World Malaria Day 2016

Over the past few years, the momentum of research and efforts on malaria has tremendously decreased malaria transmission and the number of deaths from this disease. However, in many poor tropical and subtropical countries of the world, malaria continues to be one of the leading causes of illness and death. To avoid a decline in the efforts to prevent and treat this disease, World Malaria Day on 25 April is focusing to “End Malaria for Good.” We recently spoke to Johanna Daily, MD, MS, an Associate Editor of the journal Open Forum Infectious Diseases, who answered some important questions including why malaria remains such a difficult public health challenge and if malaria can ever truly be eradicated.

You previously described the state of the fight against malaria for OUPblog readers in 2013. What major advances have there been in the prevention, diagnosis, and treatment of the disease since then?

Let’s recap the progress over the last major period of evaluation, 2001-2015: we saw 1.2 billion fewer malaria cases and 6.2 million fewer deaths globally in this period than would have occurred had rates stayed at the 2000 level. This remarkable reduction resulted from aggressive vector control, bed net distribution, effective treatment, and prevention with antimalarial agents.

Going forward, new priorities have been established. There’s a concerted effort to eliminate the transmissible form of malaria, the gametocyte, which silently circulates in humans, awaiting a mosquito bite that could perpetuate transmission. Adding a single dose of primaquine to artemisinin combination therapy to treat malaria will clear the gametocyte, a strategy that is now recommended.

There is renewed interest in the use of mass drug administration, which is treatment of the entire population in a geographic area with a curative dose of an antimalarial drug without first testing for infection. This would reduce the number of human carriers and in combination with vector control could further reduce transmission.

Why does malaria, which is preventable and curable, remain such a difficult public health challenge to address today? 

Combating malaria, like any other public health scourge, needs resources. Malaria is generally endemic in poor regions, and these communities often cannot access the tools to prevent and treat this infection. For example, antimalarial stock outages in health clinics are not uncommon in endemic regions. A critical problem is how to provide and sustain funding to allow each country to have robust malaria control programs.

There are “hotspots” of malaria transmission – 80% of malaria deaths are concentrated in just 15 countries. These regions often have ecological conditions favoring large populations of the mosquitos vector combined with a high percentage of the human population infected (either clinically ill, or as silent reservoirs). Reducing transmission in these regions will require multipronged, highly organized efforts. Often these countries are handicapped by low gross national incomes and weak health systems, both of which impede effective malaria control, treatment, and eradication programs.

Another looming problem is the emergence of artemisinin resistance in regions of South East Asia. Artemisinin is now the cornerstone drug for malaria combination therapy, and high levels of resistance would be disastrous. While there are new antimalarial compounds under development, they will require clinical trials evaluating efficacy and toxicity. Such trials are time consuming and expensive. Importantly, simple methods to track artemisinin resistance using molecular techniques are available, so we can follow this worrisome trend.

What should the public and policymakers take away from these developments?

The WHO has laid out a plan that addresses many of these issues, providing a strategy toward control and elimination. They set out an ambitious target of reducing global malaria burden by 90% in 2030.

Key principles include a by country tailored approach, enhanced in-country leadership with engagement of communities, improved monitoring and evaluation, health care equity and further innovations to achieve these goals.

What are the most promising areas of current research? 

Vaccine development remains a very active area of research. The RTS,S/AS01 vaccine demonstrated 56% efficacy (5-17 months), and 30% efficacy (6-12 weeks) against clinical malaria; it is now undergoing regulatory review. There are additional vaccines under development to provide higher efficacy, including a whole sporozoite vaccine, which is currently in clinical trials.

The theme for this year’s World Malaria Day is “end malaria for good.” In January, US President Barack Obama made a similar pledge in his State of the Union speech to lawmakers. How realistic is the goal of malaria eradication?

I am grateful that both President Bush and President Obama had global elimination of malaria on their radar screens and have supported efforts toward this end. As for how realistic this goal is, remember these key facts: it has widespread support from people all over the world, we have the technology and tools to achieve this end, and the data already show some success – an increasing number of countries are in pre-elimination status or have eliminated malaria completely. For example, the WHO European Region reported zero indigenous cases for the first time last year. In 2014, 16 additional countries reported zero indigenous cases.

We cannot lessen our commitment to fighting this parasite, which has evolved to be a powerful and formidable foe. The success stories I cited above should energize funders, public health workers, and all those involved to maintain a steady and committed focus to continue their work toward “the end of malaria for good.”

Featured Image Credit: Image provided by World Malaria Day. Used with permission.