Tuberculosis incidence among infected contacts detected through contact tracing of smear-positive patients

BACKGROUND

The contacts of people with pulmonary tuberculosis (PTB) have a high risk of becoming infected and developing tuberculosis (TB). Our aim was to determine the incidence of TB and its risk factors in a cohort of contacts with latent TB infection (LTBI) detected through contact tracing of smear-positive PTB cases.

METHODS AND FINDINGS

We performed a population-based retrospective cohort study including contacts that had LTBI, and were contacts of people with PTB who started treatment between 2008 and 2014. We followed up contacts until they developed TB or until the end date for follow-up (31st December 2016). We used Kaplan-Meier curves to compute incidence at 2 and 5 years, and Cox regression to compute hazard ratios (HR) and their 95% confidence intervals (CI). We analyzed 3097 close contacts of 565 PTB cases. After exclusion of 81 co-prevalent TB cases, 953 contacts had LTBI, of which 14 developed TB. Their risk of developing TB after two and five years was 0.7% (CI: 0.3-1.6) and 1.8% (CI: 1.1-3.1) respectively. Contacts who had not been referred for LTBI treatment had a 1.0% (CI: 0.2-4.0) risk at 5 years. Risk of developing TB at 5 years was 1.2% (CI: 0.5-3.0) among people who completed treatment, and 11.1% (CI: 5.1-23.3) for those who did not. Risk factors for TB were not completing LTBI treatment (HR 9.4, CI: 2.9-30.8) and being female (HR 3.5, CI: 1.1-11-3).

CONCLUSIONS

LTBI treatment plays a fundamental role in decreasing the risk of developing TB. It is necessary to achieve a maximum contact tracing coverage and the highest possible compliance with LTBI treatment.

Male sex workers: between safe sex and risk. Ethnography in a gay sauna in Barcelona, Spain

This ethnography was conducted in Barcelona, a city that provides different gay leisure resources, such as gay saunas. We aimed to analyze from studies on gender and masculinities, how sexuality, perception of HIV infection and other sexually transmitted infections (STIs), and preventive measures are articulated in gay sauna male sex workers (MSW). Ten in-depth interviews and observation were conducted between 2012 and 2016. Safe sex practices are more frequent with clients, while risk practices are carried out more with non-commercial partners. Sexual orientation plays an important role. Homosexuals assume riskier practices in sex work than heterosexuals. Drug use or lack of support networks were associated with higher social vulnerability and risk behaviors. Contracting HIV still creates fear, while having other STIs is perceived as part of a man's sexual life. The MSW affirms masculinity with concurrent sexual partners, breadwinner, and on the other hand, questions a heteronormative model. Interventions for the prevention of HIV and STIs in this group should consider social determinants such as inferior work alternatives and the provision of more significant social support.

Evolution of acute hepatitis C virus infection in a large European city: Trends and new patterns

The aims of this study were to describe the evolution of acute hepatitis C virus (HCV) infections since 2004 and to determine its associated factors. Acute HCV infections diagnosed in Barcelona from 2004 to 2015 were included. Incidence ratios (IR) were then estimated for sex and age groups. Cases were grouped between 2004-2005, 2006-2011 and 2012-2015, and their incidence rate ratios (IRR) were calculated. In addition, risk factors for acute HCV infection were identified using multinomial logistic regression for complete, available and multiple imputed data. 204 new HCV cases were identified. Two peaks of higher IR of acute HCV infection in 2005 and 2013 were observed. Men and those aged 35-54 had higher IR. IRR for men was 2.9 times greater than in women (95% confidence intervals (CI): 1.8 ‒ 4.7). Factors related to the period 2012-2015 (versus 2006-2011) were: a) sexual risk factor for transmission versus nosocomial (relative-risk ratio (RRR): 13.0; 95% CI: 2.3 ‒ 72.1), b) higher educated versus lower (RRR: 5.4; 95% CI: 1.6 ‒ 18.7), and c) HIV co-infected versus not HIV-infected (RRR: 53.1; 95% CI: 5.7 ‒ 492.6). This is one of the few studies showing IR and RRRs of acute HCV infections and the first focused on a large city in Spain. Sexual risk for transmission between men, higher educational level and HIV co-infection are important factors for understanding current HCV epidemic. There has been a partial shift in the pattern of the risk factor for transmission from nosocomial to sexual.