Featured Research

from universities, journals, and other organizations

Malaria kills nearly twice as many people than previously thought, but deaths declining rapidly

Date:
February 2, 2012
Source:
Institute for Health Metrics and Evaluation
Summary:
Malaria is killing more people worldwide than previously thought -- 1.2 million -- but the number of deaths has fallen rapidly as efforts to combat the disease have ramped up, according to new research. Researchers say that deaths from malaria have been missed by previous studies because of the assumption that the disease mainly kills children under age five.

Malaria caused over 1.2 million deaths worldwide in 2010, twice the number found in the most recent comprehensive study of the disease, according to researchers at IHME and the University of Queensland. This research, published in the study "Global malaria mortality between 1980 and 2010: a systematic analysis," shows that while malaria is traditionally considered a childhood disease, there is a significant disease burden in adults.

Research objective

During the past decade, attention to and funding for combatting malaria have greatly increased. Development assistance for malaria increased from $149 million in 2000 to almost $1.2 billion in 2008, which led to a rapid scale-up of malaria control in Africa.

Many efforts have been made to assess the burden of malaria and progress in fighting the disease, with different approaches leading to highly variable results. Global malaria death estimates since 2000 range from 800,000 to more than 1 million.

To aid assessment of progress toward development goals for malaria and to better focus future prevention efforts, an accurate assessment of the levels and time trends in malaria mortality by age, sex, and country is needed.

This work is part of IHME's research for the Global Burden of Diseases, Injuries, and Risk Factors 2010 Study, which will produce new estimates measuring the impact of hundreds of diseases, injuries, and risk factors in 21 regions around the world over two decades. The study is being carried out in collaboration with more than 800 researchers and includes more than 220 conditions and injuries and more than 40 risk factors.

Research findings

Researchers found that global malaria deaths increased from 995,000 in 1980 to a peak of 1.8 million in 2004. In 2010, there were 1.2 million malaria deaths, a 32% decrease since 2004. These results are largely driven by the pattern seen in sub-Saharan Africa, where deaths increased from 493,000 in 1980 to 1.6 million in 2004 and then decreased by about 30% to 1.1 million in 2010. Outside of Africa, the trend is much different, with deaths steadily decreasing from 502,000 in 1980 to 104,000 in 2010.

Although most malaria deaths are in children, the number of deaths in adults is high. In 2010, 20% of malaria deaths were in people aged 15 to 49 years, 9% were in people aged 50 to 69 years, and 6% were in those over 70 years of age. Compared to other assessments, this study estimates more deaths in individuals aged 5 years or older in 2010: 435,000 in Africa and 89,000 outside of Africa.

The risk of dying from malaria in 2010 is highest in western, eastern, and central sub-Saharan Africa. However, the risk in several countries in these regions that have scaled up malaria control efforts, including Zambia, Tanzania, Kenya, and Ethiopia, has decreased between 2000 and 2010.

Analytical approach

In order to predict levels and trends over time in malaria mortality, the authors used an approach developed and applied for other causes of mortality, including breast and cervical cancer. For 105 countries with data on malaria transmission between 1980 and 2010, they identified all data for deaths due to malaria, correcting for known biases in the data, including misclassification of deaths to causes other than malaria. Data were obtained from countries' vital registration systems and verbal autopsy studies. In a verbal autopsy, researchers interview the relatives of someone who has recently died to identify the cause of death.

Researchers studied key predictors of malaria mortality, such as prevalence of Plasmodium falciparum parasites, resistance to first-line antimalarial drugs, and vector control.

Many different models for analyzing the data were tested, including ensemble models, which are weighted averages of individual component models. To choose the final model, the researchers used out-of-sample predictive validity, which is tested by running a model with some of the data removed, and then checking the performance of the model at predicting the data that were removed.

The authors note there are differences between these results and those of other assessments, including the World Malaria Report 2011. The differences can be attributed to the larger number of malaria deaths included in this analysis, as well as child mortality estimates developed with an analysis that suggests fewer deaths from all causes than those used in the World Malaria Report. In contrast to other assessments, this study also took into account estimates of Plasmodium falciparum parasite rate from the Malaria Atlas Project, included the effect of interventions other than vector control, and developed models with rigorous out-of-sample predictive validity.

Policy implications

While substantial progress has been made in the fight against malaria over the past five years, these findings show substantially more deaths across all ages and regions than other assessments, especially in adults.

Traditionally, medical and public health schools teach that adults in countries with malaria develop immunity as children and are not likely to die from the disease. However, these results clearly show that a substantial percentage of malaria deaths occur in people aged 15 years and older, even in areas such as sub-Saharan Africa where adults are likely to be exposed to malaria as children.

The fact that malaria is a significant factor in adult mortality indicates that control strategies should shift to pay more attention to adults and underscores the dangers posed by the global economic crisis. One of the biggest forces in the decline in malaria deaths was the advent of the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM), which provided 40% of development assistance for health targeted toward malaria from 2003 to 2008.

GFATM's recent announcement that it would cancel its next round of funding threatens the gains made in preventing malaria deaths. If malaria elimination and eradication and broader health and development goals are to be achieved, donor support needs to be increased.


Story Source:

The above story is based on materials provided by Institute for Health Metrics and Evaluation. Note: Materials may be edited for content and length.


Journal Reference:

  1. Christopher JL Murray, Lisa C Rosenfeld, Stephen S Lim, Kathryn G Andrews, Kyle J Foreman, Diana Haring, Nancy Fullman, Mohsen Naghavi, Rafael Lozano, Alan D Lopez. Global malaria mortality between 1980 and 2010: a systematic analysis. The Lancet, 2012; 379 (9814): 413 DOI: 10.1016/S0140-6736(12)60034-8

Cite This Page:

Institute for Health Metrics and Evaluation. "Malaria kills nearly twice as many people than previously thought, but deaths declining rapidly." ScienceDaily. ScienceDaily, 2 February 2012. <www.sciencedaily.com/releases/2012/02/120202201740.htm>.
Institute for Health Metrics and Evaluation. (2012, February 2). Malaria kills nearly twice as many people than previously thought, but deaths declining rapidly. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2012/02/120202201740.htm
Institute for Health Metrics and Evaluation. "Malaria kills nearly twice as many people than previously thought, but deaths declining rapidly." ScienceDaily. www.sciencedaily.com/releases/2012/02/120202201740.htm (accessed August 20, 2014).

Share This




More Health & Medicine News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: World's Oldest Man Lives in Japan

Raw: World's Oldest Man Lives in Japan

AP (Aug. 20, 2014) A 111-year-old Japanese was certified as the world's oldest man by Guinness World Records on Wednesday. Sakari Momoi, a native of Fukushima in northern Japan, was given a certificate at a hospital in Tokyo. (Aug. 20) Video provided by AP
Powered by NewsLook.com
Ebola-Hit Sierra Leone's Freetown a City on Edge

Ebola-Hit Sierra Leone's Freetown a City on Edge

AFP (Aug. 19, 2014) Residents of Sierra Leone's capital voice their fears as the Ebola virus sweeps through west Africa. Duration: 00:56 Video provided by AFP
Powered by NewsLook.com
101-Year-Old Working Man Has All The Advice You Need

101-Year-Old Working Man Has All The Advice You Need

Newsy (Aug. 19, 2014) Herman Goldman has worked at the same lighting store for almost 75 years. Find out his secrets to a happy, productive life. Video provided by Newsy
Powered by NewsLook.com
Researcher Testing on-Field Concussion Scanners

Researcher Testing on-Field Concussion Scanners

AP (Aug. 19, 2014) Four Texas high school football programs are trying out an experimental system designed to diagnose concussions on the field. The technology is in response to growing concern over head trauma in America's most watched sport. (Aug. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins