Respiratory Syncytial Virus-Associated Hospitalization Rates among US Infants: A Systematic Review and Meta-Analysis.

BACKGROUND: Although global reviews of infant respiratory syncytial virus (RSV) burden exist, none have summarized data from the United States or evaluated how RSV burden estimates are influenced by variations in study design. METHODS: We performed a systematic literature review and meta-analysis of studies describing RSV-associated hospitalization rates among US infants and examined the impact of key study characteristics on these estimates. RESULTS: We reviewed 3328 articles through 14 August 2020 and identified 25 studies with 31 unique estimates of RSV-associated hospitalization rates. Among US infants <1 year of age, annual rates ranged from 8.4 to 40.8 per 1000 with a pooled rate of 19.4 (95% confidence interval [CI], 17.9-20.9). Study type influenced RSV-associated hospitalization rates (P = .003), with active surveillance studies having pooled rates (11.0; 95% CI, 9.8-12.2) that were half that of studies based on administrative claims (21.4; 19.5-23.3) or modeling approaches (23.2; 20.2-26.2). CONCLUSIONS: Applying our pooled rates to the 2020 US birth cohort suggests that 79 850 (95% CI, 73 680-86 020) RSV-associated infant hospitalizations occur each year. The full range of RSV-associated hospitalization rates identified in our review can better inform future evaluations of RSV prevention strategies. More research is needed to better understand differences in estimated RSV burden across study design.

Epidemiology of respiratory syncytial virus in Japan: A nationwide claims database analysis.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of hospitalization for bronchiolitis and pneumonia in infancy. In Japan, limited data are publicly available on RSV epidemiology and clinical characteristics among infants. METHODS: This retrospective study described RSV incidence, seasonality, patient characteristics, resource use, and clinical outcomes among Japanese children <2 years from January 2017 through December 2018. The RSV cases were identified using the Japanese Medical Data Center database. RESULTS: In the database, 9,711 and 8,509 RSV patients <2 years were identified in 2017 and 2018, respectively. Of these, 25% required hospitalization. Ninety percent of hospitalized patients did not have a known RSV risk factor. Nineteen percent of hospitalized patients experienced dehydration, and 12% had acute respiratory failure. Hospitalization lasted 1 week on average and 7% required some type of mechanical ventilation. The peak of hospitalizations occurred at 2 months. The incidence of RSV hospitalization in children <2 years was 23.2 per 1,000 person-years, which increased to 35.4 per 1,000 for infants <6 months. This age group accounted for 40% of all RSV-associated hospitalizations among children <2 years. CONCLUSIONS: Roughly one-fourth of all RSV patients <2 years were hospitalized. Ninety percent of these did not have an underlying risk condition. This underscores that RSV can cause serious disease among all young children. Three to four out of every 100 Japanese children <6 months were hospitalized for RSV, and this age group accounted for ~40% of all RSV-associated hospitalizations. Novel and broad-based RSV prevention strategies, especially those targeting young infants, are needed.

Impaired Transplacental Transfer of Respiratory Syncytial Virus-neutralizing Antibodies in Human Immunodeficiency Virus-infected Versus -uninfected Pregnant Women.

Human immunodeficiency virus (HIV)-exposed, uninfected infants have higher risks of respiratory syncytial virus-associated hospitalization than HIV-unexposed infants. Despite similar neutralizing antibody titers between HIV-infected and -uninfected women, maternal HIV infection and hypergammaglobulinemia were independently associated with lower titers in newborns. Maternal hypergammaglobulinemia was associated with lower cord-to-maternal antibody ratio.

The Burden of Pertussis Hospitalization in HIV-Exposed and HIV-Unexposed South African Infants.

BACKGROUND: There are limited data on pertussis in African children, including among human immunodeficiency virus (HIV)-exposed infants. We conducted population-based hospital surveillance to determine the incidence and clinical presentation of Bordetella pertussis-associated hospitalization in perinatal HIV-exposed and -unexposed infants. METHODS: Children <12 months of age hospitalized with any sign or symptom of respiratory illness (including suspected sepsis or apnea in neonates) were enrolled from 1 January 2015 to 31 December 2015. Detailed clinical and demographic information was recorded and respiratory samples were tested by polymerase chain reaction (PCR). RESULTS: The overall B. pertussis PCR positivity was 2.3% (42/1839), of which 86% (n = 36) occurred in infants <3 months of age. Bordetella pertussis was detected in 2.1% (n = 26/1257) of HIV-unexposed and 2.7% (n = 16/599) of HIV-exposed infants. The incidence (per 1000) of B. pertussis-associated hospitalization was 2.9 (95% confidence interval [CI], 1.8-4.5) and 1.9 (95% CI, 1.3-2.6) in HIV-exposed and HIV-unexposed infants, respectively (P = .09). The overall in-hospital case fatality ratio among the cases was 4.8% (2/42), both deaths of which occurred in HIV-exposed infants <3 months of age. Among cases, presence of cough ≥14 days (20.5%) and paroxysmal coughing spells (33.3%) at diagnosis were uncommon. Only 16 (38%) B. pertussis-associated hospitalizations fulfilled the Centers for Diseases Control and Prevention case definition of "definite" pertussis. CONCLUSIONS: Bordetella pertussis contributed to a modest proportion of all-cause respiratory illness hospitalization among black-African children, with a trend for higher incidence among HIV-exposed than HIV-unexposed infants. Maternal vaccination of pregnant women should be considered to reduce the burden of pertussis hospitalization in this population.