scholarly journals Estimation of changes in the force of infection for intestinal and urogenital schistosomiasis in countries with schistosomiasis control initiative-assisted programmes

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
Michael D. French ◽  
Thomas S. Churcher ◽  
Joanne P. Webster ◽  
Fiona M. Fleming ◽  
Alan Fenwick ◽  
...  
Keyword(s):  
Urogenital Schistosomiasis ◽  
Schistosomiasis Control ◽  
Force Of Infection ◽  
Control Initiative

scholarly journals Fine-scale heterogeneity in Schistosoma mansoni force of infection measured through antibody response

2020 ◽  
Vol 117 (37) ◽  
pp. 23174-23181
Author(s):  
Benjamin F. Arnold ◽  
Henry Kanyi ◽  
Sammy M. Njenga ◽  
Fredrick O. Rawago ◽  
Jeffrey W. Priest ◽  
...  
Keyword(s):  
Antibody Response ◽  
Schistosoma Mansoni ◽  
Seroconversion Rate ◽  
Preschool Age ◽  
Schistosomiasis Control ◽  
Control Programs ◽  
Force Of Infection ◽  
High Transmission ◽  
School Based ◽  
Preschool Age Children

Schistosomiasis is among the most common parasitic diseases in the world, with over 142 million people infected in low- and middle-income countries. Measuring population-level transmission is centrally important in guiding schistosomiasis control programs. Traditionally, human Schistosoma mansoni infections have been detected using stool microscopy, which is logistically difficult at program scale and has low sensitivity when people have low infection burdens. We compared serological measures of transmission based on antibody response to S. mansoni soluble egg antigen (SEA) with stool-based measures of infection among 3,663 preschool-age children in an area endemic for S. mansoni in western Kenya. We estimated force of infection among children using the seroconversion rate and examined how it varied geographically and by age. At the community level, serological measures of transmission aligned with stool-based measures of infection (ρ = 0.94), and serological measures provided more resolution for between-community differences at lower levels of infection. Force of infection showed a clear gradient of transmission with distance from Lake Victoria, with 94% of infections and 93% of seropositive children in communities <1.5 km from the lake. Force of infection increased through age 3 y, by which time 65% (95% CI: 53%, 75%) of children were SEA positive in high-transmission communities—2 y before they would be reached by school-based deworming programs. Our results show that serologic surveillance platforms represent an important opportunity to guide and monitor schistosomiasis control programs, and that in high-transmission settings preschool-age children represent a key population missed by school-based deworming programs.

Present and future schistosomiasis control activities with support from the Schistosomiasis Control Initiative in West Africa

Parasitology ◽  
2009 ◽  
Vol 136 (13) ◽  
pp. 1731-1737 ◽  
Author(s):  
A. GARBA ◽  
S. TOURÉ ◽  
R. DEMBELÉ ◽  
P. BOISIER ◽  
Z. TOHON ◽  
...  
Keyword(s):  
Geographical Information ◽  
Mass Treatment ◽  
African Countries ◽  
Schistosomiasis Control ◽  
Control Programmes ◽  
Set Up ◽  
Coverage Rates ◽  
Control Initiative ◽  
National Control ◽  
Soil Transmitted Helminthiasis

SUMMARYSince 2004 the West African countries of Burkina Faso, Mali and Niger have implemented national schistosomiasis and soil-transmitted helminthiasis control programmes with financial and technical support from the Schistosomiasis Control Initiative (SCI). In the first three years of the control programmes, nearly 13·5 million doses of praziquantel and albendazole have been administered against schistosomiasis and soil-transmitted helminthiasis with coverage rates varying between 67·0% and 93·9%. These treatments have resulted in a reduction of the prevalence and intensity of Schistosoma infection in the sentinel cohorts that were set up to monitor and evaluate the national control programmes. The challenges currently faced by these national control programmes are the ability to maintain the reduction in morbidity achieved thus far due to the mass treatment campaigns and ensuring sustainability. For reinforcement of surveillance, the establishment of a geographical information system is suggested in order to contribute towards enhanced sustainability of these programmes. Our new working hypothesis is that targeted control accompanied by periodic mass treatment campaigns (every two to three years) can contribute to maintaining the low levels of morbidity achieved thus far. The implementation of integrated neglected tropical disease control programmes in these countries will provide means to ensure the financial sustainability of control activities for the years to come.

Elimination of urogenital schistosomiasis in Iran: past history and the current situation

Parasitology ◽  
2016 ◽  
Vol 143 (11) ◽  
pp. 1390-1396 ◽  
Author(s):  
SHAHRAM KHADEMVATAN ◽  
SHOKROLLAH SALMANZADEH ◽  
MASOUD FOROUTAN-RAD ◽  
MOHAMMAD GHOMESHI
Keyword(s):  
Past History ◽  
Optical Microscope ◽  
Urine Samples ◽  
Surveillance Period ◽  
Endemic Region ◽  
Urogenital Schistosomiasis ◽  
National Programme ◽  
Schistosomiasis Control ◽  
Khuzestan Province ◽  
Successful Model

SUMMARYIn recent years, through a national programme for schistosomiasis control, this infection has been eliminated from Iran. The aim of this study was to report the process of significant decrease of urogenital schistosomiasis in southwestern Iran. During national programme surveillance for urogenital schistosomiasis control which was implemented by Centres for Disease Control and Prevention (CDC) of Khuzestan province from 1975 to 2013, more than 1·3 million urine samples were taken from inhabitants of high risk foci. All urine samples were gathered between 10:00 a.m and 02:00 p.m and, after centrifuging, specimens were tested under optical microscope in order to detect Schistosoma haematobium eggs. Data analysis was performed using SPSS 18 software. In this retrospective study significant reduction was seen in number of infections between 1975 and 2013. During the years 1975–1980, 1981–1990 and 1991–2000 there were 1582, 761 and 79 cases of S. haematobium, respectively. In 2001 only one case was reported from Ahvaz and indeed this was the last case of urogenital schistosomiasis in Khuzestan and of course, in Iran. Prevalence from 1·064% between 1975 and 1980 slumped to 0% in 2012–2013. During several projects for surveillance of urogenital schistosomiasis, selective population chemotherapy, snail control, population education, environmental improvement, etc were carried out throughout the surveillance period. According to elimination of S. haematobium in Khuzestan province, the only endemic region of Iran, control of disease, especially the campaign with intermediate host snails should be continued. Iran can be a successful model for countries suffering from this disease.

scholarly journals Evaluating the Impact of Biannual School-Based and Community-Wide Treatment on Urogenital Schistosomiasis in Niger

2020 ◽  
Author(s):  
Anna Elizabeth Phillips ◽  
Zilahatou Tohon ◽  
Neerav A. Dhanani ◽  
Boubacar Sofo ◽  
Issa Gnandou ◽  
...  
Keyword(s):  
Randomised Trial ◽  
Evidence Base ◽  
Cluster Randomised Trial ◽  
Relative Reduction ◽  
Preventive Chemotherapy ◽  
Urogenital Schistosomiasis ◽  
Schistosomiasis Control ◽  
School Based ◽  
Significant Difference ◽  
The Impact

Abstract Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control. Methods This was a cluster-randomised trial investigating six possible combinations of annual or biannual community-wide treatment (CWT), school-based treatment (SBT), and holidays from mass treatment over four years. The most intense arm involved two years of annual CWT followed by two years of biannual CWT, while the least intensive arm involved one year of annual SBT followed by a year without treatment and two more years of annual SBT. The primary outcome of interest was prevalence and intensity of S. haematobium among 100 children aged 9-to-12-years sampled each year. In addition, 100 children aged 5-to-8 years in their first year of school and 50 adults (aged 20-to-55 years) were tested in the first and final fifth year of the study. Results In total, data was collected from 167,500 individuals across 225 villages in nine districts within the Niger River valley, Western Niger. Overall, prevalence of S. haematobium decreased from baseline to Year 5 across all study arms. The relative reduction of prevalence was greater in biannual compared with annual treatment across all arms, however, the only significant difference was seen in areas with a high starting prevalence. Although adults were not targeted for treatment in SBT arms, a statistically significant decrease in prevalence among adults was seen in moderate prevalence areas receiving biannual (10.7% to 4.8%) SBT (p<0.001). Adults tested in the annual SBT group also showed a decrease in prevalence between Year 1 and Year 5 (12.2% to 11.0%), but this difference was not significant.Conclusions These findings are an important consideration for schistosomiasis control programs that are considering elimination and support the idea that scaling up the frequency of treatment rounds, particularly in areas of low prevalence, will not eliminate schistosomiasis. Interestingly, the finding that prevalence decreased among adults in SBT arms suggests that transmission in the community can be reduced, even where only school children are being treated, which could have logistical and cost-saving implications for the national control programmes.

scholarly journals Evaluating the impact of biannual school-based and community-wide treatment on urogenital schistosomiasis in Niger

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Anna E. Phillips ◽  
Zilahatou Tohon ◽  
Neerav A. Dhanani ◽  
Boubacar Sofo ◽  
Issa Gnandou ◽  
...  
Keyword(s):  
Randomised Trial ◽  
Cluster Randomised Trial ◽  
Relative Reduction ◽  
Preventive Chemotherapy ◽  
Urogenital Schistosomiasis ◽  
Schistosomiasis Control ◽  
School Based ◽  
Significant Difference ◽  
Control Programmes ◽  
The Impact

Abstract Background The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) coordinated a five-year study implemented in several countries, including Niger, to provide an evidence-base for programmatic decisions regarding cost-effective approaches to preventive chemotherapy for schistosomiasis control. Methods This was a cluster-randomised trial investigating six possible combinations of annual or biannual community-wide treatment (CWT), school-based treatment (SBT), and holidays from mass treatment over four years. The most intense arm involved two years of annual CWT followed by 2 years of biannual CWT, while the least intensive arm involved one year of annual SBT followed by a year without treatment and two more years of annual SBT. The primary outcome of interest was prevalence and intensity of Schistosoma haematobium among 100 children aged 9–12 years sampled each year. In addition, 100 children aged 5–8 years in their first year of school and 50 adults (aged 20–55 years) were tested in the first and final fifth year of the study. Results In total, data were collected from 167,500 individuals across 225 villages in nine districts within the Niger River valley, Western Niger. Overall, the prevalence of S. haematobium decreased from baseline to Year 5 across all study arms. The relative reduction of prevalence was greater in biannual compared with annual treatment across all arms; however, the only significant difference was seen in areas with a high starting prevalence. Although adults were not targeted for treatment in SBT arms, a statistically significant decrease in prevalence among adults was seen in moderate prevalence areas receiving biannual (10.7% to 4.8%) SBT (P < 0.001). Adults tested in the annual SBT group also showed a decrease in prevalence between Year 1 and Year 5 (12.2% to 11.0%), but this difference was not significant. Conclusions These findings are an important consideration for schistosomiasis control programmes that are considering elimination and support the idea that scaling up the frequency of treatment rounds, particularly in areas of low prevalence, will not eliminate schistosomiasis. Interestingly, the finding that prevalence decreased among adults in SBT arms suggests that transmission in the community can be reduced, even where only school children are being treated, which could have logistical and cost-saving implications for the national control programmes.

scholarly journals The Schistosomiasis Control Initiative (SCI): rationale, development and implementation from 2002–2008

Parasitology ◽  
2009 ◽  
Vol 136 (13) ◽  
pp. 1719-1730 ◽  
Author(s):  
A. FENWICK ◽  
J. P. WEBSTER ◽  
E. BOSQUE-OLIVA ◽  
L. BLAIR ◽  
F. M. FLEMING ◽  
...  
Keyword(s):  
Neglected Tropical Diseases ◽  
Integrated Control ◽  
Monitoring And Evaluation ◽  
Sub Saharan Africa ◽  
Preventive Chemotherapy ◽  
Schistosomiasis Control ◽  
Control Programmes ◽  
Sub Saharan ◽  
Management Approaches ◽  
Control Initiative

SUMMARYSchistosomiasis remains one of the most prevalent parasitic diseases in developing countries. After malaria, schistosomiasis is the most important tropical disease in terms of human morbidity with significant economic and public health consequences. Although schistosomiasis has recently attracted increased focus and funding for control, it has been estimated that less than 20% of the funding needed to control the disease in Africa is currently available. In this article the following issues are discussed: the rationale, development and objectives of the Schistosomiasis Control Initiative (SCI)-supported programmes; the management approaches followed to achieve implementation by each country; mapping, monitoring and evaluation activities with quantifiable impact of control programmes; monitoring for any potential drug resistance; and finally exit strategies within each country. The results have demonstrated that morbidity due to schistosomiasis has been reduced by the control programmes. While challenges remain, the case for the control of schistosomiasis has been strengthened by research by SCI teams and the principle that a national programme using ‘preventive chemotherapy’ can be successfully implemented in sub-Saharan Africa, whenever the resources are available. SCI and partners are now actively striving to raise further funds to expand the coverage of integrated control of neglected tropical diseases (NTDs) in sub-Saharan Africa.

A tale of a man, a worm and a snail: the schistosomiasis control initiative

2021 ◽  
Keyword(s):  
Treatment Programs ◽  
Human Populations ◽  
Schistosomiasis Control ◽  
Intestinal Worms ◽  
Control Initiative

Abstract This book contains 21 chapters that describe treatment programs for schistosomiasis and intestinal worms in 16 countries and has helped those countries provide more than 200 million treatments, mainly in schools, to deworm human populations.

scholarly journals Fine-scale heterogeneity in Schistosoma mansoni force of infection measured through antibody response

2020 ◽  
Author(s):  
Benjamin F. Arnold ◽  
Henry Kanyi ◽  
Sammy M. Njenga ◽  
Fredrick O. Rawago ◽  
Jeffrey W. Priest ◽  
...  
Keyword(s):  
Antibody Response ◽  
Schistosoma Mansoni ◽  
Preschool Age ◽  
Fine Scale ◽  
Western Kenya ◽  
Schistosomiasis Control ◽  
Control Programs ◽  
Force Of Infection ◽  
Low Sensitivity ◽  
Egg Antigen

AbstractIdentifying populations with active transmission and monitoring changes in transmission is centrally important in guiding schistosomiasis control programs. Traditionally, human Schistosoma mansoni infections have been detected in stool using microscopy, which is logistically difficult at program scale and has low sensitivity when people have low infection burdens. We compared serological measures of transmission based on antibody response to schistosomiasis soluble egg antigen (SEA) with stool-based measures of infection among 3,663 preschool-age children in an area endemic for S. mansoni in western Kenya. Serological measures of transmission closely aligned with stool-based measures of infection, and serological measures provided better resolution for between-community differences at lower levels of infection. Serology enabled fine- scale measures of heterogeneity in force of infection both geographically and by age. Our results show that serologic surveillance platforms represent an important new opportunity to guide and monitor schistosomiasis control programs.

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