Diagnosed With Severe Malaria.

Malaria is endemic in Liberia with a prevalence rate of up to 60% in some regions, and it has been a major cause of death in children under 5 years of age. Prior to the recent Ebola epidemic, we undertook a prospective, hospital-based pilot study at the National Referral Hospital in Monrovia, to characterize the presentation, accuracy of diagnosis, and treatment outcomes of children presenting for treatment of malaria. From June 2013 to May 2014, we recruited children 5 years and under who presented to the JFK Medical Center with suspected malaria. We collected both clinical and laboratory data on admission and on discharge. We enrolled 477 patients with an average age of 1.6 years. Demographic factors associated with testing negative for malaria included regular bed net use and prior treatment for malaria. The most common presenting symptoms of severe malaria in this population were headache and seizures. Of 246 patients admitted and treated for severe malaria, 33% tested negative by rapid diagnostic test and blood smear for malaria. The case fatality rate was higher for the patients who tested negative for malaria (4.9%) versus those who tested positive (0.6%). Three children who tested negative for malaria showed evidence of undiagnosed Salmonella typhi infection. These results suggest that malaria may be overdiagnosed and that the diagnoses of other infectious diseases, which present in a similar fashion, may be neglected. These findings underscore the need to develop rapid diagnostic tests to screen for alternative causes of febrile illness.

Adherence to malaria prophylaxis among travelers from a middle-income country.

Malaria is the main cause of death by infection among travelers and is preventable through a combination of chemoprophylaxis and personal protective measures. Travelers were interviewed by phone 28-90 days after returning, to assess adherence to pre-travel advice for malaria prevention. A total 57 travelers were included. Adherence to chemoprophylaxis was significantly higher among participants prescribed mefloquine (n=18; 75%) than doxycycline (n=14; 45%). Adherence to mosquito repellent and bed net use was 65% and 67%, respectively. Adherence to malaria prophylaxis was lower than expected. Further studies testing innovative approaches to motivate travelers' compliance are required.

Insecticides and Insecticide Resistance.

Vector control has significantly reduced malaria morbidity in many regions of the world where the disease was endemic and is now moving toward malaria elimination. Among the tools available for vector control, the use of long-lasting insecticidal bed nets (LLINs) and indoor residual spraying (IRS) has proved most effective. However, Anopheles mosquitoes are becoming increasingly resistant to insecticides. In this chapter, we describe the main aspects of vector control-with a particular focus on insecticidal products commonly used in vector control as well as on mechanisms of insecticide resistance. We also discuss the impact of insecticide resistance on malaria transmission.

Malaria prevention in the Buea health district in Cameroon: factors influencing Mosquito bed net use in households

Background : Insecticide treated bed nets (ITNs), though proven to be effective in preventing malaria will have little impact unless people sleep under them. Several studies have shown that owned ITNs are usually not used and that ITN use is influenced by several factors that vary between communities. Objective : To investigate the factors influencing the use of mosquito bed nets in households in the Buea Health District (BHD) in Cameroon. Material and Methods : A cross-sectional study with two-stage cluster sampling included 420 households from 35 sites. Questionnaires adapted from the Malaria Indicator Survey were used. CSPro 4.1 and Epi info 3.5.3 were used to create database and analyze respectively. Results : ITN ownership in the BHD was high (92.6%; 95% CI: 89.6%-94.9%) but ITN use was less than average (41.2%; 95% CI: 39.2%-43.3%). ITN use was least likely in the age group 5-15 years (P<0.01), in educated individuals (P<0.01) and in households with less than one ITN for two persons (P<0.01). White ITNs were less likely to be used (P<0.01). Conclusion : There is a gap between ITN ownership and use in the malaria holoendemic BHD and ITN use is associated with age of individual, level of education, colour of ITNs and household net density. Use of the highly owned ITNs could be increased by targeting the least protected 5-15 years age group and schooling individuals; by promoting school-based education on ITN use. Keywords : Insecticide-treated nets, malaria, Buea Health District

Nationwide school malaria parasitaemia survey in public primary schools, the United Republic of Tanzania

BackgroundA nationwide, school, malaria survey was implemented to assess the risk factors of malaria prevalence and bed net use among primary school children in mainland Tanzania. This allowed the mapping of malaria prevalence at council level and assessment of malaria risk factors among school children.MethodsA cross-sectional, school, malaria parasitaemia survey was conducted in 25 regions, 166 councils and 357 schools in three phases: (1) August to September 2014; (2) May 2015; and, (3) October 2015. Children were tested for malaria parasites using rapid diagnostic tests and were interviewed about household information, parents’ education, bed net indicators as well as recent history of fever. Multilevel mixed effects logistic regression models were fitted to estimate odds ratios of risk factors for malaria infection and for bed net use while adjusting for school effect.ResultsIn total, 49,113 children were interviewed and tested for malaria infection. The overall prevalence of malaria was 21.6%, ranging from < 0.1 to 53% among regions and from 0 to 76.4% among councils. The malaria prevalence was below 5% in 62 of the 166 councils and above 50% in 18 councils and between 5 and 50% in the other councils. The variation of malaria prevalence between schools was greatest in regions with a high mean prevalence, while the variation was marked by a few outlying schools in regions with a low mean prevalence. Overall, 70% of the children reported using mosquito nets, with the highest percentage observed among educated parents (80.7%), low land areas (82.7%) and those living in urban areas (82.2%).ConclusionsThe observed prevalence among school children showed marked variation at regional and sub-regional levels across the country. Findings of this survey are useful for updating the malaria epidemiological profile and for stratification of malaria transmission by region, council and age groups, which is essential for guiding resource allocation, evaluation and prioritization of malaria interventions.

Subpatent malaria in a low transmission African setting: a cross-sectional study using rapid diagnostic testing (RDT) and loop-mediated isothermal amplification (LAMP) from Zambezi region, Namibia

BackgroundSubpatent malaria infections, or low-density infections below the detection threshold of microscopy or standard rapid diagnostic testing (RDT), can perpetuate persistent transmission and, therefore, may be a barrier for countries like Namibia that are pursuing malaria elimination. This potential burden in Namibia has not been well characterized.MethodsUsing a two-stage cluster sampling, cross-sectional design, subjects of all age were enrolled during the end of the 2015 malaria transmission season in Zambezi region, located in northeast Namibia. Malaria RDTs were performed with subsequent gold standard testing by loop-mediated isothermal amplification (LAMP) using dried blood spots. Infection prevalence was measured and the diagnostic accuracy of RDT calculated. Relationships between recent fever, demographics, epidemiological factors, and infection were assessed.ResultsPrevalence of Plasmodium falciparum malaria infection was low: 0.8% (16/1919) by RDT and 2.2% (43/1919) by LAMP. All but one LAMP-positive infection was RDT-negative. Using LAMP as gold standard, the sensitivity and specificity of RDT were 2.3% and 99.2%, respectively. Compared to LAMP-negative infections, a higher portion LAMP-positive infections were associated with fever (45.2% vs. 30.4%, p = 0.04), though 55% of infections were not associated with fever. Agricultural occupations and cattle herding were significantly associated with LAMP-detectable infection (Adjusted ORs 5.02, 95% CI 1.77–14.23, and 11.82, 95% CI 1.06–131.81, respectively), while gender, travel, bed net use, and indoor residual spray coverage were not.ConclusionsThis study presents results from the first large-scale malaria cross-sectional survey from Namibia using molecular testing to characterize subpatent infections. Findings suggest that fever history and standard RDTs are not useful to address this burden. Achievement of malaria elimination may require active case detection using more sensitive point-of-care diagnostics or presumptive treatment and targeted to high-risk groups.

Influences of Community Interventions on Zika Prevention Behaviors of Pregnant Women, Puerto Rico, July 2016-June 20171.

We assessed how community education efforts influenced pregnant women’s Zika prevention behaviors during the 2016 Centers for Disease Control and Prevention–Puerto Rico Department of Health Zika virus response. Efforts included Zika virus training, distribution of Zika prevention kits, a mass media campaign, and free home mosquito spraying. We used telephone interview data from pregnant women participating in Puerto Rico’s Women, Infants, and Children Program to test associations between program participation and Zika prevention behaviors. Behavior percentages ranged from 4% (wearing long-sleeved shirt) to 90% (removing standing water). Appropriate mosquito repellent use (28%) and condom use (44%) were common. Receiving a Zika prevention kit was significantly associated with larvicide application (odds ratio [OR] 8.0) and bed net use (OR 3.1), suggesting the kit's importance for lesser-known behaviors. Offer of free residential spraying was associated with spraying home for mosquitoes (OR 13.1), indicating that women supported home spraying when barriers were removed.

Prophylaxis - A key component in malaria control

With the summer holidays fast approaching, holidaymakers will be planning their trip across Africa and the globe. Patients need to be aware of the risks of mosquito bites and contracting malaria. Malaria is endemic in the Limpopo, Mpumalanga and Northern KwaZulu-Natal provinces, with several cases of travel or Odyssean malaria being reported around South Africa. Prophylaxis is key in reducing the risk of infection by malaria. The use of insect repellents, correct clothing, bed nets and environmental control, complemented with chemoprophylaxis will greatly reduce this risk. The current South African guidelines to prevent a malaria infection include atovaquone-proguanil, doxycycline and mefloquine, with the latter drug recommended during pregnancy and when breast-feeding. Patients should be cautioned that despite implementing preventative measures, they should seek immediate medical attention if they develop ‘flu-like’ symptoms or a fever when returning from a malaria area. Appropriate prophylactic measures are key components in preventing a malaria infection and can be life-saving.

Systematic review of indoor residual spray efficacy and effectiveness against Plasmodium falciparum in Africa

Indoor residual spraying (IRS) is an important part of malaria control. There is a growing list of insecticide classes; pyrethroids remain the principal insecticide used in bednets but recently, novel non-pyrethroid IRS products, with contrasting impacts, have been introduced. There is an urgent need to better assess product efficacy to help decision makers choose effective and relevant tools for mosquito control. Here we use experimental hut trial data to characterise the entomological efficacy of widely-used, novel IRS insecticides. We quantify their impact against pyrethroid-resistant mosquitoes and use a Plasmodium falciparum transmission model to predict the public health impact of different IRS insecticides. We report that long-lasting IRS formulations substantially reduce malaria, though their benefit over cheaper, shorter-lived formulations depends on local factors including bednet use, seasonality, endemicity and pyrethroid resistance status of local mosquito populations. We provide a framework to help decision makers evaluate IRS product effectiveness.

Comparison of Malaria Control Interventions in Southern Africa

Background: There is a need of more evidence on which of the two malaria prevention methods, mosquito bednets and indoor residual spraying, is more effective than the other. Objective: To compare the effectiveness of mosquito bednets and indoor residual spraying in the prevention of malaria in Southern Africa. Based on the Health Belief Model, the research questions tested whether there is any relationship between the use of mosquito bednet or the use of indoor residual spraying and reporting fever. Materials and Methods: Using a quantitative research design, secondary data from the 2010 - 2011 Zimbabwe demographic and health survey, 2013 Namibia demographic health survey, and 2013 - 2014 Zambia demographic and health survey were analyzed using IBM/SPSS version 26. Chi-square for association, logistic regression, and multinomial logistic regression tests were conducted with significance level set at p value of ≤ .05. Results: From 2044 children who slept under mosquito bednet the night before data collection 21.8% (n = 446) reported fever during the previous two weeks prior to data collection compared to 22.1% (n = 606) of 2748 children who did not sleep under mosquito bednet. There was no statistically significant association between the use of mosquito bednet and reporting fever during the previous two weeks, x2 (1) = 0.037, p = .848, odds = .987, 95% CI [.859, 1.133]. From 2748 children who lived in dwellings that were not sprayed against mosquito 22.1% (n = 606) reported fever compared to 20.8% (n = 288) of 1387 children who lived in sprayed dwellings. There was no statistically significant association between the use of indoor residual spraying and reporting fever, x2 (1) = 0.903, p = .342, odds = .926, 95% CI [.791, 1.085]. Conclusion: The absence of significant association between mosquito bednet use or indoor residual spraying and having fever in this study could be due to the fact that fever can also manifest in conditions other than malaria. Thus, effort should be made to conduct malaria blood test before concluding whether one has malaria or not based on presence or absence of fever. Furthermore, studies focusing on malaria prevalence should consider collecting data on other variables such as malaria blood test results.