malaria in Kenya

In large tracts of Africa, malaria is one of the most common diseases, and in Kenya, this disease accounts for 1/3 of outpatient consultants and 1/5 of deaths of children under 5. Malaria's worldwide economic cost is estimated at billions of dollars. The scope and the lethality of this disease make it a priority for a variety of international health organizations, such as the World Health Organization (WHO) and the Gates Foundation, including high-profile efforts to develop a vaccine.

Malaria is a caused by transmission of a Plasmodium parasite, which are spread exclusively through Anopheles mosquitoes. There are four parasite species that differ in their lethality, so death rates are variable depending on parasite species and treatment availability. Even if an individual survives, malaria can lead to anemia, which is quite dangerous for pregnant women. Additionally, children who survive severe malaria can have mental disabilities.

Worldwide malaria transmission rates; from DPDx

Water is a critical factor in malaria transmission, because completion of the Plasmodium life cycle requires sufficient rainfall to generate pools of water for Anopheles breeding. The timing of rainfall is particularly important: for example, more Anopheles-friendly water bodies form in an intense short-term storm than if the same amount of rainfall falls over a few days. In addition to insufficient rainfall, temperature is also important: too-high temperatures can hinder Anopheles development, whereas intermediate temperatures can accelerate Anopheles development.

Current malaria risk in Kenya. from DataDredger. 

This dependence of Anopheles on water and temperature means that malaria transmission in Kenya will be substantially affected by climate change. More intense-short term storms could mean more breeding areas for Anopheles mosquitoes, but changing temperatures are also an important variable. Most projections rely on changes in temperature and indicate that malaria cases will shift their distribution with climate change. Projections suggest that malaria incidence will decrease in most of lowland Africa, where temperatures will become too cold, but will increase in highland areas where temperatures will become warm enough to support Anopheles. Such changes have already been observed in Kenya, with malaria moving up into the formerly too-cold highlands of central Kenya.

Less work focuses on the role of changes in precipitation in changing malaria incidence rates. Prior work shows that droughts tend to reduce incidence rates, and high rainfall increases Anopheles population sizes. However, uncertain predictions of changes in rainfall in Kenya make incorporating these predictions quite difficult. Most climate models predict a decrease in rainfall (see the first blog post), suggesting that rates of malaria will decrease, but it seems possible that increased variability in precipitation could change the seasonality of malaria infection.

Eradication of malaria is possible with aggressive prevention tactics. Up until the last century, malaria was common across the world, including Europe and North America, but was successfully eradicated, suggesting the same can be done in African countries such as Kenya. There have already been successes in parts of Africa, with frequency reduced by 50% in 1/3 of countries where malaria is endemic; this reduction is due in part to global health organizations such as the Global Malaria Action Plan, the Roll Back Malaria Partnership, and WHO.

Tactics to reduce incidence of malaria are fairly straightforward, and there is much room for improvement in Kenya. First, prompt diagnosis and treatment is critical; the most lethal strain of malaria is lethal within the first 24 hours. In the Lake Victoria area, 1/2 of parents do not seek treatment when their children under 5 years develop a fever, and only 1 out of 10 children is given a blood test for malaria. Two-thirds of medical facilities do not even have the capacity to diagnose malaria via a blood test. In terms of treating the disease, more than half the mothers in the coast area have not heard anything about the most common antimalarial medicine.

A woman and child underneath a mosquito net; from Healing Hearts. 

In addition to rapid diagnosis and treatment, use of insecticides and mosquito nets is critical to preventing malaria. Spraying residences with insecticides reduces the instance of malaria, but only 1 out of 10 children under 5 years sleeps in an insecticide-treated residence. The use of insecticide-treated bed nets to protect people from nighttime bites also drastically decreases incidence of malaria. However, the proportion of Kenyans owning insecticide-treated nets has stagnated since 2007, and in malaria-endemic areas, there is only 1 net for every 5 Kenyans (the nationally-recommended ratio is 1 to 2).

National efforts to prevent the spread of malaria with climate change have focused on improved prediction of outbreaks as a function of climate data, which is critical in an region of changing incidence rates. Improved prediction will allow healthcare providers to take preventative measures such as distributing nets or spraying for mosquitos, thus increasing the capacity for dealing with outbreaks in susceptible areas. For example, in the highland areas near the Mount Kenya region, where malaria has been rare historically, workers have focused on disseminating mosquito nets to people with little experience of the disease.

Administration of a malaria vaccine; from the Guardian Express. 

One of the most heartening advances in the fight against malaria in Kenya in particular and Africa in general is the recent development of a vaccine, which was tested in seven African countries, and may be ready for approval by WHO by 2015. This vaccine is effective against the most virulent Plasmodium parasite, but is not currently licensed for use as a malaria control tool.

Changes in precipitation and temperature with climate change will shift the distribution of malaria incidence in Kenya, with rates increasing the highland and decreasing in the lowlands. Given the relative unfamiliarity of highland Kenyans with this disease, as well as low rates of preventative measures, it is critical to develop effective preventative and mitigation strategies in these susceptible areas, both at the national and international level.

women and water

Girl collecting water in Kenya;
from The Water Project. 

For many Kenyans, climate change has very real consequences for daily life: many people will have to hours to get drinking water from increasingly scarce water sources. Water sources can be 2-5 km away, with people carrying 5-20 litres of water per trip, and some families using 100 litres of water per day. Water-gathering is so important that it is valued higher than the cost of unskilled labor. However, the majority of water collecting is done by women or girls. Similarly, many traditional gender roles in Kenyan communities mean that changes in precipitation with climate change will disproportionately affect Kenyan women and girls.
walk

In Kenyan communities, many chores traditionally thought of as "women's tasks" are much more connected to natural resource management than are traditional "men's tasks." Traditional women's tasks include domestic chores such as water collection, as well as cooking, cleaning, health- and childcare, and often farming; about half of all farmers in Kenya are female. Conversely, men are more often involved in economic and social pursuits within their community. Because women's tasks involve water availability and sanitation, women will be disproportionately affected by changes in water access resulting from more droughts or rainfall variability under climate change.

Potential impacts of climate change on women in Kenya; from NEMA.

Provision of water resources is generally recognized as a critical way of empowering women, because it frees up women's time and energy, and also improves health, reducing the need for female-provided healthcare. In addition, women walk a long way to get water, and often suffer the threat of violence on their walks away from home. Finally, if water is difficult to get, some girls even skip school to make trips to collect water; in a study in Morocco, girls' school attendance increased when access to water improved.

Kenyan women generally have had less decision-making power than men, including decision-making power concerning water provision, in spite of their disproportionate stake in water resource management. Men have generally controlled both the social and political aspects of decision-making, with women at the grassroots level often barred from decision-making processes. This attitude in part arose because women's domestic labor is not seen as economically-valuable "real work".

Denittah Ghati, a representative in the governmental coalition
designed to decrease gender disparity in water politics,
speaking to rural farmers. From Thomson-Reuters. 

However, due in part to the the increasingly large fraction of small-scale female farmers, as well as increased representation in government bodies, these long-held ideas about gender roles in water provisioning are being challenged at both the grassroots level and at the national scale. For example, a coalition among female representatives in Kenya's government, founded on small-scale community support, has called for an increased awareness of women's role in farming and water provisioning when designing policies. This organization has worked mainly with small farmers in rural areas, striving to empower women by making them more involved in local administrative structures' policy-making.

In a similar vein, the Kenyan government has outlined goals and tactics for decreasing the gender disparity in water politics and climate change in a recent report. This report highlights three main tactics for mitigating the effects of climate change on women: first, adaptation and mitigation strategies should consider the role of gender. Second, women should be actively involved in climate change decision making and planning. Finally, because poverty often accentuates climate change impacts, especially for underprivileged groups, the government should create a fund to support the economic activities of women. While this plan has yet to be implemented on the large scale, it provides a concrete framework for addressing gender disparity issues.

Many traditional gender roles in Kenya mean that changes in water availability and rainfall with climate change will disproportionately affect Kenyan women and girls. There has already been substantial progress made on this front, at both the grassroots and national level. In subsequent posts I will discuss the effects of increased precipitation on another issue that concerns women in their role as healthcare providers, malaria transmission.

Rain-fed agriculture

Variability in the productivity of rain-fed agricultural production will increase substantially with climate change, with important implications for food security. Malnutrition, particularly in children, is a critical concern in Kenya, with high rates of wasting and undernourishment, particularly in rural areas. Effects of climate change will likely increase the frequency and severity of malnutrition, particularly in rural areas, because the vast majority of rural Kenyans obtain their food from rain-fed agriculture. In addition, already-documented increases in prices of staple foods (also grown without irrigation), will likely lead to increased urban malnourishment as well.

A water catchment system in Kenya; from
Kenya Water for Health Organization. 

Small- scale agriculture is an important part of Kenya's economy, as well as an important source of sustenance for the rural poor. Agriculture comprises 26% of Kenya's GDP and 75% of the country's employment, primarily on small-scale farms. About 75% of total agricultural output is produced on 0.2-0.3 hectare farms. Such farms produce both marketable produce, as well as comprise the most important source of staple food production for the rural poor. Projections suggest that such small-scale farms will remain the most important source of food for most poor rural Kenyans, and thus should remain a critical component of any development plan.

These farms are primarily rain-fed, which increases Kenya's vulnerability to increased precipitation variability under climate change. Irrigated agriculture comprises only 1.7% of total agricultural land under production. This reliance on rain-fed, rather than irrigated, agriculture means Kenya is highly vulnerable to changes in precipitation patterns. Irrigated agriculture is, at least in the short-term, less volatile with respect to changing precipitation patterns than is rain-fed agriculture. Recognizing this risk, a recent report recommends an increase in irrigated agriculture from140,000 hectares to 1 million hectares to increase economic and food security in this region. The Kenyan government has invested a substantial amount of money into this operation, recently developing an initiative to bring 1 million hectares under irrigation over 5 years. Greenhouse farming, another form of irrigated agriculture, has also gained traction in recent years.

Women working in a Kenyan greenhouse; from Thomson Reuters. 

In spite of these steps towards irrigation, the potential for irrigated agriculture is limited, both logisticadlly and politically. Logistically, this increase in irrigation is close to the limit of the water resources available to Kenya. While the country has an estimated irrigation potential of ~1.3 million hectares, only about 30% of this water production is possible with available water resources; the remainder will require water harvesting and storage. Water harvesting in Kenya is currently fairly uncommon, but is becoming more widespread in rural communitites through grassroots rural initiatives. In spite of these successes, governmental support of water harvesting is critical to the success of this technique for expanding irrigated agriculture. While Kenyan policies have historically not been supportive of water harvesting for agriculture, as-yet-unimplemented new policies are paving the way for large-scale water harvesting.

Projections of rainfed maize yield with climate change; from Odera et al. 2013.

While Kenya's expansion into irrigated agriculture is critical for mitigating increased variability under climate change, there are some positive outcomes of changes in precipitation patterns with climate change. All of the leading climate models suggest that rainfall patterns over some arid- and semi-arid regions in northern Kenya will become more suitable for growing maize, Kenya's staple crop. Increases in productivity in these regions could help mitigate some of the productivity lost in other regions, but these effects are complicated by historical land-use patterns. Efforts to encourage maize cultivation in these areas have not yet begun, but must consider land tenure and migration issues.

The reliance on rainfed agriculture makes Kenya highly vulnerable to the impacts of increased variability with climate change; increased variability in rainfed agricultural production under climate change may lead to increases in malnutrition issues in both rural and urban areas.