Yemen bilharzia infection levels drop by more than half

Country prepares to expand treatment for millions more

Geneva, Switzerland
12 December 2013

The health authorities in Yemen have distributed more than 18 million doses of praziquantel to treat schistosomiasis (bilharzia) during the past 3 years, using over 45 million tablets.

Yemeni adults and children alike being treated with praziquantel during a large-scale  treatment campaign

“We plan to accelerate our campaign against bilharzia to change the lives of millions of Yemenis suffering from this disease,” said Dr Majid Al-Jonaid, Yemen’s Deputy Minister for Primary Health Care. “Today we have the means and the will to end this long cycle of suffering caused by this preventable infection.”

Both urogenital schistosomiasis due to Schistosoma haematobium and intestinal schistosomiasis due to Schistosoma mansoni are prevalent in Yemen. More than 3 million people are estimated to be infected and at least three-quarters of a million suffer from severe, chronic morbidity.

In the most affected districts, people received up to three doses of praziquantel once per year. In compliance with WHO recommendations, one tablet of albendazole or mebendazole was also coadministered to treat intestinal parasitic infections (soil-transmitted helminthiases), which are widely distributed in the country.

“WHO will support the people of Yemen in every possible way to defeat bilharzia and other neglected tropical diseases.”

Dr Lorenzo Savioli, Director, WHO Department of Control of Neglected Tropical Diseases

“This achievement is exemplary and reflects the commitment of the Government of Yemen and the dedication of all our stakeholders, particularly the World Bank and the Schistosomiasis Control Initiative” said Dr Lorenzo Savioli, Director, WHO Department of Control of Neglected Tropical Diseases. “WHO will support the people of Yemen in every possible way to defeat bilharzia and other neglected tropical diseases.”

Record-breaking intervention

In March this year, more than 9 and a half million Yemenis, comprising adults and children, were treated for both bilharzia and intestinal soil-transmitted helminthiases in two separate 4-day campaigns, compared with a total of 1.9 million people treated during the whole of 2012. To conduct these two 4-day campaigns, Yemen mobilized 30 000 health officials and community members in 263 districts of the country’s 20 governorates.

The 6-year Yemen Schistosomiasis Control Project was launched in 2010 and is supported by a US$ 25 million grant from the World Bank; its completion is due in 2016.

A technical review meeting of the Yemen Schistosomiasis Control Project , jointly organized by the Yemen Ministry of Public Health and Population, the World Bank, the Schistosomiasis Control Initiative at Imperial College London and WHO (at headquarters, the Eastern Mediterranean Regional Office and the Yemen Country Office) took place from 25 November to 6 December 2013 at WHO’s headquarters in Geneva, Switzerland, during which the first results of an impact evaluation assessment were presented.

The analysis, conducted in selected sentinel districts, shows that infection levels collected from 2000 individuals have fallen by more than half since the beginning of the project, from 20% at baseline to 8%, with less than 4% harbouring severe infections. These accomplishments have been certified by an independent assessment conducted by an external auditing firm.

Last week’s workshop was attended by delegates from Yemen’s Ministry of Public Health and Population, led by the Deputy Minister for Primary Health Care Dr Majid Al-Jonaid, as well as by the partners supporting the project.

The recommended WHO treatment for bilharzia is praziquantel at 40mg/kg of body weight, single-administration. The medicine is used at regular intervals depending on the prevalence of infection. For Yemen, praziquantel is procured by WHO with support from the World Bank, while albendazole and mebendazole are donated through WHO by GlaxoSmithKline and Johnson & Johnson, respectively.

Praziquantel has been used successfully over the past 30 years to control schistosomiasis in many countries.


Schistosomiasis is a chronic, parasitic disease caused by blood flukes (trematode worms) of the genus Schistosoma. Transmission has been documented in 78 countries; however, those requiring mass treatment directed to high-risk population groups live in 52 countries.

School-based treatment ensures high compliance and treating children regularly prevents chronic conditions in adulthood

In 2012, more than 42 million people, 83% of whom are in sub-Saharan Africa, were treated for schistosomiasis.

Intestinal schistosomiasis can result in abdominal pain, diarrhoea and blood in the stool, while the classic sign of urogenital schistosomiasis is haematuria (blood in the urine). Fibrosis of the bladder and ureters, and kidney and liver damage are diagnosed in advanced cases.

Experience from China and Egypt demonstrates that preventive chemotherapy (mass treatment without individual diagnosis) with high coverage can result in significant impacts on indices of infection and also reduced transmission.

Treatment several times during childhood is likely to prevent disease in adulthood.

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Yemenis’ triumph against bilharzia as infection rates halved (Photo story)