Re-emergence of Diphtheria in Guinea: An Outbreak Analysis of Vaccination and Disease Control Perspectives

This study presented the key characteristics of patients who tested positive for diphtheria during the outbreak in the Republic of Guinea in 2023 and assessed the influence of some risk factors on disease development.

The clinical diagnosis of diphtheria was confirmed by detecting diphtheria toxin genes in nasopharyngeal samples collected from suspected patients via 2 reverse transcription-quantitative polymerase chain reaction tests. Bivariate analyses with the χ² test and the Fisher's exact test were conducted to explore possible associations between diphtheria positivity and various sociodemographic, clinical, and exposure factors.

In total, 444 samples obtained from suspected cases were analyzed. In 90 (20.3%) cases, the condition was confirmed using quantitative polymerase chain reaction, with an overall fatality rate of 8.9% (n = 8). On average, deaths occurred 2 days after admission, with 6 (75.0%) of 8 (6 girls and 2 boys) deaths recorded within the first 3 months after the epidemic onset. The clinical characteristics included sore throat (91%), fever (90%), whitish throat membrane (83%), throat redness (81%), and dyspnea (28%). The risk factors were age <15 years, no prior vaccination, and contact with a patient with diphtheria. A whitish throat membrane and dyspnea were significantly associated with diphtheria positivity.

This study emphasized that diphtheria remains a major and potentially fatal disease, despite vaccination and early symptom recognition. The identification of characteristic signs-particularly a whitish throat membrane and dyspnea-is important for reducing disease severity and mortality.