Table 1.
In-flight transmission studies
| Study | Year | Country | Number of passengers and crew | Number of index cases | Number of passengers and crew traced (%) | Number of secondary cases identified (%) | Attack rate (%) | Number of secondary cases within two rows (%) | Number of secondary cases outside the area of two rows (%) | Strength of evidence |
|---|---|---|---|---|---|---|---|---|---|---|
| Bae | 2020 | South Korea | 299 px; 10 crew; 8 medical staff | 6 px | 299 px; 10 crew; 8 medical staff (100%) | 1 px | 1/311 (0.32%) | 0 | 1 | RT-PCR, no data on Ct |
| Chen | 2020 | China | 335 px; 11 crew | 15 px | 335 px; 11 crew (100%) | 1 px | 1/331 (0.30%) | 1 | 0 | RT-PCR, no data on Ct |
| Choi | 2020 | China | 294 px; unknown no of crew members | 2 px | 2 crew (only symptomatic COVID-19 cases and known contacts of those and other cases were identified and traced) (1.36%) | 2 crew | N/A | N/A | N/A | RT-PCR, no data on Ct, GS |
| Eldin | 2020 | France | Not specified | 1 px | 3 px | 1 px | N/A | Not specified | Not specified | RT-PCR, no data on Ct |
| Hoehl | 2020 | Germany | 102 px | 7 px | 71 px (69.60%) | 2 px | 2/71. | 2 px | 0 | RT-PCR, no data on Ct; SARS-CoV-2 IgG |
| Khanh | 2020 | Vietnam | 201 px; 16 crew | 1 px | 168 px; 16 crew (83.40%) | 14px; 1 crew | 15/184 (8.15%) | 11 px | 1 px; 1 crew | RT-PCR, no data on Ct |
| Kong—flight 1 | 2021 | China | 59 px | 1 px | 58 px (98.3%) | 3 px (unclear) | N/A | 0 | 3 px | RT-PCR, no data on Ct |
| Kong—flight 2 | 2021 | China | 232 px | Unspecified | 232 px (100%) | 2 px | N/A | Not specified | Not specified | Symptomatic, exposure to COVID-19; RT-PCR negative, no data on Ct |
| Murphy | 2020 | Ireland | 49 px; 12 crew | Unknown (1 to 7) | 37 px (60.65%) | 4 to 12 | 4/41 (9.8%) to 12/48 (25%) | Not specified | Not specified | GS 5/13 px |
| Ng | 2020 | Singapore | 94 px | 2 px | 92 px (96.66%) | 1 (1.08%) | 1/92 (1.08%) | Not specified | Not specified | RT-PCR, no data on Ct |
| Nir-Paz | 2020 | Israel | 11 px | 2 px | 11 px | 0 | 0 | 0 | 0 | Index cases—RT-PCR positive (Ct 34 and Ct 24), positive viral cultures |
| Park | 2020 | Korea | Not specified | 30 px | Not specified | 1 crew | N/A | N/A | N/A | RT-PCR positive, Ct < 40 |
| Pavli—flight 1 | 2020 | Greece | 164px; 6 crew | 2 px | 163 px, 6 crew (99.41%) | 4 px, 1 crew | 5/167 (2.99%) | 4 px, 1 crew | 0 | RT-PCR, no data on Ct |
| Pavli—flights 2 | 2020 | Greece | 2203px, 110 crew | 21 px | 870px, 90 crew (41.50%) | 4 px, 1 crew | 5/960 | 4 px, 1 crew | 0 | RT-PCR, no data on Ct |
| Schwartz | 2020 | Canada | approx. 350 px, unspecified number of crew | 1 | Unclear | 0 | N/A | 0 | 0 | RT-PCR, no data on Ct |
| Speake | 2020 | Australia | 241 px | 18 px | 46 px (19.8%) | 8 px | 8/223 | 5 px | 3 px | RT-PCR; no data on Ct. GS; viral cultures |
| Swadi | 2021 | New Zealand | 86 px | 2 px | 86 px (100%) | 4 px | 4/84 (4.76%) | 4 | 0 | RT-PCR, with Ct data; GS |
| Yang | 2020 | China | 325 px | 1 px | 9 px, 9 crew (5.53%) | 9 px | N/A | Not specified | Not specified | RT-PCR, no data on Ct |
| Zhang XA—flight 1 | 2020 | China | Unspecified | 2 px | 8 px, 1 crew | 0 px | N/A | 0 | 0 | Epidemiologic data; RT-PCR negative in 1 px; RT-PCR not done in asymptomatic cases (5px, 1 crew); no data on Ct |
| Zhang XA—flight 2 | 2020 | China | 343 px, 21 crew | Unclear; minimum 3 px | 325 px, 11 crew (92.3%) | Unclear, max 7 px | N/A | Not specified | Not specified | RT-PCR, no data on Ct |
| Zhang J | 2020 | China | 14 505 | 159 px | 161 px (1.10%) | 2 px | 0.14 ‰ | Not specified | Not specified | RT-PCR, no data on Ct |
Abbreviations: px, passengers.