Representative Contact Diaries for Modeling the Spread of Infectious Diseases in Taiwan

Fu, Yang-chih; Wang, Da-Wei; Chuang, Jen-Hsiang

We construct contact patterns and social-mixing groups based on the average number of contacts, duration of each contact, and frequency of contact for all age groups. To facilitate easier modeling, we first convert each category of contact duration into mean contact duration. For example, we use 2.5 minutes for ''less than 5 minutes,'' 12 minutes for ''5-19 minutes,'' 37 minutes for ''15-59 minutes,'' 150 minutes for ''1 to 4 hours,'' and 240 minutes for ''more than 4 hours.'' For the same reason, we create mean contact frequency, a specific fraction for each category of contact frequency, such as 1 for ''daily,'' 0.5 for ''almost daily,'' 1.5/7 for ''once or twice weekly,'' 1.5/30 for ''once or twice monthly,'' 0.5/30 for ''less than once per month,'' and 1/365 for ''never.'' We then calculate weighted contact duration by multiplying mean contact duration by mean contact frequency. Next, by dividing weighted contact duration by 1,440 (the number of minutes in a day), we obtain weighted contact probabilities. Based on the same principle, we are also able to calculate interpersonal weighted contact probabilities in various social-mixing group settings.