Socioeconomic Deprivation and Pertussis Incidence in Dublin and Midlands

Abstract

Aims
Pertussis incidence increased substantially in Ireland in 2024. This study examined the relationship between pertussis incidence and area-level socioeconomic deprivation in the HSE Dublin and Midlands region in 2024.

Methods
All 121 confirmed cases in the HSE Dublin and Midlands region in 2024 were collated, alongside demographic and clinical information. Each case was assigned the deprivation score of its residential Small Area using the Pobal HP Deprivation Index. Denominator population data from Health Atlas were used to calculate cumulative incidence and Poisson regression was used to assess the association with deprivation.

Results
Incidence rose from 1.2 cases per 100,000 in the most affluent areas to 15.4 cases per 100,000 in the most deprived. Every one-step increase in deprivation category was associated with a 16% increase in pertussis incidence (IRR 1.16, 95% CI 1.03–1.31, p = 0.016). Pairwise comparisons showed that deprived areas had a pertussis incidence up to 13 times higher than in the most affluent communities.

Discussion
Pertussis incidence increased progressively with area-level socioeconomic deprivation, with the highest incidence observed in the most disadvantaged communities. These results highlight major inequalities in pertussis burden and show the need for targeted vaccination campaigns in deprived areas.