Assessing the Epidemiological Characteristics and Clinical Burden of Respiratory Syncytial Virus (RSV) Infection in Children Aged 0-24 Months in Primary Healthcare Settings of Ho Chi Minh City, Vietnam (2026 - 2028)
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- Enrollment
- 2,000
- Locations
- 3
Study Overview
Brief Summary
This is a prospective, observational, multicenter study employing continuous, convenience sampling, stratified by study site and by fortnightly interval, enrolling until the target sample sizes are achieved over the first epidemiological season (2026) and the second epidemiological season (2027). The study population includes children aged 0 to 24 months presenting to the outpatient or inpatient facilities of the study sites with signs and symptoms of acute respiratory infection (ARI). In Vietnam there is no single guideline for diagnosing ARI, but rather there are guidelines specific to clinical conditions such as pharyngitis, rhinitis, tonsilitis, or pneumonia. This study will use an operational definition where ARI is defined as the presence of one or more of the following clinical features: cough, rhinorrhea, sore throat, dyspnea, and / or fever.
RSV testing using nasopharyngeal (NP) swabs will be collected from all eligible children with consent to participate in the study; if a NP swab is not feasible, a mid-turbinate nasal swab will be used. Specimens will be transported to a central laboratory for real-time, reverse transcription-polymerase chain reaction (RT-PCR) testing.
Furthermore, the stored viral transport media from all the RSV-positive samples will be used for whole genome sequencing (WGS) to determine the subgroup (A or B) of the circulating RSV strains and to analyze the genotype.
The parent or legally acceptable representative (LAR) of pediatric patients will provide information regarding the patient's demography, such as the family's socioeconomic status and household environment (e.g., exposure to tobacco smoke, overcrowding). The children's immunization history and their mothers' immunization history (i.e., vaccines such as influenza and Tdap received during the pregnancy as part of a maternal immunization program) will be established, which is not to estimate vaccine effectiveness but to document the level of vaccine uptake in these populations during the study. Children with maternal RSV vaccination will be excluded.
Crucially, the parent or LAR also will report on the child's complete medical history, including perinatal / pregnancy history, presence of congenital anomaly, previous history of illness, and detailed history and clinical course of the current illness episode. Maternal hypertension and history of immunological factors will not be explored. Data on the medical treatment will be abstracted from the patients' medical records.
One month after the outpatient clinic visit or hospital discharge, the parent or LAR will be contacted via mobile phone to ascertain the children's current health status and to collect information on the family's direct costs due to the illness.
Detailed Description
This is a prospective, observational, multicenter study employing continuous, convenience sampling until the target sample size is achieved (N=2,000). (In this field investigation, healthcare workers will look to enroll potentially eligible patients presenting in their outpatient clinic or inpatient hospital setting. The study population includes children aged 0 to 24 months presenting to the outpatient or inpatient facilities of the study sites with symptoms of acute respiratory infection (ARI).
Participants will receive treatment for their acute respiratory infections strictly in accordance with the standard of care guidelines at the respective research sites. The study's design is a low-interventional study. Infants and children eligible for inclusion in the study and whose parents or LAR have provided consent will have a low intervention nasopharyngeal swab for RSV testing. Patients will also be tested for influenza as per site standard of care and per investigator's judgement. There will be no changes to the patient's treatment regimen or clinical care during their outpatient visit or hospitalization.
The study will be carried out over a period of 24 months, from May 2026 to May 2028, to capture seasonal variations in RSV proportion in two rainy seasons.
The study population will include children aged 0 to 24 months presenting with acute respiratory infection (ARI) to the outpatient or inpatient facilities of the three selected study sites: Dĩ An Health Center, Ba Ria General Hospital, and Lê Văn Thịnh Hospital (all in Ho Chi Minh City).
During the physical examination of pediatric patients presenting at the study sites, the attending physician will notify the study team if any child aged 0-24 months meets the ARI case definition. The study team will then approach the parent or LAR to introduce the team and the study's purpose, and to perform a preliminary assessment of the patient's eligibility.
Study Design
- Study Type
- Observational
- Observational Model
- Other
- Time Perspective
- Cross Sectional
Eligibility Criteria
- Ages
- 0 Months to 24 Months (Child)
- Sex
- All
- Accepts Healthy Volunteers
- No
Inclusion Criteria
- •Children aged 0 to <24 months (i.e., less than two years old).
- •Children presenting with a diagnosis of acute respiratory infection (ARI), defined as an illness with one or more of the following symptoms: cough, rhinorrhea, sore throat, dyspnea (including wheezing, tachypnea, or apnea/increased work of breathing), sepsis (for infants aged <6 months), and/or fever.
- •Children residing in the lowest administrative division (Phường / Xã) in Vietnam that is designated for the specific study site (outpatient clinic or community hospital). As patients live in the same administrative district as the healthcare facility, this will facilitate follow-up and ensure that the study results are representative of the range of severity of ARI presenting to each specific study site.
- •Parent or LAR provides written informed consent for their child's participation.
Exclusion Criteria
- •Children whose mothers received a maternal RSV vaccine during pregnancy or who have themselves received RSV-specific monoclonal antibodies (mAbs).
- •Children with a known non-respiratory cause for hospitalization.
- •Children with respiratory symptoms lasting over 14 days.
- •Children hospitalized elsewhere within the preceding 4 days, excluding admission to the Emergency Department.
- •Children already enrolled in another RSV study within the preceding 3 months.