High level of Schistosoma mansoni infection in pre-school children in Sierra Leone highlights the need in targeting this age group for praziquantel treatment

• Published in: Acta tropica 2012-11, Vol.124 (2), p.120-125
• Main Authors: Hodges, Mary H., Paye, Jusufu, Koroma, Manso M., Nyorkor, Emanuel D., Fofonah, Ibrahim, Zhang, Yaobi
• Format: Article
• Language: English
• Subjects: Animals; Anthelmintics - administration & dosage; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiparasitic agents; Ascaris lumbricoides; Biological and medical sciences; Child, Preschool; Cross-Sectional Studies; data collection; Diseases caused by trematodes; feces; Feces - parasitology; Female; General aspects; geographical distribution; Health Policy; Helminthic diseases; hookworms; Humans; Infectious diseases; Male; Mass drug administration; Medical sciences; monitoring; Neglected tropical diseases; Parasitic diseases; Pharmacology. Drug treatments; praziquantel; Praziquantel - administration & dosage; Pre-school children; preschool children; Prevalence; Schistosoma mansoni; Schistosoma mansoni - isolation & purification; Schistosomiases; Schistosomiasis; Schistosomiasis mansoni - epidemiology; Sierra Leone; Sierra Leone - epidemiology; Soil-transmitted helminth; surveys; Topography, Medical; Trichuris trichiura; villages
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2012.07.005

The effect of mass drug administration for STH performed six monthly for children 12–59 months of age since 2006 was investigated. [Display omitted] ► Overall adjusted S. mansoni prevalence was 11% and mean intensity was 33.5epg. ► In Kono: 27% of children were moderately or heavily infected with S. mansoni. ► Post-MDA the overall prevalence of A. lumbricoides and T. trichiura was low. ► Post-MDA hookworm prevalence was 22.8% and intensity 112.5epg in hard to reach sites. ► Post-MDA the overall prevalence of any STH was 39.3% in hard to reach sites. Schistosomiasis and soil-transmitted helminth (STH) infections are endemic in Sierra Leone. The consequences of these diseases to pre-school children are well understood. The national control program currently does not target this group of children for schistosomiasis, while mass drug administration (MDA) has been performed six monthly for STHs in children 12–59 months of age since 2006. To assist the national decision on MDA strategy to control schistosomiasis and STH, three cross-sectional surveys were conducted in pre-school children in 2009–2011 as part of routine surveillance performed in different areas and in different phases of MDA, including known ‘Hard to Reach’ villages where consistently poor coverage results were seen in recent MDA. Thirty 4–5 year-old children were randomly selected per site and a stool sample from each child was examined by Kato-Katz thick smear. Pooled data were analyzed for schistosomiasis and separate sets of data were presented for STHs. In total 61 sites were surveyed and a total of 1803 children were examined. The overall prevalence and intensity of Schistosoma mansoni was 11.2% (95% CI 9.7–12.8) and 33.5epg (95% CI 19.7–47.3). Relatively high level of infection was found in Kono (35.4% and 102.9epg), Tonkolili (30.4% and 142.3epg) and Koinadugu (20.8% and 47.0epg). There were 8.1% of children 4–5 years old moderately or heavily infected with S. mansoni. Overall level of STH infections were generally low, with hookworm 8.4–22.8%, Ascaris lumbricoides 0.2–17.2%, and Trichuris trichiura 0.9–2.6% in three surveys. However, prevalence of hookworm and A. lumbricoides was relatively high in those hard-to-reach villages even two months after MDA. Relatively high levels of S. mansoni infections were found in children aged 4–5 years old in Sierra Leone, in line with geographical distribution of the disease observed in older children in the country. The results suggest that this grou