Survival of people living with HIV who defaulted from tuberculosis treatment in a cohort, Recife, Brazil

Clayton copula for survival data with dependent censoring: An application to a tuberculosis treatment adherence data

Ignoring the presence of dependent censoring in data analysis can lead to biased estimates, for example, not considering the effect of abandonment of the tuberculosis treatment may influence inferences about the cure probability. In order to assess the relationship between cure and abandonment outcomes, we propose a copula Bayesian approach. Therefore, the main objective of this work is to introduce a Bayesian survival regression model, capable of taking into account the dependent censoring in the adjustment. So, this proposed approach is based on Clayton's copula, to provide the relation between survival and dependent censoring times. In addition, the Weibull and the piecewise exponential marginal distributions are considered in order to fit the times. A simulation study is carried out to perform comparisons between different scenarios of dependence, different specifications of prior distributions, and comparisons with the maximum likelihood inference. Finally, we apply the proposed approach to a tuberculosis treatment adherence dataset of an HIV cohort from Alvorada-RS, Brazil. Results show that cure and abandonment outcomes are negatively correlated, that is, as long as the chance of abandoning the treatment increases, the chance of tuberculosis cure decreases.

HIV and Substance Use in Latin America: A Scoping Review

This scoping review aims to explore the interplay between substance use (SU) and HIV in Latin America (LA). Database searches yielded 3481 references; 196 were included. HIV prevalence among people who used substances (PWUS) ranged from 2.8–15.2%. SU definitions were variable throughout studies, and thus data were not easily comparable. In 2019, only 2% of new HIV infections were attributed to injection drug use (IDU) in LA. Factors associated with HIV among PWUS included being female, IDU and homelessness, and PWUS were likely to engage in risky sexual behaviors, start antiretroviral treatment late, have poor adherence, have treatment failure, be lost to follow-up, have comorbidities, and experience higher mortality rates and lower quality of life, as has been reported in PLWH with SU in other regions. Five intervention studies were identified, and only one was effective at reducing HIV incidence in PWUS. Interventions in other regions have varying success depending on context-specific characteristics, highlighting the need to conduct more research in the LA region. Though progress has been made in establishing SU as a major concern in people living with HIV (PLWH), much more is yet to be done to reduce the burden of HIV and SU in LA.

Mortality and survival of tuberculosis coinfected patients living with AIDS in São Paulo, Brazil: a 12-year cohort study

Background

TB is still one of the leading causes of death among HIV patients. This study evaluates the effect of TB on the mortality rate, survival time, and predictors of survival in patients with AIDS living in different areas in São Paulo State (SPS).

Methods

Retrospective cohort of adolescents and adults with AIDS, diagnosed between 2003 and 2007 and followed-up until 2014. Data were obtained from the Brazilian Ministry of Health. Mortality rates were estimated by person-years. Survival analysis used the date of diagnosis as the reference for the construction of Kaplan–Meier curves. The Cox model was used for the investigation of survival-associated factors.

Results

A total of 35,515 patients were included, of whom 63.0% were male; 64.7% at the age group of 30 to 49 years, 64.4% were white, 12.9% co-infected with TB, and 37.6% had CD4 count above 200 cells/mm³ at diagnosis of AIDS. The 12-year survival probabilities were 74.1% and 55.7% among patients without and with TB co-infection, respectively. After adjustment for sex, age and year of diagnosis, the following exposures were independently associated with lower survival: residing in municipalities of the Interior (Hazard ratio (HR) = 1.43) and Coastal Area (HR = 1.9); illiteracy (HR = 2.61); being co-infected with TB (HR = 1.70); CD4 count below 200 cells/mm³ at AIDS diagnosis (HR = 2.31); viral load above 500 copies/ml at AIDS diagnosis (HR = 1.99); HAART1 regimen (one non-nucleoside reverse transcriptase inhibitor or boosted old protease inhibitors) (HR = 1.94).

Conclusion

The impact of TB on survival of AIDS was heterogeneous, and affected by age, years of formal education, early AIDS diagnosis, and proper ARV treatment. These factors may not fully explain the different survival outcomes in each of the four regions within the same state. These results may subsidize focused interventions and public health policies conveying specific needs in each of the areas.

Mortality and associated factors among adult patients on tuberculosis treatment in Tanzania: A retrospective cohort study

INTRODUCTION

Tuberculosis (TB) is the global leading cause of death from an infectious agent. Tanzania is among the 30 high TB burden countries with a mortality rate of 47 per 100,000 population and a case fatality of 4%. This study assessed mortality rate, survival probabilities, and factors associated with death among adult TB patients on TB treatment in Tanzania.

METHODS

A retrospective cohort study was conducted utilizing case-based national TB program data of adult (≥15 years) TB cases enrolled on TB treatment from January 2017 to December 2017. We determined survival probabilities using the Kaplan-Meier estimator and a Cox proportional hazard model was used to identify independent risk factors of TB mortality. Hazard ratios and their respective 95% confidence intervals were reported.

RESULTS

Of 53,753 adult TB patients, 1927 (3.6%) died during TB treatment and the crude mortality rate was 6.31 per 1000 person-months. Male accounted for 33,297 (61.9%) of the study population and the median (interquartile range [IQR]) age was 40 (30-53) years. More than half 1027 (56.7%) of deaths occurred in first two months of treatment. Overall survival probabilities were 96%, and 92% at 6th and 12th month respectively. The independent risk factors for TB mortality among TB patients included: advanced age ≥ 45 years (adjusted hazard ratio (aHR) = 1.74, 95% confidence interval (CI) = 1.45-2.08); receiving service at the hospital level (aHR = 1.22, 95% CI = 1.09-1.36); TB/HIV co-infection (aHR = 2.51, 95% CI = 2.26-2.79); facility-based direct observed therapy (DOT) option (aHR = 2.23, 95% CI = 1.95-2.72); having bacteriological unconfirmed TB results (aHR = 1.58, 95% CI = 1.42-1.76); and other referral type (aHR = 1.44, 95% CI = 1.16-1.78).

CONCLUSION

Advanced age, TB/HIV co-infection, bacteriological unconfirmed TB results, other referral types, receiving service at facility-based DOT option and obtaining service at the hospital level were significant contributors to TB death in Tanzania. Appropriate targeted intervention to improve TB referral systems, improve diagnostic capacity in the primary health facilities, minimize delay and misdiagnosis of TB patients might reduce TB mortality.

Survival time and distance to access specialized treatment among people living with HIV/Aids in the state of Alagoas, Brazil

OBJECTIVE

To evaluate the effect of the distance between the place of residence and the specialized treatment service on the survival time of people living with HIV/Aids in Alagoas, Northeast Brazil.

METHODS

Data from the notification and mortality systems related to individuals aged 13 years or older diagnosed with the infection between 2007 and 2013 were used. The cases were observed for a period of follow-up until December 2017. For the analyses, the Pearson's χ2 test, Kaplan-Meier method, and Cox regression were adopted according to the outcome of the case, place of residence, distance to the health unit, population size of the municipality of residence, sex, skin color/ethnicity, and age.

RESULTS

Of the 2,732 analyzed cases, 760 individuals died of Aids-related causes. The average estimate of survival time for individuals residing in the capital was 98.6 months (95%CI 96.1-101). Among residents of inland cities, the estimate was 92.7 months (95%CI 89.3-96.1). There was a significant difference in curves throughout the period. The group residing in inland municipalities and those traveling a distance of >70 km had a higher average relative risk of death (RR=1.21, 95%CI 1.05-1.4 and RR=1.18, 95%CI 1.01-1.39, respectively).

CONCLUSION

Living in or near the capital decreases the average relative risk of death. In order to increase the survival time of HIV/Aids patients in Alagoas, it is suggested to decentralize specialized health care, that is, to create regional centers to care for these people.

Structural Prediction and Mutational Analysis of Rv3906c Gene of Mycobacterium tuberculosis H37Rv to Determine Its Essentiality in Survival

The emergence of tuberculosis is at the peak; therefore to station it at its lower level we hereby try bioinformatics approach against Mycobacterium tuberculosis [M. tuberculosis] pathogenesis. Rv3906c is a conserved hypothetical gene of M. tuberculosis and contains many GTP binding protein motif DXXG which demonstrate that this gene might be processed in a GTP binding or in GTP hydrolyzing manner. This gene shows interaction with its adjacent genes as well as pcnA which is a polymerase and localized in the extracellular region and found to be a soluble protein. Rv3906c has binding pockets for calcium atom at various positions which prove that calcium might have some role during the process of this gene. GTP binding protein motif DXXG is present in various positions and calcium binds at this site with a C-score of 0.25. Mutational analysis on this motif shows the large decrease of stability after mutation of aspartate residue with glycine. Stress conditions like pH and temperature also change stability of the protein. A decrease in stability at this position might play a role in inhibition of survival of the pathogen. These computational studies of this gene might be a successful step towards drug development against tuberculosis.