Chronic inflammation of blood vessels could help explain high childhood mortality in malaria regions

Recurrent episodes of malaria cause chronic inflammation in blood vessels that might predispose to future infections and may increase susceptibility to cardiovascular disease, a Wellcome Trust study in Malawian children finds.

The findings could explain the indirect burden of on childhood deaths in areas where the disease is highly prevalent and children experience multiple clinical episodes of malaria in a year.

Malaria is caused by infection with a parasite that starts by infecting the liver and then moves into red blood cells. The most deadly of the malaria parasites is Plasmodium falciparum because of its ability to cause inflammation in blood vessel walls, making them more sticky so that the infected red blood cells can cling to the sides. Being able to stick to the blood vessels in allows the parasite to hide away from the immune system, a process called . When it occurs in the brain it causes a more severe form of the disease called , associated with seizures, coma and sometimes death.

It was thought that the changes in the that enable the infected to stick would resolve quickly once the cells had been cleared; however, the new findings show that inflammation is still present up to one month later.

Researchers from the Malawi-Liverpool-Wellcome Clinical Research Programme at the University of Malawi College of Medicine in Blantyre, Malawi, looked at 190 children with uncomplicated, mild or cerebral malaria compared with healthy children of the same age. They found that the changes were most pronounced in children with cerebral malaria, with the levels of one inflammatory molecule remaining 22 times higher than in healthy controls one month after the initial infection.

Dr Chris Moxon, a Wellcome Trust Clinical PhD Fellow and first author of the study, explains: "These findings suggest that children who live in areas of high malaria transmission have persistently inflamed blood vessels, and that could have significant effects on their long term health. It could leave them more susceptible to repeated and more severe infections with malaria, but also with other bacteria and viruses. Chronic changes to the like these could an important contributing factor to cardiovascular disease later in life."

Professor Rob Heyderman, lead author and Director of MLW, added: "If follow-up studies in other populations confirm these findings, we should consider whether existing anti-inflammatory drugs such as statins may be able to limit these effects. Short courses of statins could be targeted to children with severe and recurrent disease to try and limit the severity of future infections but this would need to be evaluated in well-conducted clinical trials."

Around 300 million clinical episodes of malaria are caused by infection with the parasite P. falciparum each year. The disease is transmitted by mosquitos and children living in areas where the parasite is particularly prevalent may receive more than one infective bite per day, resulting in repeated clinical episodes of malaria over the course of the year.

Studies have shown that reducing malaria transmission in a population such as this can reduce the number of childhood deaths from any cause by up to 70%, an effect that is much greater than can be explained by reducing malaria alone. The findings from this new study, published today in the Journal of Infectious Diseases, could offer some explanation for the unexplained mortality in areas where is high.

More information: C.A. Moxon et al. Persistent endothelial activation and inflammation after Plasmodium falciparum infection in Malawian children. Journal of Infectious Diseases, 2013. [epub ahead of print]

add to favorites email to friend print save as pdf

Related Stories

Malaria's severity reset by mosquito

May 30, 2013

(Medical Xpress)—For the first time, researchers have proven that the way in which malaria is transmitted to the host affects how severe the resulting infection will be.

Researchers reveal malaria's deadly grip

Jun 05, 2013

Researchers at the University of Copenhagen, in collaboration with Seattle Biomedical Research Institute, the University of Oxford, NIMR Tanzania and Retrogenix LTD, have identified how malaria parasites ...

Australian researchers close in on malaria vaccine

Jul 02, 2013

Australian researchers said Tuesday they were closing in on a potential vaccine against malaria, with a study showing their treatment had protected mice against several strains of the disease.

Recommended for you

Restrictions lifted at British bird flu farm

6 hours ago

Britain on Sunday lifted all restrictions at a duck farm in northern England after last month's outbreak of H5N8 bird flu, the same strain seen in recent cases across Europe.

Recorded Ebola deaths top 7,000

Dec 20, 2014

The worst Ebola outbreak on record has now killed more than 7,000 people, with many of the latest deaths reported in Sierra Leone, the World Health Organization said as United Nations Secretary-General Ban ...

Liberia holds Senate vote amid Ebola fears (Update)

Dec 20, 2014

Health workers manned polling stations across Liberia on Saturday as voters cast their ballots in a twice-delayed Senate election that has been criticized for its potential to spread the deadly Ebola disease.

Evidence-based recs issued for systemic care in psoriasis

Dec 19, 2014

(HealthDay)—For appropriately selected patients with psoriasis, combining biologics with other systemic treatments, including phototherapy, oral medications, or other biologic, may result in greater efficacy ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.