Fig 1.
Flow chart of search strategy and study selection for the secondary attack rate (SAR).
Table 1.
Description of studies included in the review and analysis of household secondary attack rate (SAR).
Fig 2.
Forest plot of household secondary attack rates (SAR).
ES is the estimated SAR, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Fig 3.
Forest plot of household transmission risk by symptom status of index case.
RR is the estimated risk ratio, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Fig 4.
Forest plot of household secondary attack rates (SAR) by symptom status of index case.
ES is the estimated SAR, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Fig 5.
Forest plot of household transmission risk by adult and children close contact.
RR is the estimated risk ratio, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Fig 6.
Forest plot of household secondary attack rates (SAR) by adult and children close contact.
ES is the estimated SAR, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Fig 7.
Forest plot of household transmission risk by relationship to index case.
RR is the estimated risk ratio, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Fig 8.
Forest plot of household secondary attack rates (SAR) by relationship to index case.
ES is the estimated SAR, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Table 2.
Description of studies included in the review and analysis of healthcare secondary attack rate (SAR).
Fig 9.
Forest plot of secondary attack rates (SAR) in healthcare settings.
ES is the estimated SAR, with 95% confidence intervals (CI). I-squared is the percentage of between-study heterogeneity that is attributable to variability in the true effect, rather than sampling variation.
Table 3.
Studies of secondary attack rate (SAR) in settings outside household and healthcare.