SCHISTOSAMO INFECTION

Schistosamo Infection



Schistosamo Infection

Introduction

Two main forms of human schistosomiasis or bilharzia exist in Africa - urinary schistosomiasis caused by Schistosoma haematobium infection and intestinal schistosomiasis caused by Schistosoma mansoni infection. There are around 165 million people in sub-Saharan Africa with the disease: about 112 million with urinary schistosomiasis and about 54 million with intestinal schistosomiasis.1-3 The mainstay of the current strategy recommended by WHO against schistosomiasis is morbidity control through preventive chemotherapy with praziquantel (PZQ).4,5 Schistosome morbidity is mainly caused by eggs trapped in various parts of the human body, depending on the species of schistosomes, hence the fundamental aim of morbidity control is to reduce intensity of infection by drug treatment. Several national control programmes on schistosomiasis and soil-transmitted helminthiasis (STH) are now being implemented across sub-Saharan Africa with financial and technical support from the Schistosomiasis Control Initiative. We have previously reported the successful implementation of the national control programme on intestinal schistosomiasis and STH using annual treatment strategy through school-based drug delivery for schoolchildren and community-based drug delivery for adults at high risk, and the great impact achieved on reducing morbidity and infection in Uganda in eastern Africa.We now report the impact of biennial treatment strategy on urinary schistosomiasis through both school- and community-based drug deliveries for school-age children in Burkina Faso in western Africa. Burkina Faso is a land-locked country in western Africa with a total population of about 13 million, of which approximately 3.65 million are school-age children. S. haematobium is the main species prevalent throughout the country with focal prevalence of up to 100%, while S. mansoni is present mainly in the southern and western regions. Some small-scale control activities with treatment had taken place in some areas in the past, but the national control programme did not start until 2004. Full national coverage of treatment was achieved in 2005. A total of more than 3.3 million school-age children received their first treatment, representing 90.8% of the estimated school-age population in the country. Our results at one year post-treatment showed that treatment significantly reduced infection and morbidity by S. haematobium.14 The current paper presents the parasitological impact of a single treatment on schistosomiasis 2 years after treatment.

Methods

National control programme

Details about the national schistosomiasis control programme supported by the Schistosomiasis Control Initiative were described elsewhere.7,11 The control strategy adopted by the Ministry of Health was modified from the WHO guidelines and involved treatment once every two years to all school-age children (5-15 years old).4,5 Synergistic treatment for STH was also given to those who received treatment for schistosomiasis. The first treatment with PZQ and albendazole was implemented during 2004 and 2005 in a staggered two-phased campaign. Due to the low school enrolment rate in Burkina Faso, treatment was carried out both through schools and communities targeting school-age children not attending school. As described previously,11 the treatment campaign was coordinated and supervised by the Ministry of Health staff, involving education authorities and local communities. A specific national 'treatment week' was designated in October each year ...