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Investigation of genetic markers for drug resistance in Schistosoma haematobium parasites in Pemba

Resistance Evaluation and Surveillance Initiative for Schistosomiasis Treatment

Status
Recruiting
Phases
Unknown
Study type
Observational
Source
ISRCTN
Registry ID
ISRCTN59331501
Enrollment
34000
Registered
2024-10-24
Start date
2024-11-01
Completion date
Unknown
Last updated
2025-09-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Schistosoma haematobium Infections and Infestations

Interventions

The study is designed as an observational study with the following components: 1. Cross-sectional surveys: Collect single urine samples from students in 15 schools that were also part of the Zanzibar

Sponsors

Swiss Tropical and Public Health Institute
Lead Sponsor

Eligibility

Sex/Gender
All

Inclusion criteria

Inclusion criteria: The study population will consist of children attending 17 schools in Pemba, Tanzania: 1. Attendance of grades 1-7 in one among the 17 schools selected to be part of the study 2. Aged 5-16 years 3. Randomised to participate in the study (if the number of attending children is greater than required) 4. Written informed consent signed by the parents 5. Written assent signed by the participant if aged 12-16 years old

Exclusion criteria

Exclusion criteria: 1. Not attending any of the 17 selected schools 2. Not attending grades 1-7 3. Not aged 5-16 years 4. Not randomised to participate in the study (if the number of attending children is greater than required) 5. No written informed consent signed by the parents submitted 6. No written assent signed by the participant if aged 12-16 years old 7. Clinically significant severe disease

Design outcomes

Primary

MeasureTime frame
Frequency of praziquantel resistance associated single nucleotide polymorphisms (SNPs) in S. haematobium miracidia collected in the school surveys in 2024/25 as measured using whole genome sequencing (WGS) methodologies and bioinformatic pipelines/tools.

Secondary

MeasureTime frame
1. Genome assemblies and TRPMPZQ SNP profiles of S. haematobium miracidia from 17 different schools in Pemba, collected in 2024/25, as measured using WGS methodologies and bioinformatic pipelines/tools 2. Genome assemblies and TRPMPZQ SNP profiles of S. haematobium miracidia from the same 17 schools in Pemba, collected as part of the ZEST study in 2012 and 2017, and archived in SCAN, as measured using WGS methodologies and bioinformatic pipelines/tools 3. Genome assemblies and TRPMPZQ SNP profiles of S. haematobium miracidia collected before and after MDA from two different schools in Pemba in 2024/25, as measured using WGS methodologies and bioinformatic pipelines/tools 4. Spatiotemporal genetic diversity patterns of S. haematobium populations across Pemba in 2012, 2017 and 2024/25, as measured by the fixation index (FST) 5. Associations between genetic variants and PZQ sensitivity measured by ERR in two different schools in Pemba in 2024/25, based on pairwise comparisons of parasite sub-populations in terms of the FST, partitioned by the individual-level egg reduction rates 6. Associations between genetic variants and PZQ sensitivity in terms of Ca2+ influx in HEK293 cells, measured by functional profiling of TRPMPZQ SNPs in two different schools in Pemba in 2024/25 7. Prevalence and intensity of S. haematobium infections in schoolchildren from 17 schools in 2024/25, as measured by urine filtration 8. Prevalence and intensity of S. haematobium infections in schoolchildren from two schools before and after MDA in 2024/25, as measured by urine filtration 9. Individual and population-level S. haematobium ERR of MDA in two different locations in Pemba in 2024/25, based on the population-level arithmetic mean egg counts before and after treatment 10. Model-predicted impact of praziquantel MDA and praziquantel resistance mitigation strategies on trends in S. haematobium infection prevalence and intensity and drug efficacy (ERR) 11. Cost-efficient survey strategies for p

Countries

Tanzania

Contacts

Public ContactStefanie Knopp
s.knopp@swisstph.ch+41 (0)612848727

Outcome results

None listed

Source: ISRCTN (via WHO ICTRP) · Data processed: Feb 4, 2026