Mechanical transmission of SARS-CoV-2 by house flies

Parasites & Vectors

Table 1 Acquisition study: Detection of SARS-CoV-2 viral RNA and infectious virus in flies

Substrate group	4 h of exposure		24 h of exposure
Substrate group	PCR+, flies/N (copy number/µl of sample)	VI /IFA+, flies/N	PCR+, flies/N (copy number /µL of sample)	VI/ IFA+, flies/N
Medium only (negative control)	0/10 (ND)	0/10	0/10 (ND)	0/10
Virus-spiked medium (positive control)	10/10 (2.1 × 10⁶)^a	0/10	10/10 (4.1 × 10⁵)^a	0/10
Virus-spiked milk	10/10 (3.1 × 10⁶)^b	2/10	10/10 (3.8 × 10⁶)^b	2/10

IFA, Immunofluorescent assay; N, total number of flies; ND, not detected; VI, virus isolation
^aStandard deviation (SD) of virus-spiked medium group flies at 4 and 24 h exposure: 2.8 × 10⁶ and 1.6 × 10⁵, respectively
^bSD of virus-spiked milk group flies at 4 and 24 h exposure: 1.8 × 10⁶ and 2.2 × 10⁶, respectively

ISSN: 1756-3305