Early Microbiologic Markers of Pulmonary Tuberculosis Treatment Outcomes.

Rationale: Earlier biomarkers of pulmonary tuberculosis (PTB) treatment outcomes are critical to monitor shortened anti-TB treatment (ATT). Objectives: To identify early microbiologic markers of unfavorable TB treatment outcomes. Methods: We performed a subanalysis of 2 prospective TB cohort studies conducted from 2013 to 2019 in India. We included participants aged ⩾18 years who initiated 6-month ATT for clinically or microbiologically diagnosed drug-sensitive PTB and completed at least one follow-up visit. Sputum specimens were subjected to a baseline Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF) assay, acid-fast bacilli (AFB) microscopy and liquid and solid cultures, and serial AFB microscopy and liquid and solid cultures at weeks 2, 4, and 8. Poisson regression was used to assess the impact of available microbiologic markers (test positivity, smear grade, time to detection, and time to conversion) on a composite outcome of failure, recurrence, or death by 18 months after the end of treatment. Models were adjusted for age, sex, nutritional status, diabetes, smoking, alcohol consumption, and regimen type. Results: Among 1,098 eligible cases, there were 251 (22%) adverse TB treatment outcomes: 127 (51%) treatment failures, 73 (29%) recurrences, and 51 (20%) deaths. The primary outcome was independently associated with the Xpert MTB/RIF assay (medium-positive adjusted incidence rate ratio [aIRR], 1.91; 95% confidence interval [CI], 1.07-3.40; high-positive aIRR, 2.51; 95% CI, 1.41-4.46), positive AFB smear (aIRR, 1.48; 95% CI, 1.06-2.06), and positive liquid culture (aIRR, 1.98; 95% CI, 1.21-3.23) at baseline; Week 2 positive liquid culture (aIRR, 1.47; 95% CI, 1.04-2.09); and Week 8 positive AFB smear (aIRR, 1.63; 95% CI, 1.06-2.50) and positive liquid culture (aIRR, 1.54; 95% CI, 1.07-2.22). There was no evidence of Mycobacterium tuberculosis growth in the Mycobacterium Growth Indicator Tube at Week 4 conferring a higher risk of adverse outcomes (aIRR, 1.25; 95% CI, 0.89-1.75). Conclusions: Our analysis identifies Week 2 respiratory mycobacterial culture as the earliest microbiologic marker of unfavorable PTB treatment outcomes.

High prevalence of cryptococcal antigenaemia amongst asymptomatic advanced HIV patients in Pune, India.

BACKGROUND: The World Health Organization recommends routine cryptococcal antigen (CrAg) screening in advanced AIDS patients initiating antiretroviral treatment (ART). India has yet to adopt this strategy as the burden of cryptococcal antigenaemia is unknown. METHODS: A prospective study was conducted in a large public sector ART centre and the inpatient wards of Sassoon Hospital, Pune, India. All consenting patients> 18 years of age with CD4 count <100 cells/mm3 were screened for CrAg by latex agglutination assay. Those with positive CrAg underwent cerebrospinal fluid analysis, chest radiograph and abdominal ultrasound to rule out cryptococcal disease. The impact of CrAg positivity on all-cause mortality was assessed by logistic regression analysis. RESULTS: Amongst 208 AIDS patients with CD4 cells <100 cells/mm3 who underwent CrAg testing, median age was 40 (interquartile range [IQR], 35-49) years, 134 (64%) were male and median CD4 count was 64.5 cells/mm3 (IQR, 37-82). Overall, 16 (8%, 95% confidence interval [CI], 4-12) patients were positive for CrAg, of which 8 (50%) had CD4 cells <50 cells/mm3 and 3 (19%) CrAg-positive patients had incidental cryptococcal meningitis. At 6-month follow-up, the case fatality rate was higher amongst CrAg-positive patients (38%) compared with CrAg-negative patients (18%) (P = 0.06). After adjusting for age, sex, CD4 count and ART, there was a trend towards increased all-cause mortality (adjusted OR, 3.18, 95% CI, 0.60-16.88,P= 0.17). CONCLUSIONS: We found an 8% prevalence of cryptococcaemia amongst adult AIDS patients with CD4 cells <100 cells/mm3. Given the high fatality rates observed, routine screening for CrAg should be considered for all Indian persons with advanced HIV disease.

Utility of Line Probe Assay for the Early Detection of Multidrug-Resistant Pulmonary Tuberculosis.

BACKGROUND: Despite endorsement of the line probe assay (LPA) for the diagnosis of drug-resistant pulmonary tuberculosis patients, there is limited data available on the performance of LPAs in India, especially from high burden states like Maharashtra, for the early diagnosis and detection of drug resistance, in order to initiate timely and appropriate treatment. OBJECTIVE: To evaluate the utility of the line probe assay (LPA) for the early diagnosis of drug-resistant pulmonary tuberculosis as compared to the 'Gold standard' 1% proportion method (PM). MATERIALS AND METHODS: A total of 687 patients suspected of pulmonary tuberculosis were screened. One hundred samples (95 sputum and 5 BAL), positive for Acid Fast Bacilli (AFB) by Ziehl Neelson (ZN) smears, were included in the study. Digested and decontaminated specimens were subjected directly to the LPA (Genotype MTBDR@ plus assay) and were processed in parallel using the conventional culture on the Lowenstein-Jensen (LJ) medium followed by drug susceptibility testing (DST) using the PM. RESULTS: All the 100 samples gave interpretable results on LPA with a turnaround time of 24-48 hours as opposed to six to eight weeks taken by the 1% proportion method. Sensitivity for the detection of rifampicin, isoniazid, and multidrug resistance (MDR) was 98.1, 92.1, and 95%, respectively, with a specificity of 97.8% for rifampicin and 98.33% for MDR detection. It also had the additional advantage of allowing a study of mutation patterns. CONCLUSIONS: High performance characteristics and a short turnaround time makes LPA an excellent diagnostic tool, for an early and accurate diagnosis, in a high MDR- TB-prevalent region, as reflected from our data.

Mycobacterium avium-intracellulare brain abscess in HIV-positive patient.

Mycobacterial opportunistic infections are a major cause of morbidity and mortality among patients living with HIV (PLHIV) worldwide. Nontuberculous mycobacterial (NTM) infection is one of the leading causes of opportunistic infection in patients with advanced acquired immunodeficiency syndrome i.e., with CD4 count less than 50/cu.mm. Mycobacterium avium complex (MAC) is among the most common opportunistic bacterial infections in those patients with advanced immunodeficiency apart from cryptococcal meningitis, progressive multifocal leukoencephalopathy, etc. Common presentations of mycobacterium avium complex are fever, lymphadenitis and respiratory disease. Immune reconstitution disease is also known to manifest with MAC infections in PLHIV on highly active antiretroviral therapy. Very few cases of central nervous system involvement due to NTM infection have been described. We are reporting a case of advanced acquired immunodeficiency who presented with brain abscess due to Mycobacterium avium intracellulare.