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Scrub Typhus Antibiotic Resistance Trial

NCT03083197 · Status: ACTIVE_NOT_RECRUITING · Phase: PHASE4 · Type: INTERVENTIONAL · Enrollment: 177

Last updated 2026-04-28

No results posted yet for this study

Summary

Study type: Randomized Control Treatment Trial

Study population: Male and female patients with ≥15 years of age and acute scrub typhus

Duration: 2 years

Study Design: Prospective, open-label, randomized-controlled treatment trial in patients ≥15 years old admitted to hospital with acute scrub typhus. Randomization into 3 oral treatment arms (each n=59 patients, total n=177): i) 7 days of doxycycline, ii) 3 days of doxycycline, and iii) 3 days of azithromycin

Primary Objective: To evaluate the clinical and microbiological responses in scrub typhus patients to three oral treatment regimens: 7 days of doxycycline, 3 days of doxycycline, and 3 days of azithromycin

Secondary Objectives:

1. To perform pharmacokinetic/pharmacodynamics (PK/PD) characterization of the therapeutic responses for doxycycline and azithromycin, incl. serial bacterial load measurements.
2. To define clinical, bacterial, pathophysiological and pharmacological factors associated with disease severity, fever-clearance times (FCT), treatment failures and relapse/re-infection.
3. To determine the minimum inhibitory concentrations (MIC) of clinical Orientia tsutsugamushi isolates to doxycycline, azithromycin and chloramphenicol, using in vitro growth-inhibition assays
4. To genotype all clinical isolates using whole genome sequencing for comparative genomics.
5. To dissect the natural immune response in scrub typhus, using antigen-specific cellular immune and antibody studies, and cytokine profiling

Conditions

  • Scrub Typhus

Interventions

DRUG

Doxycycline 7 days

loading dose 200mg PO, then 100mg PO every 12 hours for 7 days

DRUG

Doxycycline 3 days

loading dose 200mg PO, then 100mg PO every 12 hours for 3 days

DRUG

Azithromycin 3 days

loading dose 1000mg PO on day 1, then 500mg PO every 24 hours on days 2 and 3

Sponsors & Collaborators

  • Shoklo Malaria Research Unit

    collaborator OTHER

  • Chiangrai Prachanukroh Hospital

    collaborator OTHER

  • Mae Suai District Hospital

    collaborator UNKNOWN

  • Mae Chan District Hospital

    collaborator UNKNOWN

  • Mae Fa Luang District Hospital

    collaborator UNKNOWN

  • University of Oxford

    lead OTHER

Principal Investigators

  • Assoc. Prof. Daniel Paris · Mahidol-Oxford Tropical Medicine Research Unit, Bangkok, Thailand

Study Design

Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Model
PARALLEL

Eligibility

Min Age
15 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2017-10-15
Primary Completion
2026-10-31
Completion
2028-10-31

Countries

  • Thailand

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT03083197 on ClinicalTrials.gov