In 1998, the Roll Back Malaria partnership – the largest global platform in history for coordinated action towards reducing the burden of malaria – was created to fund a series of health initiatives and malaria control interventions in affected countries. However, in spite of large successes in reducing both the incidence of and fatalities from the disease, malaria remains a significant cause of morbidity and death globally. In particular, Africa is the world region with the greatest number of cases: in 2016, of the 445,000 deaths from malaria globally, 91% were in Africa.
Luckily, a number of tools and technologies are available to prevent and cure the disease. In particular, sleeping under a treated mosquito net is highly effective in preventing the disease. However, while the private returns of prevention are high, the adoption of antimalarial products and behaviors remains unfortunately too low in endemic areas.
After providing background information on infection with malaria, we present research on the beneficial impact of malaria prevention on a series of outcomes and review the explanations for the low adoption rates of prevention technologies.
Malaria is spread by the bite of Anopheles mosquitoes infected with a protozoan parasite. Children under 5 and pregnant women are very vulnerable to infection, because they have not yet developed immunity against the infection (children under 5) and because they temporarily lose their immunity (pregnant women). Technologies to prevent malaria include insecticide-treated net (ITN) and long-lasting insecticidal net (LLIN) usage and indoor residual spraying (IRS), among others. Treated bed nets prevent mosquito biting while repelling or killing mosquitoes. While older ITNs require periodic insecticide retreatment, newer LLINs remain effective for several years without retreatment. IRS is the process of spraying the interior walls of a dwelling with insecticide.
Beneficial effects of prevention and eradication
A large economics and medical literature finds that malaria prevention and eradication have a significant effect on health and economic outcomes. Malaria prevention and eradication directly decrease mortality and improve health status and anthropometric outcomes. In addition, beyond these direct effects on health, prevention and eradication have a positive effect on education, income, wealth, and employment outcomes. Interestingly, research on the impact of prevention and eradication exploits both historical and recent data from a number of different countries, which implies that these effects are robust.
Barriers to prevention
The main reason behind the low take-up of bed nets lies in household financial constraints and high prices of bed nets. For example, treated bed nets are unaffordable to many households in sub-Saharan Africa. This implies that free distribution of bed nets (or distribution with a high subsidy) is the most promising avenue for increasing take-up. There are also other reasons why free or highly subsidized bed nets are a good strategy. First, bed net usage creates positive externalities by reducing the number of vectors of the disease. Second, there is no evidence that free distribution increases wastage on individuals who do not actually need the nets. Finally, the increased usage from free distribution and highly subsidized prices allows more individuals to learn the benefits of bed nets by using them. For all these reasons, there is a wide agreement among policymakers and researchers that bed nets should be distributed for free or at a highly subsidized price in affected areas.
In addition to financial constraints, lack of information also acts as a barrier to prevention. Information on health products is acquired not only thanks to public information campaigns, but also by using the products themselves (learning-by-doing) and by observing the preventive behavior of others (social learning). This finding implies that enabling learning and raising awareness through informational campaigns can improve preventive behaviors.
Finally, there is a growing interest in using concepts from behavioral economics to explore the role of psychological factors in malaria prevention. In particular, one recent article finds that a financial commitment mechanism (in which individuals in India commit to retreat a bed net in the future) is effective at increasing bed net retreatment. There remain ample opportunities for researchers to test insights of behavioral economics to malaria preventive behavior.
Malaria prevalence remains high in some regions of the world (in sub-Saharan Africa in particular). Since the benefits of prevention are large and significant, and adoption of preventive behavior unfortunately too low, identifying the factors behind malaria preventive behaviors is critically important. The main barrier to malaria prevention is undoubtedly the financial constraint, and the free or highly subsidized distribution of bed nets appears to be an effective pricing strategy. However, the role of information is also significant and some psychological cues could be used to strengthen prevention. While economic research has mainly investigated demand-side factors of malaria prevention, we believe that future research should focus on the supply side. In particular, understanding logistic problems in the delivery of health products (including shortages) is a promising avenue for future research.
Featured image: An Anopheles stephensi mosquito shortly after obtaining blood from a human (the droplet of blood is expelled as a surplus). Public Domain via Wikimedia Commons.