The spread of AIDS and the re-emergence of tuberculosis in Catalonia, Spain

Tackling Drug-Resistant Tuberculosis: New Challenges from the Old Pathogen Mycobacterium tuberculosis

Antibiotics have played a crucial role in the reduction in the incidence of TB globally as evidenced by the fact that before the mid-20th century, the mortality rate within five years of the onset of the disease was 50%. The use of antibiotics has eliminated TB as a devastating disease, but the challenge of resistance to anti-TB drugs, which had already been described at the time of the introduction of streptomycin, has become a major global issue in disease management. Mismanagement of multidrug-resistant tuberculosis (MDR-TB) cases, resulting from intermittent drug use, prescription errors, and non-compliance of patients, has been identified as a critical risk factor for the development of extensively drug-resistant tuberculosis (XDR-TB). Antimicrobial resistance (AMR) in TB is a multi-factorial, complex problem of microbes evolving to escape antibiotics, the gradual decline in antibiotic development, and different economic and social conditions. In this review, we summarize recent advances in our understanding of how Mycobacterium tuberculosis evolves drug resistance. We also highlight the importance of developing shorter regimens that rapidly reach bacteria in diverse host environments, eradicating all mycobacterial populations and preventing the evolution of drug resistance. Lastly, we also emphasize that the current burden of this ancient disease is driven by a combination of complex interactions between mycobacterial and host factors, and that only a holistic approach that effectively addresses all the critical issues associated with drug resistance will limit the further spread of drug-resistant strains throughout the community.

Prisoners co-infected with tuberculosis and HIV: a systematic review

INTRODUCTION

Almost from the beginning of the HIV epidemic in 1981, an association with tuberculosis (TB) was recognized. This association between HIV and TB co-infection has been particularly evident amongst prisoners. However, despite this, few studies of TB in prisons have stratified results by HIV status. Given the high prevalence of HIV-positive persons and TB-infected persons in prisons and the documented risk of TB in those infected with HIV, it is of interest to determine how co-infection varies amongst prison populations worldwide. For this reason we have undertaken a systematic review of studies of co-infected prisoners to determine the incidence and/or prevalence of HIV/TB co-infection in prisons, as well as outcomes in this group, measured as treatment success or death.

METHODS

A literature search was undertaken using the online databases PubMed, Embase, IBSS, Scopus, Web of Science, Global Health and CINAHL Plus. No restrictions were set on language or publication date for article retrieval, with articles included if indexed up to 18 October 2015. A total of 1975 non-duplicate papers were identified. For treatment and outcome data all eligible papers were appraised for inclusion; for incidence/prevalence estimates papers published prior to 2000 were excluded from full text review. After full text appraisal, 46 papers were selected for inclusion in the review, 41 for incidence/prevalence estimates and nine for outcomes data, with four papers providing evidence for both outcomes and prevalence/incidence.

RESULTS

Very few studies estimated the incidence of TB in HIV positive prisoners, with most simply reporting prevalence of co-infection. Co-infection is rarely explicitly measured, with studies simply reporting HIV status in prisoners with TB, or a cross-sectional survey of TB prevalence amongst prisoners with HIV. Estimates of co-infection prevalence ranged from 2.4 to 73.1% and relative risks for one, given the other, ranged from 2.0 to 10.75, although some studies reported no significant association between HIV and TB. Few studies provided a comparison with the risk of co-infection in the general population.

CONCLUSIONS

Prisoners infected with HIV are at high risk of developing TB. However, the magnitude of risk varies between different prisons and countries. There is little evidence on treatment outcomes in co-infected prisoners, and the existing evidence is conflicting in regards to HIV status influence on prisoner treatment outcomes.PROSPERO Number: CRD42016034068.

Tuberculosis, injecting drug use and integrated HIV-TB care: a review of the literature

BACKGROUND

People who inject drugs (PWID) are at increased risk of tuberculosis (TB) and reduced retention in treatment. There is a need to document strategies for integrated delivery of HIV, TB and drug dependency care.

METHODS

This article reviews the literature on rates of TB mono- and co-infection, and published and grey literature descriptions of TB and HIV-TB care, among PWID.

RESULTS

Latent TB infection prevalence was high and active disease more common among HIV-positive PWID. Data on multidrug-resistant TB and co-infections among PWID were scarce. Models of TB care fell into six categories: screening and prevention within HIV-risk studies; prevention at TB clinics; screening and prevention within needle-and-syringe-exchange (NSP) and drug treatment programmes; pharmacy-based TB treatment; TB service-led care with harm reduction/drug treatment programmes; and TB treatment within drug treatment programmes. Co-location with NSP and opioid substitution therapy (OST), combined with incentives, consistently improved screening and prevention uptake. Small-scale combined TB treatment and OST achieved good adherence in diverse settings. Successful interventions involved collaboration across services; a client-centred approach; and provision of social care. No peer-reviewed studies described models of integrated HIV-TB care for PWID but grey literature highlighted key components: co-located services, provision of drug treatment, multidisciplinary staff training; and remaining barriers: staffing inefficiencies, inadequate funding, police interference, and limited OST availability.

CONCLUSIONS

Integration with drug treatment improves PWID engagement in TB services but there is a need to document approaches to HIV-TB care, improve surveillance of TB and co-infections among PWID, and advocate for improved OST availability.

Incidence of tuberculosis infection among healthcare workers: risk factors and 20-year evolution

OBJECTIVE

To determine the incidence of latent tuberculosis infection (LTBI), and risk factors for tuberculosis skin test (TST) conversion among Healthcare workers (HCWs) during a 20-year follow-up period.

DESIGN

Prospective cohort analysis. Surveillance was conducted from January 1, 1988, to December 31, 2007.

SETTING

600-bed tertiary referral hospital in Barcelona, Spain.

PARTICIPANTS

HCWs in risk for occupational tuberculosis (TB) exposure, with negative baseline TST, direct contact with patients and/or biological samples and at least one follow-up visit with TST.

METHODS

TST is performed in HCWs with no previous history of TB or no previous positive TST. When TST is negative this test is performed once a year in high-risk workers, or at least every 2 years according to the hospital's guidelines. In all cases an interview questionnaire to gather information on possible risk factors was performed.

RESULTS

The study included 614 HCWs, 27% worked in areas of risk for TB exposure. Annual incidence rate had decreased from 46.8 per 100 person-years in 1990 to 1.08 per 100 person-years in 2007. Cumulative incidence was higher in HCWs who work in high-risk areas (p = 0.004) and in time periods from 1990 to 1995, and from 1996 to 2001 (p < 0.0001). Cox regression model showed a hazard ratio of 1.55 (CI 95%; 1.05-2.27) in high-risk workers, adjusted by gender, age and professional status.

CONCLUSIONS

Incidence of LTBI among HCWs is high, although it decreased throughout the follow-up period. It is crucial to maintain surveillance programs in HCWs.

[Effects of HIV status and other variables on the outcome of tuberculosis treatment in Spain]

OBJECTIVE

To analyze the effect of human immunodeficiency virus (HIV) status and other variables on the outcome of tuberculosis treatment in Spain.

PATIENTS AND METHODS

Multicenter retrospective cohort study in 6 autonomous communities of Spain (from May 1996 to April 1997). Data on treatment outcome were collected for new cases of tuberculosis in accordance with European guidelines. Follow up of patients continued for 3 months after scheduled end of treatment.

RESULTS

Of the 4899 patients included, 3417 (69.7%) had a satisfactory outcome, 438 (8.9%) died before or during treatment, and 1044 (21.4%) had a potentially unsatisfactory outcome. On stratification by HIV status, satisfactory outcome, mortality, and potentially unsatisfactory outcome were reported for 43.4%, 21.5%, and 35.1%, respectively, of HIV-positive patients; 71%, 6.2%, and 22.8%, respectively, of HIV-negative patients; and 74.3%, 7.5%, and 18.2%, respectively, of patients with no HIV status available. HIV modified the effect of several variables on the outcome of treatment, and so separate logistic regression models for each HIV category were constructed. Among HIV-positive patients, mortality increased in patients with neoplastic disease and in users of drugs by nonintravenous routes of administration, whereas potentially unsatisfactory outcomes increased in intravenous drug users and in women.

CONCLUSIONS

In Spain, the outcome of tuberculosis treatment is much worse in HIV-positive patients. Drug use and presence of neoplastic disease substantially affect mortality.

Twenty years of pulmonary tuberculosis in children: what has changed?

OBJECTIVES

To compare the frequency, clinical and radiologic manifestations and source of infection of pulmonary tuberculosis in children treated in our hospital during two decades (1978 through 1987 and 1988 through 1997) and to evaluate the influence of the emergence of HIV infection (since 1985) and the effect of the discontinuation of Calmette-Guérin bacillus (BCG) vaccination (since 1987) on childhood tuberculosis.

METHODS

We reviewed 324 children diagnosed with pulmonary tuberculosis in our hospital during the 20 years (1978 through 1997). The data from 2 decades, 1978 through 1987 and 1988 through 1997, were compared. BCG vaccination in Spain was discontinued in 1987, and HIV infection emerged significantly as a public health problem.

RESULTS

An increase in the number of children with single hilar adenopathy was observed (32.2% in 1978 through 1987 vs. 43.4%, in 1988 through 1997, P < 0.05) in comparison with those with parenchymal involvement or a mixed pattern (62.4% in 1978 through 1987 vs. 45.7% in 1988 to 1997). Frequency in extrapulmonary manifestations in both periods was similar, with a nonsignificant trend toward a lower rate of tuberculous meningitis in the latter decade (10.4 vs. 5.6%, P = 0.07). We were able to identify an adult source case for 67.1% of the children (100 of 149) in the first decade vs.58.3% (102 of 175) in the second (P = NS); 10.8% of adult contacts but only 2.3% of children (all of them in the second period) were HIV-positive.

CONCLUSIONS

Discontinuation of BCG vaccination and emergence of HIV infection have had little influence on childhood tuberculosis in our area.

[Risk factors associated to tuberculosis patients with positive sputum microscopy]

OBJECTIVE

The main factor responsible for producing new cases of tuberculosis by exogen transmission is the existence of Mycobacterium tuberculosis in the sputum of tuberculosis patients. The objective of this study was to determine the risk factors associated to positive smear tuberculosis cases in Lleida (Spain).

METHODS

We studied new cases of tuberculosis over the period 1992-1998. The variables considered were: age, gender, coinfection with HIV, injection drug use (IDU), consumption of alcohol, existence of caverns in thorax X-ray, and laboratory results of direct smear examination. We calculated the incidence rates for 100,000 persons-year. The association between the dependent variable case of tuberculosis with positive Mycobacterium tuberculosis smear and the remaining independent variables were assessed obtaining odds ratios (OR) and 95% confidence intervals (CI) (crude cOR and adjusted aOR by non conditional logistic regression).

RESULTS

We detected 905 new cases of tuberculosis. The rates in the period 1992-1998 decreased from 38.8 to 30.8. 44.9% of cases (n = 406) presented a positive direct smear. There was a positive association between the risk of being a positive smear patient and having caverns in thorax x-ray (aOR = 6.8; 95% CI, 4.8-95), being male (aOR = 1.8; 95% CI, 1.3-2.6) and consuming alcohol (aOR = 1.6; 95% CI,1.1-2.3) and this risk was significant lower in those under 15 years old (aOR = 0.2; 95% CI, 0.1-0.5), and coinfection with HIV (aOR = 0.5; 95% CI, 0.3-0.9).

CONCLUSIONS

HIV infection implies a reduced impact in endemecity of tuberculosis. Study of contacts and the implementation of directly observed treatment must be considered not only for coinfected HIV cases and IDU but also for adult males, especially those who consume alcohol, particularly when they have caverns.

[Tuberculosis notification from 1987 to 1999 for the public health area of the community of Valencia (Spain)]

OBJECTIVE

Under notification of tuberculosis (TB) is common worldwide but has hardly been studied in Spain. The objective of this study was to determine how many cases of TB are reported in our health care area.

MATERIAL AND METHOD

Between 1987 and 1999 we carried out a direct study of the incidence and reporting of TB cases in our area (106,632 inhabitants on the census). Cases were taken from mandatory notification, pathology and bacteriology files and were then reviewed.

RESULTS

Of the 410 TB cases diagnosed, 378 were residents of the area (annual incidence: 27/100,000 inhabitants), 223 of whom were reported (54%). Forty-eight patients were under 15 years of age. Sixty-seven percent of the pediatric cases and 53% of the adult cases were reported (n.s.). Of the 78 cases with HIV co-infection, only 32% were reported, in contrast with 60% of HIV-negative cases (p < 0.001). Of the 300 cases with pulmonary involvement, 56% were reported, versus 50% of those with exclusively extrapulmonary involvement (n.s.). For the 149 with positive Ziehl-Neelsen stain, 61% were reported, in contrast with 51% of those who were smear negative (n.s.). Diagnosis was based on clinical signs in 65 cases (16%), 51% of which were reported, versus 55% of those in which diagnosis was based on bacteriology or histology consistent with TB (n.s.). Overall under notification tended to decrease during the study period (r = 0.73, p < 0.005). Under notification also tended to decrease for patients with pulmonary involvement (r = 0.83, p < 0.0001) and for those with positive Ziehl-Neelsen staining of sputum (r = 0.79, p< 0.001). Likewise, under notification also decreased for HIV negative patients (r = 0.74, p < 0.02) but not significantly so for HIV positive patients r = 0.44, n.s.).

CONCLUSIONS

Direct quantification of cases revealed a significant degree of under notification that is tending to decrease. Under notification is greatest for HIV-positive patients and is not changing. No differences were seen for smear positive and smear negative patients, by pulmonary or extra-pulmonary involvement, for clinical versus laboratory diagnosis, or for patients who were younger or older than 15 years of age. Reporting should be improved so that measures to decrease the incidence of TB can be taken.

Phthisiology at the dawn of the new century

Tuberculosis (TB) has been and continues to be one of the most significant pathogens in terms of human morbidity and mortality. Although the resurgence of TB has been held in check in most developed countries, the epidemic rages on in most developing countries of the world. The specter of drug resistance is becoming a more credible challenge in many parts of the world, dimming the prospects of eventual elimination. However, great opportunities are arising as well, with an unprecedented focus on the global aspects of TB control. This article will review the status of TB today and put into perspective the prospects for its elimination in the coming century.

Pulmonary and extrapulmonary tuberculosis at AIDS diagnosis in Spain: epidemiological differences and implications for control

OBJECTIVE

To ascertain the differential factors associated with pulmonary versus extrapulmonary tuberculosis (TB) at AIDS diagnosis in Spain.

DESIGN

Analysis of AIDS surveillance data.

METHODS

Data about AIDS patients, aged 12 years and over, diagnosed in 1995 were taken from the Spanish AIDS Register. The respective proportions of cases presenting with pulmonary and extrapulmonary TB at AIDS diagnosis were analysed by gender, age, HIV transmission category, prison record, province, country of origin and CD4+ lymphocyte count. A multivariate analysis was carried out using logistic regression analysis.

RESULTS

Of 6161 AIDS cases analysed, 20.1% presented with pulmonary TB and 20.4% with extrapulmonary TB. Overall, TB showed association with men, age under 30 years, injecting drug users (IDU), cases of heterosexual HIV transmission, and concurrent or past stay in prison. Frequency of TB proved no different among foreign-born patients. Pulmonary and extrapulmonary TB showed a similar distribution for most of the variables. Current prison inmates registered a high risk of pulmonary TB [adjusted odds ratio (OR), 4.2; 99% confidence interval (CI), 3.1-5.8] compared with patients without prison record, and ex-prison inmates registered an intermediate risk (OR, 2.3; 99% CI, 1.8-3.0). Among patients with TB at AIDS diagnosis, pulmonary TB was associated with subjects currently in prison (OR, 2.1; 99% CI, 1.5-3.0) and injecting drug use (OR, 1.5; 99% CI, 1.0-2.4). Pulmonary TB presented with higher CD4+ lymphocyte counts than extrapulmonary TB (P < 0.001).

CONCLUSIONS

The results suggest the importance that recent transmission of TB may be having among young adults, IDU and prison inmates in particular, and calls for a review of control strategies.