Background: The role of fomites in the transmission of SARS-CoV-2 is unclear.
Aim: To assess whether SARS-CoV-2 can be transmitted through fomites, using evidence from viral culture studies.
Methods: Searches were conducted in the World Health Organization COVID-19 Database, PubMed, LitCovid, medRxiv, and Google Scholar to December 31^{st}, 2021. Studies that investigated fomite transmission and performed viral culture to assess the cytopathic effect (CPE) of positive fomite samples and confirmation of SARS-CoV-2 as the cause of the CPE were included. The risk of bias using a checklist modified from the modified Quality Assessment of Diagnostic Accuracy Studies – 2 (QUADAS-2) criteria was assessed.
Findings: Twenty-three studies were included. The overall risk of bias was moderate. Five studies demonstrated replication-competent virus from fomite cultures and three used genome sequencing to match fomite samples with human clinical specimens. The mean cycle threshold (C_{T}) of samples with positive viral culture was significantly lower compared with cultured samples that returned negative results (standardized mean difference: -1.45; 95% confidence interval (CI): -2.00 to -0.90; I^{2} = 0%; P < 0.00001). The likelihood of isolating replication-competent virus was significantly greater when C_{T} was <30 (relative risk: 3.10; 95% CI: 1.32 to 7.31; I^{2} = 71%; P = 0.01). Infectious specimens were mostly detected within seven days of symptom onset. One study showed possible transmission of SARS-CoV-2 from fomites to humans.
Conclusion: The evidence from published studies suggests that replication-competent SARS-CoV-2 is present on fomites. Replication-competent SARS-CoV-2 is significantly more likely when the PCR C_{T} for clinical specimens and fomite samples is <30. Further studies should investigate the duration of infectiousness of SARS-CoV-2 and the frequency of transmission from fomites.
【저자키워드】 COVID-19, SARS-CoV-2, systematic review, Transmission, fomite, viral culture,