The Natural Immune Response In Pediatric Scrub Typhus In Chiangrai
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 170
- 试验地点
- 1
- 主要终点
- Cellular immune response to Orientia tsutsugamushi
研究概览
简要总结
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]
详细描述
Primary Objective:
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.
Secondary Objectives:
- 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.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Scrub Typhus Patients (STP) Cohort inclusion criteria
- •Age >6 months to ≤18 years (STP consist of pediatrics only)
- •Scrub Typhus Rapid test positivity (SDm Standard Diagnostics RDT, Korea)
- •O. tsutsugamushi PCR-positivity (if PCR capability is available by the start of the study)
- •Fever in ≤ 14 days of presentation to Hospital
- •Willingness to participate in the study and written informed assent previously obtained from the patient, and written informed consent obtained from the patient's parent(s), guardian(s) or representative(s)
- •Scrub Typhus Exposed (STE) Cohort inclusion criteria
- •Age >6 months to ≤18 years and age >18 years (STE consist of paediatrics and adult )
- •Historical diagnosis of scrub typhus, as defined by rapid diagnostic test, serology and/or PCR positivity (more than 2 years ago), or living in an endemic area with high risk of previous exposure.
- •Currently well and healthy
- •Willingness to participate in the study and written informed assent previously obtained from the patient, and written informed consent obtained from the patient's parent(s), guardian(s) or representative(s)
- •Scrub Typhus Healthy (STH) Cohorts inclusion criteria
- •Age >18 years (STH consist of adults only)
- •Currently well, no medical problems requiring hospital specialist supervision
- •Willingness to participate in the study and written, informed consent previously obtained
- •Residing in Bangkok for at least the 2 past recent years
排除标准
- •Scrub Typhus Patients (STP) Cohort exclusion criteria:
- •Current TB or TB treatment in ≤ 6 months (contains Orientia-effective antimicrobial)
- •Documented HIV infection, use of steroids, chemotherapy, other immunosuppressant therapy or herbal remedies containing steroids and/or pregnancy
- •Scrub Typhus Exposed (STE) Cohort exclusion criteria:
- •Significant acute intercurrent illness at the time of blood draw including fever >37.5°C or infection (including TB) requiring antibiotics
- •Documented HIV infection, use of steroids, chemotherapy, other immunosuppressant therapy or herbal remedies containing steroids and/or pregnancy
- •Scrub Typhus Healthy (STH) Cohorts exclusion criteria:
- •Previous history of scrub typhus
- •Significant acute intercurrent illness at the time of blood draw including fever >37.5°C or infection (including TB) requiring antibiotics
- •Documented HIV infection, use of steroids, chemotherapy, other immunosuppressant therapy or herbal remedies containing steroids and/or pregnancy
结局指标
主要结局
Cellular immune response to Orientia tsutsugamushi
时间窗: 2 years
Characterize the cellular immune response to Orientia tsutsugamushi, based on immune cell phenotyping and quantitation of effector, memory \& regulatory T cell functions.
次要结局
- T-cell subsets during the scrub typhus infection(2 years)
- Adaptive immune response to Orientia tsutsugamushi(2 years)
- Antibody isotypes during the scrub typhus infection(2 years)