Achieve Malaria Elimination Research Articles

Unravelling the impact of insecticide-treated bed nets on childhood malaria in Malawi

BackgroundTo achieve malaria elimination it is essential to understand the impact of insecticide-treated net (ITNs) programmes. Here, the impact of ITN access and use on malaria prevalence in children in Malawi was investigated using Malaria Indicator Survey (MIS) data.MethodsMIS data from 2012, 2014 and 2017 were used to investigate the relationship between malaria prevalence in children (6–59 months) and ITN use. Generalized linear modelling (GLM), geostatistical mixed regression modelling and non-stationary GLM were undertaken to evaluate trends, spatial patterns and local dynamics, respectively.ResultsMalaria prevalence in Malawi was 27.1% (95% CI 23.1–31.2%) in 2012 and similar in both 2014 (32.1%, 95% CI 25.5–38.7) and 2017 (23.9%, 95% CI 20.3–27.4%). ITN coverage and use increased during the same time period, with household ITN access growing from 19.0% (95% CI 15.6–22.3%) of households with at least 1 ITN for every 2 people sleeping in the house the night before to 41.7% (95% CI 39.1–44.4%) and ITN use from 41.1% (95% CI 37.3–44.9%) of the population sleeping under an ITN the previous night to 57.4% (95% CI 55.0–59.9%). Both the geostatistical and non-stationary GLM regression models showed child malaria prevalence had a negative association with ITN population access and a positive association with ITN use although affected by large uncertainties. The non-stationary GLM highlighted the spatital heterogeneity in the relationship between childhood malaria and ITN dynamics across the country.ConclusionMalaria prevalence in children under five had a negative association with ITN population access and a positive association with ITN use, with spatial heterogeneity in these relationships across Malawi. This study presents an important modelling approach that allows malaria control programmes to spatially disentangle the impact of interventions on malaria cases.

Individual variation in Plasmodium vivax malaria risk: Are repeatedly infected people just unlucky?

Extensive research has examined why some people have frequent Plasmodium falciparum malaria episodes in sub-Saharan Africa while others remain free of disease most of the time. In contrast, malaria risk heterogeneity remains little studied in regions where P. vivax is the dominant species. Are repeatedly infected people in vivax malaria settings such as the Amazon just unlucky? Here, we briefly review evidence that human genetic polymorphism and acquired immunity after repeated exposure to parasites can modulate the risk of P. vivax infection and disease in predictable ways. One-fifth of the hosts account for 80% or more of the community-wide vivax malaria burden and contribute disproportionally to onward transmission, representing a priority target of more intensive interventions to achieve malaria elimination. Importantly, high-risk individuals eventually develop clinical immunity, even in areas with very low or residual malaria transmission, and may constitute a large but silent parasite reservoir.

Effect of Ivermectin® on survivorship and fertility of Anopheles arabiensis in Ethiopia: an in vitro study

BackgroundInnovative vector control tools are needed to counteract insecticide resistance and residual malaria transmission. One of such innovative methods is an ivermectin (IVM) treatment to reduce vector survival. In this study, a laboratory experiment was conducted to investigate the effect of ivermectin on survivorship, fertility and egg hatchability rate of Anopheles arabiensis in Ethiopia.MethodsAn in vitro experiment was conducted using 3–5 days old An. arabiensis adults from a colony maintained at insectary of Tropical and Infectious Diseases Research Center, Jimma University (laboratory population) and Anopheles mosquitoes reared from larvae collected from natural mosquito breeding sites (wild population). The mosquitoes were allowed to feed on cattle blood treated with different doses of ivermectin (0 ng/ml, 5 ng/ml, 10 ng/ml, 20 ng/ml, 40 ng/ml and 80 ng/ml). During each feeding experiment, the mosquitoes were held in cages and blood-fed using a Hemotek feeder. Mortality and egg production were then recorded daily for up to 9 days. Time to death was analysed by a Cox frailty model with replicate as frailty term and source of mosquito (wild versus laboratory), treatment type (ivermectin vs control) and their interaction as categorical fixed effects. Kaplan Meier curves were plotted separately for wild and laboratory populations for a visual interpretation of mosquito survival as a function of treatment.ResultsBoth mosquito source and treatment had a significant effect on survival (P < 0.001), but their interaction was not significant (P = 0.197). Compared to the controls, the death hazard of An. arabiensis that fed on ivermectin-treated blood was 2.3, 3.5, 6.5, 11.5 and 17.9 times that of the control for the 5 ng/ml, 10 ng/ml, 20 ng/ml, 40 ng/ml, and 80 ng/ml dose, respectively. With respect to the number of hatched larvae, hatched pupae and emerged adults per fed mosquitoes, a significant difference was found between the control and the 5 ng/ml dose group (P < 0.001). The number of hatched larvae and pupae, and emerged adults decreased further for the 10 ng/ml dose group and falls to zero for the higher doses.ConclusionTreating cattle blood with ivermectin reduced mosquito survival, fertility, egg hatchability, larval development and adult emergence of An. arabiensis in all tested concentrations of ivermectin in both the wild and laboratory populations. Thus, ivermectin application in cattle could be used as a supplementary vector control method to tackle residual malaria transmission and ultimately achieve malaria elimination in Ethiopia.

Management of Insect Borne Human Diseases – A Case Study on Novel Bio-Larvicide for Mosquito Borne Diseases Including Dengue

In India National Vector Borne Diseases Control programme is an umbrella organization for management and control of six out of eight insect-borne human diseases, viz., Malaria, Lymphatic Filariasis (LF), Kala-azar, Dengue/ Chikungunya, and Japanese Encephalitis. Of these, India is committed for elimination of the first three diseases from the country. 8.6% of India’s total population belongs to tribal community yet contribute 21% of Plasmodium falciparum infection and 29% of malaria-related deaths. There is an urgent need to implement novel strategies to overcome insecticide resistance in Anopheles culicifacies that transmit 60-70% of malaria cases in India. One such strategy is to use Chilodonella uncinata, an indigenous, maternally transmitted, facultative protozoan bio-larvicide with many biological control properties against mosquito vectors. In view of the above, if India really aims to achieve malaria elimination by 2030, there is an urgent need that tribal regions are given more attention.

Behavioural determinants of malaria risk, prevention, and care-seeking behaviours among forest-goers in Cambodia

BackgroundCambodia has made significant progress towards achieving malaria elimination by 2025. Cases continue to decrease and are primarily concentrated in forested areas. Forest-goers are most at risk of malaria due to their proximity to the forest, poor sleeping conditions, frequent mobility, and distance from health services. Consistent use of long-lasting insecticidal nets or hammock nets (LLINs/LLIHNs), early diagnosis and treatment of cases are central to reducing disease burden. The aim of this study was to understand forest-goers’ knowledge, attitudes, and practices related to malaria prevention and care-seeking, and to identify key behavioural determinants of LLIN/LLIHN use and prompt care-seeking within 24 h of developing a fever.MethodsA mixed-methods study design consisting of a cross-sectional survey and qualitative in-depth interviews was implemented in two Cambodian provinces. Survey participants (N = 654) were recruited using respondent driven sampling. Interview participants (N = 28) were selected using purposive sampling. Findings from the survey were analysed using univariate and bivariate analysis and multivariate weighted logistic regression. Interviews were coded and analysed using thematic content analysis.ResultsAll study participants had heard of malaria and 98% knew that malaria was transmitted by mosquitoes. LLIN/LLIHN ownership was high (94%). Although 99% of participants perceived LLIN/LLIHN use as an important malaria prevention measure, only 76% reported using one during their last visit to the forest. Only 39% of survey participants who reported seeking care did so within the recommended 24 h from fever onset during their last febrile illness. Among all study participants, 43% did not seek any healthcare during their last febrile episode. In controlled regression models, perceived community social norms were significantly associated with LLIN/LLIHN use (OR: 2.7, 96% CI 1.99–2.64) and care-seeking within 24 h of fever onset (OR: 1.7, 95% CI 1.00–2.88). Social support from other forest-goers was also significantly associated with LLIN/LLIHN use (OR: 4.9, 95% CI 1.32–18.12).ConclusionsStudy findings are consistent with other studies on LLIN/LLIHN use and care-seeking behaviours. While rates of LLIN/LLIHN ownership were high among the study population, rates of use were not as high. More concerning were the delayed care-seeking behaviours. Social behaviour change activities should incorporate social norms and social support as mechanisms for behaviour change given the identified positive correlations with LLIN/LLIHN use and prompt care-seeking.

Narrative Review: Quintuple Helixs Model for Malaria Elimination in Indonesia

Malaria continues to impact the health and economies of people around the world. Further steps need to be taken in accordance with the Global Technical Strategy for malaria to prevent malaria transmission. Quintuple helix model is an integrated effort that involves cross-sector in controlling malaria cases in an area. The implementation of the quintuple helix model is expected to be used as consideration and input for policy makers in an effort to achieve malaria elimination in Indonesia by 2030. The purpose of this study is to eliminate malaria in Indonesia with the quintuple helix model. This study uses a systematic review narrative method that is used to identify study topics selectively on interesting and recent issues. Malaria control in Indonesia is carried out using the national resilience approach. The results obtained from the academic aspect for malaria control must be met, both in terms of educational background qualifications, from the industrial aspect of the economic system included in the quintuple helix model, from the government aspect the control program must be compiled under the Ministry of Health, from the media aspect where the media is one of the an important index in the management of malaria in an area, and from an environmental aspect that aims to prevent, limit vector breeding and reduce mosquito contact with humans. The quintuple helix model is expected to be an innovation in malaria control in Indonesia. By involving academia and social community, industry, government, environmental engineering and the media. It is hoped that each sector can provide roles that are in accordance with their duties and functions

Determinants of health seeking behaviours for malaria treatment in Cameroon

Background: Household health-seeking behaviour for malaria treatment is an important policy concern in malaria-endemic African countries. This paper aims to shed light on the determinants of household’s health-seeking behaviour for malaria treatment in Cameroon.Methods: The cross-sectional study used secondary data from the fourth Cameroonian household consumption survey conducted by the National Institute of Statistics. A stratified, 2-stage sampling was implemented with a sample of 918 households which sought malaria treatment from different alternatives providers. The multinomial probit model was used to estimate the probability based on socio-demographic and economics determinants for a household to choose between different types of providers of malaria treatment.Results: The findings of this study indicate that, the alternative providers for malaria treatment were: public health facilities (61.1%), private health facilities (8.5%), traditional healers (1.4%), pharmacies (4.6%), informal vendor (18%), other types of recourse (6.4%). The decision to choose the provider for malaria treatment depends on factors such as household head, region, level of education, religion, area of residence, socio-professional category, and gender. The level of education appears to be an important determinant of a household’s seeking behaviour. Those with higher education are more likely to seek care at formal health facilities.Conclusions: Health policy-makers need to strive to improve the socio-demographic and economic conditions and sensitize households on the appropriate alternative ways to ensure the universal access to diagnosis and effective treatment of malaria in line with the global strategies recommended by WHO to achieve malaria elimination by 2030.

India could harness public-private partnerships to achieve malaria elimination.

Public-private partnerships (PPP) have been beneficial in different sectors like infrastructure development and service sector across the world, including in India. Such partnerships in the healthcare sector have also been successful in providing access to affordable medical attention to all sections of society. These partnerships between public and private entities have proven to be beneficial in controlling malaria in high burden districts of India and taking these areas to the brink of elimination, thus setting examples to follow. The two successful ones are the Comprehensive Case Management Project (CCMP) in Odisha which is now adopted by the state, and the Malaria Elimination Demonstration Project (MEDP) which has nearly eliminated malaria from the highly endemic district of Mandla in Madhya Pradesh. Here we propose that non-government and semi-government actors may be given vital roles in the malaria elimination efforts till 2030 and beyond. These partners will add value to the national programme and may have the potential to develop and test different models of malaria elimination in real-life settings that the government programme can absorb sustainably.

Reducing malaria transmission in forest-going mobile and migrant populations in Lao PDR and Cambodia: protocol for stepped-wedge cluster-randomised controlled trial

BackgroundCountries of the Greater Mekong Sub-region aim to achieve malaria elimination by 2030. In the region, malaria is concentrated in high-risk areas and populations such as forest-going mobile and migrant populations (MMPs). However, routine protective measures such as long-lasting insecticidal nets do not prevent all infectious bites in these high-risk populations. Evidence for the effectiveness of a personal protection package tailored to forest-going MMPs which is acceptable, feasible, and cost-effective for reducing malaria transmission is required to inform the malaria elimination toolkit in the region.MethodsA personal protection package consisting of long-lasting insecticidal hammock net, insect repellent and health communication pamphlet was developed in consultation with relevant implementing partners from Cambodia and Lao PDR. An open stepped-wedge cluster-randomised controlled trial will be conducted over a period of 12 months in a minimum of 488 villages (~ 428 in Lao PDR and ~ 60 in Cambodia) to evaluate the effectiveness of the personal protection package. Villages will be randomised into 11 blocks, with blocks transitioned in random order from control to intervention states at monthly intervals, following a 1-month baseline period. The primary outcome of the trial is the prevalence of Plasmodium spp. infection diagnosed by rapid diagnostic test. Difference in prevalence of malaria infection will be estimated across intervention and control periods using generalized linear mixed modelling. Nested within the stepped-wedge cluster-randomised controlled trial is a mixed-methods study to explore the acceptability of the personal protection package, feasibility of implementing a personal protection package as a vector control intervention, and knowledge, attitude and practice of MMPs regarding malaria prevention; and cost-analysis to determine the cost-effectiveness of implementing a personal protection package.DiscussionThis study, using a rigorous design and mixed-methods methodology, will evaluate whether a personal protection package can reduce residual malaria transmission among forest-going MMPs in Cambodia and Lao PDR. It will also measure implementation research outcomes such as effectiveness of the intervention package, cost-effectiveness, acceptability, and feasibility, in order to inform potential national and regional policy.Trial registration This trial was prospectively registered on ClinicalTrials.gov (NCT05117567) on 11th November 2021

Plasmodium malariae Detected by Microscopy in the International Bordering Area of Mizoram, a Northeastern State of India

Northeastern states of India share international borders with Myanmar, China, Bangladesh, and Bhutan, contributing 7.45% of the overall malaria cases in the country. Mizoram accounts for the highest malaria burden in the northeastern states, with perennial transmission in the hilly and deep-forested areas. Plasmodium falciparum (93%) is the most prevalent human Plasmodium species, followed by P. vivax; however, information on P. ovale and P. malariae is negligible. Rapid diagnostic tests (RDTs) are the most preferred malaria diagnostic tool followed by microscopy in this high malaria-endemic region. The present epidemiological study was carried out in July and August 2019 to assess the malaria burden in and around the Chawngte primary health center, Lawngtlai District of Mizoram, using RDTs and microscopy as diagnostic tools. World Health Organization-certified level I microscopists examined the blood smears. Diagnosis using RDTs resulted in 151 malaria cases (P. falciparum: 136; P. vivax: 15) out of 948 screened fever cases. However, blood smear examination detected 179 cases (P. falciparum: 154; P. vivax: 17; mixed P. falciparum + P. vivax infection: 3; P. malariae: 5). Analysis revealed that the risk of malaria infection was higher in the ≥5-year-old subjects than in the under-5 age group. The mean parasite density of P. malariae (1455.00/μL blood) was the lowest; cf. with P. falciparum: 12,275.08/μL blood. Surveillance at the point-of-care level using microscopy was able to detect all the four human Plasmodium species and their mixed infections, including P. malariae, which were missed with RDTs. Thus, the quality of microscopy along with trained manpower should be strengthened to diagnose all human malaria parasite species (particularly P. malariae and P. ovale) until the molecular tools are deployed at the field level to achieve malaria elimination by 2030.

Surveillance to achieve malaria elimination in eastern Myanmar: a 7-year observational study

BackgroundThe collection and utilization of surveillance data is essential in monitoring progress towards achieving malaria elimination, in the timely response to increases in malaria case numbers and in the assessment of programme functioning. This paper describes the surveillance activities used by the malaria elimination task force (METF) programme which operates in eastern Myanmar, and provides an analysis of data collected from weekly surveillance, case investigations, and monitoring and evaluation of programme performance.MethodsThis retrospective analysis was conducted using data collected from a network of 1250 malaria posts operational between 2014 and 2021. To investigate changes in data completeness, malaria post performance, malaria case numbers, and the demographic details of malaria cases, summary statistics were used to compare data collected over space and time.ResultsIn the first 3 years of the METF programme, improvements in data transmission routes resulted in a 18.9% reduction in late reporting, allowing for near real-time analysis of data collected at the malaria posts. In 2020, travel restrictions were in place across Karen State in response to COVID-19, and from February 2021 the military coup in Myanmar resulted in widescale population displacement. However, over that period there has been no decline in malaria post attendance, and the majority of consultations continue to occur within 48 h of fever onset. Case investigations found that 43.8% of cases travelled away from their resident village in the 3 weeks prior to diagnosis and 36.3% reported never using a bed net whilst sleeping in their resident village, which increased to 72.2% when sleeping away from their resident village. Malaria post assessments performed in 82.3% of the METF malaria posts found malaria posts generally performed to a high standard.ConclusionsSurveillance data collected by the METF programme demonstrate that despite significant changes in the context in which the programme operates, malaria posts have remained accessible and continue to provide early diagnosis and treatment contributing to an 89.3% decrease in Plasmodium falciparum incidence between 2014 and 2021.

Malaria time series in the extra-Amazon region of Brazil: epidemiological scenario and a two-year prediction model

BackgroundIn Brazil, malaria is caused mainly by the Plasmodium vivax and Plasmodium falciparum species. Its transmission occurs in endemic and non-endemic areas. Malaria geography in Brazil has retracted and is now concentrated in the North region. The Brazilian Amazon region accounts for 99% of Brazil's cases. Brazil’s extra-Amazon region has a high frequency of imported cases and in 2019 presented a mortality rate 123 times higher than the Amazon region. Extra-Amazon cases present risks of reintroduction. This study aims to characterize the epidemiological scenario for malaria in the extra-Amazon region of Brazil from 2011 to 2020 with a two-year forecast.MethodsTime-series study with description of malaria cases and deaths registered in Brazilian extra-Amazon region from 2011 to 2020. Public data from the Notifiable Diseases Information System (Sinan) and the Mortality Information System (SIM) were used. Descriptive analysis, incidence, and notification rates were calculated. Flow charts analysed the flux between Places of Probable Infection (PI) and places of notification. The prediction model utilized a multiplicative Holt-winters model for trend and seasonality components.ResultsA total of 6849 cases were registered. Cases were predominantly white males with 9 to 11 years of education, mostly between 30 and 39 years old. Imported cases accounted for 78.9% of cases. Most frequent occupations for imported cases are related to travelling and tourism activities. Among autochthonous cases, there is a higher frequency of agriculture and domestic economic activities. In the period there were 118 deaths due to malaria, of which 34.7% were caused by P. falciparum infections and 48.3% were not specified. The most intense flows of imported cases are from Amazonas and Rondônia to São Paulo, Rio de Janeiro, and Paraná. The prediction estimates around 611 cases for each of the following two years.ConclusionThe time series allows a vast epidemiological visualization with a short-term prediction analysis that supports public health planning. Government actions need to be better directed in the extra-Amazon region so the objective of eliminating malaria in Brazil is achieved. Carrying out quality assessments for information systems and qualifying personnel is advisable. Malaria outside the Amazon region is mainly due to imported cases and delay in diagnosis is associated with a higher fatality rate. Better strategies to diagnose and treat suspected cases can lead to lower risk of deaths and local outbreaks that will be important for achieving malaria elimination in Brazil.

Asymptomatic School-Aged Children Are Important Drivers of Malaria Transmission in a High Endemicity Setting in Uganda.

Achieving malaria elimination requires a better understanding of the transmissibility of human infections in different transmission settings. This study aimed to characterize the human infectious reservoir in a high endemicity setting in eastern Uganda, using gametocyte quantification and mosquito feeding assays. In asymptomatic infections, gametocyte densities were positively associated with the proportion of infected mosquitoes (β = 1.60; 95% CI, 1.32–1.92; P < .0001). Combining transmissibility and abundance in the population, symptomatic and asymptomatic infections were estimated to contribute to 5.3% and 94.7% of the infectious reservoir, respectively. School-aged children (5–15 years old) contributed to 50.4% of transmission events and were important drivers of malaria transmission.

Rethinking human resources and capacity building needs for malaria control and elimination in Africa.

Despite considerable success in controlling malaria worldwide, progress toward achieving malaria elimination has largely stalled. In particular, strategies to overcome roadblocks in malaria control and elimination in Africa are critical to achieving worldwide malaria elimination goals-this continent carries 94% of the global malaria case burden. To identify key areas for targeted efforts, we combined a comprehensive review of current literature with direct feedback gathered from frontline malaria workers, leaders, and scholars from Africa. Our analysis identified deficiencies in human resources, training, and capacity building at all levels, from research and development to community involvement. Addressing these needs will require active and coordinated engagement of stakeholders as well as implementation of effective strategies, with malaria-endemic countries owning the relevant processes. This paper reports those valuable identified needs and their concomitant opportunities to accelerate progress toward the goals of the World Health Organization's Global Technical Strategy for Malaria 2016-2030. Ultimately, we underscore the critical need to re-think current approaches and expand concerted efforts toward increasing relevant human resources for health and capacity building at all levels if we are to develop the relevant competencies necessary to maintain current gains while accelerating momentum toward malaria control and elimination.

Cross-border malaria drivers and risk factors on the Brazil\u2013Venezuela border between 2016 and 2018

Globally, cross-border importation of malaria has become a challenge to malaria elimination. The border areas between Brazil and Venezuela have experienced high numbers of imported cases due to increased population movement and migration out of Venezuela. This study aimed to identify risk factors for imported malaria and delineate imported malaria hotspots in Roraima, Brazil and Bolivar, Venezuela between 2016 and 2018. Data on malaria surveillance cases from Roraima, Brazil and Bolivar, Venezuela from 2016 to 2018 were obtained from national surveillance systems: the Brazilian Malaria Epidemiology Surveillance Information System (SIVEP-Malaria), the Venezuelan Ministry of Health and other non-government organizations. A multivariable logistic regression model was used to identify the risk factors for imported malaria. Spatial autocorrelation in malaria incidence was explored using Getis-Ord (Gi*) statistics. During the study period, there were 11,270 (24.3%) and 4072 (0.7%) imported malaria cases in Roraima, Brazil and Bolivar, Venezuela, respectively. In the multivariable logistic regression for Roraima, men were 28% less likely to be an imported case compared to women (Adjusted Odds Ratio [AOR] = 0.72; 95% confidence interval [CI] 0.665, 0.781). Ages 20–29 and 30–39 were 90% (AOR = 1.90; 95% CI 1.649, 2.181) and 54% (AOR = 1.54; 95% CI 1.331, 1.782) more likely to be an imported case compared to the 0–9 year age group, respectively. Imported cases were 197 times (AOR = 197.03; 95% CI 175.094, 221.712) more likely to occur in miners than those working in agriculture and domestic work. In Bolivar, cases aged 10–19 (AOR = 1.75; 95% CI 1.389, 2.192), 20–29 (AOR = 2.48; 95% CI 1.957, 3.144), and 30–39 (AOR = 2.29; 95% CI 1.803, 2.913) were at higher risk of being an imported case than those in the 0–9 year old group, with older age groups having a slightly higher risk compared to Roraima. Compared to agriculture and domestic workers, tourism, timber and fishing workers (AOR = 6.38; 95% CI 4.393, 9.254) and miners (AOR = 7.03; 95% CI 4.903, 10.092) were between six and seven times more likely to be an imported case. Spatial analysis showed the risk was higher along the international border in the municipalities of Roraima, Brazil. To achieve malaria elimination, cross-border populations in the hotspot municipalities will need targeted intervention strategies tailored to occupation, age and mobility status. Furthermore, all stakeholders, including implementers, policymakers, and donors, should support and explore the introduction of novel approaches to address these hard-to-reach populations with the most cost-effective interventions.

Detection of asymptomatic malaria in Asian countries: a meta-analysis of diagnostic accuracy

BackgroundAchieving malaria elimination requires the targeting of the human reservoir of infection, including those patients with asymptomatic infection. The objective was to synthesise evidence on the accuracy of the rapid-onsite diagnostic tests (RDTs) and microscopy for the detection of asymptomatic malaria as part of the surveillance activities in Asian countries.MethodsThis was a meta-analysis of diagnostic test accuracy. Relevant studies that evaluated the diagnostic performance of RDTs and microscopy for detection of asymptomatic malaria were searched in health-related electronic databases. The methodological quality of the studies included was assessed using the QUADAS-2 tool.ResultsTen studies assessing RDT and/or microscopy were identified. The diagnostic accuracies in all these studies were verified by PCR. Overall, the pooled sensitivities of RDT, as well as microscopy for detection of any malaria parasites in asymptomatic participants, were low, while their pooled specificities were almost ideal. For the detection of Plasmodium falciparum, pooled sensitivity by RDT (59%, 95%CI:16–91%) or microscopy (55%, 95%CI: 25–82%) were almost comparable. For detection of Plasmodium vivax, pooled sensitivity of RDT (51%, 95% CI:7–94%) had also the comparable accuracy of microscopy (54%, 95%CI,11–92%). Of note are the wide range of sensitivity and specificity.ConclusionThe findings of this meta-analysis suggest that RDTs and microscopy have limited sensitivity and are inappropriate for the detection of asymptomatic Plasmodium infections. Other methods including a combination of PCR-based strategies, Loop-Mediated Isothermal Amplification (LAMP) technique must be considered to target these infections, in order to achieve malaria elimination. However, more data is needed for the wide acceptance and feasibility of these approaches. Studies to explore the role of asymptomatic and sub-patent infections in the transmission of malaria are of critical importance and are recommended.

Scientific achievements and reflections after 20 years of vector biology and control research at the Pu Teuy mosquito field research station, Thailand

Additional vector control tools are needed to supplement current strategies to achieve malaria elimination and control of Aedes-borne diseases in many settings in Thailand and the Greater Mekong Sub-region. Within the next decade, the vector control community, Kasetsart University (KU), and the Ministry of Higher Education, Science, Research and Innovation must take full advantage of these tools that combine different active ingredients with different modes of action. Pu Teuy Mosquito Field Research Station (MFRS), Department of Entomology, Faculty of Agriculture, Kasetsart University (KU), Thailand was established in 2001 and has grown into a leading facility for performing high-quality vector biology and control studies and evaluation of public health insecticides that are operationally relevant. Several onsite mosquito research platforms have been established including experimental huts, a 40-m long semi-field screening enclosure, mosquito insectary, field-laboratory, and living quarters for students and researchers. Field research and assessments ranged from ‘basic’ investigations on mosquito biology, taxonomy and genetics to more ‘applied’ studies on responses of mosquitoes to insecticides including repellency, behavioural avoidance and toxicity. In the course of two decades, 51 peer-reviewed articles have been published, and 7 masters and 16 doctoral degrees in Entomology have been awarded to national and international students. Continued support of key national stakeholders will sustain MFRS as a Greater Mekong Subregion centre of excellence and a resource for both insecticide trials and entomological research.

Malaria treatment-seeking behaviour and its associated factors: A cross-sectional study in rural East Nusa Tenggara Province, Indonesia.

The World Health Organization recommends seeking medical treatment within 24 hours after transmission of malaria to reduce the risk of severe complications and its onwards spread. However, in some parts of Indonesia, including East Nusa Tenggara Province (ENTP), this adherence is not achieved for a range of reasons including delays in visiting health centres. This study aims to determine factors related to the poor understanding of appropriate malaria treatment-seeking behaviour (AMTSB) of rural adults in ENTP. AMTSB was defined as seeking treatment at professional health facilities within 24 hours of the onset of malaria symptoms. A cross-sectional study was conducted in the East Sumba, Belu, and East Manggarai district of ENTP between October and December 2019. A multi-stage cluster sampling procedure was applied to enrol 1503 participants aged between 18 and 89 years of age. Data were collected through face-to-face interviews. Multivariable logistic regression analyses were used to assess significant factors associated with the poor understanding of AMTSB. Eighty-six percent of participants were found to be familiar with the term malaria. However, poor understanding level of AMTSB in rural adults of ENTP achieved 60.4% with a 95% confidence interval (CI): 56.9-63.8. Poor understanding of AMTSB was significantly higher for adults with no education (adjusted odds ratio (AOR) 3.42, 95% CI: 1.81, 6.48) compared to those with a diploma or above education level; having low SES (AOR: 1.87, 95% CI: 1.19, 2.96) compared to those having high SES; residing at least three kilometres (km) away from the nearest health facilities (AOR: 1.73, 95% CI: 1.2, 2.5) compared to those living within one km from the nearest health service; and working as farmer (AOR: 1.63, 95% CI: 1.01-2.63) compared to those working at government or non-government sector. Whilst, other factors such as ethnicity and family size were not associated with the poor understanding of AMTSB. The proportion of rural adults having a poor understanding of AMTSB was high leading to ineffective implementation of artemisinin-based combination therapies as the method to treat malaria in ENTP. Improving awareness of AMTSB for rural adults having low level education, low SES, working as a farmer, and living at least three km from the nearest health facilities is critical to support the efficacy of malaria treatment in ENTP. This method will support the Indonesian government's objective to achieve malaria elimination by 2030.

Malaria Epidemiology Along the Indian Districts Bordering Bhutan and Implications for Malaria Elimination in the Region.

It is important for malaria-endemic countries to address malaria control across international borders, and in particular to prioritize appropriate rapid diagnosis, treatment and surveillance. Bhutan and India aim to achieve malaria elimination by 2023 and 2030 respectively. Malaria elimination along the Indo-Bhutan border is of common concern. We delineated malaria epidemiology along the border to provide a blueprint for focusing malaria control efforts in key foci within this region. Epidemiological data from 2015 to 2019 were analyzed, as the most drastic reductions in malaria burden across most parts of India were witnessed in this time frame. Several areas of concern include low surveillance in most border districts, favorable climatic conditions for perennial malaria transmission, and movement of potential parasite carriers because of the porous borders. India and Bhutan need to control the importation/exportation of malaria cases. We highlight the foci of concern for which implementing tailor-made malaria control strategies may benefit both countries.

Malaria prevention interventions beyond long-lasting insecticidal nets and indoor residual spraying in low- and middle-income countries: a scoping review

BackgroundSignificant progress in malaria prevention during the past two decades has prompted increasing global dialogue on malaria elimination. Recent reviews on malaria strategies have focused mainly on long-lasting insecticidal nets (LLINs) and indoor residual spraying (IRS), with little emphasis on other prevention methods. This article is a scoping review of literature on malaria prevention methods beyond LLINs and IRS in low- and middle-income countries (LMICs).MethodsThis scoping review found articles published between from 1994 to 2020. Studies were obtained from a search of the PubMed, the Cochrane Library and Social Science abstracts. Grey literature and manual search of secondary references was also done. The search strategy included all study designs but limited only to English. Three independent reviewers performed the selection and characterization of articles, and the data collected were synthesized qualitatively.ResultsA total of 10,112 studies were identified among which 31 met the inclusion criteria. The results were grouped by the 3 emerging themes of: housing design; mosquito repellents; and integrated vector control. Housing design strategies included closing eves, screening of houses including windows, doors and ceilings, while mosquito repellents were mainly spatial repellents, use of repellent plants, and use of plant-based oils. Integrated vector control included larvae source management. Evidence consistently shows that improving housing design reduced mosquito entry and malaria prevalence. Spatial repellents also showed promising results in field experiments, while evidence on repellent plants is limited and still emerging. Recent literature shows that IVM has been largely ignored in recent years in many LMICs. Some malaria prevention methods such as spatial repellents and IVM are shown to have the potential to target both indoor and outdoor transmission of malaria, which are both important aspects to consider to achieve malaria elimination in LMICs.ConclusionThe scoping review shows that other malaria prevention strategies beyond LLINs and IRS have increasingly become important in LMICs. These methods have a significant role in contributing to malaria elimination in endemic countries if they are adequately promoted alongside other conventional approaches.