Page 58 - Contributed Paper Session (CPS) - Volume 8

CPS2184 M Lutfor Rahman

Transmission network analysis of infectious
disease in Portugal
1
2
M Lutfor Rahman , Carla Nunes
1 Institute of Statistical Research & Training, University of Dhaka, Bangladesh
2 National School of Public Health, NOVA University of Lisbon, Portugal

Abstract
Proper identification of the key factors responsible for an infectious disease
transmission would contribute to control rapid spread of the disease. This
study aims to model transmission network of an infectious disease focused on
a case-study of tuberculosis network in Portugal. Characteristics of index-
patients (confirmed TB diseased), contacts and exposition were considered.
There were 495 participants in the study, considering 69 were index patients
(confirmed TB diseased) and 426 identified contacts. Identified contacts were
screened at the TB centre and other relevant information was collected at the
time of screening. Some different methods were applied in a sequential order:
simple measures of association, binary logistic regression, hierarchical logistic
regression and network logistic regression. These different models have
different assumptions, namely independency between observations and
index-contact relationship of the network, and the results were compared.
Based on binary logistic regression only the factors symptomatic period of
index patients, sputum, age of contacts, and exposure duration were
responsible for contacts being infected. The hierarchical logistic regression
selected the factors age, diabetes mellitus, sleeping together as important
variables for TB infection. The network regression reveals that the older age of
the contacts and household interaction are the risk factors of TB infection. The
network logistic regression was better to model the TB transmission using a
lower number of variables, being a promising tool in the analysis of infectious
disease with lower methodological limitations.

Keywords
Tuberculosis; transmission; network logistic regression; risk factors

1. Introduction
Infectious disease, also known as communicable or transmissible disease,
is caused by infectious agents including viruses, bacteria, fungi, parasites, and
other macro parasites. Emerging infectious diseases continue to expose
national and global unpreparedness for prevention and control of disease
outbreaks. Tuberculosis is an infectious disease usually caused by the
Mycobacterium, thus the disease known as Mycobacterium tuberculosis or M.
Tuberculosis. According to World Health Organization (WHO) tuberculosis

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