Table 1.

Summary of identified studies

Paper	Quality rating for incubation data	Number of casesa	Median incubation period (days)	Mean incubation period (days)	Range (days)	Individual case data
Tigertt et al. [31]	Good	21	14	18	9–18	Yes
Dupont et al. [34]	Good	2	8.5	8.5	8–9	Yes
Wagner-Wiening [32]b,c	Moderate	174	18	17.8	2d32	Yes
Porten et al [6]b,e	Moderate	165	21	20	2–36	Yes
Whelan et al. [5]	Moderate	32	Unknown	20.7	9–43	No
O'Connnor et al. [38]b	Moderate	22	32	32	15–60	Yes
Kosatsky et al. [35]	Moderate	13	13	12.5	8–18	Yes
Pinsky et al. [39]	Moderate	11	Unknown	Unknown	15–19	No
Buhariwalla et al. [36]	Moderate	3	11	11	8–14	Yes
Marmion et al. [37]c	Moderate	3	17	16.7	15–18	Yes
Porten et al. [6]b,f	Low	131	21	21.59	4–48	Yes
Langley et al. [40]	Low	12	24	24.58	19–30	Yes
Marrie et al. [41]	Low	Unclear	14	Unknown	4–30	No
Lin et al. [42]	Low	1	3	–	–	Yes
Kindmark et al. [43]	Low	1	10	–	–	Yes
Raoult et al. [44]	Low	1	7	–	–	Yes
Schleenvoigt et al. [45]	Low	1	14	–	–	Yes
Selvaggi [46]	Low	Unclear	22	Unknown	3–45	No
Harvey et al. [47]	Very low	28	18.5	Unknown	14–23	No
Huebner et al. [48]	Very low	18	Unknown	Unknown	13–18 (although unclear from text)	No
Marrie et al. [49]	Very low	11	Unknown	Unknown	12–21	No
Deutsch et al. [50]	Very low	3	Unknown	Unknown	14–23	No
Holland et al. [30]	Very low	5	Unknown	Unknown	14–16 days	No
Qazi et al. [51]	Very low	1	22	22	–	Yes

^aNumber of cases where the derivation of the incubation period was possible.

^bInformation from published study/poster supplemented through personal communication with authors.

^cSelected subset of cases which provides information on incubation period.

^dDiffers from information provided on an epidemic curve, minimum incubation period taken from text.

^eLaboratory confirmed cases only.

^fNon-laboratory-confirmed cases.