Analysis of social contact data and mixing pattern relevant to the spread of infectious disease

In the last years I have been involved in the analysis of the so-called “Who Acquires Infection From Whom” (WAIFW) matrix. This matrix is commonly estimated from survey in which respondents are asked about the age (and other covariates) of their daily contacts. A good estimation of this matrix, especially concerning the age of the respondents and the age of the contacts is necessary to understand the spread of infectious diseases.

In collaboration with Niel Hens from Universiteit Hasselt and Universiteit Antwerpen (Belgium), I have been developing an approach which smooth such matrix (over age of respondents/contacts) over the diagonal and the columns and enforcing symmetry over the main diagonal. The former assumption is important because people age through time and we assume contact rates for consecutive time points to be similar. Symmetry is assumed at the population level and it is due to the fact that we expect that if A meets B, also B meets A.