In 2010, 90% of all malaria deaths occurred in populations living in the African region of the World Health Organization. Although the past 10 years have seen major investments in malaria control in Africa, new research suggests that almost 60% of the population continue to live in moderate- and high-risk infection areas.
This is according to a study recently published in The Lancet.
To reach their findings, researchers from the Kenya Medical Research Institute, the World Health Organization (WHO) Office for Africa, and the University of Oxford in the UK analyzed data from 26,746 community-based surveys of parasite prevalence since 1980.
The surveys included 3,575,418 people from 44 malaria-endemic countries and territories in Africa.
Using this data, the investigators estimated the proportion of the population aged between 2 and 10 years who were infected with varying levels of a malaria-causing parasite called Plasmodium falciparum across Africa between 2000 and 2010.
The team wanted to see how this initiative had impacted malaria control in Africa from 2000 up to a decade later.
Increase of population in moderate- to high-infection areas
The researchers found that between 2000 and 2010, the estimated number of people living in areas with high malaria transmission reduced by 16%, from 218.6 million to 183.5 million.
However, the number of people living in areas deemed as moderate- to high-risk of infection increased by 57%, from 178.6 million in 2000 to 280.1 million in 2010.
The researchers point out that a part of this increase is attributable to population growth. There are now 200 million more people living in malaria-endemic regions of Africa than there were in 2000.
The research team also found that the number of people living in very low-risk areas increased by 64% over the 10-year period, from 78.2 million to 128.2 million, with four countries (Cape Verde, Eritrea, South Africa and Ethiopia) demonstrating malaria transmission levels that indicate realistic malaria elimination.
Continued support for malaria control needed
However, the investigators say it is a concern that the number of people living in moderate- to high-risk infection areas has increased.
They point out that just 10 countries account for 87.1% of these people, and three of these countries are not a part of the WHO Malaria Situation Room - a worldwide joint initiative that aims to provide support to the 10 countries with the highest malaria burden in Africa.
Dr. Abdisalan Mohamed Noor, of the Kenya Medical Research Institute-Wellcome Trust Research Program and co-author of the study, notes that the international community has heavily invested in malaria control over the past 13 years.
In 2000, worldwide malaria control investment stood at around $100 million. In 2013, it almost reached the $3 billion mark. But the researchers stress that although this study shows some successes of joint initiatives, further support is needed.
"In a period of global economic recession, these results emphasize the need for continued support for malaria control, not only to sustain the gains that have been made, but also to accelerate the reduction in transmission intensity where it still remains high.
If investments in malaria are not sustained, hundreds of millions of Africans run the risk of rebound transmission, with catastrophic consequences."
In a comment piece linked to the study, Prof. Brian Greenwood, of the London School of Hygiene and Tropical Medicine in the UK, and Dr. Kwado Koram, of the Noguchi Memorial Institute of Medical Research in Ghana, agree that more could be done to improve malaria control in high-risk countries.
"However," they add, "a focus on elimination must not result in a reduction in support for development of new methods (drugs, insecticides, vaccines and new approaches to vector control), and improved delivery methods, which will be needed in large areas of sub-Saharan Africa before malaria transmission can be reduced to the level at which elimination becomes a credible prospect."
Last year, Medical News Today reported on a study from the Centers for Disease Control and Prevention (CDC), revealing that the number of malaria cases in the US has reached a 40-year high.