Age-specific hospitalization risk of primary and secondary respiratory syncytial virus infection among young children. (November 2022)

• Record Type: Journal Article
• Authors: Nakajo, Ko; Nishiura, Hiroshi
• Is Part Of: International journal of infectious diseases. Volume 124(2022)
• Page Start: 14
• Page End: 20
• Publication Date: 2022-11
• Subjects: Epidemiology -- Statistical model -- Respiratory syncytial virus -- RSV -- Hospitalization -- Japan; Communicable diseases -- Periodicals; Communicable Diseases -- Periodicals; Communicable diseases; Periodicals; Electronic journals; 616.9
• DOI: 10.1016/j.ijid.2022.09.008
• Languages: English
• ISSNs: 1201-9712

Abstract

Highlights: Respiratory syncytial virus is the leading cause of hospitalization among infants aged under 12 months. Age-specific risk of respiratory syncytial virus–associated hospitalizations in Japan was investigated. The hospitalization risk during primary infection was highest in infants. The relative risk of hospitalization owing to secondary infection was small. Abstract: Objectives: Elucidating the infection dynamics that lead to severe respiratory syncytial virus (RSV) pneumonia and hospitalization among young children are critical. We explored the role of infection parity as well as age in months for RSV-associated hospitalization among young children in Japan. Methods: We used a sequential transmission catalytic model to capture the transmission mechanisms of RSV among infants in an endemic state. We investigated data on the age-dependent seroprevalence and incidence rate of hospitalization in Japan, and jointly estimated the age-specific risk of hospitalization during primary RSV infection and relative risk of hospitalization during secondary infection in children aged <5 years. Results: The estimated risk of hospitalization with primary infection was 0.08 (95% CI: 0.05-0.14) in infants aged 0-2 months. The estimated relative risk of hospitalization owing to secondary infection was 0.18 (95% CI: 0.01-2.04). Conclusion: Our simple models successfully captured the infection dynamics of RSV among young children in Japan. The age group of early infancy may be most vulnerable to infection and hospitalization, offering key insights into future vaccinations. The burden of hospitalization from secondary infection may be less important in young children.