World Malaria Day: Five Challenges in the Fight Against the Disease
The number of cases and deaths related to malaria has been declining steadily for 15 years. That is great news. But, before we celebrate too much, we have to remember that the World Health Organization has shown that the disease continues to kill more than 400,000 people each year. Ninety percent of the deaths occur in Africa. Seventy percent are children.
What does that mean? For one thing, it means that we — all of us working on malaria, leaders the world over, and drug researchers and developers — still have to improve prevention, diagnosis and treatment efforts. We have to find ways to limit the spread of the infecting parasite. And we have to address many other challenges that the disease poses.
Doctors Without Borders/Médecins Sans Frontières (MSF) treated around 2.35 million malaria cases around the world in 2015. Today, on World Malaria Day, we’re calling on the international community and global health bodies to show that they’re ready to take up the challenge by combining multiple strategies and recognizing that it’s no one thing, but rather a combination of factors, that helps malaria stay deadly and destructive. These include:
1. The Impact of Climate Change
In 2012, 2014, and 2015, MSF teams observed big malaria spikes in several sub-Saharan African countries, including Democratic Republic of Congo (DRC), Central African Republic (CAR), Uganda, and Mali. In Yida, South Sudan, for example, MSF treated three times as many malaria cases at our clinics last year than we had the year before (7,500 in 2014 to approximately 20,000 in 2015).
The reasons for this increase are complex, but climate change looks like a big one. El Niño, for instance, a climate event responsible for rising temperatures and increased rainfall, seems to play a major role — not only in places that knew malaria all too well before, but also in regions that previously had been spared the worst of it.
2. Resistance to Insecticides
Vector control efforts are a key component of malaria control strategies. They seek to reduce human exposure to mosquitos by, for example, providing people with insecticide-treated mosquito nets or spraying insecticide in and around homes to eliminate mosquito larvae.
The WHO says that more than half of Africa’s population had access to a mosquito net in 2014, compared to 2 percent in 2000. However, mosquitos have shown an increasing resistance to pyrethroids, the main insecticides used to treat the nets. Documentation remains limited, but several countries where MSF works have reported that the insecticides aren’t working as well as they used to. Nonetheless, these same nets, with the same insecticide, are still being employed in several countries where the disease is rife.
3. Finding Effective — and Lasting — Prevention Strategies
In 2012, MSF teams in Mali and Chad staged one of the first large-scale seasonal malaria chemoprevention campaigns (SMC), which means they provided pre-emptive malaria treatment to children in places where the disease was seasonally endemic. Since then, MSF has incorporated the strategy into the national policies of 13 countries in the Sahel. More than 15 million children should be covered in 2016.
SMC means distributing anti-malaria treatments on a preventative basis during the high transmission months — the predictable seasonal “spikes”. It has shown very promising results, including up to 80 percent fewer cases of simple malaria and up to 70 percent fewer severe cases in places it was implemented. In addition, by combining SMC with other medical activities such as malnutrition care and vaccinations, our teams can help parents address several causes of infant mortality at the same time.
This strategy is not intended to become a permanent tool to combat the disease, however. The impact of these distributions remains of limited duration and ceases several weeks after they end. So it is worth doing for the time being to save lives, but we still need more comprehensive, longer-lasting solutions.
4. Parasitic Resistance to Anti-Malarials
Since 2001, the WHO has recommended using artemisinin-based combination therapies (ACT, which uses a drug from Chinese traditional medicine) to treat malaria. ACTs replace earlier drugs, such as chloroquine and sulphadoxine-pyrimethamine, which have become ineffective because the plasmodium parasite, which causes malaria, has become increasingly resistant to them.
The use of these new treatments contributed significantly to the remarkable reduction in the number of malaria-related deaths in the last 15 years. However, resistance to artemisinin has been documented in some regions (Southeast Asia and Latin America, in particular). This was enabled at least in part by the use of monotherapies (artemisinin alone, not in combination with other drugs), counterfeit and poor-quality drugs, and treatment interruptions once symptoms have abated. It could get worse and become a greater threat to public health, too, because there won’t be any replacements for artemisinin treatment available for several years.
5. The Search for an Effective Vaccine
After decades of fruitless research, RTS,S (Mosquirix©) is the first malaria vaccine to have completed clinical development. However, its efficacy is limited, particularly against the severe forms of the disease, and it is complicated to use. It requires four doses, two of which have to be separated by 18 months.
In October 2015, WHO’s Strategic Advisory Group of Experts on Immunization (SAGE) recommended small-scale pilot projects involving this vaccine to study its conditions of use. MSF hasn’t wanted to participate in this research because it seems like it would be too difficult to introduce the vaccine in poor countries, particularly given the low level of protection anticipated and the limited information available regarding its safety.
MSF continues to call for ongoing research to develop a safe, efficacious, inexpensive vaccine that is easy to use in developing countries. This is a call that needs to be answered by pharmaceutical companies, research bodies, and national and international health bodies alike if we want the keep up the momentum in the fight against malaria.