A Prospective, Epidemiological Study to Assess the Disease Burden of Respiratory Syncytial Virus Associated, Suspected Lower Respiratory Tract Infections in Newborns, From 0 to 2 Years of Age and Risk of Development of Wheeze and Asthma From 0 to 6 Years of Age

The purpose of this study is to assess the incidence and associated healthcare utilization of RSV-associated, suspected LRTI in a general population of infants from birth up to 2 years of age, and also to assess the accuracy of a newly developed LRTI case definition and severity scale compared to two existing definitions. The study will also assess the population attributable risk percent of RSV LRTI on the development of wheeze and asthma from 0 to 6 years of age.

New born infants from various countries over the world will be followed up for up to two years for the occurrence of Lower Respiratory Tract Infections. Through active and passive surveillance, any suspected case will be identified, assessed during an examination visit and followed up until completion through a diary card. Full symptomology will be assessed during the examination visit. The disease course and all healthcare utilization will be subsequently collected through a two-week diary card and contact with ay healthcare providers involved in management of the disease. RSV detection will occur through quantitative PCR of collected nasal swabs. A baseline cord blood serum sample of all subjects and a follow-up blood serum sample from a sub-cohort will also be collected to assess antibody levels at various points in time and in relation to risk of RSV LRTI. For extension period, pertaining to wheeze and asthma (Epoch 002): Subjects' parent(s)/LAR(s) will be asked to re-consent and subjects will be followed up through quarterly contacts up to the age of 6 years. Data collection will also occur from medical charts retrospectively for those who have a gap period between the end of the primary study and providing re-consent for the extension. The extension involves enrolment visit (at 2nd birthday \[on completion of primary study or as soon as possible thereafter\]) and quarterly surveillance contacts.