Scrub Typhus Pediatric Immunology Study (NIRPS)
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|ClinicalTrials.gov Identifier: NCT02398162|
Recruitment Status : Completed
First Posted : March 25, 2015
Last Update Posted : September 20, 2018
This is an observational study of the natural immune response to scrub typhus in patients recruited from Chiangrai Prachanukroh Hospital, N-Thailand. Febrile patients with a positive IgM rapid diagnostic test will be asked if they wish to take part in a study to improve the understanding of how the body responds to scrub typhus. Blood samples will be collected from each participant ("STP", n=60) at baseline (the day of presentation to hospital), 2 weeks later in hospital, 12 weeks after baseline at the clinic visit and 1 year later. Data on clinical presentation and relapses will be recorded. Control subjects are scrub typhus exposed patients from a rural village in the caption area of Prachanukroh Hospital ("STE", n=80; approx. 40 children and 40 adults), and healthy adults blood donors from Bangkok ("STH" n=30) - these subjects will be enrolled for one single blood sample. The study team will also collect eschar swab specimens from STP group and a non-invasive specimen of the dark crust on the day of enrollment.
Funder: Li Ka Shing Foundation [Grant C13004]
|Condition or disease||Intervention/treatment|
|Scrub Typhus||Procedure: Multi Blood Collections Procedure: Single Blood Collection|
o To measure and characterize the memory and effector T-cell responses, as well as the humoral response in young patients with acute scrub typhus and to compare theseThese acute responses will be compared to responses in the convalescent phase of the same individuals at 2, 12 and 52 weeks later, as well as to scrub typhus-exposed controls and to healthy controls.
- To establish ELISpot and flow cytometer based immunology assays using human samples collected in rural areas of high scrub typhus endemicity.
- To set up a prospective cohort study of paediatric scrub typhus in a region of high endemicity
Description of the Study Sites and Population Chiangrai Prachanukroh Hospital in Chiangrai province, N-Thailand is ideally suited for this study. We have a well-established collaboration, due to a previously completed multi-year fever study and an excellent relationship with local senior doctors, staff and the hospital-based laboratory. There is a very high rate of scrub typhus cases admitted to the infectious diseases ward and the recent establishment of a MORU (Mahidol Oxford Tropical Medicine Research Unit) satellite laboratory within the hospital facilities, make this study site unique and highly suited for performing this research project. This study will contribute significantly towards the long-term aim of developing the Chiangrai study site towards an immunogenicity monitoring field site for vaccine trials.
The 'scrub typhus' patients (STP) are febrile children recruited from the ID and/or pediatric wards at Prachanukroh hospital during an acute hospitalization due to scrub typhus, and followed up as described above.
The scrub typhus 'exposed' cohort (STE) will consist of children and adults recruited from two villages in an area where scrub typhus is reported as a common disease. This cohort has a high risk of previous contact with scrub typhus, and it is unknown if they had an asymptomatic or sub-clinical infection in the past, but we expect the presence of some form of immune memory regarding cellular and/or humoral immunity in a large proportion of these subjects.
The healthy scrub typhus naïve control group (STH) does not necessarily need to include children, as the principle is to compare a non-exposed immune response to previously exposed and/or acute cellular responses. Thus, the 'Healthy Cohort' will be recruited from the staff at MORU and/or the Faculty of Tropical Medicine in Bangkok.
|Study Type :||Observational|
|Actual Enrollment :||170 participants|
|Official Title:||The Natural Immune Response In Pediatric Scrub Typhus In Chiangrai|
|Actual Study Start Date :||July 15, 2015|
|Actual Primary Completion Date :||October 17, 2017|
|Actual Study Completion Date :||October 17, 2017|
Scrub Typhus Patients (STP, n=60) Cohort. Blood samples will be collected at baseline (the day of presentation to hospital), 2 weeks later in hospital, 12 weeks after baseline at the clinic visit and 1 year later. Data on clinical presentation and relapses will be recorded. Eschar swab specimens and a non-invasive specimen of the dark crust will be also collected from STP group on the day of enrollment.
Procedure: Multi Blood Collections
At baseline (the day of presentation to hospital), 2 weeks, 12 weeks and 1 year later.
Scrub Typhus Exposed (STE, n=80) Cohort. Single blood sample collection.
Procedure: Single Blood Collection
On the enrollment day
Scrub Typhus Healthy (STH, n=30) Cohort. Single blood sample collection
Procedure: Single Blood Collection
On the enrollment day
- Cellular immune response to Orientia tsutsugamushi [ Time Frame: 2 years ]Characterize the cellular immune response to Orientia tsutsugamushi, based on immune cell phenotyping and quantitation of effector, memory & regulatory T cell functions.
- T-cell subsets during the scrub typhus infection [ Time Frame: 2 years ]Identification of T-cell subsets affected by apoptosis during the course of acute scrub typhus.
- Antibody isotypes during the scrub typhus infection [ Time Frame: 2 years ]Determination of the antibody isotypes and their dynamics involved in natural scrub typhus infection.
- Adaptive immune response to Orientia tsutsugamushi [ Time Frame: 2 years ]Characterisation of the adaptive immune response to Orientia tsutsugamushi, measured by ex vivo interferon-gamma ELISPOT in spot forming cells per million peripheral blood mononuclear cells (SFC/106PBMC), using four Orientia antigens (whole cell antigen, 56kDa, 47kDa and scaC) in samples of acute disease and long term follow up.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02398162
|Chiangrai Prachanukroh Hospital|
|Chiang Rai, Thailand|
|Principal Investigator:||Dr.Daniel Paris, MD||Mahidol Oxford Tropical Medicine Research Unit|