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BackgroundIn 2013, a tuberculosis (TB) outbreak occurred in a middle school in Henan province of China. An outbreak survey was carried out in the school.ObjectivesThis study was undertaken to investigate the detection rate of TB cases and those with strong Mantoux positive (SMP), defined as tuberculin skin test (TST) indurations of 15mm or larger and/or blisters, necrosis or lymphangitis, and to identify their risk factors.MethodsThe TST, chest x-ray/radiography, and TB-suspicious symptoms interview were used to screen for TB cases. Their diagnosis was made by sputum smear microscopy, liquid culture, computed tomography (CT), and diagnostic therapy if necessary. We retrospectively analyzed the outbreak survey data of 4082 students and 278 staff in the school. Logistic regression models were used to identify the risk factors associated with SMP and TB disease.ResultsApproximately 3.55% of students and 16.55% of staff were SMP. SMP rate in students was significantly lower than that in staff (p

Host defense peptides (HDPs) play a critical role in innate immunity. Specific modulation of endogenous HDP synthesis by dietary compounds has been regarded as a novel approach to boost immunity and disease resistance in animal production. 1,25-dihydroxy vitamin D3 (1,25D3) is well known as a powerful HDP inducer in humans, but limited information about the effect of 1,25D3 on HDPs in poultry is available. Here, we sought to examine whether 1,25D3 could stimulate avian β-defensin (AvBD) expression in chickens. We used chicken embryo intestinal epithelial cells (CEIEPCs) and peripheral blood mononuclear cells (PBMCs) to study the effect of 1,25D3 on the expression of AvBDs. We observed that 1,25D3 is able to up-regulate the expression of several AvBDs in CEIEPCs and PBMCs, whereas it increased the amounts of AvBD4 mRNA in CEIEPCs only in the presence of lipopolysaccharide (LPS). On the other hand, LPS treatment not only inhibited the expression of CYP24A1 but also altered the expression pattern of VDR in CEIEPCs. Furthermore, AvBDs were not directly regulated by 1,25D3, as cycloheximide completely blocked 1,25D3-induced expression of AvBDs. Our observations suggest that 1,25D3 is capable of inducing AvBD gene expression and is a potential antibiotic alternative through augmentation of host innate immunity as well as disease control in chickens. [ABSTRACT FROM AUTHOR]