Rheumatic fever

Professor Michael Baker leads Wellington researchers who are studying rheumatic fever to better understand its causes, and potential intervention such as improved housing conditions and use of probiotics.

Investigating household crowding as a risk factor

Acute rheumatic fever (ARF) and its sequelae, chronic rheumatic heart disease, remain important causes of morbidity and mortality worldwide, but there is little recent information about risk factors. The aim of this study was to examine the association between ARF and household crowding in New Zealand between 1996 and 2005.

Census and hospitalisation data integrated

This ecologic study used hospitalization data and census data to calculate incidence rates by census area unit (CAU). Rates of ARF were examined in relation to individual factors (age, ethnicity) and area factors based on the CAU of home address (household crowding, New Zealand deprivation index, household income, and proportion of children aged 5–14 years). The multivariate relationship between ARF incidence and CAU-based variables was assessed using a zero-inflated negative binomial model.

Significant, and positive relationship to crowding determined

This study included 1249 new cases of ARF between 1996 and 2005. At the univariate level, ARF rates were associated with household crowding across all age groups and ethnicities. ARF rates were significantly and positively related to household crowding after controlling for age, ethnicity, household income, and the density of children in the neighborhood. The incidence rate ratio was 1.065 (95% confidence interval, 1.052–1.079) for the total population.

Reducing household crowding supportive to improving health

In New Zealand, ARF rates are associated with household crowding at the CAU level. This finding supports action to reduce household crowding to improve health and reduce health inequalities. Our conclusion could be further investigated using a case-control study.

Reference

Jaine, R., Baker, M., & Venugopal, K. (2011). Acute rheumatic fever associated with household crowding in a developed country. Pediatric Infectious Disease Journal, 30(4), 315-319.
doi: 10.1097/INF.0b013e3181fbd85b