Malaria

Key points: World malaria report 2017

29 November 2017

The World malaria report 2017 presents a comprehensive state of play in global progress in the fight against malaria up to the end of 2016. It tracks progress in investments in malaria programmes and research, malaria prevention, diagnosis and treatment, surveillance, trends in malaria disease burden, malaria elimination, and threats in tackling malaria and safeguarding the investments made.

Investments in malaria programmes and research

Malaria control and elimination investments

In 2016, an estimated US$ 2.7 billion was invested in malaria control and elimination efforts globally by governments of malaria endemic countries and international partners.

The majority (74%) of investments in 2016 were spent in the WHO African Region, followed by the WHO regions of South-East Asia (7%), the Eastern Mediterranean and the Americas (each 6%), and the Western Pacific (4%).

Governments of endemic countries contributed 31% of total funding (US$ 800 million) in 2016.

The United States of America (USA) was the largest international source of malaria financing in 2016, providing US$ 1 billion (38%), followed by the United Kingdom of Great Britain and Northern Ireland (United Kingdom) and other international donors, including France, Germany and Japan.

More than half (57%) of resources in 2016 were channelled through the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund).

Investment outlook

Although funding for malaria has remained relatively stable since 2010, the level of investment in 2016 is far from what is required to reach the first milestone of the GTS, which is a reduction of at least 40% in malaria case incidence and mortality rates globally when compared to 2015 levels.

To reach this milestone, the GTS estimated that annual funding would need to increase to US$ 6.5 billion per year by 2020. The US$ 2.7 billion invested in malaria in 2016 represents less than half (41%) of that amount.

Stepping up investments in malaria research and development is key to achieving the GTS targets. In 2015, US$ 572 million was spent in this area, representing 83% of the estimated annual need for research and development.

Deliveries of malaria commodities

Insecticide-treated mosquito nets

Between 2014 and 2016, a total of 582 million insecticide-treated mosquito nets (ITNs) were reported by manufacturers as having been delivered globally.

Of this amount, 505 million ITNs were delivered in sub-Saharan Africa, compared with 301 million bednets in the preceding 3-year period (2011–2013).

Data from national malaria control programmes (NMCPs) in Africa indicate that, between 2014 and 2016, 75% of ITNs were distributed through mass distribution campaigns.

Rapid diagnostic tests

An estimated 312 million rapid diagnostic tests (RDTs) were delivered globally in 2016. Of these, 269 million were delivered in the WHO African Region.

The number of RDTs distributed by NMCPs increased between 2010 and 2015, but fell from 247 million in 2015 to 221 million in 2016. The decrease was entirely in sub-Saharan Africa, where distributions dropped from 219 million to 177 million RDTs over the 2015–2016 period.

Artemisinin-based combination therapy

An estimated 409 million treatment courses of artemisinin-based combination therapy (ACT) were procured by countries in 2016, an increase from 311 million in 2015. Over 69% of these procurements were reported to have been made for the public sector.

The number of ACT treatments distributed by NMCPs to the public sector increased from 192 million in 2013 to 198 million in 2016. Most of the NMCP distributions of ACTs (99%) in 2016 occurred in the WHO African Region.

Preventing malaria

Vector control

Across sub-Saharan Africa, household ownership of at least one ITN increased from 50% in 2010 to 80% in 2016. However, the proportion of households with sufficient nets (i.e. one net for every two people) remains inadequate, at 43% in 2016.

More people at risk of malaria in Africa are sleeping under an ITN. In 2016, 54% of the population was protected by this intervention, an increase from 30% in 2010.

Fewer people at risk of malaria are being protected by indoor residual spraying (IRS), a prevention method that involves spraying the inside walls of dwellings with insecticides. Globally, IRS protection declined from a peak of 5.8% in 2010 to 2.9% in 2016, with decreases seen across all WHO regions. In the WHO African Region, coverage dropped from 80 million people at risk in 2010 to 45 million in 2016.

The declines in IRS coverage are occurring as countries change or rotate insecticides to more expensive chemicals.

Preventive therapies

To protect women in areas of moderate and high malaria transmission in Africa, WHO recommends “intermittent preventive treatment in pregnancy” (IPTp) with the antimalarial drug sulfadoxinepyrimethamine. Among 23 African countries that reported on IPTp coverage levels in 2016, an estimated 19% of eligible pregnant women received the recommended 3 or more doses of IPTp, compared with 18% in 2015 and 13% in 2014.

In 2016, 15 million children in 12 countries in Africa’s Sahel subregion were protected through seasonal malaria chemoprevention (SMC) programmes. However, about 13 million children who could have benefited from this intervention were not covered, mainly due to a lack of funding. Since 2012, SMC has been recommended by WHO for children aged 3-59 months living in areas of highly seasonal malaria transmission in this subregion.

Diagnostic testing and treatment

Accessing care

Prompt diagnosis and treatment is the most effective means of preventing a mild case of malaria from developing into severe disease and death. Among national-level surveys completed in 18 countries in sub-Saharan Africa between 2014 and 2016 (representing 61% of the population at risk), a median of 47% (interquartile range [IQR]: 38–56%) of children with a fever (febrile) were taken to a trained medical provider for care. This includes public sector hospitals and clinics, formal private sector facilities and community health workers.

More febrile children sought care in the public sector (median: 34%, IQR: 28–44%) than in the private sector (median: 22%, IQR: 14–34%). However, the surveys from Africa also indicate that a high proportion of febrile children did not receive medical attention (median: 39%, IQR: 29–44%). Possible reasons include poor access to health-care providers or lack of awareness among caregivers.

Diagnosing malaria

Among 17 national-level surveys completed in sub-Saharan Africa between 2014 and 2016, the proportion of children with a fever who received a finger or a heel stick – suggesting that a malaria diagnostic test may have been performed – was greater in the public sector (median: 52%, IQR: 34–59%) than in both the formal and informal private sector.

Testing of suspected cases in the public health system increased in most WHO regions since 2010. The WHO African Region recorded the biggest rise, with diagnostic testing in the public health sector increasing from 36% of suspected cases in 2010 to 87% in 2016.

Treating malaria

Among 18 household surveys conducted in sub-Saharan Africa between 2014 and 2016, the proportion of children aged under 5 years with a fever who received any antimalarial drug was 41% (IQR: 21–49%).

A majority of patients (70%) who sought treatment for malaria in the public health sector received ACTs, the most effective antimalarial drugs. Children are more likely to be given ACTs if medical care is sought at public health facilities than in the private sector.

To bridge the treatment gap among children, WHO recommends the uptake of integrated community case management (iCCM). This approach promotes integrated management of common life-threatening conditions in children – malaria, pneumonia and diarrhoea – at health facility and community levels. In 2016, 26 malaria-affected countries had iCCM policies in place, of which 24 had started implementing those policies. An evaluation from Uganda found that districts with iCCM experienced a 21% increase in care-seeking for fever compared with districts without an iCCM policy in place.

Outside the WHO African Region, only a handful of countries in each of the other regions reported having such policies in place, though data on the level of implementation are unavailable for most countries.

Malaria surveillance systems

Effective surveillance of malaria cases and deaths is essential for identifying the areas or population groups that are most affected by malaria, and for targeting resources for maximum impact. A strong surveillance system requires high levels of access to care and case detection, and complete reporting by all health sectors, whether public or private.

In 2016, 37 out of 46 countries in the WHO African Region indicated that at least 80% of public health facilities had reported data on malaria through their national health information system. Rates vary within other WHO regions. For example, in the WHO Eastern Mediterranean Region, only 3 out of 8 countries had 80% or more public health facilities reporting in 2016.

Among 55 countries where the burden of malaria was estimated, 31 countries have a malaria case reporting rate by surveillance systems of less than 50%. This includes the high-burden countries of India and Nigeria.

Global and regional malaria trends in numbers

Malaria cases

In 2016, an estimated 216 million cases of malaria occurred worldwide (95% confidence interval [CI]: 196–263 million), compared with 237 million cases in 2010 (95% CI: 218–278 million) and 211 million cases in 2015 (95% CI: 192–257 million).

Most malaria cases in 2016 were in the WHO African Region (90%), followed by the WHO South-East Asia Region (3%) and the WHO Eastern Mediterranean Region (2%).

Of the 91 countries reporting indigenous malaria cases in 2016, 15 countries – all in sub-Saharan Africa, except India – carried 80% of the global malaria burden.

The incidence rate of malaria is estimated to have decreased by 18% globally, from 76 to 63 cases per 1000 population at risk, between 2010 and 2016. The WHO South-East Asia Region recorded the largest decline (48%) followed by the WHO Region of the Americas (22%) and the WHO African Region (20%).

Despite these reductions, between 2014 and 2016, substantial increases in case incidence occurred in the WHO Region of the Americas, and marginally in the WHO South-East Asia, Western Pacific and African regions.

Plasmodium falciparum is the most prevalent malaria parasite in sub-Saharan Africa, accounting for 99% of estimated malaria cases in 2016. Outside of Africa, P. vivax is the predominant parasite in the WHO Region of the Americas, representing 64% of malaria cases, and is above 30% in the WHO South- East Asia and 40% in the Eastern Mediterranean regions.

New data from improved surveillance systems in several countries in the WHO African Region indicate that the number of malaria cases presented in this year’s report are conservative estimates. WHO will review its malaria burden estimation methods for sub-Saharan Africa in 2018.

Malaria deaths

In 2016, there were an estimated 445 000 deaths from malaria globally, compared to 446 000 estimated deaths in 2015.

The WHO African Region accounted for 91% of all malaria deaths in 2016, followed by the WHO South- East Asia Region (6%).

Fifteen countries accounted for 80% of global malaria deaths in 2016; all of these countries are in sub-Saharan Africa, except for India.

All regions recorded reductions in mortality in 2016 when compared with 2010, with the exception of the WHO Eastern Mediterranean Region, where mortality rates remained virtually unchanged in the period. The largest decline occurred in the WHO regions of South-East Asia (44%), Africa (37%) and the Americas (27%).

However, between 2015 and 2016, mortality rates stalled in the WHO regions of South-East Asia, the Western Pacific and Africa, and increased in the Eastern Mediterranean and the Americas.

Malaria elimination

Globally, more countries are moving towards elimination: in 2016, 44 countries reported fewer than 10 000 malaria cases, up from 37 countries in 2010.

Kyrgyzstan and Sri Lanka were certified by WHO as malaria free in 2016.

In 2016, WHO identified 21 countries with the potential to eliminate malaria by the year 2020. WHO is working with the governments in these countries – known as “E-2020 countries” – to support their elimination acceleration goals.

Although some of E-2020 countries remain on track to achieve their elimination goals, 11 have reported increases in indigenous malaria cases since 2015, and 5 countries reported an increase of more than 100 cases in 2016 compared with 2015.

Challenges to achieving a malaria-free world

Some of the challenges impeding countries’ abilities to stay on track and advance towards elimination include lack of sustainable and predictable international and domestic funding, risks posed by conflict in malaria endemic zones, anomalous climate patterns, the emergence of parasite resistance to antimalarial medicines and mosquito resistance to insecticides.

WHO is supporting malaria emergency responses in Nigeria, South Sudan, Venezuela (Bolivarian Republic of) and Yemen, where ongoing humanitarian crises pose serious health risks. In Nigeria’s Borno State, WHO supported the launch of a mass antimalarial drug administration campaign that reached an estimated 1.2 million children aged under 5 years in targeted areas. Early results point to a reduction in malaria cases and deaths in this state.

Funding

In 34 out of 41 high-burden countries, which rely mainly on external funding for malaria programmes, the average level of funding available per person at risk in the past 3 years (2014–2016) reduced when compared with 2011–2013. Exceptions were Democratic Republic of the Congo, Guinea, Mauritania, Mozambique, Niger, Pakistan and Senegal, which recorded increases.

Among the 41 high-burden countries, overall, funding per person at risk of malaria remains below US$ 2.

Histidine-rich protein 2 deletions

In some settings, increasing levels of histidine-rich protein 2 gene (HRP2) deletions threaten the ability to diagnose and appropriately treat people infected with falciparum malaria. An absence of the HRP2 gene enables parasites to evade detection by HRP2-based RDTs, resulting in a false-negative test result. Although the prevalence of HRP2 gene deletions in most high-transmission countries remains low, further monitoring is required.

Drug resistance

ACTs have been integral to the recent success of global malaria control, and protecting their efficacy for the treatment of malaria is a global health priority.

Although multidrug resistance, including artemisinin (partial) resistance and partner drug resistance, has been reported in five countries of the Greater Mekong subregion (GMS), there has been a massive reduction in malaria cases and deaths in this subregion. Monitoring the efficacy of antimalarial drugs has led to timely treatment policy updates across the GMS.

In Africa, artemisinin (partial) resistance has not been reported to date and first-line ACTs remain efficacious in all malaria endemic settings.

Insecticide resistance

Of the 76 malaria endemic countries that provided data for 2010 to 2016, resistance to at least one insecticide in one malaria vector from one collection site was detected in 61 countries. In 50 countries, resistance to 2 or more insecticide classes was reported.

In 2016, resistance to one or more insecticides was present in all WHO regions, although the extent of monitoring varied.

Resistance to pyrethroids – the only insecticide class currently used in ITNs – is widespread. The proportion of malaria endemic countries that monitored and subsequently reported pyrethroid resistance increased from 71% in 2010 to 81% in 2016. The prevalence of confirmed resistance to pyrethroids differed between regions, and was highest in the WHO African and Eastern Mediterranean regions, where it was detected in malaria vectors in over two thirds of all sites monitored.

ITNs continue to be an effective tool for malaria prevention, even in areas where mosquitoes have developed resistance to pyrethroids. This was evidenced in a large multicountry evaluation coordinated by WHO between 2011 and 2016, which did not find an association between malaria disease burden and pyrethroid resistance across study locations in 5 countries.