A large epidemic of a necrotic skin infection in the Democratic Republic of São Tomé and Principe: an epidemiological study

• Published in: International journal of infectious diseases 2021-10, Vol.110, p.S69-S76
• Main Authors: Subissi, Lorenzo, Sousa, Andreza, Ba, Ibrahima, Perrocheau, Anne, Quick, Joshua, Meredith, Luke, Augustinho, Edmilson, Sousa, Beni Carvalho, Lima, Vania, Luiz, Jose, Diallo, Amadou Bailo, Djingarey, Mamoudou Harouna, Da Cruz, Claudina Augusto, Pontes, Feliciana Sousa, Tomé Palmer, Maria, Conceição, Marisa, Santana Gil, Vilfrido, Fall, Ibrahima Socé
• Format: Article
• Language: English
• Subjects: cellulitis; climate change; epidemiology; necrosis; skin infection; time-series analysis
• ISSN: 1201-9712; 1878-3511
• DOI: 10.1016/j.ijid.2021.06.050

•We report on an epidemic of a necrotic skin infection with a high attack rate•The cause of the epidemic remained unclear because of lack of diagnostic capacity•Relative humidity and heavy rain were associated with increased infection cases In 2016–18, the Democratic Republic of São Tomé and Príncipe suffered a necrotic skin infection epidemic. A surveillance system was established after increased hospitalisations for this infection. Microbiology results were available for samples analysed in December 2016 and March 2017 using whole genome sequencing and metagenomics. Negative binomial regression was used to study the association of weather conditions with monthly case counts in a time-series analysis. From October 2016 to October 2018, the epidemic cumulative attack rate was 1.5%. The first peak lasted 5 months, accounting for one-third of total cases. We could not conclusively identify the aetiological agent(s) due to the country's lack of microbiology capacity. Increased relative humidity was associated with increased monthly cases (incidence rate ratio (IRR) 1.05, 95% CI 1.02–1.09), and higher precipitation in the previous month with a higher number of cases in the following month (months with 0–49 mm rainfall compared with months with 50–149 mm and ≥150 mm: IRR 1.44, 95 % CI 1.13–1.78 and 1.50, 95% CI 1.12–1.99, respectively). This epidemic was favoured by increased relative humidity and precipitation, potentially contributing to community-based transmission of ubiquitous bacterial strains superinfecting skin wounds. World Health Organization Regional Office for Africa, Ministry of Health