Detection of Mycobacterium tuberculosis from the stool of HIV sero-positive individuals suspected of pulmonary tuberculosis

Abstract

BackgroundThe impact of tuberculosis (TB) is exacerbated in Africa because of the human immunodeficiency virus (HIV) pandemic. Pulmonary tuberculosis (PTB) diagnosis is difficult in HIV-infected patients and negative sputum results are more common which leads to diagnostic delay and increases morbidity and mortality. Extra-pulmonary samples such as stool may be easier to obtain and our approach may therefore significantly improve PTB detection in people living with HIV.ObjectiveTo detect Mycobacterium tuberculosis from the stool of HIV sero-positive individuals suspected of pulmonary TB.MethodA total of 117 HIV-infected individuals from three public health facilities in Addis Ababa, Ethiopia were enrolled consecutively in the study. Paired morning sputum and stool samples were simultaneously collected from anti-retroviral therapy (ART) naïve individuals living with HIV and suspected for PTB. The diagnostic accuracy of the smear microscopy, culture and region of difference (RD)9–based polymerase chain reaction (PCR) in stool was compared with the accuracy of sputum testing. Chi-square test and kappa value were used to compare different method used.ResultsSputum culture positivity for mycobacteria was confirmed in 33(28.2%) of the study subjects. Of 33 individuals positive for sputa culture, 10 individuals were observed to be stools culture positive. Of the 84 individuals negative for mycobacteria by sputum culture, three (3.6%) were stool culture positive and thus, the sensitivity and agreement between stool culture as compare to sputum culture were 30.3% and 0.33, respectively. Of 117 individuals, 11(9.4%) were sputum smear positive and of 11 sputum smear positive three were also stool smear positive. While of the 106 sputum smear negative individuals’, only one was stool smear positive resulting in 12.1% sensitivity and 0.18 agreements against sputum culture. On the other hand, the sensitivity of RD9-based PCR directly on stool was 69.7% by considering sputum culture as a reference standard. Moreover, RD9-based PCR directly on sputum detected 7(6.0%) individuals who were sputum culture negative for M. tuberculosis.ConclusionM. tuberculosis was detected in stool of individuals living with HIV who were negative for sputum smear microscopy and culture. Hence, examination of stool samples alongside with sputum samples increases the detection of PTB in individuals living with HIV.

Prevalence and Clinical Profiling of Dysglycemia and HIV Infection in Persons With Pulmonary Tuberculosis in Brazil

“…However, a study in 132 people with HIV described that the male population has a strong association with smoking, and in turn there is a strong interaction between smoking and alcohol consumption in infected men with HIV (39) which is consistent with the results of our study. Immunodeficiency and a decreased inflammatory response can inhibit sputum production in individuals with HIV; such cases also tend to have fewer atypical findings on radiographs (40), which coincides with the overall low percentage of cough and lower frequency of abnormal x-rays found in the TBDM-HIV, TBPDM-HIV and TB-HIV groups. Among the groups of individuals living with HIV, the TBDM-HIV presented a higher proportion of abnormal x-rays and self-reported cough.…”

Prevalence and Clinical Profiling of Dysglycemia and HIV infection in Persons with Pulmonary Tuberculosis in Brazil

“…However, a study in 132 people with HIV described that the male population has a strong association with smoking, and in turn there is a strong interaction between smoking and alcohol consumption in infected men with HIV (Bhatta et al, 2018) which is consistent with the results of our study. Immunodeficiency and a decreased inflammatory response can inhibit sputum production in individuals with HIV; such cases also tend to have fewer atypical findings on radiographs (Abaye et al, 2017), which coincides with the overall low percentage of cough and lower frequency of abnormal x-rays found in the TBDM-HIV, TBPDM-HIV and TB-HIV groups. Among the groups of individuals living with HIV, the TBDM-HIV presented a higher proportion of abnormal x-rays and self-reported cough.…”

Rapid molecular diagnostics of tuberculosis resistance by targeted stool sequencing

“…Identification of M. tuberculosis complex in stool specimens by polymerase chain reaction (PCR), typically with the GeneXpert® MTB/RIF (Xpert), has demonstrated sensitivity between 60 and 70% against culture on respiratory specimens in children and adults [ 9 , 10 ]. Hence, stool is now accepted as a diagnostic specimen to detect M. tuberculosis complex in children and PLHIV who have difficulty producing sputum [ 11 , 12 ]. Sensitivity may be improved through specialized DNA extraction protocols [ 13 ].…”