Table 2.

 Characteristics of the first 23 fatal cases of influenza A (H1N1) 2009 virus infection in Japan (as of 6 October 2009)

ID	Sex	Age group (years)*	Any documented comorbidity	Time from onset to death (days)	Time from hospitalization to death (days)	Antiviral treatment within 48 h after onset	Intensive care unit admission	Intubation
1	Male	50–59	Yes	7	4	No	Yes	No
2	Female	80–89	Yes	7	7	Unknown	No	Yes
3	Male	70–79	Yes	3	2	Yes	No	No
4	Male	30–39	Yes	8	3	No	Yes	Yes
5	Female	70–79	Yes	1	1	Unknown	No	No
6	Male	60–69	Yes	9	6	Yes	Yes	No
7	Female	20–29	Yes	21	21	No	Yes	Yes
8	Female	30–39	Yes	3	1	Yes	No	No
9	Female	60–69	Yes	3	2	Yes	No	Yes
10	Female	40–49	Yes	2	1	Unknown	No	No
11	Male	70–79	Yes	4	4	No	No	No
12	Male	10–19	Yes	16	15	Unknown	Yes	Yes
13	Male	90–99	Yes	4	4	Yes	No	No
14	Male	40–49	Yes	5	1	No	No	No
15	Male	90–99	Yes	4	1	Yes	No	No
16	Female	60–69	Yes	9	9	Yes	Yes	No
17	Female	70–79	Yes	11	9	No	Yes	Yes
18	Female	60–69	No	4	1	Yes	No	No
19	Male	0–9	Yes	3	2	Yes	Yes	Yes
20	Male	40–49	Yes	10	10	Unknown	Yes	Yes
21	Female	40–49	No	9	5	No	No	Yes
22	Male	0–9	No	5	4	Yes	Yes	Yes
23	Male	0–9	No	10	9	Yes	Yes	Yes

*Age is given in discrete 10‐year intervals as privacy protection for the limited number of severe cases in Japan.