The Clinical Epidemiology of Scrub Typhus in Humans, Chiggers and Rodents
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Oxford
- Enrollment
- 1,200
- Primary Endpoint
- Identify key mite vectors and rodent hosts involved in scrub typhus natural history, human infection, and disease virulence
Study Overview
Brief Summary
This study to collect and identify rodents and mites across transects through diverse habitats used by the human community from a localised area identified as a scrub typhus 'hot spot'.
Detailed Description
Study design:
The project will undertake a detailed investigation of one human community, and its environment, at risk of scrub typhus:
Chiggers, Rodents & Habitat Study:
Transects across diverse habitats determining spatial distribution of species of chiggers and rodents. This will be performed 3x/year.
High-resolution habitat mapping. Comparison of genomes of O. tsutsugamushi detected in different environments, using attempted WGS.
Study Design
- Study Type
- Observational
- Observational Model
- Cohort
- Time Perspective
- Prospective
Eligibility Criteria
- Ages
- 10 Years to — (Child, Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Acute scrub typhus (Group 1)
- •Presenting with fever >38 C and testing positive by scrub typhus RDT.
- •Male or Female, aged 10 years or above.
- •Participant is willing and able to give informed consent for participation in the study.
- •Scrub typhus serosurvey (Group 2)
- •Villagers living in an environment in which scrub typhus is known to be present, who are asymptomatic.
- •Male or Female, aged 10 years or above.
- •Participant is willing and able to give informed consent for participation in the study.
Exclusion Criteria
- •Acute scrub typhus (Group 1)
- •Villagers/patients under 10 years of age.
- •Those unwilling to give written informed consent.
- •Scrub typhus serosurvey (Group 2)
- •Villagers/patients under 10 years of age.
- •Those unwilling to give written informed consent.
Outcomes
Primary Outcomes
Identify key mite vectors and rodent hosts involved in scrub typhus natural history, human infection, and disease virulence
Time Frame: up to 24 months
determine the diversity of O. tsutsugamushi genotypes infecting rodents and mites and link these to their geographical distribution and associated habitat characteristics.
Time Frame: up to 24 months
Correlate the frequency of O. tsutsugamushi in mites and rodents with habitat characteristics, to define interactions between distribution and transmission dynamics.
Time Frame: up to 24 months
Secondary Outcomes
- Identify human-derived O. tsutsugamushi genotypes to define genomic relationships between human, rodent and mite-derived genotypes.(up to 24 months)
- To interlink the distribution of O. tsutsugamushi positive mites, rodents and humans with habitat characteristics to propose interventions to reduce the risk of human disease.(up to 24 months)
- Identify putative determinants of human infection/virulence(up to 24 months)
- Determine changes in scrub typhus antibody titres over time and identify acutely infected scrub typhus cases(up to 24 months)