Category Archives: Agriculture

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. http://www.who.int/publications/almaata_declaration_en.pdf

[ii] United Nations. The Millennium Development Goals Report 2014. New York, 2014. http://www.un.org/en/development/desa/publications/mdg-report-2014.html

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

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.”

DSCN3692a

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.

Laboring under the burden of malaria

Today is Labor Day in the United States. This holiday was first celebrated in 1882 with a parade in New York. Many countries observe a similar holiday on May 1st.  Regardless of the date, we should always consider the impact of malaria on the labor force of endemic countries and the subsequent economic impact of the disease.

dscn9118sm.JPGFor example, in Vietnam, Morel and colleagues conclude that, “Whilst government provision of malaria treatment keeps the direct costs relatively low, the overall loss in income due to illness can still be significant given the poverty amongst this population, especially when multiple cases of malaria occur annually within the same household.” The article goes on to document the cost in terms of loss of household productive workdays.

In India, Kumar and colleagues documented that, “The maximum DALYs lost (53.25%) were in the middle productive ages from 15 to 44 years of age, followed by children < 14 years of age (27.68%), and 19% in those > 45 years of age.” They continue by describing efforts to calculate the economic burden of the disease over the past 75 years.

A study of Ethiopian farmers who reported a malaria-like illness “stayed in bed for a mean duration of 7.8 days. Suspected, in this rural population, is a cycle of malnutrition, disease, and activity restriction that begins in childhood. Needed are interventions that reduce the prevalence of childhood stunting and health services that provide adequate prevention and treatment of diseases such as malaria.”

There is hope for workers. O’Meara et al. report, “substantial, lasting declines linked to scale-up of specific interventions,” in southern African countries. Countries in the Horn of Africa have also, “experienced substantial decreases in the burden of malaria linked to the introduction of malaria control measures.” In other countries the switch to ACTs after chloroquine began to fail, “led to immediate improvements; in others malaria reduction seemed to be associated with the scale-up of insecticide-treated bednets and indoor residual spraying.”

Will elimination of malaria lift endemic countries out of poverty? To find out, we need to achieve universal coverage and maintain a high level of intervention.

(see updated Ghana Advocacy News)

Deforestation, Agriculture and Malaria

While there have been some doubts that climate change will cause more malaria, there is little doubt expressed that deforestation is one of the major contributors to the malaria problem.  Actually a link is found between deforestation and malaria.

Yasuoka and Levins looked at anophelene ecology changes in relation to deforestation. They learned that, “Although niche width of anopheline species was not associated with density changes, sun preference was significantly associated with an increase in density. This study suggests the possibility of predicting potential impacts of future deforestation on vector density by using information on types of planned agricultural development and the ecology of local anopheline species.”

dscn4558sm.JPGTheir review of reports from across the malaria-endemic parts of the would found that although the mechanisms that link malaria and deforestation are complex, there were clearly examples of direct effects on some anopheline species either because of habitat changes or because of land use changes, particularly agriculture.

Vittor and colleagues have recently examined deforestation and malaria in the Peruvian Amazon.  Their study concluded that, “Multivariate analysis identified seasonality, algae, water body size, presence of human populations, and the amount of forest and secondary growth as significant determinants of A. darlingi presence. We conclude that deforestation and associated ecologic alterations are conducive to A. darlingi larval presence, and thereby increase malaria risk.”

Ultimately the elimination of malaria will require our links with broader development and environment partners.

Artemisinin – production, resistance, change

The fate of artemisinin in malaria control may be affected from the plant source to the parasites in humans according to two recent web postings.  Some challenges may result from people willing to change quickly, while others may be slow to react.

Sociolingo Africa has provided an update on artemisinin production in Uganda.  The situation of decreasing prices amid increasing demand was seen as puzzling.  The farmers who had begun cash crop production of artemisinin were now seeing ‘leaves rotting in the fields’ and were being encouraged to grow “Davana; Chillies; Fennel; Jasmine Rose; Ginger; Vettiver; Basil; and many more others, most of which are used in the production of essential oils and perfumes” by the Indian companies that were in fact guiding the Ugandan production of artemisinin.

It is possible, considering any commodity market, that diversification is a wise move on the part of the company.  Clearly there are efforts afoot (e.g. AMFm, Clinton Foundation) to reduce to cost that consumers pay in order to make the artemisinin-based combination therapy (ACT) drugs available thus, creating possibly more downward pressure on pricing.

In the early days of ACT promotion prices of the drug were said to be high because of the uncertainties in the procurement processes of endemic countries.  International mechanisms by organizations such as the Global Fund and WHO to coordinate this process while also increasing the supply to reach coverage targets also mean that production could confidently increase while prices of the final product could reduce.

So back to Uganda – there is likely now greater competition among producers of artemisinin in many countries – including the Ugandan farmers – in line with increasing demand projections. These farmers changed in reponse to the companies’ projections. At least in this case if substitute crops are provided, they may not suffer too much, but the fate of such farmers in other endemic countries such as Kenya where artemisinin farming has been introduced may not be so clear.

On the other side of the continent there are worries about parasite resistance to artemisinin.  In Nigeria ASNS News notes that, “Dr. Paul Orhi, Director General of NAFDAC (National Agency for Food and Drug Administration and Control), is quoted in the local press that the main reason for (growing emergence of resistance) was because people were not taking proper doses and that they still use monotherapy instead of combining two drugs appropriately.”

While it may take time for the resistance to spread from Southeast Asia where it has recently been documented, the Nigerian concern is real.  The irony is that there does not need to be worry about monotherapy if NAFDAC were to be bold and withdraw the registration of the numerous artesunate monotherapies currently on the market in Nigeria.

The current policy of NAFDAC is to allow those monotherapy drugs already registered to stay on the market until their registrations expire – some as late as 2012.  If NAFDAC were bold enough to change now and withdraw those registrations, its Director General would have less to worry about.  Proper training of health and pharmacy workers in both public, private and commercial sectors to counsel those receiving ACTs on the proper regimen would also reduce his worry about improper dosing.

Timely and appropriate change is needed to protect and increase the malaria drug supplies we have now, while research continues to find new medicines as the need will most certainly arise.

Growing pains – Artemesia annua

This morning the Daily Monitor of Uganda reported that, “At least 30,000 farmers in the districts of Kabale, Kisoro and Ntungamo who are growers of a medicinal plant that is a raw material for anti-malaria drugs are angry that the company that urged them to grow the plant has closed shop leaving them counting losses.” The artemisinin extracted from these leaves is the base for the current recommended first-line treatment of malaria – artemisinin-based combination therapy (ACTs).

tdr9300523.jpgIt certainly seemed like a good idea in theory to grow A. annua in endemic countries and involve local farmers and the pharmaceutical industry in ACT production and at the same time promote economic development. But as the Daily Monitor shows, this can be a complicated process.  The leaves need to be harvested at just the right time to get the maximum concentration of the antimalarial drug.  The company complained to the Monitor that they were disappointed with their farmers who adulterated the quality:“Most of our farmers harvested Artemisia leaves before they matured. This lowered the artemisinin content.”

IRIN News explained that “In Kenya, the project is being spearheaded by East African Botanicals, which provides seedlings and supports both large- and small-scale farmers in a bid to rapidly increase the volume of plants.” The company spokesperson described their operations thus –

“By the end of 2005, we will have an estimated 1,200 hectares of the crop growing in Kenya,” explained a representative from the company. “We are also growing in Tanzania and Uganda, but still we cannot meet the demand. I am not able to overstate the shortage of this raw material worldwide. What we are growing is definitely making an impact on the shortage but not on the scale needed at the moment. “Everything we are doing is towards a very rapid scale-up of production: contracting more large- and small-scale farmers; planting more hectares; and finding ways to harvest the crop much faster,” he said.

IRIN also reports on efforts in Indonesia to grow A. annua. A government spokeswoman said, “farmers in Tawangmangu, where the soil was suitable for artemisia annua, traditionally grew vegetables and needed assurances that switching to the herb would bring them more benefit.  She expected Indonesia would be able to produce its own Artemisinin by 2010.” One hopes that these farmers will not be left without food crops or artemisinin profits like their Ugandan counterparts.

To make local production of Artemesia annua work there needs to be planning and coordination among government agencies, farmers, and the pharmaceutical industry. Botanical Extracts EPZ Limited in Kenya does claim to be making a profit from locally grown artemisinin, and so it should be possible for all partners to come together for success. The role of agriculture extension in educating farmers and helping them develop a safety net when A. annua crops fail is essential.

Finally, as we have stressed before, we hope that the eventual production of artemisinin synthetically or through biological processes will not render these farmers’ efforts useless.