Table

Characteristics of measles cases by case classification, Porto, Portugal, 11 February−22 April 2018 (n = 211)

Confirmed cases Probable cases Total number of notified cases
n % n % n %
CHP 85 88.5 80 97.6 196 92.9
Other 11 11.5 2 2.4 15 7.1
Female 60 62.5 52 63.4 135 64.0
Male 36 37.5 30 36.6 76 36.0
0–17 1 1.0 3 3.7 5 2.4
18–29 50 52.1 20 24.4 79 37.4
30–39 39 40.6 32 39.0 85 40.3
40–49 5 5.2 11 13.4 22 10.4
50–59 1 1.0 7 8.5 10 4.7
60–69 0 0.0 3 3.7 4 1.9
70–79 0 0.0 5 6.1 5 2.4
80–89 0 0.0 1 1.2 1 0.5
Maculopapular rash 84 87.5 63 76.8 147 69.7
Fever and any of cough, coryza, conjunctivitis 35 36.5 33 40.2 68 32.2
Confirmed in first analysis 80 83.3 0 0.0 80 37.9
Confirmed in second analysis a 16 16.7 0 0.0 16 7.6
No vaccination or measles history 5 5.2 12 14.6 21 10.0
One dose of measles vaccine 11 11.5 14 17.1 29 13.7
Two or more doses of measles vaccine 67 69.8 44 53.7 126 59.7
Presumptive immunity due to disease c 2 2.1 2 2.4 5 2.4
Unknown 11 11.5 10 12.2 30 14.2
Without epidemiologic link b 1 1.0 0 0.0 0 0.0
Non-HCW 9 9.4 23 28.0 38 18.0
HCW 86 89.6 59 72.0 173 82.0
Physicians 31 36.0 13 22.0 49 28.3
Nurses 20 23.3 27 45.8 60 34.7
Health technicians 6 7.0 3 5.1 11 6.4
Medical students 12 14.0 5 8.5 19 11.0
Nursing students 5 5.8 0 0.0 5 2.9
Support staff 12 14.0 11 18.6 29 16.8

CHP: Centro Hospitalar do Porto; HCW: healthcare workers;

a For cases where the first laboratory confirmation samples were negative or not conclusive, second samples were necessary to exclude any false negatives or to exclude IgM false positive results in unvaccinated individuals through evidence of posterior seroconversion at about 10 days after the first laboratory analysis.

b Probably the primary case of the outbreak.

c Presumptive immunity due to disease: auto reported or documented previous measles infection.