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  • Rapid disease mapping could guide treatment in South Sudan

[NAIROBI] Rapid mapping to quickly determine precise distribution and prevalence of major neglected tropical diseases (NTDs) such as schistosomiasis and lymphatic filariasis can help guide evidence-based interventions, a study reveals.

The study, conducted in South Sudan and published in PloS One last month (20 December), used surveys to map the prevalence of certain NTDs and determine where treatment is needed the most.

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"Rapid mapping is very important to help gather information for interventions into NTDs and for national policymaking," says Simon Brooker, one of the report authors and a Wellcome Trust senior research fellow at the Kenya Medical Research Institute.

"South Sudan has the highest number of total infections of NTDs in Africa," Brooker tells SciDev.Net, adding that the distribution and prevalence of major neglected tropical diseases varies considerably across the three states

In the study, three states of South Sudan were surveyed from May to September 2010 to identify areas where levels of schistosomiasis, lymphatic filariasis or soil-transmitted helminthiasis were high enough to make their populations eligible for mass preventive drug treatment programmes targeting these diseases.

The study involved taking more than 12,000 urine and stool samples from children from 193 sites to test for schistosome and soil-transmitted helminth infection, and nearly 4,000 blood samples from adults from 50 sites to test for lymphatic filariasis.

The survey mapped the areas where some 1.4 million people should be treated against schistosomiasis, where 1.3 million people require annual treatment to treat lymphatic filariasis and where 1.2 million need regular treatment against soil-transmitted helminths.

The survey provides further evidence that rapid mapping to target preventive drug treatment is important for public health due to this marked spatial variation of disease and the resulting need for evidence-based targeting of treatments, he says.

Charles Chunge, director of the Centre for Tropical and Travel Medicine in Nairobi, Kenya, tells SciDev.Net that rapid mapping followed by interventions to control such diseases is therefore vital not just for South Sudan, but also for the whole of Africa.

The researchers conclude that "the challenge now remains to complete NTD mapping in the remaining states in the country, and to regularly provide treatment to eligible populations".

This article has been produced by SciDev.Net's Sub-Saharan Africa desk.

Link to full paper

References

PLoS ONE doi:10.1371/journal.pone.0052789 (2012)