Table 1. Patient characteristics and laboratory results for patients with laboratory-confirmed measles during the outbreak in the Gothenburg area, Sweden, December 2017–January 2018 (n = 28).

Patient	Infection typea	Age group (years)	Doses of measles vaccine received	Days from onset of rash to sampling	Symptoms	Fulfilled EU criteria for confirmed caseb	Infected others
1	N	21–30	0	3	R F K C Z	Yes	Yes
2	N	31–40	0	3	R F C	Yes	Yes
3	N	0–10	0	2	R F C Z	Yes	Yes
4	N	0–10	0	1	R F C	Yes	No
5	N	31–40	0	0	R F C	Yes	No
6	N	0–10	0	0	R F C	Yes	No
7	N	0–10	0	0	R F C	Yes	Yes
8	N	51–60	0	4	R F K C	Yes	Yes
9	N	31–40	0	4	R F C	Yes	No
10	N	0–10	0	1	R F K C	Yes	No
11	N	0–10	0	1	R F K C	Yes	No
12c	N	31–40	0	5	R F K C	Yes	No
13	B	21–30	1d	1	R F	No	No
14	B	31–40	2	1	R F	No	No
15	B	31–40	2	0	R F	No	No
16	B	31–40	2	0	R F	No	No
17	B	11–20	1d	0	R F	No	No
18	B	41–50	1d	1	R F C	Yes	No
19	B	31–40	2	1	R F K	Yes	No
20	B	51–60	1d	1	R F K C	Yes	No
21	B	31–40	1d	0	R F	No	No
22	B	21–30	1	1	R F	No	No
23	B	31–40	1	0	R F K Z	Yes	No
24	B	31–40	1	0	R F C	Yes	No
25	B	51–60	2	0	R	No	No
26	B	31–40	1d	2	R F	No	No
27	B	21–30	1d	3	R F	No	No
28	B	51–60	1	1	R F K C	Yes	No

B: breakthrough infection; C: cough; EU: European Union; F: fever; K: conjunctivitis; N: naïve infection; ND: not done; R: rash; Z: coryza.

^a Breakthrough infection was defined as a confirmed case of measles in an individual with history of vaccination and/or positive IgG levels (> 399 mIU/mL) in acute serum at or after onset of rash (if taken within 4 days), regardless of whether post-exposure prophylaxis was given or not.

^b Fulfilled both clinical and laboratory criteria according to the EU case definition.

^c Patient 12 had no history of vaccination against measles and no history of measles infection. This patient presented low levels of IgG (579 mIU/mL) at first sampling 5 days after onset of rash and had received post-exposure measles vaccine 7 days before onset of rash.

^d Reported at least one dose of measles vaccine, not documented.