Michelle C. Dimitris (Canada)
Children's Hospital of Eastern Ontario (CHEO) Research InstituteAuthor Of 1 Presentation
EXAMINING THE RELATIONSHIP BETWEEN RESPIRATORY SYNCYTIAL VIRUS, INFLUENZA, AND ROTAVIRUS SEASONS' TIMING AND SEVERITY, AND INFANT AGE AT VIRAL SEASONS' PEAKS, WITH SUBSEQUENT CHILDHOOD ASTHMA
Abstract
Backgrounds:
Most infants are exposed to respiratory syncytial virus (RSV) in the first year of life. Studies have observed an association between severe RSV infection and asthma, yet it is unclear if this relationship is causal or due to underlying factors that increase susceptibility to both conditions. One study partially mitigated the influence of these factors by examining the relationship between infant age at winter virus peak and subsequent asthma. We extended this approach by examining infant age at RSV, influenza, and rotavirus peaks, as well as proxies for the timing and severity of RSV, influenza, and rotavirus seasons, and their relationships with subsequent incidence of childhood asthma.
Methods
We analyzed province-wide administrative data for 1,437,731 infants born in Ontario, Canada from 2002-2013. We ascertained RSV, influenza, and rotavirus hospitalizations by 1 year and asthma by 5 years of age using inpatient/outpatient ICD-9/10 codes. We used regression models to investigate: (1) infant age in the calendar week with highest incidence of hospitalization for each virus and subsequent asthma (unit of analysis infant); (2) incidence of RSV-, influenza-, and rotavirus-related hospitalizations by 1 year and asthma by 5 years (unit of analysis calendar week of birth).
Results:
We observed highest likelihood of subsequent asthma at infant ages of approximately 13-, 11-, and 16-weeks during RSV, influenza, and rotavirus peaks, respectively. We observed apparent seasonal variation in childhood asthma by infant week of birth. The relationship between RSV seasonal variation and asthma appeared small in magnitude, while an unexpected relationship between rotavirus seasonal variation and asthma emerged (Figure).
Conclusions/Learning Points:
We find limited evidence in support of a causal relationship between RSV and asthma, and suggest further investigation of other mechanisms, including underlying seasonal characteristics.
Presenter of 1 Presentation
EXAMINING THE RELATIONSHIP BETWEEN RESPIRATORY SYNCYTIAL VIRUS, INFLUENZA, AND ROTAVIRUS SEASONS' TIMING AND SEVERITY, AND INFANT AGE AT VIRAL SEASONS' PEAKS, WITH SUBSEQUENT CHILDHOOD ASTHMA
Abstract
Backgrounds:
Most infants are exposed to respiratory syncytial virus (RSV) in the first year of life. Studies have observed an association between severe RSV infection and asthma, yet it is unclear if this relationship is causal or due to underlying factors that increase susceptibility to both conditions. One study partially mitigated the influence of these factors by examining the relationship between infant age at winter virus peak and subsequent asthma. We extended this approach by examining infant age at RSV, influenza, and rotavirus peaks, as well as proxies for the timing and severity of RSV, influenza, and rotavirus seasons, and their relationships with subsequent incidence of childhood asthma.
Methods
We analyzed province-wide administrative data for 1,437,731 infants born in Ontario, Canada from 2002-2013. We ascertained RSV, influenza, and rotavirus hospitalizations by 1 year and asthma by 5 years of age using inpatient/outpatient ICD-9/10 codes. We used regression models to investigate: (1) infant age in the calendar week with highest incidence of hospitalization for each virus and subsequent asthma (unit of analysis infant); (2) incidence of RSV-, influenza-, and rotavirus-related hospitalizations by 1 year and asthma by 5 years (unit of analysis calendar week of birth).
Results:
We observed highest likelihood of subsequent asthma at infant ages of approximately 13-, 11-, and 16-weeks during RSV, influenza, and rotavirus peaks, respectively. We observed apparent seasonal variation in childhood asthma by infant week of birth. The relationship between RSV seasonal variation and asthma appeared small in magnitude, while an unexpected relationship between rotavirus seasonal variation and asthma emerged (Figure).
Conclusions/Learning Points:
We find limited evidence in support of a causal relationship between RSV and asthma, and suggest further investigation of other mechanisms, including underlying seasonal characteristics.