Table 2.

Exposed contacts.

	July	August	September	October	November	Total
N index case	40	143	488	1542	2430	4622
N exposed	307	1165	3288	8464	13,029	26,253
N quarantined	281	1087	3164	7538	11,999	24,069
N quarantined per index case	7.0	7.6	6.5	4.9	4.9	5.2
N quarantined within ± 14 days
of symptom onset	6	37	216	476	694	1429
$\%$ of quarantined ($\%$)	2.1	3.4	6.8	6.3	5.8	5.9
Per index case	0.15	0.26	0.47	0.31	0.32	0.31

The table reports data for the 26,253 exposed contacts with Helsinki residence (the total number of exposed contacts was 31,837; see text). For each month, the table shows the number of index cases, exposed contacts, exposed individuals that were quarantined and their proportion per index case, and the number and proportion of quarantined that are identified as infected within ± 14 days of quarantine onset. In addition, the last line shows the number of exposed contacts that are identified as infected within ± 14 days of quarantine onset, per index case.