Pneumonia Hospitalizations among American Indian and Alaska Native Children after a Decade of Pneumococcal Vaccine
American Indian and Alaska Native (AI/AN) children experience high rates of pneumonia compared with the general US child population. 7-valent pneumococcal conjugate vaccine (PCV7) introduction in 2000 resulted in a significant decline in pneumonia hospitalization rates among the US child population; however, data are lacking for the impact of PCV7 on pneumonia in AI/AN children.
METHODS:
A retrospective analysis of pneumonia hospitalizations during 1997-2011 was conducted using the Indian Health Service direct and contract inpatient data to calculate hospitalization rates per 100,000 for AI/AN children <5 years of age. Hospitalizations were classified as pneumonia if pneumonia was the first-listed diagnosis or listed after a first-listed diagnosis of sepsis, meningitis or empyema. Average annual hospitalization rates were compared with published US child population rates using the Nationwide Inpatient Sample.
RESULTS:
From 1997-1999 to 2007-2009 the average annual rate of pneumonia hospitalizations declined from 3006 to 2224 (26%) for AI/AN <2 years of age, compared with 1274 to 723 (43.2%; 95% CI 34.9-51.6) for the general US child population <2 years of age. In both, the largest decline occurred in 1997-99 to 2001-2006 after PCV7 introduction. Among AI/AN, an additional decline (6.7%; 2224 to 2075) occurred from 2007-2009 to 2010-2011. Pneumonia hospitalization rates decreased in AI/AN 2-4 year olds (24.5; 560 to 423) for 1997-1999 to 2007-2009 compared to a decline of 12.5% (95% CI 2.4 to 22.6), for the 2-4 year old general US population.
CONCLUSIONS: Pneumonia hospitalization rates among AI/AN and US general child population <2 years declined dramatically after PCV7 introduction; however, AI/AN rates remain significantly higher. Rate declines for AI/AN continued through 2010-2011. AI/AN children 2-4 years also experienced substantial declines in the decade after PCV7. These findings likely represent the impact of PCV7 vaccination, housing improvements, and increased availability of in-home piped water.