Using tuberculosis patient characteristics to predict future cases with matching genotype results

摘要

>Setting: United States.>Background: It is unknown whether tuberculosis (TB) case or patient characteristics can predict the likelihood of future related TB cases.>Objective: To estimate the likelihood for future related cases, i.e., cases with matching TB genotypes within the same county diagnosed within the 2 years following the year of reporting of each included case.>Design: We considered all TB cases with genotyping results reported in the United States during 2004–2010. Predictive scores were calculated based on patient characteristics by dividing the number of patients who were not the last case in a county-level TB genotype cluster by the total number of patients.>Results: Overall, there was a 30.8% chance that a future related case would be detected during the 2 years following the report year of any given case. Future related cases were detected in 34.7% of instances following the diagnosis of smear-positive cases, 51.9% of instances following the diagnosis of a homeless patient and 45.2% of instances following the diagnosis of a patient who reported substance abuse. Predictive scores ranged by race (White 13.9%, Native Hawaiian 43.8%) and age group (⩾65 years 13.1%, 0–4 years 43%), and were higher for US-born patients.>Conclusions: Behavioral and sociodemographic factors can help predict the likelihood of future related cases and can be used to prioritize contact investigations.