Table 3. Estimated reproduction number from included COVID-19 epidemiological parameters studies published between 1 January and 30 April 2020.
| Study authors | Online publication date |
Study period | Sample size | Method | Setting | Estimate | Uncertainty interval | Uncertainty measure |
|---|---|---|---|---|---|---|---|---|
| Wu et al. (46) | 23 January 2020 | 10 January 2020 –12 January 2020 | 41 | Zoonotic transmission – Cauchemez et al. 2013 (47) |
Wuhan/Hubei | 0.3 | 0.17–0.44 | 95% CI |
| Li et al. (16) | 29 January 2020 | Up to 22 January 2020 | 425 | Transmission model with renewal equations |
Wuhan/Hubei | 2.2 | 1.4–3.9 | 95% CI |
| Riou and Althaus (48) | 30 January 2020 | Up to 18 January 2020 | 50 | Stochastic transmission model |
Wuhan/Hubei | 2.2 | 1.4–3.8 | 90% HDI |
| Zhao et al. (49) | 30 January 2020 | 10 January 2020 –24 January 2020 |
2033 | Exponential growth model method | Mainland China | 2.24 –3.58 |
1.96–2.55 to 2.89–4.39 |
95% CI |
| Wu et al. (50) | 31 January 2020 | 1 December 2019 –28 January 2020 | 55 | Differential equation – SEIR compartment model |
International | 2.68 | 2.47–2.86 | 95% CrI |
| Zhao et al. (51) | 1 February 2020 | 1 December 2019 –24 January 2020 | 41 | Exponential growth model method | Mainland China | 2.56 | 2.49–2.63 | 95% CI |
| Tang et al. (52) | 7 February 2020 | 10 January 2020 –15 January 2020 | 41 | Differential equation – SEIR compartment model |
Mainland China | 6.47 | 5.71–7.23 | 95% CI |
| Ki and Task Force for 2019-nCoV (18) | 9 February 2020 | 20 January 2020 – 8 February 2020 |
26 | Estimated from transmission chains | Republic of Korea | 0.48 | 0.25–0.84 | 95% CI |
| Zhou et al. (53) | 12 February 2020 | Up to 25 January 2020 | 2820 | Differential equation – SEIR compartment model |
Mainland China | 2.83–3.28 | - | - |
| Jung et al. (54) | 14 February 2020 | 31 December 2019 –24 January 2020 | 92 | Exponential growth model method | Mainland China | 2.1; 3.2 | 2.0–2.2; 2.7–3.7 | 95% CI |
| Zhang et al. (55) | 22 February 2020 | Up to 16 February 2020 | 355 | Cori et al. methodology (56) | Cruise ship | 2.28 | 2.06–2.52 | 95% CI |
| Lai et al. (57) | 25 February 2020 | Up to 4 February 2020 | 52 | Coalescent-based exponential growth and a birth-death skyline method | Mainland China | 2.6 | 2.1–5.1 | 95% CI |
| Chen et al. (58) | 28 February 2020 | 7 December 2019 –1 January 2020 | Not specified | Bats-Hosts-Reservoir-People transmission network model | Wuhan/Hubei | 3.58 | - | - |
| Rocklov, Sjodin and Wilder-Smith (59) | 28 February 2020 | 21 January 2020 –19 February 2020 | 3700 | Differential equation – SEIR compartment model |
Cruise ship | 14.8 | - | - |
| Mizumoto and Chowell (60) | 29 February 2020 | 20 January 2020 –17 February 2020 | 3711 | Discrete time integral equation |
Cruise ship | 5.8 | 0.6–11.0 | 95% CrI |
| Fang, Nie and Penny (61) | 6 March 2020 | 20 January 2020 –29 February 2020 | 35 329 | Differential equation – SEIR compartment model |
Mainland China | 2.35–3.21 | - | - |
| Zhou et al.70 | 10 March 2020 | 10 January 2020 –31 January 2020 |
44 | Differential equation – SEIR compartment model |
Mainland China | 5.3167 | - | - |
| Kucharski et al.71 |
11 March 2020 | 1 December 2019 –11 February 2020 | Not specified |
Differential equation – SEIR compartment model |
Wuhan/Hubei | 2.35 | 1.15–4.77 | 95% CI |
| Yang and Wang72 | 11 March 2020 | 23 January 2020 –10 February 2020 | Not specified |
Differential equation – SEIR compartment model |
Wuhan/Hubei | 4.25 | - | - |
| Zhao and Chen73 | 11 March 2020 | 20 January 2020 –30 January 2020 |
Not specified |
Differential equation – SEIR compartment model |
Mainland China | 4.7092 | - | - |
| Choi and Ki74 | 12 March 2020 | 29 December 2019 –3 January 2020 |
Not specified |
Differential equation – SEIR compartment model |
Wuhan/Hubei | 4.028 | 4.010–4.046 | 95% CI |
| - | - | 20 January 2020 –17 February 2020 |
30 | - | Republic of Korea | 0.555 | 0.509–0.602 | 95% CI |
| Kuniya75 | 13 March 2020 | 15 January 2020 –29 February 2020 |
239 | Differential equation – SEIR compartment model |
Japan | 2.6 | 2.4–2.8 | 95% CI |
| Remuzzi and Remuzzi76 | 13 March 2020 | 19 February 2020 –8 March 2020 | Unclear | Exponential growth model method | Italy | 2.76–3.25 | - | - |
| Li et al.77 | 16 March 2020 | 10 January 2020 –23 January 2020 |
801 | Differential equation – SEIR compartment model |
Mainland China | 2.38 | 2.03–2.77 | 95% CrI |
| Shim et al.78 | 17 March 2020 | 20 January 2020 –26 February 2020 |
6284 | Generalized growth model | Republic of Korea | 1.5 | 1.4–1.6 | 95% CI |
| Du et al.49 | 19 March 2020 | 21 January 2020 –8 February 2020 |
752 | Not stated | Mainland China | 1.32 | 1.16–1.48 | 95% CI |
| Wu et al.50 | 19 March 2020 | 1 December 2019 –28 February 2020 |
45 771 | Differential equation – SEIR compartment model |
Wuhan/Hubei | 1.94 | 1.83–2.06 | 95% CrI |
| Yuan et al.79 | 28 March 2020 | 23 February 2020 –9 March 2020 |
Not specified |
Exponential growth model method; Wallinga time dependent method |
Italy | 3.27; 3.10 | 3.17–3.38; 2.21–4.11 | 95% CI |
| - | - | - | - | - | France | 6.32; 6.56 | 5.72–6.99; 2.04–12.26 | 95% CI |
| - | - | - | - | - | Spain | 5.08; 3.95 | 4.51–5.74; 0–10.19 | 95% CI |
| - | - | - | - | - | Germany | 6.07; 4.43 | 5.51–6.69; 1.83–7.92 | 95% CI |
| Anastassopoulou et al.80 | 31 March 2020 | 11 January 2020 –10 February 2020 |
Not specified |
Differential equation – SEIR compartment model |
Wuhan/Hubei | 4.6 | 3.56–5.65 | 90% CI |
| Ferretti et al.81 | 31 March 2020 | Up to end March 2020 | 40 transmission pairs |
Exponential growth model method | Mainland China | 2 | 1.7–2.5 | 90% CI |
| Huang et al.82 | 31 March 2020 | 13 January 2020 –9 March 2020 |
80 754 | Differential equation – SEIR compartment model |
Mainland China | 2.23–2.51 | - | - |
| Tian et al.83 | 31 March 2020 | 31 December 2019 –23 January 2020 | Not specified |
Differential equation – SEIR compartment model |
Mainland China | 3.15 | 3.04–3.26 | 95% BCI |
| Zhu and Chen34 | 2 April 2020 | 1 December 2019 –23 January 2020 |
Not specified |
Poisson Transmission Model |
Mainland China | 2.47 | 2.39–2.55 | 95% CI |
| Sanche et al.37 | 7 April 2020 | 15 January 2020 –30 January 2020 |
140 | Differential equation – SEIR compartment model |
Mainland China | 5.7 | 3.8–8.9 | 95% CI |
| Zhao et al.84 | 8 April 2020 | 1 December 2019 –8 January 2020 |
Not specified |
Differential equation – SEIR compartment model |
Wuhan/Hubei | 2.5 | 2.4–2.7 | 95% CI |
| Pan, Liu and Wang85 | 10 April 2020 | 5 December 2019 –8 March 2020 | 32 583 | Cori et al. methodology112 | Wuhan/Hubei | 3.82 | 3.72–3.93 | 95% CrI |
| Abbott et al.86 | 14 April 2020 | Up to 25 January 2020 | 1975 | Stochastic branching process model |
Mainland China | 2.8–3.8 | - | - |
| Puci et al. | 14 April 2020 | 22 March 2020 –29 March 2020 |
975 | Differential equation – SEIR compartment model |
Italy | 1.82 | 1.51–2.01 | 95% CI |
| Du et al.87 | 16 April 2020 | 1 December 2019 –22 January 2020 |
19 | Exponential growth method | Mainland China | 1.9 | 1.47–2.59 | 95% CrI |
| Torres-Roman et al.88 | 17 April 2020 | 6 March 2020 –15 March 2020 |
Not specified |
Cori et al. methodology112 |
Peru | 2.97 | - | - |
| Tsang et al.89 | 20 April 2020 | 15 January 2020 –3 March 2020 |
Not specified |
Exponential growth model | Mainland China | 2.8–3.5 | - | - |
| Muniz- Rodriguez et al.90 |
22 April 2020 | 19 February 2020 –19 March 2020 |
978 | Exponential growth model; renewal equations method | Islamic Republic of Iran | 4.4; 3.5 | 3.9–4.9; 1.3–8.1 | 95% CI |
| Zhuang et al.91 | 22 April 2020 | Up to 5 March 2020 | Not specified |
Stochastic model, maximum likelihood estimation approach |
Italy | 2.6; 3.3 | 2.3–2.9; 3.0–3.6 | 95% CI |
| - | - | - | - | - | Republic of Korea | 2.6; 3.2 | 2.3–2.9; 2.9–3.5 | 95% CI |
| Gatto et al.92 | 23 April 2020 | 24 February 2020 –23 March 2020 |
107 | Differential equation – SEIR compartment model |
Italy | 3.6 | 3.49–3.84 | 95% CI |
| Han et al.93 | 23 April 2020 | 21 January 2020 –15 February 2020 |
482 | Exponential growth model method | Mainland China | 2.9 | 1.8–4.5 | 95% CI |
| Caicedo-Ochoa et al.94 |
25 April 2020 | Up to 23 March 2020 (first 10 days after reaching 25 cases in each location) | Not specified |
Cori et al. methodology112 Two serial intervals used: 7.5 days; 4.7 days |
Spain | 6.48; 2.9 | 5.97–7.02; 2.67–3.14 | 95% CrI |
| - | - | - | - | - | Italy | 6.41; 2.83 | 6.11–6.71; 2.70–2.96 | 95% CrI |
| - | - | - | - | - | Ecuador | 12.86; 3.95 | 12.05–13.68; 3.70–4.21 | 95% CrI |
| - | - | - | - | - | Panama | 7.19; 3.67 | 6.37–8.08; 3.25–4.13 | 95% CrI |
| - | - | - | - | - | Brazil | 6.53; 2.91 | 5.85–7.25; 2.60–3.23 | 95% CrI |
| - | - | - | - | - | Chile | 5.79; 2.67 | 5.32–6.28; 2.45–2.89 | 95% CrI |
| - | - | - | - | - | Colombia | 5.65; 2.67 | 5.04–6.29; 2.38–2.98 | 95% CrI |
| - | - | - | - | - | Peru | 5.24; 2.36 | 4.68–5.83; 2.11–2.63 | 95% CrI |
| - | - | - | - | - | Mexico | 4.94; 2.42 | 4.37–5.56; 2.14–2.72 | 95% CrI |
| Bi et al.47 | 27 April 2020 | 14 January 2020 –12 February 2020 |
48 | Estimated from transmission chains | Mainland China | 0.4 | 0.3–0.5 | 95% CI |
| Distante et al.95 | 27 April 2020 | Up to 29 March 2020 | Not specified |
Exponential growth method | Italy | 3.6 | - | - |
| Ndairou et al.96 | 27 April 2020 | 4 January 2020 –9 March 2020 |
Not specified |
Differential equation – SEIR compartment model |
Wuhan/Hubei | 0.945 | - | - |
| Peirlinck et al.97 | 27 April 2020 | 21 January 2020 –4 April 2020 |
311 357 | Differential equation – SEIR compartment model |
United States of America | 5.3 | ± 0.95 | SD |
| Adegboye et al.98 |
28 April 2020 | 27 February 2020 –11 April 2020 |
318 | Cori et al. methodology112 |
Nigeria | 2.71 | - | - |
| Ganyani et al.55 | 30 April 2020 | 14 January 2020 –27 February 2020 |
91 | Exponential growth model method | Singapore | 1.25 | 1.17–1.34 | 95% CrI |
| - | - | - | 135 | Exponential growth model method | Mainland China | 1.41 | 1.26–1.58 | 95% CrI |
| Ivorra et al.99 | 30 April 2020 | 1 December 2019 –29 March 2020 |
Not specified |
Differential equation – SEIR compartment model |
Mainland China | 4.2732 | - | - |
Multiple estimates of the reproduction number for the same population within the same study are shown in the same row and separated by a semicolon. Estimates of the incubation period in the same study for different populations are shown in separate rows.
bCI: Bayesian confidence interval; CI: confidence interval; CrI: credible interval; HDI: high density interval; SD: standard deviation; SEIR: susceptible-exposed-infected-recovered.
Notes: Sample size reported is the sample size used to calculate the serial interval, not necessarily the whole study sample. All estimates are reported to the number of decimal places provided in each study.