日本のクラスタ分析
日本クラスタ分析
- 22 プライマリーケース
- 無症状または発症前、9
- 16プライマリーケース
- 5 発症前日、4発症日
原文
We identified 22 probable primary case-patients who had symptoms develop before they had contact with other case-patients in a cluster or who had prior epidemiologic links before contact with a cluster. We did not identify probable primary cases for nosocomial clusters. We believe these 22 case-patients contributed to the incidence of clusters. Demographic data show that 9 (41%) probable primary case-patients were female and 13 (59%) were male. The most frequently observed age groups among probable primary cases were 20–29 years (n = 6; 27%) and 30–39 years (n = 5, 23%) (Figure 2, panel A). For 16 clusters, we determined the date of transmission from probable primary case-patients to other case-patients in a cluster and found 41% (9/22) of probable primary case-patients were presymptomatic or asymptomatic at the time of transmission; only 1 had a cough at the time of transmission (Figure 2, panel B). Of the 22 probable primary case-patients, 45% (10/22) had cough at the time of diagnosis. Of the 16 probable primary case-patients with the determined date of transmission, transmission occurred one day before illness onset for 5 (31%) case-patients and on the same day of illness onset for 4 (25%) case-patients (Figure 2, panel C). All age groups demonstrated presymptomatic or asymptomatic transmission.
