Table 3.

Estimates of transmission and proportion of asymptomatic secondary cases

Type of secondary attack rate and proportion of asymptomatic secondary cases	% (95% CI)	n/N
Household SAR†	45.7 (39.7–51.7)	126/276
Household SAR symptomatic secondary cases with positive RT-PCR^	35.9 (30.3–41.9)	99/276
Per-person SAR‡	32.6 (28.1–37.4)	200/644
Per-person SAR symptomatic secondary cases with positive RT-PCR^	19.3 (15.7–23.5)	118/644
Proportion asymptomatic secondary cases§	10.5 (6.8–15.8)	21/200

^†Number of households with at least one secondary case divided by the number of households at risk

^Including only symptomatic and RT-PCR positive secondary cases

^‡Per-person SAR is estimated by using a GEE model taking into account clustering in households

^§Number asymptomatic divided by the total number of secondary cases