Incidence and risk factors of tuberculosis among the elderly population in China: a prospective cohort study.

BACKGROUND: China is facing challenges of the shifting presentation of tuberculosis (TB) from younger to elderly due to an ageing population, longer life expectancy and reactivation disease. However, the burden of elderly TB and influence factors are not yet clear. To fill the gap, we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China. METHODS: In this cohort established in 2013 through a prevalence survey conducted in selected sites, a total of 34 076 elderlies without TB were enrolled into two-year follow-up. We used both active and passive case findings to find out all TB patients among them. The person-year (PY) incidence rates for both bacteriologically positive TB and active TB were calculated. Cox proportional regression model was performed to test effect of risk factors, and the population attributable fraction (PAF) of each risk factor contributing to incident TB among elderlies was calculated. RESULTS: Over the two-year follow-up period, a total of 215 incident active TB were identified, 62 of which were bacteriologically positive. The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100 000 PY (95% CI: 417.4-546.2 per 100 000 PY) and 138.9 per 100 000 PY (95% CI: 104.4-173.5 per 100 000 PY), respectively. Incident cases detected by active case finding were significantly higher (P < 0.001). Male, non-Han nationality, previously treated TB, ex/current smoker and body mass index (BMI) < 18.5 presented as independent predictors for developing TB disease. For developing bacteriologically positive TB, the biggest contribution was from self-reported ex or current smoker (18.06%). And, for developing active TB, the biggest contribution was from non-Han nationality (35.40%), followed by male (26.80%) and age at 75 years and above (10.85%). CONCLUSIONS: Ageing population in China had a high TB incidence rate and risk to develop TB disease, implying that National TB Program (NTP) needs to prioritize for elderly. Active case finding should be applied capture more active TB cases among this particular population, especially for male, non-Han nationality, and those with identified risk factors.

The NLRP3 inflammasome and stroke.

Inflammasome pattern recognition receptors, which belong to the family of multi-meric proteins, play an important role in innate immunity, including NLRPs, NLRC, and NAIP. Among these receptors, NLRP3 (nucleotide-binding domain (NOD)-like receptor protein 3) inflammasome may activate the inflammation and participate in atherosclerosis, pathophysiology of myocardial infarction, resultin ischemia/reperfusion injury and stroke and other cardiovascular diseases. Effective regulation of NLRP3 may help prevent or even treat stroke. In recent years, the role of inflammation in stroke has attracted much attention, and the in-depth study of its mechanism of action is gradually clear. This mini-review focuses on the association of regulatory mechanisms of NLRP3 inflammasome with the development of stroke, which may supply some clues for future therapies and novel drug targets for stroke.

[The incidence discriminant model for close contacts of active tuberculosis patients].

OBJECTIVE: To establish a discriminant model and to provide a relatively accurate scientific basis for the early diagnosis of tuberculosis (TB) and detection of the close contacts. METHODS: Through logistic regression analysis, key factors were selected according to Bayes theory and key factors of TB incidence of the close contacts were screened as well as a discriminant model was established. RESULTS: The non-TB incidence discriminant function of the close contacts was described as: Y1= -39.831 (constant) + 1.927 X1 (sputum-frequency) + 3.528 X2 (education) + 0.309 X3 (contact time) + 5.893 X4 (evade) +2.140 X5 (ventilation) + 8.706 X6 (cough) + 30.970 X7 (fever). The discriminant function of non-TB incidence of the close contacts was as: Y2 =-57.875 (constant) + 2.343 X1 (sputum-frequency) + 3.965 X2 (education) + 0.361 X3 (contact time) + 6.296 X4 (evade) + 1.348 X5 (ventilation) + 12.984 X6 (cough) + 36.555 X7 (fever). CONCLUSION: The discriminant model night be used to contribute to the early diagnosis, early intervention and timely treatment on those close contacts of tuberculosis cases.

[Logistic analysis on risk factors related to smear positive pulmonary tuberculosis].

OBJECTIVE: To explore the risk factors on relapsing tuberculosis related to smear positive pulmonary tuberculosis which had been cured for five years. METHODS: Patients with smear positive pulmonary tuberculosis registered in 1995 from ten countries in Hubei province were studied and logistic regression was used for data analysis. RESULTS: The 5-year relapse rate of smear positive pulmonary tuberculosis was 3.85 percent. Risk factors related to relapse would include being non-modeled county, negative smear after treated for three months, the class of retreatment, management of non-DOTS, method of chemotherapy and patients that did not get treated by the tuberculosis institute, with odds ratios of 0.15, 4.62, 3.68, 5.88 and 6.47, respectively. CONCLUSION: Effect standard, regulation DOTS and the centralized management measure might have had effects on decreasing the relapse rate.