Method 3. We make use of the Wallinga and Teunis' method for estimation of R t from the imputed data [26] . This method uses the daily case counts of cases and assumes the serial interval is known. We make the same assumptions for the serial interval as in method 2. The method calculates the relative probability a case on day i infects a case on day j as: Table 1 . Observed lag-time between date of symptom onset and date of specimen collection, incidence rate ratio (IRR) and significance value of the covariates significant in the Poisson regression model. where p k is the probability of a serial interval of length k. Then the estimate for the reproductive number for case i, is: