system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Secondary attack rate is a measure of-
assistant
The correct answer is  Secondary attack rate is defined as the number of exposed persons developing the disease within the range of incubation period. It was initially developed to measure the spread of an infection within a family, household or any closed aggregate of persons who have had contact with a case of disease (refer pgno:100 park 23 rd edition)