Outbreak investigation of Streptococcus pyogenes in South Gondar Zone, Amhara Region, North west Ethiopia, 2023

Abstract

<title>Abstract</title> Background Despite being in existence for hundreds of years, Streptococcus pyogenes remains a significant cause of global morbidity and mortality, with a particular impact in resource-limited settings like Ethiopia. The investigation was undertaken to identify the etiologic agent and control the outbreak, identifying the potential risk factors, describe its epidemiology and to prevent further similar outbreak. Methods Unmatched community-based case-control with descriptive cross-sectional survey were conducted in Soth Gondar Zone of Andabet and Dera districts from December 10, 2022 to January 10, 2023). Active cases search was done through house-to-house by using epidemiological linked case definition and a total of 914 residents were attacked by the outbreak. A face-to-face interview using structured questionnaire was carried out to collect data. Epi data version 4.6 and STATA version 17 software were used for data entry and analysis respectively. Binary logistic regression analysis was computed and variables with P-value of ≤ 0.05 were considered as statistically significant risk factors. Result Group A beta-hemolytic streptococcus pyogenes was identified during the outbreak investigation. The overall attack rate of the infection was 22.2 per 1000 population. The logistic regression analysis revealed that, contact with cases (OR = 5.98; 95% CI 2.91–12.25), poor personnel hygiene (OR = 0.37, 95 a% CI (0.2–0.66), shortage of water for hygiene (OR = 2.2; 95% CI 1.27–3.76), poor wearing style (OR = 0.41; 95% CI 0.23–0.70) and history of injury (OR = 9. 8; 95% CI 5.85–18.41) were statically significant risk factors. Conclusions Contact with cases, poor hygiene practice, poor wearing style, shortage of water for hygiene, and history of injury were the risk factor for streptococcus pyogenic transmission. Avoiding direct contact with cases, encourage hygiene practice, preventing individuals from injury and improving wearing style should be recommended. S. pyogenes infection should be included in the public health surveillance system for urgent response.