[Prevalence and risk factors of latent tuberculosis infection in close contacts of tuberculosis patients among non-resident populations in Shanghai, China].

OBJECTIVE: To investigate the prevalence of latent tuberculosis (TB) infection (LTBI), and to identify the risk factors in close contacts of pulmonary TB patients among non-resident population in Shanghai. METHODS: The study subjects were the close contacts of pulmonary TB patients among non-resident populations in Xuhui, Minhang and Songjiang Districts in Shanghai from 2013 to 2014.Questionnaire interview was applied to collect the socio-demographics, TB-related clinical and TB exposure information from the enrolled TB patients and their close contacts. The T-SPOT.TB test was used to identify the infection of M. TB. LTBI was defined as a positive T-SPOT.TB result inthe absence of signs and symptoms related to TB. RESULTS: In total, 182 pulmonary TB patients and 360 close contacts were enrolled in the present study. The mean age of the close contacts was (34±14) years(range, 2-83 years), including 160 men and 200 women. The T-SPOT.TB test and TB related examination revealed that 17.2% (62/360) of the close contacts were latently infected with M. TB. All the LTBI subjects were household contacts (χ(2)=16.814, P<0.001). In multivariate analysis, the risk of LTBI was statistically associated with the presence of TB symptoms of the index case (OR=2.696, 95%CI: 1.060-6.857) and duration of exposure (OR=1.007, 95%CI: 1.001-1.014); whereas there were no statistically significant associations among age, gender, diagnostic delay of index case, environment of contact place and the risk of LTBI among the studied close contacts. CONCLUSIONS: The prevalence of LTBI in close contacts of pulmonary TB patients among non-resident population in Shanghai is 17.2%.Contact with patients with TB symptoms and longer duration of exposure might increase the risk of LTBI.

[AOX Pollution in Wastewater Treatment Process of Dyeing and Dyestuff Chemical Industries].

Selecting six large-scale dyeing factories and four large-scale dyestuff chemical factories in the well-developed Yangtze River Delta region, this study aimed to investigate the AOX pollution status in the raw wastewater as well as in the activated sludge treatment system. The components of AOX were characterized by GC-MS. Results showed that AOX concentration was low in wastewater from the six dyeing enterprises, ranging 0. 15-1. 62 mg.L-1 in the raw wastewater and 0. 06-1. 30 mg.L-1 in the biologically treated effluent. All the biologically treated effluent met the emission limits of 8 mg.L-1 in the Discharge Standard of Water Pollutants for Dyeing and Finishing of Textile Industry. Sludge in five factories with AOX was below 621 mg.kg-1, only one factory was with high AOX concentration of 3 280 mg.kg-1. By comparison, AOX concentration greatly varied between the wastewater from dyestuff chemical factories, was 1. 70 mg.L-1 to 78. 72 mg.L-1 in the raw wastewater and was 1. 88 mg.L-1 to 33. 11 mg.L-1 in the biologically treated effluent. AOX concentration in the activated sludge was as high as 960-2,297 mg.kg-1. Chlorobenzenes, chloronitrobenzenes, chloroanilines, chlorine nitroanilines and halophenols were typical TOX components detectable in the dyestuff chemical wastewater. Halophenols and chlorine nitroanilines could be efficiently removed. Single chloroanilines and single chloronitrobenzenes seemed to be easier removable than polychlorinated anilines and polychlorinated nitrobenzenes. Polychlorinated benzenes were also easily removal but the products chlorobenzene was hard to remove.