Abstract
Monitoring and evaluation (M&E) programmes are used to collect data which are required to assess the impact of current interventions on their progress towards achieving the World Health Organization (WHO) goals of morbidity control and elimination as a public health problem for schistosomiasis. Prevalence and intensity of infection data are typically collected from school-aged children (SAC) as they are relatively easy to sample and are thought to be most likely to be infected by schistosome parasites. However, adults are also likely to be infected. We use three different age-intensity profiles of infection for Schistosoma mansoni with low, moderate and high burdens of infection in adults to investigate how the age distribution of infection impacts the mathematical model generated recommendations of the preventive chemotherapy coverage levels required to achieve the WHO goals. We find that for moderate prevalence regions, regardless of the burden of infection in adults, treating SAC only may achieve the WHO goals. However, for high prevalence regions with a high burden of infection in adults, adult treatment is required to meet the WHO goals. Hence, we show that the optimal treatment strategy for a defined region requires consideration of the burden of infection in adults as it cannot be based solely on the prevalence of infection in SAC. Although past epidemiological data have informed mathematical models for the transmission and control of schistosome infections, more accurate and detailed data are required from M&E programmes to accurately determine the optimal treatment strategy for a defined region. We highlight the importance of collecting prevalence and intensity of infection data from a broader age-range, specifically the inclusion of adult data at baseline (prior to treatment) and throughout the treatment programme if possible, rather than SAC only, to accurately determine the treatment strategy for a defined region. Furthermore, we discuss additional epidemiological data, such as individual longitudinal adherence to treatment, that should ideally be collected in M&E programmes.
Highlights
Schistosomiasis is a neglected tropical disease (NTD) caused by parasitic worms which may infect the intestines (Schistosoma mansoni or S. japonicum) or urinary tract (S. haematobium)
I.e. baseline prevalence 10–50% in school-aged children (SAC), we found that the World Health Organization (WHO) goals were likely to be achieved within 5 years following biennial treatment of 75% SAC only
For high prevalence settings, we found that the WHO goals were not likely to be achieved within 5 to 15 years following annual treatment with coverage at 75% of SAC only (Fig 3; aligning with previous work [3])
Summary
Schistosomiasis is a neglected tropical disease (NTD) caused by parasitic worms which may infect the intestines (Schistosoma mansoni or S. japonicum) or urinary tract (S. haematobium). The World Health Organization (WHO) has set goals of morbidity control and elimination as a public health problem, i.e. reaching 5% and 1% prevalence of heavy-intensity infections in school-aged children (SAC; 5–14 years of age), respectively [2]. The overall aim is to achieve these goals using mass drug administration (MDA) of praziquantel at the treatment frequency and coverage level recommended by the WHO [1, 2]. The current WHO recommendations are treatment of SAC once every 3 years in low prevalence settings (
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
