Prospective surveillance for invasive Staphylococcus aureus and group A Streptococcus infections in a setting with high community burden of scabies and impetigo

ABSTRACT Background Invasive Staphylococcus aureus (iSA) and group A Streptococcus (iGAS) infections impose significant health burdens globally. Both bacteria commonly cause skin and soft tissue infection (SSTI), which can result in invasive disease. Understanding of iSA and iGAS incidence remains limited in settings with high SSTI burden. Methods Prospective surveillance for admissions with iSA or iGAS was conducted at the referral hospital in Fiji’s Northern Division over 48 weeks between July 2018-June 2019. Results There were 55 admissions for iSA and 15 for iGAS, (incidence; 45.2 and 12.3 per 100,000 person-years respectively). Highest incidence was found in those aged ≥65 years s (59.6 per 100,000 person-years for both). Indigenous Fijians (iTaukei) had higher iSA incidence (71.1 per 100,000 person-years) compared to other ethnicities (incidence risk ratio 9.7, 95% CI 3.5-36.9). SSTIs were found in the majority of iSA (75%) and iGAS (53.3%) cases. Thirteen out of the 14 iGAS strains isolated belonged to emm-cluster D (n = 5) or E (n = 8). Case fatality rate was high for iSA (10.9%) and iGAS (33.3%). Conclusions The incidence of iSA and iGAS in Fiji is very high. SSTIs are common clinical foci for iSA and iGAS. Both diseases carry a substantial risk of death. Improved control strategies are needed to reduce the burden of these diseases in Fiji.