Background: Given the time spent by children at school, there is an urgent need to increase our understanding of the potential for Strep A transmission in this setting to inform prevention strategies. This study aimed to determine if Strep A could be detected using environmental settle plates and swabbing high touch surfaces in two remote Western Australian schools.
Methods: Six classrooms in two Kimberley schools (Derby and Broome) were assessed. Students were observed for 20 minutes in their classroom and from this the twenty highest-touch items/surfaces were identified. Environmental swabs were cultured using Colistin Nalidixic Acid agar plates. Seven settle plates were placed in each occupied classroom at varied heights for four hours to test for possible airborne or droplet transmission. The primary outcome of each sample was presence or absence of Strep A.
Results: A mixture of environmental Staphylococcus, Coliform and some types of filamentous fungi were present on all agar plates. There were early indications of haemolytic colonies however further testing revealed these to be Bacillus subtili. Strep A was not present on any settle plates. Of the 120 environmental swabs collected, none were positive for the presence of Strep A. Three swabs across two classrooms at the same school were positive for Streptococcus canis (Strep G).
Conclusions: Strep A was not detected in Kimberley classrooms using environmental swabs or settle plates. While the presence of non-Strep A bacteria supports the validity of these methods, this study is to be replicated in March 2022 and may elucidate further results.