Eschar Investigations in Scrub Typhus

Completed

• Conditions: Scrub Typhus
• Interventions: Other: Non-invasive eschar samples + blood; Other: Non-invasive eschar samples+eschar biopsy+lymph node fine-needle aspiration biopsy+blood; Other: Non-invasive eschar samples+eschar biopsy+blood; Other: Blood+Skin sample

• Registration Number: NCT02915861
• Lead Sponsor: University of Oxford

Brief Summary

This is an observational study of patients with scrub typhus (rapid diagnostic test/quantitative polymerase chain reaction (RDT/qPCR) positive) and an inoculation eschar present on examination, recruited from Chiangrai Prachanukroh Hospital, North of Thailand.

In this study, we aim to:

* Investigate relevant pathogen dissemination dynamics, early innate immune response, and pathogen-host interactions in scrub typhus using a minimal set of easily accessible samples; the inoculation eschar (crust or biopsy), whole blood and - where possible - a lymph node fine-needle aspiration (FNA).

* Determine the potential use of the inoculation eschar for improving early diagnostics and assessing the diversity of human pathogenic strains; by evaluating non-invasive swabs and scrapings, as well as biopsies for molecular diagnostics templates.

* Dissect the underlying patho-biology associated with the inoculation eschar and in a subgroup, including the draining lymph node; by defining the spectrum of infected cells via microscopy and double-immune labeling; by determining cytokine and RNA gene expression profiles in blood peripheral blood mononuclear cell (PBMCs) and eschar samples.

Data sharing:

No future analysis or study of legacy data/specimens including data sharing for purposes not specified in the protocol will be done without seeking further regulatory (EC/IRB) approval

* Any requests for data sharing will be considered by MORU's data sharing committee

* Any data subsequently shared will be anonymised and will not include personal identifiers

Detailed Description

Scrub typhus patients will be recruited into the scrub typhus patient (EXP) arm of the study. There will be 3 sub-groups:

* EXPa (n=12) will have blood and non-invasive eschar samples collected (consent to study, declined biopsy).

* EXPb (n=12) will have blood, non-invasive eschar samples, and an eschar biopsy collected (consent to study, draining lymph node (LN) inaccessible).

* EXPc (n=12) will have blood, non-invasive eschar samples, eschar biopsy, and LN FNA collected (consent to study, draining LN accessible).

Samples will be collected at baseline (all) and 2 weeks (blood only).

Control participants will be recruited into the scrub typhus control.

- EXC (n=12) are healthy individuals, attending hospital for elective/minor surgery or treatment of minor skin injury, and normally reside in a scrub typhus endemic region. Blood and a skin sample will be collected at baseline only.

Basic Information
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Recruitment & Eligibility
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Study & Design
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Trial Locations

Study Timeline

• Study First Submitted: 2016-09-22
• Study First Submitted QC: 2016-09-22
• Study First Posted: 2016-09-27
• Study Start: 2017-06-30
• Primary Completion: 2021-05-31
• Study Completion: 2021-05-31
• Status Verified: 2021-07
• Last Update Submitted: 2021-07-29
• Last Update Posted: 2021-08-05

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 44

Inclusion Criteria

Not provided

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Exclusion Criteria

Not provided

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
EXPa	Non-invasive eschar samples + blood	Scrub typhus patients: Group A
EXPc	Non-invasive eschar samples+eschar biopsy+lymph node fine-needle aspiration biopsy+blood	Scrub typhus patients: Group C
EXPb	Non-invasive eschar samples+eschar biopsy+blood	Scrub typhus patients: Group B
EXC	Blood+Skin sample	Control group

Primary Outcome Measures

Name	Time	Method
Characterisation of cytokine and RNA gene expression profiles within the eschar, lymph node, and blood in vivo and comparisons with profiles of uninfected target cells.	2 years
Phenotypic characterisation of the major subset of Orientia tsutsugamushi (OT) infected leucocytes within eschar, lymph node, and blood during the dissemination phase of OT in vivo.	2 years

Secondary Outcome Measures

Name	Time	Method
Establishing the usefulness of non-invasive eschar samples from patients with acute scrub typhus for diagnostics for OT and for genotyping +/- whole-genome sequencing.	2 years
Comparisons to parallel studies in the non-human primate model with emphasis on dissemination dynamics, immunomodulation, and the innate and adaptive immune responses to OT; contributing to vaccine development.	2 years
Define and contrast the eschar histo-pathological findings in this study in Thailand to previous findings from Laos, where the Gilliam strain predominates.	2 years

Trial Locations

Locations (1)

Chiangrai Prachanukroh Hospital; 🇹🇭 Chiang Rai, Thailand