RESCEU Study: Defining the Burden of Disease of Respiratory Syncytial Virus in Europe in Infants

This will be a multi-country, multicenter, prospective, observational cohort study conducted across 3 consecutive years to determine the incidence of RSV infection, RSV associated MA-ARTI and RSV related hospitalization in a birth cohort of healthy subjects, recruited from the general population. At birth parents will be asked by a member of the study team to participate in the active cohort. If enrolled, a nasopharyngeal sample, a blood sample, a buccal sample, and urine and stool samples will be collected from the baby in the first week after birth. The blood sample will be collected by means of a heel prick or a venepuncture, if possible, in combination with an already scheduled moment of blood sampling. Respiratory tract symptoms will be assessed weekly during the RSV season by telephone or email or (daily) telephone app. If a child experiences a new episode of ARTI according to the parents, the study team will visit the child to collect a nasopharyngeal sample, 200µl is used to perform a point of care (POC) test for RSV, and the rest will be stored for additional viral testing by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). If RSV is positive, parents will be asked informed consent to obtain additional blood, nasopharyngeal, urine and stool samples at the time of RSV infection and 6-8 weeks after RSV infection. Parents of all children in the active cohort will be asked yearly to fill in a questionnaire until age 3 years maximum or till end of study (defined as the moment that the last included subject has been followed up for 12 months). If parents decline to participate in the active birth cohort, informed consent will be asked for passive follow up. Parents of participants in passive follow-up will be asked to fill in a questionnaire at birth and after one year. If their child was admitted to the hospital because of an ARTI, clinical data will be collected retrospectively from the hospital. Participating hospitals will perform RSV tests as part of standard diagnostic care in children \<1 year of age who are admitted with ARTI. Only children with hospitalization due to ARTI will be followed up by a yearly questionnaire until age 3 years maximum or till end of study (defined as the moment that the last included subject has been followed up for 12 months).