Background: Pertussis remains a major public health concern in low- and middle-income countries despite the availability of effective vaccines. In Ethiopia, recurrent outbreaks continue to occur, particularly in hard-to-reach rural settings. Objectives: The aim of this study was to investigate a pertussis outbreak, identify associated risk factors, and evaluate the effectiveness of implemented interventions in Sayient Woreda, Northwest Ethiopia. Methods: An observational, community-based, unmatched case–control study with a house-to-house approach was conducted from October 25, 2018, to January 22, 2019. A total of 50 cases and 100 controls were selected using simple random sampling. Data were collected through face-to-face interviews using a pre-tested World Health Organization-adopted questionnaire. Data were cleaned, coded, and entered into Epi Info™ (version 7.2.1.0) and exported to SPSS (version 23) for analysis. Variables with a p < 0.05 with 95% confidence interval were considered independent risk factors for pertussis infection in multivariable logistic regression analysis. Results: The overall attack rate was 3.1/1000 population. The age of the affected individuals ranged from 3 months to 28 years, with a median age of 10 years (Interquartile Range (IQR): 0.7–12). Females accounted for 56.6% of the reported cases. Following the implementation of cephalexin therapy and active case search, a substantial decline in incident cases was observed. Independent risk factors for pertussis infection were inadequate awareness on transmission mode (adjusted odds ratio = 1.61, 95% confidence interval: 1.33–9.54), inadequate prevention and control measures (adjusted odds ratio = 4.64, 95% confidence interval: 2.19–9.83), household contact with a confirmed case (adjusted odds ratio = 6.99, 95% confidence interval: 1.19–41.15), being unvaccinated (adjusted odds ratio = 3.62, 95% confidence interval: 1.97–5.50), and unknown vaccination status (adjusted odds ratio = 1.77, 95% confidence interval: 1.96–16.08). Conclusions: A substantial pertussis outbreak occurred in Sayient Woreda, predominantly affecting children and adolescents. Inadequate community awareness, close household contact, and incomplete or unknown vaccination status significantly contributed to transmission. Strengthening routine immunization and enhancing community awareness are important for preventing future outbreaks.
Kassie et al. (Wed,) studied this question.