Peer-reviewed article

Diphtheria and pertussis outbreaks in the Americas: a scoping review of epidemiology, vaccination trends and control strategies, 2013-2024.

Anne Eudes Jean Baptiste, Courtney N Sciarratta, Marcela Contreras, Christian Hertlein, Carmelita L Pacis et al. · 18 Mar 2026

Abstract

OBJECTIVES: To describe the themes identified in the epidemiology of diphtheria and pertussis outbreaks in the Americas (2013-2024), with a particular focus on vaccination coverage, trends and control strategies. DESIGN: Scoping review. DATA SOURCES: Systematic searches were conducted in PubMed and Embase (2024), supplemented by a search of Latin American and Caribbean Health Sciences Literature (LILACS) in December 2025. Regional case data and vaccination coverage were sourced from the Pan American Health Organization (PAHO)/WHO and UNICEF electronic joint reporting form (eJRF). ELIGIBILITY CRITERIA: The study reviewed literature and health reports focusing on diphtheria and pertussis outbreaks and vaccination coverage. DATA EXTRACTION AND SYNTHESIS: Thematic analysis identified themes in the literature on the epidemiology and control strategies of diphtheria and pertussis as well as outbreak reporting and mortality. The retrospective regional data analysis encompassed aggregated eJRF data (2013-2024) on cases and on diphtheria-pertussis-containing vaccination coverage. RESULTS: Of 82 articles identified across 14 countries, 28 met the inclusion criteria. Diphtheria cases peaked in 2017-2018 and have been on an upward trend since. Pertussis cases surged to 66 184 in 2024, with 10 countries reporting high numbers and 17 having their third dose of the vaccine against diphtheria, tetanus and pertussis (DTP3) coverage below 90%. Outbreaks are often linked to low DTP3, inconsistent vaccination coverage, gaps in maternal and booster doses, inadequate surveillance and socioeconomic disparities. However, two countries with high DTP3 coverage (eg, the USA, Canada) still experienced pertussis outbreaks, showing the disease's complexity. Experts recommend scaling up vaccination and strengthening surveillance to address these challenges. CONCLUSIONS: Diphtheria and pertussis are resurging in the Americas. The growing number of 'zero-dose' children and socioeconomic disparities in vulnerable communities are exacerbating the problem. A comprehensive approach is recommended, prioritising increased vaccination efforts, strengthened surveillance and ensuring equitable access to healthcare services.