Household presentation of acute gastroenteritis in a primary care sentinel network: retrospective database studies.

BACKGROUND: Acute gastroenteritis (AGE) is a highly transmissible condition spreading rapidly between individuals and within households. Rotavirus vaccination was introduced in the UK in 2013. The study objectives were to investigate how acute gastroenteritis incidence changed over 25 years and household incidence of AGE since 2013.
METHODS: Repeated cross-sectional study of Royal College of General Practitioners Research and Surveillance Centre network. We used a negative binomial model to report incidence rate ratio (IRR) using the last 5 years data. We also conducted a retrospective cohort analysis, using a shared gamma frailty model (2013-2017). We explored the impact of child under 5- years, household size, socioeconomic status quintile, and rurality.
RESULTS: In the cross-sectional analysis, the IRR of AGE in households with a child of under 5 years was 12.20 (95%CI 11.08-13.45-, p < 0.001) compared with households without; the IRR fell across IMD quintiles, for example there is a 37% decrease in incidence comparing IMD quintile 1 to quintile 5 (95%CI -0.52-0.76, p < 0.001), The cohort study revealed that the presence of an under 5 in the household was associated with a higher risk of household presentation (HR = 6.29, 95% CI 5.61-7.06, p < 0.001). In addition, we observe a reduction in risk of presentation from the most to the least deprived socioeconomic quintile (second quintile: HR = 0.74 (95%CI 0.59-0.92), to least deprived quintile, HR = 0.55 (95%CI 0.41-0.74). We saw a lower association with male gender, white ethnicity and living outside London, but an increased association with increasing household size.
CONCLUSIONS: The incidence of AGE has changed over time: pre-school children, larger households, and living in London were associated with higher rates, and male gender and higher economic status associated with lower rates.