Table 1

Characteristics and clinical presentation of cases of the Q fever outbreak, Bizkaia, Spain, December 2020–October 2021 (n = 108 cases)

Epidemiological data Group investigated Total (n = 132)
Climbers (n = 9) Visitors (n = 108) Staffa (n = 15)
Cases (n)
Confirmed 5 81 2 88
Probable 1 16 3 20
Total 6 97 5 108
Visit date to the cave Dec 2020–Jan 2021 Mar 2021–Apr 2021 May 2021–Oct 2021 Dec 2020–Oct 2021
Median age in years (range)
Males 37 (29–48) 40 (1–68) 43 (22–58) 42 (1–68)
Females NA 40 (6–61) 31 (31) 39 (6–61)
n % n % n % n %
Sex
Males 6 100 59 60.8 4 80.0 69 63.9
Females 0 0 38 39.2 1 20.0 39 36.1
Clinical presentation
Pneumonia 5 83.3 48 49.5 0 0 53 49.0
Fever 1 16.7 42 43.3 2 40.0 45 41.7
Asymptomatic 0 0 7 7 3 60 10 9
Seroconversion 4 66.7 48 49.5 1 20.0 53 49.1
Hospitalisation 4 66.7 23 23.7 0 0.0 27 25.0

a Cleaning and disinfection team and a regional police officer.

NA: not applicable.