Healthy children younger than one year of age are hospitalized for illness attributable to influenza at rates similar to those for adults at high risk for influenza. The rate of hospitalization decreases markedly with age. Influenza accounts for a substantial number of outpatient visits and courses of antibiotics in children of all ages.

No abstract

This study sought to quantify influenza-related serious morbidity in pregnant women, as measured by hospitalizations for or death from selected acute cardiopulmonary conditions during predefined influenza seasons. The study population included women aged 15-44 years who were enrolled in the Tennessee Medicaid program for at least 180 days between 1974 and 1993. In a nested case-control study, 4,369 women with a first study event during influenza season were compared with 21,845 population controls. The odds ratios associated with study events increased from 1.44 (95% confidence interval (CI) 0.97-2.15) for women at 14-20 weeks' gestation to 4.67 (95% CI 3.42-6.39) for those at 37-42 weeks in comparison with postpartum women. A retrospective cohort analysis, which controlled for risk factors identified in the case-control study, identified 22,824 study events during 1,393,166 women-years of follow-up. Women in their third trimester without other identified risk factors for influenza morbidity had an event rate of 21.7 per 10,000 women-months during influenza season. Approximately half of this morbidity, 10.5 (95% CI 6.7-14.3) events per 10,000 women-months, was attributable to influenza. Influenza-attributable risks in comparable nonpregnant and postpartum women were 1.91 (95% CI 1.51-2.31) and 1.16 (95% CI -0.09 to 2.42) per 10,000 women-months, respectively. The data suggest that, out of every 10,000 women in their third trimester without other identified risk factors who experience an average influenza season of 2.5 months, 25 will be hospitalized with influenza-related morbidity.

No abstract

Timing of birth in relationship to winter virus season confers a differential and definable risk of developing early childhood asthma, establishing winter virus seasonality as a causal factor in asthma development. Delay of exposure or prevention of winter viral infection during early infancy could prevent asthma.

Background-Infants hospitalized for bronchiolitis have a high rate of early childhood asthma. It is not known whether bronchiolitis severity correlates with the risk of early childhood asthma or with asthma-specific morbidity.

In 1989, the state of Tennessee adopted a new birth certificate which incorporates changes recommended by the National Center for Health Statistics in the revised US Standard Certificate of Live Birth. The data now being collected are intended to provide improved information for understanding maternal and infant health issues. To assess data quality, the authors compared information reported on the 1989 Tennessee birth certificates with the same data obtained from an ongoing case-control study in which the delivery hospital medical records of mothers and infants were reviewed by trained nurse abstractors using a structured data collection instrument. Cases (n = 1,016) were all infants born in Tennessee in 1989 with birth weights less than 1,500 g or other infants who died during the first 28 days of life. The infants were identified from linked birth-death certificate files. Control infants (n = 634) were randomly selected from the noncase population. The most reliable information obtained from birth certificates was descriptive demographic data and birth weight. The quality of information obtained from the new birth certificate checkboxes varied. Routine medical procedures were better reported on the birth certificates than relatively uncommon conditions and occurrences, even serious ones. Caution is needed in using birth certificate data for assessment of maternal medical risk factors, complications of labor and delivery, abnormal conditions of the newborn, and congenital anomalies, since sensitivity is low.

The rate of IPD among children with SCD who are aged <5 years has decreased markedly since the introduction of routine administration of PCV to young children.