Category Archives: Agriculture

Malaria News Today 2020-10-01

News focuses on getting a handle on urban malaria in Uganda and Tanzania. Listen to a program on the disease burden of malaria in Africa.  Chad reports a high test positivity rate. Algeria is re-experiencing malaria after it was officially eliminated. Links for more details are found in each section.

Modelling and mapping the intra-urban spatial distribution of Plasmodium falciparum parasite rate using very-high-resolution satellite derived indicators

Stefanos Georganos, Oscar Brousse, Moritz Lennert, and others in International Journal of Health Geographics report on the rapid and often uncontrolled rural–urban migration in Sub-Saharan Africa is transforming urban landscapes expected to provide shelter for more than 50% of Africa’s population by 2030. Case studies include two Sub-Saharan African cities, Kampala and Dar es Salaam.

Openly accessible land-cover, land-use, population and OpenStreetMap data were employed to spatially model Plasmodium falciparum parasite rate standardized to the age group 2–10 years (PfPR2–10) in the two cities through the use of a Random Forest (RF) regressor. The RF models integrated physical and socio-economic information to predict PfPR2–10 across the urban landscape. Intra-urban population distribution maps were used to adjust the estimates according to the underlying population.

The results suggest that the spatial distribution of PfPR2–10 in both cities is diverse and highly variable across the urban fabric. Dense informal settlements exhibit a positive relationship with PfPR2–10 and hotspots of malaria prevalence were found near suitable vector breeding sites such as wetlands, marshes and riparian vegetation. In both cities, there is a clear separation of higher risk in informal settlements and lower risk in the more affluent neighborhoods. Additionally, areas associated with urban agriculture exhibit higher malaria prevalence values. This study demonstrates the importance of remote sensing as an epidemiological tool for mapping urban malaria variations at large spatial extents, and for promoting evidence-based policy making and control efforts.

Malaria: Africa’s nagging health burden

Listen to Episode Nine of Africa Science Focus is on malaria, which is one of the biggest killers on the continent. “Malaria is so common you can get it anywhere, anyhow, any time,” Jessica, a malaria sufferer in Liberia, tells the programme. This is because Africa’s mosquitoes are “supremely efficient vectors of malaria disease”, says the World Health Organization’s David Schellenberg.

Malaria: More than 500K cases reported in Chad, Deadliest disease in country

According to data from the National Committee for Epidemic Control (CTNLE), out of the 943,040 malaria tests conducted between 1 January and 13 September 2020, a total of 571,258 cases were confirmed (60.5 percent), with 1,280 deaths across the country. In addition close to 1,140,000 suspected cases based on clinical symptoms but who have not been tested. Among these suspected cases, 1,368 people have died. The most affected provinces are, among others, Logone oriental (with a total of 80,930 cases), Mandoul (82 258 cases), Moyen-Chari (60 207 cases), Tandjle (55 777 cases) and N’Djamena (53 976 cases).

Officials say the situation is slightly better than last year around the same period when 689,563 cases were confirmed and 1,323 died – a difference of 118,305 cases and 43 deaths. However, the situation has worsened compared to 2017 and 2018 when the number of confirmed cases were 524,148 and 534,781 (with 957 and 922 deaths) respectively.

Algeria faces new malaria cases one year after victory over deadly disease

Algeria Tuesday registered over 1,000 cases of malaria, one year after the World Health Organization (WHO) declared the country malaria-free. The cases, according to the health ministry, are imported cases and have been spotted in five governorates namely Tamanrasset (918), Adrar (96), Illizi (89), Ouargla (5) and Ghardaïa (2).

The ministry noted that every year, in September after first rains, the country often registers imported malaria cases, hailing from Sahel neighboring countries or Algerians who sojourned in those countries. The WHO in May 2019, declared Algeria malaria-free. The certification is awarded to countries after three straight years of zero home-born cases of malaria.

Malaria News Today 2020-09-23/24

Today the issue of water is important for malaria mosquito propagation, both in irrigation and flooding. Artificial skin enables testing of mosquito biting. Fake medicines for malaria and other conditions threaten Africa’s health. Archived RDTs can aid surveillance. Finally there is concern for co-infection with both malaria and dengue leading to severe disease. Follow links below to read details.

Impact of sugarcane irrigation on malaria vector Anopheles mosquito fauna, abundance and seasonality in Arjo-Didessa, Ethiopia

Despite extensive irrigation development in Ethiopia, limited studies assessed the impact of irrigation on malaria vector mosquito composition, abundance and seasonality. This study aimed to evaluate the impact of sugarcane irrigation on species composition, abundance and seasonality of malaria vectors. Adult Anopheles mosquitoes were collected using CDC light traps from three irrigated and three non-irrigated clusters in and around Arjo-Didessa sugarcane irrigation scheme in southwestern Ethiopia.

Overall, 2108 female Anopheles mosquitoes comprising of six species were collected. The ongoing sugarcane irrigation activities in Arjo-Didessa created conditions suitable for malaria transmitting Anopheles species diversity and abundance. This could drive malaria transmission in Arjo-Didessa and its environs in both dry and wet seasons. Currently practiced malaria vector interventions need to be strengthened by including larval source management to reduce vector abundance in the irrigated areas.

Prevalence of and risk factors for severe malaria caused by Plasmodium and dengue virus co-infection

A systematic review and meta-analysis examined co-infection with both Plasmodium and dengue virus (DENV) infectious species could have serious and fatal outcomes if left undiagnosed and without timely treatment. The present study aimed to determine the pooled prevalence estimate of severe malaria among patients with co-infection, the risk of severe diseases due to co-infection, and to describe the complications of severe malaria and severe dengue among patients with co-infection. Relevant studies published between databases between 12 September 1970 and 22 May 2020 were identified and retrieved.

The present study found that there was a high prevalence of severe malaria among patients with Plasmodium and DENV co-infection. Physicians in endemic areas where these two diseases overlap should recognize that patients with this co-infection can develop either severe malaria or severe dengue with bleeding complications, but a greater risk of developing severe dengue than severe malaria was noted in patients with this co-infection.

South Sudan: Flooding deepens a humanitarian crisis in Pibor area

Today, however, the Pibor River has swelled to make parts of the town inaccessible and is threatening the clinic. Many neighborhoods cannot be reached by foot, and a local ferry is too expensive for many who live in the area. A mobile MSF team is providing medical care in hard-to-reach areas. “Our focus is now on malaria, measles and flooding,” said Josh Rosenstein, MSF deputy head of mission. “Today we are reaching out to the community through our daily mobile clinics, treating the most severe illnesses. We’re also implementing our flood contingency plan, which includes building additional flood defenses around the clinic to ensure we can continue to provide medical services, as the water level is rising at an alarming speed.”

Stratifying malaria receptivity in Bangladesh using archived rapid diagnostic tests

Surveillance of low-density infections and of exposure to vectors is crucial to understand where malaria elimination might be feasible, and where the risk of outbreaks is high. Archived rapid diagnostic tests (RDTs), used by national malaria control and elimination programs for clinical diagnosis, present a valuable, yet rarely used resource for in-depth studies on malaria epidemiology. 1022 RDTs from two sub-Districts in Bangladesh (Alikadam and Kamalganj) were screened by qPCR for low-density Plasmodium falciparum and Plasmodium vivax infections, and by ELISA for Anopheles salivary gland antibodies as a marker for exposure to vectors.

Concordance between RDT and qPCR was moderate. qPCR detected 31/1022 infections compared to 36/1022 diagnosed by RDT. Exposure to Anopheles was significantly higher in Kamalganj despite low transmission, which could be explained by low bed net use. Archived RDTs present a valuable source of antibodies for serological studies on exposure to vectors. In contrast, the benefit of screening archived RDTs to obtain a better estimate of clinical case numbers is moderate. Kamalganj could be prone to outbreaks.

New tool mimics human skin to allow detailed study of mosquito biting

eLife: Researchers develop a human skin mimic to study mosquito biting in high resolution without using humans as ‘bait.’ The tool, which uses an artificial blood meal and a surface that mimics human skin, will provide detailed understanding of blood feeding without using human subjects as bait. It can also fit conveniently into a backpack, allowing the study of mosquitoes in laboratory and natural environments.

Blood feeding is essential for mosquitoes to reproduce, but it is during blood feeds on human hosts that they pass on pathogens such as malaria. It consists of a bite ‘substrate’ – a transparent, temperature-controlled surface that mimics body temperature to attract mosquitoes. An artificial meal is applied on top of this and covered with a commonly used membrane that mosquitoes can pierce. The meal resembles blood, allowing mosquitoes to engorge and increase their weight by two to threefold. This bite substrate is then placed in a transparent cage, and an external camera records the mosquitoes’ behaviour. The team tested biteOscope with four medically important species of mosquito.

Counterfeiting of Fake Drugs in Africa: current situation, causes and countermeasures

The more desirable a product is the higher the tendency to replicate it and meet that parcel of consumers that want to join the trend but cannot pay the price. Profit is one of the many reasons that make counterfeit an attractive business for many.  Africa, unfortunately but not surprisingly, is one of the most affected continents, comprehensible since its markets have become a huge target for second generation goods, with a major focus on pharmaceutical drugs.

The World Health Organization (hereinafter, WHO) stated that 42% of all fake medicine reported to them between the years of 2013 and 2017 was linked to the African continent and we expect that these numbers fall short of reality. Africa is seriously affected by it and one clear example is the anti-malarial medication. Anti-malarials and antibiotics are amongst the most commonly reported as fake or substandard medical products.

Malaria News Today 2020-09-15

Malaria Journal released three articles ranging from the relation between malaria and agricultural irrigation, artemisinin resistance on the Myanmar-China border, and efforts at costing malaria elimination interventions. PLoS Medicine examined the quality of malaria clinical management in children. Finally, Frontiers in Cellular and Infection Microbiology reported on a new drug against malaria and toxoplasmosis. Click on links to read more details.

Minimal tillage and intermittent flooding farming systems show a potential reduction in the proliferation of Anopheles mosquito larvae in a rice field in Malanville, Northern Benin

Irrigation systems have been identified as one of the factors promoting malaria disease around agricultural farms in sub-Saharan Africa. However, if improved water management strategy is adopted during rice cultivation, it may help to reduce malaria cases among human population living around rice fields.

A clear reduction of larva density was observed with both intermittent flooding systems applied to minimal tillage (MT?+?IF?+?NL) and intermittent flooding applied to deep tillage (DT?+?IF?+?AL), showing that intermittent flooding could reduce the abundance of malaria vector in rice fields. Recommending intermittent flooding technology for rice cultivation may not only be useful for water management but could also be an intentional strategy to control mosquitoes vector-borne diseases around rice farms.

No evidence of amplified Plasmodium falciparum plasmepsin II gene copy number in an area with artemisinin-resistant malaria along the China–Myanmar border

The emergence and spread of artemisinin resistance in Plasmodium falciparum poses a threat to malaria eradication, including China’s plan to eliminate malaria by 2020. Piperaquine (PPQ) resistance has emerged in Cambodia, compromising an important partner drug that is widely used in China in the form of dihydroartemisinin (DHA)-PPQ. Several mutations in a P. falciparum gene encoding a kelch protein on chromosome 13 (k13) are associated with artemisinin resistance and have arisen spread in the Great Mekong subregion, including the China–Myanmar border. Multiple copies of the plasmepsin II/III (pm2/3) genes, located on chromosome 14, have been shown to be associated with PPQ resistance.

DHA-PPQ for uncomplicated P. falciparum infection still showed efficacy in an area with artemisinin-resistant malaria along the China–Myanmar border. There was no evidence to show PPQ resistance by clinical study and molecular markers survey. Continued monitoring of the parasite population using molecular markers will be important to track emergence and spread of resistance in this region.

Costing malaria interventions from pilots to elimination programmes

Malaria programmes in countries with low transmission levels require evidence to optimize deployment of current and new tools to reach elimination with limited resources. Recent pilots of elimination strategies in Ethiopia, Senegal, and Zambia produced evidence of their epidemiological impacts and costs. There is a need to generalize these findings to different epidemiological and health systems contexts. Drawing on experience of implementing partners, operational documents and costing studies from these pilots, reference scenarios were defined for rapid reporting (RR), reactive case detection (RACD), mass drug administration (MDA), and in-door residual spraying (IRS). These generalized interventions from their trial implementation to one typical of programmatic delivery. In doing so, resource use due to interventions was isolated from research activities and was related to the pilot setting. Costing models developed around this reference implementation, standardized the scope of resources costed, the valuation of resource use, and the setting in which interventions were evaluated. Sensitivity analyses were used to inform generalizability of the estimates and model assumptions.

Populated with local prices and resource use from the pilots, the models yielded an average annual economic cost per capita of $0.18 for RR, $0.75 for RACD, $4.28 for MDA (two rounds), and $1.79 for IRS (one round, 50% households). Intervention design and resource use at service delivery were key drivers of variation in costs of RR, MDA, and RACD. Scale was the most important parameter for IRS. Overall price level was a minor contributor, except for MDA where drugs accounted for 70% of the cost. The analyses showed that at implementation scales comparable to health facility catchment area, systematic correlations between model inputs characterizing implementation and setting produce large gradients in costs. Prospective costing models are powerful tools to explore resource and cost implications of policy alternatives. By formalizing translation of operational data into an estimate of intervention cost, these models provide the methodological infrastructure to strengthen capacity gap for economic evaluation in endemic countries. The value of this approach for decision-making is enhanced when primary cost data collection is designed to enable analysis of the efficiency of operational inputs in relation to features of the trial or the setting, thus facilitating transferability.

Quality of clinical management of children diagnosed with malaria: A cross-sectional assessment in 9 sub-Saharan African countries between 2007–2018

Appropriate clinical management of malaria in children is critical for preventing progression to severe disease and for reducing the continued high burden of malaria mortality. This study aimed to assess the quality of care provided to children under 5 diagnosed with malaria across 9 sub-Saharan African countries. We used data from the Service Provision Assessment (SPA) survey. SPAs are nationally representative facility surveys capturing quality of sick-child care, facility readiness, and provider and patient characteristics across 9 countries, including Uganda (2007), Rwanda (2007), Namibia (2009), Kenya (2010), Malawi (2013), Senegal (2013–2017), Ethiopia (2014), Tanzania (2015), and Democratic Republic of the Congo (2018).

In this study, we found that a majority of children diagnosed with malaria across the 9 surveyed sub-Saharan African countries did not receive recommended care. Clinical management is positively correlated with the stocking of essential commodities and is somewhat improved in more recent years, but important quality gaps remain in the countries studied. Continued reductions in malaria mortality will require a bigger push toward quality improvements in clinical care. Despite increases in the distribution of malaria tests and effective antimalarial medications, significant gaps in the quality of care for pediatric malaria are present in these 9 countries. Further improvements in quality of malaria care may require a better understanding of remaining barriers and facilitators to appropriate management.

Novel drug could be a powerful weapon in the fight against malaria and toxoplasmosis

Princeton researchers are making key contributions toward developing a promising new treatment for the widespread and devastating diseases toxoplasmosis and malaria.
The Princeton scientists specialize in preparing the drug compound into a medicine that is both safe and effective for humans and able to reach its intended sites of action in the body in sufficient doses. An international team of scientists found the new drug—designated JAG21—to be highly effective against parasites in cell-based studies in the lab. After the discovery, team representatives contacted Princeton’s Robert Prud’homme for help in translating the JAG21 compound into a deliverable medication. Prud’homme is a co-author of a study, published in June 2020 in Frontiers in Cellular and Infection Microbiology, that describes the compound and its excellent preliminary results in mice.

The Weekly Tropical Health News 2019-07-13

In the past week more attention was drawn to the apparently never-ending year-long Ebola outbreak in the northeast of the Democratic Republic of the Congo. Regarding other diseases, there is new information on the RTS,S malaria vaccine, river prawns have been found to play a biological control role in schistosomiasis, and an update from the World Health Organization on essential medicines and diagnostics. New malaria vector control technologies are discussed.

Second Largest Ebola Outbreak One Year On

Ronald A. Klain and Daniel Lucey in the Washington Post observed raised concern that, “the disease has since crossed one border (into Uganda) and continues to spread. In the absence of a trajectory toward extinguishing the outbreak, the opposite path — severe escalation — remains possible. The risk of the disease moving into nearby Goma, Congo — a city of 1 million residents with an international airport.”

They added their voices to a growing number of experts who are watching this second biggest Ebola outbreak in history and note that, “As the case count approaches 2,500 with no end in sight, it is time for the WHO to declare the outbreak a public health emergency of international concern — a ‘PHEIC’ — to raise the level of global alarm and signal to nations, particularly the United States, that they must ramp up their response.” They call for three actions: 1) improved security for health workers in the region, 2) stepped up community engagement and 3) extended health care beyond Ebola treatment. The inability to adequately respond to malaria, diarrheal diseases and maternal health not only threated life directly, but also threated community trust, putting health workers’ lives at risk.

Olivia Acland, a freelance journalist based in DRC, reporting for the New Humanitarian describes the insecurity and the recent “wave of militia attacks in the Democratic Republic of Congo’s northeastern Ituri province has left hundreds dead and roughly 300,000 displaced in recent weeks, triggering a new humanitarian crisis in a region.” Specifically, “Ituri, a fertile region rich in gold deposits, has been an epicentre of conflict in Congo for decades. Between 1999 and 2003, around 60,000 people were killed here, as a power struggle between rebel groups escalated into ethnic violence,” related to traditional tensions between Hema cattle herders and Lendu farmers with roots in Belgian colonization.

Updates from the DRC Ministry of Health report on average 11 new Ebola cases per day in the past week. So far over 160,000 people have been vaccinated, and yet the spread continues. The Ministry also describes new protocol contains three vaccinations strategies that can be used depending on the environment in which confirmed cases are found including:

  • Classic Ring: The classic strategy of vaccinating contacts of confirmed cases and contact contacts.
  • Enlarged ring: It is also possible to vaccinate all inhabitants of houses within 5 meters around the outbreak of a confirmed case.
  • Geographical Ring: In an area where team safety can not be guaranteed, they can vaccinate an entire village or neighborhood.

Malaria Vaccines, Essential Drugs and New Vector Control Technologies

Halidou Tinto and colleagues enrolled two age groups of children in a 3-year extension of the RTS,S/AS01 vaccine efficacy trial: 1739 older children (aged 5–7 years) and 1345 younger children (aged 3–5 years). During extension, they reported 66 severe malaria cases. Overall they found that, “severe malaria incidence was low in all groups, with no evidence of rebound in RTS,S/AS01 recipients, despite an increased incidence of clinical malaria in older children who received RTS,S/AS01 compared with the comparator group in Nanoro. No safety signal was identified,” as seen in The Lancet.

WHO has updated the global guidance on medicines and diagnostic tests to address health challenges, prioritize highly effective therapeutics, and improve affordable access. Section 6.5.3 presents antimalarial medicines including curative treatment (14 medicines) for both vivax and falciparum and including tablets and injectables. Prophylaxis includes 6 medicines including those for IPTp and SMC. The latest guidance can be downloaded at WHO.

Paul Krezanoski reports on a new technology to monitor bednet use and tried it out in Ugandan households. As a result. “Remote bednet use monitors can provide novel insights into how bednets are used in practice, helping identify both households at risk of malaria due to poor adherence and also potentially novel targets for improving malaria prevention.

In another novel technological approach to vector control, Humphrey Mazigo and co-researchers tested malaria mosquito control in rice paddy farms using biolarvicide mixed with fertilizer in Tanzanian semi-field experiments. The intervention sections (with biolarvicide) had lowest mean mosquito larvae abundance compared to control block and did not affect the rice production/harvest.

Prawns to the Rescue in Senegal Fighting Schistosomiasis and Poverty

Anne Gulland reported how Christopher M. Hoover et al. discovered how prawns could be the key to fighting poverty and schistosomiasis, a debilitating tropical disease. They found that farming the African river prawn could fight the disease and improve the lives of local people, because the African river prawn is a ‘voracious’ predator of the freshwater snail, which is a carrier of schistosomiasis.

The researchers in Senegal said that, “market analysis in Senegal had shown there was significant interest among restaurant owners and farmers in introducing prawns to the diet.” The prawn could also for the basis of aquaculture in rice paddies and remove the threat of schistosomiasis from the rice workers.

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Agriculture and Promotion of Food Security Can Affect Malaria Transmission

The link between malaria and food security in a global context has been made. The influence of malaria on food security was examined. Now the connection between agriculture practices/food security and malaria is pursued below.

A common complaint with programs that distribute insecticide-treated bednets to prevent malaria is that the nets may be used for other purposes that the intended effort to prevent infected mosquitoes from biting people. All informants interviewed for a study in Western Zambia reported that ITNs are regularly used for fishing and the misuse is widespread. Unsustainable fishing practices, drought and population pressure were mentioned as reasons for fishery decline. The implication was that the use of free ITNs for fishing at least saved the population money in a time of declining fortunes.

A broader review of the ITNs for fishing issue was done through contacting expert witnesses across Africa. Mosquito net fishing (MNF) was found to be a broadly pan-tropical activity, particularly prevalent in sub-Saharan Africa. The authors found that, “Perceived drivers of MNF were closely related to poverty, revealing potentially complex and arguably detrimental livelihood and food security implications.”

The mosquito breeding potential of dams cuts across Africa with the number of dams located in malarious areas projected to increase according to Kibret and colleagues. This is because “The population at risk of malaria around existing dams and associated reservoirs, is estimated to increase from 15 million in 2010 to 21-23 million in the 2020s, 25-26 million in the 2050s and 28-29 million in the 2080s.” In addition, areas with dams but without malaria transmission at present, will likely transition to regions of unstable transmission due to climate change.

Likewise, a study in Ethiopia starts with the assertion that, “Dams are important to ensure food security and promote economic development in sub-Saharan Africa,” and then stresses the importance of understanding the consequences of these projects. The researchers found that “the mean monthly malaria incidence and anopheline larval density was generally higher in the dam villages than in the non-dam villages” in all the three dam settings studied. So while dams can increase agricultural production, the authors concluded that, “the presence of dams intensifies malaria transmission in lowland and midland ecological settings.”

Hydro-agricultural projects include dams and irrigation. Human bait mosquito captures volunteers in hydro-agricultural and river bank sites in Cameroon Akono et al. found that mosquito biting rates were higher in hydro-agricultural sites of less urbanized and urban settings than in natural river banks sites. An additional implication is that urban farming, an important component of food security, may influence mosquito and malaria prevalence.

Stoler and colleagues pursued this question of urban agriculture. The odds of self-reported malaria are significantly higher for women in Accra, Ghana who are living within 1 km of urban agriculture compared with all women living near an irrigation source, the association disappearing beyond this critical distance. Likewise in Kumasi, Afrane et al. learned that “adult and larval mosquito abundance and larval survival were high in the irrigated fields in the irrigated (urban) vegetable farm. This therefore, contributed significantly to adult mosquito populations and hence malaria transmission in the city.”

Even agricultural practices in smaller subsistence farms can foster malaria mosquito breeding. Practices found in southwest Nigeria include collection of pools of water in the farms for soaking cassava tubers, digging of trenches, irrigation of farms, and the presence of fish ponds.

Communities can perceive how agricultural practices may contribute to malaria. In Tanzania a fair number of rural respondents associated growing of rice with malaria. They also noted that the need to sleep on their farms at times meant they could not benefit from the mosquito nets hanging back in their house, some hours walk away. The idea of rice cultivation and malaria was tested in central Kenya. Mwangangi and co-researchers found that, “Rice fields and associated canals were the most productive habitat types,” for malaria mosquito breeding. Overall, Mboera et al. found, “evidence that malaria transmission risk varies even between neighbouring villages and is influenced by agro-ecosystems.”

Although we can establish the two-way link or intersection between malaria and food security, we can see that recommended joint or integrated programming may not always be optimal at various levels from the nation to the community. Greater collaboration between health and agricultural ministries and agencies is needed, supported by national policies that see malaria and food production as part of overall national development goals.

Malaria Affects Agriculture and Food Security

The connections between malaria and food security are recognized in various international health and development frameworks. Below is a look at one side of the equation, how malaria in the household affects food security and agricultural production.

Lewnard and colleagues reported that severe food insecurity was associated with increased risk for positive malaria tests among the Batwa pygmies in Uganda. Also malaria control interventions were associated with decreases in child mortality, accounting for the effect of rainfall and food security in central Tanzania. The authors concluded that achieving targets like the MDGs, “requires the contribution of many health interventions, as well as more general improvements in socio-environmental and nutritional conditions,” i.e. an integrated development approach.

A study in Niger hypothesized that Unconditional Cash Transfers (UCT) would have a positive impact on food security. Two different UTC regimens were tested along with a supplemental food package, but ironically the study found no difference in endline food security between arms. The group felt that the results were possibly driven by increased fever/malaria in children, and thus nonfood related drivers of malnutrition, such as disease, may limit the effectiveness of UCTs.

Tusting and co-researchers recognize that agricultural development interventions reduce poverty. They also documented that relative agricultural success was associated with higher socio-economic position, which in turn, was associated with lower human biting rate of malaria-infected mosquitoes. They conclude that “Further interdisplinary research is needed to understand fully the complex pathways between poverty and malaria and to develop strategies for sustainable malaria control.” One possible pathway would be malaria prevention interventions. A study in Ghana reported that, “Children who slept under a bednet were also more likely than those who did not to live in a food secure household.”

Malaria interventions can also affect agricultural productivity. In a Zambian experiment, access to subsidized bed nets was randomly assigned at the community level, and 516 farmers were followed over a one-year farming period. The researchers found “large positive effects of preventative health investment on productivity: among farmers provided with access to free nets, harvest value increased by US$ 76, corresponding to about 14.7% of the average output value.”

Malaria and other endemic diseases affect agricultural productivity, income, and thus quality of housing

Studying the effects of malaria on employees of an oil palm plantation in Papua New Guinea, Pluess and team found that, “on average, an employee sick with malaria was absent for 1.8 days, resulting in a total of 9,313 workdays lost.” This is an indirect influence on a family’s food security.

farming communities often have access only to small medicine shops in the markets

Seeking malaria care can have untoward effects when fees are attached to health services. Johnson and co-researchers report that, “The qualitative data reveal multi-faceted health and socioeconomic effects of user fees, and illustrate that user fees for health care may impact quality of care, health outcomes, food insecurity, and gender inequality, in addition to impacting health care utilization and household finances.”

Malaria can deprive the household of funds needed for food. It can also reduce the ability of the family to work and produce or buy food. Such economic, social and nutritional impacts need to be taken into account in developing intersectoral malaria policies.

Global Frameworks Link Malaria and Food Security

Forty years ago the Alma Ata Declaration on Primary Health Care became one of the first global frameworks to consider health in the context of development.[i] Specifically the Declaration stated that, “Economic and social development, based on a New International Economic Order, is of basic importance to the fullest attainment of health for all and to the reduction of the gap between the health status of the developing and developed countries.” Within that, 8 essential services were articulated. One was “Promotion of food supply and proper nutrition,” and another emphasized, “Prevention and control of locally endemic diseases.” This set the stage for future efforts that could place malaria control and food security on an integrated platform.

Twenty years later world leaders came together to establish the Millennium Development Goals (MDGs),[ii] an 8-goal framework for tackling the most pressing development challenges. As part of Goal 1, Eradicate extreme poverty and hunger, Target 1.C aimed to halve, between 1990 and 2015, the proportion of people who suffer from hunger, which was thought to be best understood by analysing the different dimensions of food security. One dimension was “Nutritional failures are the consequence not only of insufficient food access but also of poor health conditions and the high incidence of diseases such as diarrhoea, malaria, HIV/AIDS and tuberculosis.” Thus Goal 6, Combat HIV/AIDS, malaria and other diseases,” set Target 6.C to have halted by 2015 and begun to reverse the incidence of malaria and other major diseases.

While recognizing some major successes in the MDGs, the global community again came together to conceptualize a new framework to take off after the MDG process ended in 2015. The new Sustainable Development Goals (SDGs) had 17 components and many sub-goals with the purpose of painting as full a picture of a desired social, economic, environmental, health and political landscape as possible.[iii] Goal 2 focused on ending hunger, achieving food security and improving nutrition, and promoting sustainable agriculture. Unlike Alma Ata and the MDGs, the health goal appears a bit diffuse: Goal 3 was to ensure healthy lives and promote well-being for all at all ages. Among 13 sub-goals was 3.3 that stated by 2030, end the epidemics of AIDS, tuberculosis, malaria and neglected tropical diseases and combat hepatitis, water-borne diseases and other communicable diseases.

A thorough reading of the three mentioned documents/frameworks importantly shows that malaria and food security do not exist in isolation. Their potential interaction and intersection happen in a context of poverty, the environment and climate change.

[i] World Health Organization and UNICEF. Declaration of Alma-Ata, International Conference on Primary Health Care, Alma-Ata, USSR, 6-12 September 1978.

[ii] United Nations. The Millennium Development Goals Report 2014. New York, 2014.

[iii] United Nations. Transforming Our World: The 2030 Agenda for Sustainable Development. A/RES/70/1.

Malarious Occupations

Often the focus of malaria case management and malaria prevention is on children under five years of age and pregnant women. Adults generally can be at higher risk for getting malaria because of their occupations, as was seen in two recent publications.

The Asian Scientist reporting on Bangladesh explained that “Slash-and-burn farmers … are exposed to a higher risk of malaria infection.”  The report notes that not only are woodcutters and jhum (slash-and-burn) cultivators at increased risk of being infected by malaria and but they are also endangering their families.

The researchers at the Centre for Vaccine Sciences and the Centre for Population, Urbanisation and Climate Change of the icddr,b, in collaboration with the Johns Hopkins Malaria Research Institute, Baltimore, reported that “jhum cultivators and people living with them had 1.6 times higher odds of being infected with malaria than non-jhum cultivators.”

The study also appeared in the American Journal of tropical Medicine and Hygiene where the authors observed that “Possible mechanisms cited in the study for the observed higher malaria incidence among jhum cultivators include increased exposure to mosquitoes, sleeping away from home unprotected by bed nets and lack of access to health services.”


Wild cat Gold mining in Burkina Faso also exposes miners to malaria.

Gold mining is another ‘vulnerable occupation, according to a study in Venezuela. Daniel Pardo of BBC News posted photographs that show how mining creates water-filled pits as breeding sites and also the substandard living quarters of the miners where mosquitoes have easy access to victims.

According to the BBC, “Venezuela used to be a world leader in managing malaria, but is now the only country in Latin America where incidence of the disease is increasing. Around 75,000 people were infected last year, and according to government figures, 60% of cases were in Sifontes, a tiny region of the country where gold mining – where workers drill for gold in mosquito-friendly standing water – is booming, and healthcare is scarce. “

These two experiences challenge our ideas of focusing control on only certain groups who are perceived as vulnerable. If we are to eliminate malaria, we need to identify all at risk populations, especially those in rural and hard to reach areas like miners and farmers.

This situation also tells us that much of the occupational risk of malaria is created by humans who overlook health costs in the economic calculations about their work. Clearly we cannot eliminate malaria without collaboration among the health and economic sectors in an effort to promote the overall welfare of populations.

Earth Day, Green Cities, Urban Agriculture and Malaria

According to the UN Food and Agriculture Organization (FAO), about six years ago following a global food crisis, a United Nations high-level task force called for a paradigm shift in urban planning, to one that encourages urban and peri-urban food production. By including urban agriculture in urban land use considerations, planners hoped to achieve benefits ranging from improved food security, economic development to greener environments.

FAO recognizes that there are complex political issues involved in meeting the vision of promoting urban agriculture, including basic access to land, water and other resources, before the benefits can be realized. The issue is further complicated by malaria in some urban environments.

Prathiba De Silva and John Marshall observed that, “Malaria transmission in urban and periurban areas is highly focused around vector breeding sites, which tend to be more numerous in areas of lower socioeconomic status. Control strategies should therefore adopt an element of spatial targeting rather than targeting a wide urban area uniformly. Vector breeding sites are common in areas with slum-like conditions and in areas where urban agriculture is practiced.”

In another study Christophe Antonio-Nkondjio and colleagues concluded that, “The data confirm high selection pressure on mosquitoes originating from urban areas and suggest urban agriculture rather than pollution as the major factor driving resistance to insecticide.” Similarly, Seidahmed et al. observed

— Urban gardens along the banks of the Niger River in Bamako, Mali —

different urban agriculture land use patterns between urban and peri-urban areas as well as differences in insecticide resistance.

These studies suggest that urban planners not only need to consider urban agriculture in land use planning but also need a strong working relationship with public health authorities. Both need to work on pesticide use issues. Green cities can be places that help feed their populations, but they can also be places that a strong focus on local land use can be used to prevent malaria.

Malaria, Farms and Mobility

Whether overnight stays in farming huts poses a risk of malaria infection is a question being asked by researchers in Laos. Daisuke Nonaka and colleagues determined that “staying overnight in farming huts was not associated with an increased risk of malaria infection in the setting where ITNs were widely used in farming huts.”

Net use was greater in the rainy reason than dry in both farm huts (95% vs 66%) and main residences (82% vs 86%), and there were fewer nets on average in huts in the dry (1.1) and rainy seasons (2.3). The average number in main residences decreased from 3.1 in the dry to 2.1 in the rainy seasons.  This implies some movement of both people and nets between residences and seasons.

Another interesting finding was that there was higher prevalence of malaria when 5 or more people shared a net. Though the findings do not specify whether these sharing practices vary by residence or season, one might suspect a bit more crowding in the farm huts, and this should be explored.

village-huts-sm.jpgEnsuring adequate number of ITNs to achieve universal coverage when people have one residence is a big challenge. In fact most procurement estimates are based on population, not residences.  Are there enough nets to cover all sleeping spaces, even if this means extra nets for a family?

Researchers in Tanzania when net supplies were not as large as today found that, “The household’s location at the time of interview (whether at their farm or village homes) was associated with parasitemia, and those residing at their farms were more likely to be parasitemic than those at their village houses, all other things held constant.”

Likewise, we found that mobility between farm and town settlements affected availability and use of cloth filters to prevent guinea worm.  Absence from the farm settlement at the time of ivermectin distribution is an important factor that affects coverage in onchocerciasis prevention efforts.

Unlike bednets, cloth filters for guinea worm can be more easily carried from one residence to another, and ivermectin pills can be kept easily until a mobile villager comes back.  Bednets by themselves pose challenges of hanging in even one residence, but ultimately we need to address the challenge of matching bednet supplies with the fact that rural people can have more than one residence in order to eliminate the disease.