The World Health Organization (WHO) has released the World Malaria Report 2018.
Malaria is caused by Plasmodium parasites. The parasites are spread to people through the bites of infected female Anopheles mosquitoes, called “malaria vectors.” There are more than 400 different species of Anopheles mosquito; around 30 are malaria vectors of major importance. All of the important vector species bite between dusk and dawn. The long lifespan and strong human-biting habit of the African vector species is the main reason why nearly 90% of the world’s malaria cases are in Africa. Vector control is the main way to prevent and reduce malaria transmission.
Partial immunity is developed over years of exposure, and while it never provides complete protection, it does reduce the risk that malaria infection will cause severe disease. For this reason, most malaria deaths in Africa occur in young children, whereas in areas with less transmission and low immunity, all age groups are at risk.
There are 5 parasite species that cause malaria in humans, and 2 of these species – P. falciparum and P. vivax – pose the greatest threat.
In a non-immune individual, symptoms usually appear 10–15 days after the infective mosquito bite. The first symptoms – fever, headache, and chills – may be mild and difficult to recognize as malaria. If not treated within 24 hours, P. falciparum malaria can progress to severe illness, often leading to death.
Children with severe malaria frequently develop one or more of the following symptoms:
- severe anaemia,
- respiratory distress in relation to metabolic acidosis, or
- cerebral malaria.
In adults, multi-organ involvement is also frequent. In malaria endemic areas, people may develop partial immunity, allowing asymptomatic infections to occur.
Populations at considerable risk include infants, children under 5 years of age, pregnant women and patients with HIV/AIDS, as well as non-immune migrants, mobile populations and travellers.
In 2017, there were an estimated 219 million cases of malaria in 90 countries. Although there were an estimated 20 million fewer malaria cases in 2017 than in 2010, data
for the period 2015–2017 highlight that no significant progress in reducing global malaria cases was made in this time-frame. Five countries accounted for nearly half of all malaria cases worldwide:
- Nigeria (25%),
- the Democratic Republic of the Congo (11%),
- Mozambique (5%),
- India (4%) and
- Uganda (4%).
The 10 highest burden countries in Africa reported increases in cases of malaria in 2017 compared with 2016. Of these, Nigeria, Madagascar and the Democratic Republic of the Congo had the highest estimated increases, all greater than half a million cases. In contrast, India reported 3 million fewer cases in the same period, a 24% decrease compared with 2016.
The incidence rate of malaria declined globally between 2010 and 2017, from 72 to 59 cases per 1000 population at risk. Although this represents an 18% reduction over the period, the number of cases per 1000 population at risk has stood at 59 for the past 3 years.
The WHO South-East Asia Region continued to see its incidence rate fall – from 17 cases of the disease per 1000 population at risk in 2010 to 7 in 2017 (a 59% decrease). All other WHO regions recorded either little progress or an increase in incidence rate. The WHO Region of the Americas recorded a rise, largely due to increases in malaria transmission in Brazil, Nicaragua and Venezuela (Bolivarian Republic of). In the WHO African Region, the malaria incidence rate remained at 219 cases per 1000 population at risk for the second year in a row.
The WHO African Region continues to carry a disproportionately high share of the global malaria burden. In 2017, the region was home to 92% of malaria cases and 93% of malaria deaths.
- In 2017, P. falciparum accounted for 99.7% of estimated malaria cases in the WHO African Region, as well as in the majority of cases in the WHO regions of South-East Asia (62.8%), the Eastern Mediterranean (69%) and the Western Pacific (71.9%).
- P. vivax is the predominant parasite in the WHO Region of the Americas, representing 74.1% of malaria cases.
In 2017, there were an estimated 435 000 deaths from malaria globally, compared with 451 000 estimated deaths in 2016, and 607 000 in 2010.
Children aged under 5 years are the most vulnerable group affected by malaria. In 2017, they accounted for 61% (266 000) of all malaria deaths worldwide.
The WHO African Region accounted for 93% of all malaria deaths in 2017. Although the WHO African Region was home to the highest number of malaria deaths in 2017, it also accounted for 88% of the 172 000 fewer global malaria deaths reported in 2017 compared with 2010.
This year’s report includes a section on malaria-related anaemia, a condition that, left untreated, can result in death, especially among vulnerable populations such as pregnant women and children aged under 5 years.
Data from household surveys conducted in 16 high-burden African countries between 2015 and 2017 show that, among children aged under 5 years, the prevalence of any anaemia was 61%, mild anaemia 25%, moderate anaemia 33% and severe anaemia 3%. Of children who tested positive for malaria, the prevalence of any anaemia was 79%, mild anaemia 21%, moderate anaemia 50% and severe anaemia 8%.
Total funding for malaria control and elimination reached an estimated US$ 3.1 billion in 2017. Contributions from governments of endemic countries amounted to US$ 900 million, representing 28% of total funding.
To reach the Global Technical Strategy for malaria 2016-2030 (GTS 2030) targets, it is estimated that annual malaria funding will need to increase to at least US$ 6.6 billion per year by 2020.
Link to the WHO news release:
Link to World Malaria Report 2018:
Link to ‘World Malaria Report at a glance’ WHO page:
Link to Questions and Answers on World Malaria Report 2018:
Link to WHOs factsheet on malaria (updated 19 November 2018):