科学与发展网络(SciDev.Net)

A sickle cell among its normally-shaped counterparts

EM Unit, UCL Medical School, Royal Free Campus

[NAIROBI] Thousands of African children with sickle cell anaemia are dying needlessly every year from preventable infections, say researchers.

About 230,000 children are born every year with sickle cell anaemia in Africa. The genetic disease causes the formation of sickle-shaped red blood cells which block blood vessels, leading to pain, infections and organ damage.

Ninety per cent of the estimated 200,000 African children with the disease who die each year do so before diagnosis.

A new study, published in The Lancet today (10 September), has confirmed suspicions that a large proportion of these deaths are caused by bacterial infections.

The researchers, from the KEMRI-Wellcome Trust centre, screened 40,000 children admitted to a Kenyan hospital over ten years for bacterial infections. Of the 2,000 children with bacteraemia, more than 100 had sickle cell anaemia — 26 times the level expected in the general population.

The researchers estimate that in Kilifi, where the study was conducted, a quarter of deaths are children with sickle cell anaemia, with bacterial infections accounting for a substantial proportion.

Lead researcher Tom Williams, a Wellcome Trust Senior Fellow and Reader in Tropical Medicine at the University of Oxford, says that these deaths could be easily prevented with immunisation.

"Every child has a chance of getting a bacterial infection but a child with sickle cell anaemia has [a much higher chance] than one without."

"Our study provides strong impetus for the introduction of vaccination programmes for all children in Africa, a move that will dramatically improve the survival chances of children born with sickle cell anaemia. Health policies need to be based on solid evidence such as this research, rather than on rumour and personal preference."

Strepococcus pneumonia and Haemophilus influenza type b account for more than half of bacterial infections. Both can cause death via meningitis or pneumonia but there are vaccines available.

Williams also calls for more screening to quantify the prevalence and death rate of sickle cell anaemia in Africa.

"It is possible to gain numbers of children dying of malaria and other infections. However, there is always little information on those who die of sickle cell anaemia." 

Link to full paper in The Lancet*