Calculate primary attack rate AR = cases / population at risk × 100% and secondary attack rate SAR = secondary cases / susceptible contacts of primary cases × 100%. Key outbreak investigation metrics.
Enter the values for the scenario you are assessing. Calculate primary attack rate AR = cases / population at risk × 100% and secondary attack rate SAR = secondary cases / susceptible contacts of primary cases × 100%. Key outbreak investigation metrics. Use the attack rate result to inform your calculation.