The Association between Long-Term DDT or DDE Exposures and an Altered Sperm Epigenome-a Cross-Sectional Study of Greenlandic Inuit and South African VhaVenda Men.

Background: The organochlorine dichlorodiphenyltrichloroethane (DDT) is banned worldwide owing to its negative health effects. It is exceptionally used as an insecticide for malaria control. Exposure occurs in regions where DDT is applied, as well as in the Arctic, where its endocrine disrupting metabolite, dichlorodiphenyldichloroethylene (DDE) accumulates in marine mammals and fish.

Community perceptions, acceptability, and the durability of house screening interventions against exposure to malaria vectors in Nyimba district, Zambia.

Background: House screening remains conspicuously absent in national malaria programs despite its recognition by the World Health Organization as a supplementary malaria vector-control intervention. This may be attributed, in part, to the knowledge gap in screen durability or longevity in local climatic conditions and community acceptance under specific cultural practices and socio-economic contexts. The objectives of this study were to assess the durability of window and door wire mesh screens a year after full house screening and to assess the acceptability of the house screening intervention to the participants involved.

House Screening Reduces Exposure to Indoor Host-Seeking and Biting Malaria Vectors: Evidence from Rural South-East Zambia.

This study evaluated the impact of combining house screens with long-lasting insecticidal nets (LLINs) on mosquito host-seeking, resting, and biting behavior. Intervention houses received house screens and LLINs, while control houses received only LLINs. Centre for Disease Control light traps, pyrethrum spray collections and human landing catches were used to assess the densities of indoor and outdoor host-seeking, indoor resting, and biting behavior of malaria vectors in 15 sentinel houses per study arm per sampling method.

Geo-epidemiology of malaria incidence in the Vhembe District to guide targeted elimination strategies, South-Africa, 2015-2018: a local resurgence.

In South Africa, the population at risk of malaria is 10% (around six million inhabitants) and concern only three provinces of which Limpopo Province is the most affected, particularly in Vhembe District. As the elimination approaches, a finer scale analysis is needed to accelerate the results. Therefore, in the process of refining local malaria control and elimination strategies, the aim of this study was to identify and describe malaria incidence patterns at the locality scale in the Vhembe District, Limpopo Province, South Africa.

Household living conditions and individual behaviours associated with malaria risk: a community-based survey in the Limpopo River Valley, 2020, South Africa.

Background: Over the past decade, implementation of multiple malaria control strategies in most countries has largely contributed to advance the global malaria elimination agenda. Nevertheless, in some regions, seasonal epidemics may adversely affect the health of local populations. In South Africa, Plasmodium falciparum malaria is still present, with the Vhembe District experiencing an incidence rate of 3.

Anopheles rufipes implicated in malaria transmission both indoors and outdoors alongside Anopheles funestus and Anopheles arabiensis in rural south-east Zambia.

Background: The primary malaria vector-control interventions, indoor residual spraying and long-lasting insecticidal nets, are effective against indoor biting and resting mosquito species. Consequently, outdoor biting and resting malaria vectors might elude the primary interventions and sustain malaria transmission. Varied vector biting and resting behaviour calls for robust entomological surveillance.

Veterinary growth promoters in cattle feedlot runoff: estrogenic activity and potential effects on the rat male reproductive system.

The contribution of veterinary growth promoters (VGP) to the environmental burden of endocrine-disrupting chemicals (EDCs) is largely unknown. At cattle feedlots, the excrement of cattle may contain VGPs, which can contaminate aquatic systems and pose reproductive health risks. The study identifies VGPs used at cattle feedlots in South Africa and confirms associated estrogenic activity in feedlot runoff water.

Predicting malaria cases using remotely sensed environmental variables in Nkomazi, South Africa.

There has been a conspicuous increase in malaria cases since 2016/2017 over the three malaria-endemic provinces of South Africa. This increase has been linked to climatic and environmental factors. In the absence of adequate traditional environmental/climatic data covering ideal spatial and temporal extent for a reliable warning system, remotely sensed data are useful for the investigation of the relationship with, and the prediction of, malaria cases.

Challenges to the implementation of malaria policies in Malawi.

Background: Despite malaria prevention initiatives, malaria remains a major health problem in Malawi, especially for pregnant mothers and children under the age of five. To reduce the malaria burden, Malawi established its first National Malaria Control Programme in 1984. Implementation of evidence-based policies contributed to malaria prevalence dropping from 43% in 2010 to 22% in 2017.

Mosquito community composition in South Africa and some neighboring countries.

Background: A century of studies have described particular aspects of relatively few mosquito species in southern Africa, mostly those species involved with disease transmission, specifically malaria and arboviruses. Patterns of community composition such as mosquito abundance and species diversity are often useful measures for medical entomologists to guide broader insights and projections regarding disease dynamics and potential introduction, spread or maintenance of globally spreading pathogens. However, little research has addressed these indicators in southern Africa.

Estrogenic activity, selected plasticizers and potential health risks associated with bottled water in South Africa.

Potential endocrine disrupting chemicals (EDCs) are present in bottled water from various countries. In South Africa (SA), increased bottled water consumption and concomitant increases in plastic packaging create important consequences for public health. This study aimed to screen SA bottled water for estrogenic activity, selected target chemicals and assessing potential health risks.

Alterations in male reproductive hormones in relation to environmental DDT exposure.

DDT [1, 1, 1-trichloro-2,2-bis (p-chlorophenyl)-ethane] compounds are used for indoor residual spraying (IRS) to control malaria mosquitoes. DDT is an endocrine disruptor chemical in experimental conditions, but little is known of adverse effects related to living conditions with continual uptake across a time span by all possible means of exposure. Based on estrogenic and/or anti-androgenic effects found in animal studies, we hypothesized that chronic DDT/DDE exposures in men may be associated with changes in male reproductive hormones.

Mosquito-borne arboviruses of African origin: review of key viruses and vectors.

Key aspects of 36 mosquito-borne arboviruses indigenous to Africa are summarized, including lesser or poorly-known viruses which, like Zika, may have the potential to escape current sylvatic cycling to achieve greater geographical distribution and medical importance. Major vectors are indicated as well as reservoir hosts, where known. A series of current and future risk factors is addressed.

Development of a framework to improve the utilisation of malaria research for policy development in Malawi.

Background: The existing gap between research evidence and public health practice has attributed to the unmet Millennium Development Goals in Africa and consequently, has stimulated the development of frameworks to enhance knowledge translation. These efforts aim at maximising health research utilisation in policy and practice to address the world's disease burdens, including malaria. This study aimed at developing a contextual framework to improve the utilisation of malaria research for policy development in Malawi.

Endocrine Disruptors and Health Effects in Africa: A Call for Action.

Background: Africa faces a number of unique environmental challenges. Unfortunately, it lacks the infrastructure needed to support the comprehensive environmental studies that could provide the scientific basis to inform environmental policies. There are a number of known sources of endocrine-disrupting chemicals (EDCs) and other hazardous chemicals in Africa.

Estrogenic activity, chemical levels and health risk assessment of municipal distribution point water from Pretoria and Cape Town, South Africa.

Endocrine disrupting chemicals (EDCs) are ubiquitous in the environment and have been detected in drinking water from various countries. Although various water treatment processes can remove EDCs, chemicals can also migrate from pipes that transport water and contaminate drinking water. This study investigated the estrogenic activity in drinking water from various distribution points in Pretoria (City of Tshwane) (n = 40) and Cape Town (n = 40), South Africa, using the recombinant yeast estrogen screen (YES) and the T47D-KBluc reporter gene assay.

Malaria research in Malawi from 1984 to 2016: a literature review and bibliometric analysis.

Background: Malaria research can play a vital role in addressing the malaria burden in Malawi. An organized approach in addressing malaria in Malawi started in 1984 by the establishment of the first National Malaria Control Programme and research was recognized to be significant. This study aimed to assess the type and amount of malaria research conducted in Malawi from 1984 to 2016 and its related source of funding.

Changing the policy for intermittent preventive treatment with sulfadoxine-pyrimethamine during pregnancy in Malawi.

Background: The growing resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine (SP) treatment for uncomplicated malaria led to a recommendation by the World Health Organization for the use of artemisinin-based combination therapy. Inevitably, concerns were also raised surrounding the use of SP for intermittent prevention treatment of malaria during pregnancy (IPTp) amidst the lack of alternative drugs. Malawi was the first country to adopt intermittent prevention treatment with SP in 1993, and updated in 2013.

Field effectiveness of microbial larvicides on mosquito larvae in malaria areas of Botswana and Zimbabwe.

Background: The successful control of malaria vectors requires the control of both the larval and adult stages. The adult control methods through indoor residual spraying (IRS) and use of long-lasting insecticidal nets (LLINs) continue to be widely used with some high measure of success. Larval control methods are also being used by a number of National Malaria Control Programmes (NMCPs) with limited understanding of its contribution.

Facilitating factors and barriers to malaria research utilization for policy development in Malawi.

Background: Research on various determinants of health is key in providing evidence for policy development, thereby leading to successful interventions. Utilization of research is an intricate process requiring an understanding of contextual factors. The study was conducted to assess enhancing factors and barriers of research utilization for malaria policy development in Malawi.

Malaria research and its influence on anti-malarial drug policy in Malawi: a case study.

Background: In 1993, Malawi changed its first-line anti-malarial treatment for uncomplicated malaria from chloroquine to sulfadoxine-pyrimethamine (SP), and in 2007, it changed from SP to lumefantrine-artemether. The change in 1993 raised concerns about whether it had occurred timely and whether it had potentially led to early development of Plasmodium falciparum resistance to SP. This case study examined evidence from Malawi in order to assess if the policy changes were justifiable and supported by evidence.

Effects of environmental endocrine disruptors, including insecticides used for malaria vector control on reproductive parameters of male rats.

The male reproductive system is sensitive to endocrine disrupting chemicals (EDCs) during critical developmental windows. Male Sprague-Dawley rats were exposed in utero-, during lactation- and directly to 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), 1,1,-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and a mixture of DDT, deltamethrin (DM), p-nonylphenol (p-NP) and phytoestrogens, at concentrations found in a malaria-area. After dosing for 104 days, histological assessments and reproductive-endpoints were assessed.

Acceptability and effectiveness of a monofilament, polyethylene insecticide-treated wall lining for malaria control after six months in dwellings in Vhembe District, Limpopo Province, South Africa.

Background: South Africa uses indoor residual spraying (IRS) for vector control in its malaria control programme (MCP). Insecticide-treated wall linings (ITWLs) offer possible advantages over IRS and long-lasting, insecticide-treated nets (LLINs). This study assessed the user acceptability and perceived effectiveness, and the durability, including efficacy through bioassays, of a newly developed, monofilament polyethylene ITWL.