Table 2. Characteristics of household contacts of primary cases of pertussis, Catalonia and Navarre, Spain, 2012–13 (n = 2,852).

Characteristic of household contact	Number	%
Sex
Male	1,340	47.0
Female	1,512	53.0
Age in years
< 1	150	5.3
1	58	2.0
2–3	132	4.6
4–6	200	7.0
7–10	221	7.7
11–18	209	7.3
19–40	967	33.9
> 40	915	32.1
Household contacts
Cohabitant	2,034	71.3
Non-cohabitant	818	28.7
Relationship to primary case
Mother	556	19.5
Father	510	17.9
Sibling	518	18.2
Grandparent	330	11.6
Child	139	4.9
Partner	100	3.5
Othera	699	24.5
Number of contacts in the household
≤ 2	226	7.9
3–4	1,133	29.7
> 4	1,493	52.3
Vaccination status (≤ 18 years)b
Fully vaccinated	581	64.4
Undervaccinated due to age	94	10.4
Undervaccinated	27	3.0
Unvaccinated	49	5.4
Unvaccinated due to age	53	5.9
Unknown/no answer	97	10.8
Received chemoprophylaxisc
Yes	2,284	80.1
No	406	14.2
Unknown	162	5.7

^a Caregiver, family friend or neighbour.

^b Vaccination status was categorised as fully vaccinated (≥ 4 doses of vaccine), undervaccinated (< 4 doses), unvaccinated (no dose), undervaccinated due to age (< 4 doses) and unvaccinated due to age (no dose).

^C Azithromycin was used.