Tuberculosis burden in China: a high prevalence of pulmonary tuberculosis in household contacts with and without symptoms

Zhongwei Jia,Weiguo Xu,Liqiong Bai,Jinkou Zhao,Tianhao Zhang,Xiaoxin He,Shiming Cheng,Peiru Zhang,David C Christiani,Yan Ma

doi:10.1186/1471-2334-14-64

Abstract

BackgroundIn the context of decreasing tuberculosis prevalence in China, we examined the effectiveness of screening household contacts of tuberculosis patients.MethodsA tuberculosis survey was conducted in 2008. All 3,355 household contacts of notified tuberculosis cases were examined with a questionnaire interview, chest X-ray and three sputum smear tests. The effectiveness was examined by comparing the prevalence of pulmonary tuberculosis in household contacts with or without presenting clinical symptoms against the respective notification rates. Regression models were used to evaluate the factors associated with pulmonary tuberculosis.ResultsOf the 3,355 household contacts, 92 members (2.7%) had pulmonary tuberculosis, among which 46 cases were asymptomatic. The prevalence of pulmonary tuberculosis and smear positive cases in household contacts without symptoms were 20 and 7 times higher than the notification rates in 2008, while those in household contacts with symptoms were 247 and 108 times higher than notification rates, respectively. The patients detected were mainly Index Cases’ spouses, sisters/brothers and those who were in contact with female Index Cases.ConclusionsThe present study provides convincing evidence that household contacts of notified tuberculosis cases are at higher risk of developing tuberculosis. Routine screening for household contacts without any symptoms is recommended for sustained tuberculosis control in China as well as in the world.

Highlights

In the context of decreasing tuberculosis prevalence in China, we examined the effectiveness of screening household contacts of tuberculosis patients
More positive pulmonary tuberculosis patients have been detected in this pilot than routine surveillance [2], which inspired a more extensive case detection among all household contacts considering the Mega health investment in health medical reform to eliminate tuberculosis from population [12]
Notified cases were the number of pulmonary tuberculosis cases registered in tuberculosis national surveillance system (TBNSS)

Summary

Introduction

In the context of decreasing tuberculosis prevalence in China, we examined the effectiveness of screening household contacts of tuberculosis patients. By 2005, the coverage of DOTS has achieved 100% at county scale while the case detection rate and the cure rate of the new sputum smear positive patients reached 79%and 91% respectively in China, indicating that China met the WHO’s staggered global targets for detection and treatment of tuberculosis cases [6,7,8,9]. In 2007, China’s Ministry of Health piloted a new screening strategy among suspects in household contacts of notified tuberculosis cases (Index Cases) in several regions to inform a possible screening strategy nationwide [11]. More positive pulmonary tuberculosis patients have been detected in this pilot than routine surveillance [2], which inspired a more extensive case detection among all household contacts considering the Mega health investment in health medical reform to eliminate tuberculosis from population [12]. Since 2008, a rigid screening strategy in household contacts with symptoms has been tentatively extended to the household contacts without symptoms

Methods

Results

Conclusion