Asociación Micobacterias-VIH/SIDA en Pacientes Atendidos en un Hospital Universitario en Bogotá, Colombia

[Prevalence and risk factors associated to tuberculosis and non-tuberculous mycobacterial infections in HIV-positive patients in Bogotá]

INTRODUCTION

Tuberculosis is one of the most widely distributed infectious diseases worldwide. It is the most common cause of mortality among AIDS patients. In Colombia, 12,918 tuberculosis cases were notified, and 926 deaths were reported in 2015.

OBJECTIVE

To determine the prevalence and risk factors associated to mycobacterial infections in HIVpositive patients in two public hospitals from Bogotá.

MATERIALS AND METHODS

A prospective and descriptive study was carried out by an active search for tuberculosis cases and non-tuberculous mycobacterial infections in HIV-positive patients. We considered demographic, social, clinical, and personal habits as variables. Statistical analyses were done using Stata 13™ software.

RESULTS

Three hundred and fifty six patients were included, 81.2% were men and 18.8% were women; the mean age was 36.5 years. Tuberculosis infection had a frequency of 19.9% (95% CI: 15.9-24.5%) and non-tuberculous mycobacterial infection had a 3.9% frequency (95% CI: 2.16-6.5%). Bivariate analysis showed a statistically significant association between tuberculosis infection and CD4+ T cell counts (p=0.003), viral load (p=0.008), antiretroviral therapy (p=0.014), and body mass index (BMI) <18 kg/m2 (p=0.000). In non-tuberculous mycobacterial infections there was a statistically significantassociation with BMI (p=0.027) and CD4+ T cell counts (p=0.045).

CONCLUSION

Factors associated with an impaired immune system caused by HIV infection are an important risk factor for developing tuberculosis. The lack of antiretroviral therapy and the BMI were also important risk factors for tuberculosis.

Assessment of mycobacteremia detection as a complementary method for the diagnosis of tuberculosis in HIV-infected patients

The purpose of this investigation was to assess the usefulness of mycobacteremia detection in human immunodeficiency virus (HIV) patients with suspected tuberculosis. The study included 47 patients with suspected tuberculosis and confirmed HIV infection. A first blood sample was incubated in a BACTEC 9050 MB system, while white blood cells isolation was performed on a second blood specimen before incubation in a BACTEC MGIT 960 system. The third specimen was taken from the affected organs of each patient according to their clinical profile. Twelve (25.5%) patients were positive for mycobacterial infection identified by any of the methods used. Ten (21.2%) were positive for Mycobacterium tuberculosis and 2 (4.3%) for M. avium. Six patients were diagnosed by the culture of specimen from affected organs only, whilst three other patients were positive exclusively for blood cultures. Three additional patients were diagnosed by both methods. Four patients with negative cultures were ultimately diagnosed with tuberculosis by measuring the adenosine deaminase levels. Mycobacteremia detection can be used to increase the sensitivity of the diagnosis of tuberculosis and other mycobacteria in patients with HIV. However, it cannot be used as the sole diagnostic method. Clinical specimen cultures do not provide 100% diagnostic accuracy and it is, therefore, critical to further improve the mycobacteria detection sensitivity.