1397. Modern Lineages of Mycobacterium tuberculosis Were Recently Introduced in Western India and Demonstrate Increased Transmissibility

Background

Mycobacterium tuberculosis (Mtb) transmissibility may vary between lineages (or variants) and this may contribute to the slow decline of tuberculosis incidence. The objective of our study was to compare transmissibility across four major lineages (L1-4) of Mtb in Pune, India.

Methods

We performed whole-genome sequencing (WGS) of Mtb isolated from sputum culture of adult patients with pulmonary TB. We performed genotypic susceptibility testing for both first- and second-line drugs using a previously validated random forest predictor. We identified single nucleotide polymorphisms and generated a multiple sequence alignment excluding drug resistance conferring mutations to avoid skewing the phylogeny due to convergent evolution in these regions. We used Bayesian molecular dating to generate phylogenies and compared tree characteristics using a two-sample Kolmogorov-Smirnov (KS) test.

Results

Of the 642 isolates from distinct study participants that underwent WGS, 612 met quality criteria. The median age of participants was 31 years (range 18-74), the majority were male (64.7%) and sputum smear-positive (83.3%), and 6.7% had co-infection with HIV (Table 1). There was no significant difference in baseline characteristics between lineages. The majority of isolates belonged to L3 (44.6%). The majority (61.1%) of multidrug-resistant (MDR, resistant to isoniazid and rifampin) isolates belonged to L2. In phylogenetic analysis, we found evidence of higher transmissibility of L2 as indicated by shorter branch lengths (i.e., less time had elapsed between transmission and sampling) and more genetic similarity (smaller pairwise single nucleotide polymorphism [SNP] distances) among L2 isolates as compared to other lineages (Figure 1). Branching times for L2 and L4 were smaller than L1 and L3 indicating recent introduction into the region (p < 0.001 [KS test]).

Figure 1: Lineage-wise distribution of A) phylogenetic tree branch lengths (log) and B) pairwise single nucleotide polymorphism (SNP) distance, using 612 tuberculosis isolates from Pune, India. P values calculated using two-sample Kolmogorov-Smirnov test.

Table 1: Demographic characteristics of study participants included in the study, by lineage.

Conclusion

Modern Mtb lineages (L2 and L4) were relatively recently introduced in western India, as compared to older lineages (L1 and L3), with the more drug-resistant L2 showing higher transmissibility. These findings highlight the need for early detection and treatment initiation to interrupt transmission with important implications for antimicrobial stewardship and heightened surveillance of TB resistance rates.

Disclosures

All Authors: No reported disclosures

Measuring TB drug levels in the hair in adults and children to monitor drug exposure and outcomes

INTRODUCTION: Testing for anti-TB drugs in small hair samples may serve as a non-invasive tool to measure cumulative drug exposure and/or adherence, as these determine treatment success. We aimed to assess how well hair assays of TB drugs predict TB treatment outcomes.METHODS: A small thatch of hair, ~30 strands, was cut from the occipital region in adults and children from a prospective TB cohort in India. Isoniazid (INH), acetyl-INH and pyrazinamide (PZA) were extracted from the hair samples and quantified using liquid-chromatography-tandem mass spectrometry. The relationship between drug concentrations in hair and time to unfavourable outcomes was assessed using Cox-proportional hazards regression models.RESULTS: A two-fold increase in hair acetyl-INH concentrations in the 264 participants in our cohort with hair assays for TB drugs indicated a lower hazard of unfavourable TB treatment outcomes (aHR 0.67, 95%CI 0.44-1.02) and TB treatment failure (aHR 0.65, 95%CI 0.42-1.01). Higher summed concentrations (a summed measure of INH and acetyl-INH) indicated a lower hazard of treatment failure (aHR 0.69, 95%CI 0.45-1.05)CONCLUSION: Hair levels of INH and its metabolite may predict TB treatment outcomes, indicating the potential utility of this measure to assess and optimise TB treatment outcomes.

Unhealthy alcohol use independently associated with unfavorable TB treatment outcomes among Indian men

BACKGROUND: Approximately 10% of incident TB cases worldwide are attributable to alcohol. However, evidence associating alcohol with unfavorable TB treatment outcomes is weak.METHODS: We prospectively evaluated men (≥18 years) with pulmonary TB in India for up to 24 months to investigate the association between alcohol use and treatment outcomes. Unhealthy alcohol use was defined as a score of ≥4 on the Alcohol Use Disorders Identification Test-Concise (AUDIT-C) scale at entry. Unfavorable TB treatment outcomes included failure, recurrence, and all-cause mortality, analyzed as composite and independent endpoints.RESULTS: Among 751 men, we identified unhealthy alcohol use in 302 (40%). Median age was 39 years (IQR 28-50); 415 (55%) were underweight (defined as a body mass index [BMI] <18.5 kg/m²); and 198 (26%) experienced an unfavorable outcome. Unhealthy alcohol use was an independent risk factor for the composite unfavorable outcome (adjusted incidence rate ratio [aIRR] 1.47, 95% CI 1.05-2.06; P = 0.03) and death (aIRR 1.90, 95% CI 1.08-3.34; P = 0.03), specifically. We found significant interaction between AUDIT-C and BMI; underweight men with unhealthy alcohol use had increased risk of unfavorable outcomes (aIRR 2.22, 95% CI 1.44-3.44; P < 0.001) compared to men with BMI ≥18.5 kg/m² and AUDIT-C <4.CONCLUSION: Unhealthy alcohol use was independently associated with unfavorable TB treatment outcomes, highlighting the need for integrating effective alcohol interventions into TB care.

Delays and barriers to early treatment initiation for childhood tuberculosis in India

BACKGROUND: India accounts for 27% of global childhood tuberculosis (TB) burden. Understanding barriers to early diagnosis and treatment in children may improve care and outcomes.METHODS: A cross-sectional study was performed among 89 children initiated on anti-TB treatment from a public hospital in Pune during 2016, using a structured questionnaire and hospital records. Health care providers (HCPs) were defined as medical personnel consulted about the child's TB symptoms. Time-to-treatment initiation (TTI) was defined as the number of days between onset of TB symptoms and anti-TB treatment initiation. Based on Revised National TB Control Programme recommendations, delayed TTI was defined as >28 days.RESULTS: Sixty-seven (75%) of 89 enrolled children had significant TTI delays (median 51 days, interquartile range [IQR] 27-86). Sixty-six (74%) children visited 1-8 HCPs in the private sector before approaching the public sector. The median HCP delay was 28 days (IQR 10-75). Bacille Calmette-Guérin vaccination (aOR 10.96, P = 0.04) and loss of appetite (aOR 4.44, P = 0.04) were associated with delayed TTI.CONCLUSION: The majority of the children had TTI delays due to delays by HCPs in the private sector. Strengthening HCP competency in TB symptom screening and encouraging early referrals are crucial for rapid scaling up of early treatment initiation in childhood TB.

Rooting behaviour and soil properties in different bamboo species of Western Himalayan Foothills, India

Due to extensive root system, connected rhizome bamboos are considered suitable for improving soil properties within a short period, though most of the claims are anecdotal and need to be supported with quantified data. The study evaluates seven bamboo species viz., Bambusa balcooa, Bambusa bambos, Bambusa vulgaris, Bambusa nutans, Dendrocalamus hamiltonii, Dendrocalamus stocksii and Dendrocalamus strictus for their rooting pattern and impact on soil health properties. Coarse and fine root intensity was maximum in B. vulgaris. Coarse root biomass ranged from 0.6 kg m⁻³ in B. nutans to 2.0 kg m⁻³ in B. vulgaris and B. bambos. Fine root biomass ranged from 1.1 kg m⁻³ in B. nutans to 4.5 kg m⁻³ in D. hamiltonii. Contribution of fine roots in terms of intensity and biomass was much higher than coarse roots. Fine root biomass showed declining trend with increase in soil depth in all the species. During sixth year, the litter fall ranged from 8.1 Mg ha⁻¹ in D. stocksii to 12.4 Mg ha⁻¹ in D. hamiltonii. Among soil physical properties significant improvement were recorded in hydraulic conductivity, water stable aggregates and mean weight diameter. Soil pH, organic carbon and available phosphorus under different species did not reveal any significant changes, while significant reduction was observed in total nitrogen and potassium. Significant positive correlation was observed between WSA and iron content. Soil microbial population and enzyme activities were higher in control plot. Considering root distribution, biomass, soil hydraulic conductivity and water stable aggregates, B. bambos, B. vulgaris and D. hamiltonii are recommended for rehabilitation of degraded lands prone to soil erosion.

Barriers to screening and isoniazid preventive therapy for child contacts of tuberculosis patients

BACKGROUND

India's guidelines recommend tuberculosis (TB) screening of household contacts aged <6 years and isoniazid preventive therapy (IPT) for children without active disease. We evaluated the current status and barriers to screening and IPT provision among the child contacts of TB patients.

METHODS

Questionnaire and health record data were collected from index cases and health care providers (HCPs) at Sassoon General Hospital, Pune, India.

RESULTS

Of 80 adult TB cases, 24 (30%) reported that an HCP recommended TB screening of their child contacts; 49/178 (28%) child contacts were screened. Sixteen (33%) children had active TB, and 28 (85%) of those who screened negative were prescribed IPT. Nineteen (76%) HCPs reported recommending child contact screening. Only 8 (32%) reported ever prescribing IPT. Lack of TB screening and IPT provision for child contacts was associated with inadequate HCP counseling (aOR 19.5, P < 0.001), a non-parent index case (aOR 3.72, P = 0.008) and lack of postgraduate HCP qualification (aOR 19.12, P = 0.04).

CONCLUSIONS

TB screening and IPT provision for child contacts of adults with TB were infrequent. Many screened children had active TB. Universal, timely TB screening and IPT for exposed children are urgently needed to reduce pediatric TB in India.

Trends in HbA1c levels and implications for diabetes screening in tuberculosis cases undergoing treatment in India

SETTING

The optimal timing of screening for diabetes mellitus (DM) among tuberculosis (TB) cases is unclear due to the possibility of stress hyperglycemia.

DESIGN

We evaluated adult (18 years) pulmonary TB cases at treatment initiation as well as at 3 months, 6 months and 12 months. DM was identified by self-report (known DM) or glycated hemoglobin (HbA1c)  6.5% (new DM). Trends in HbA1c levels during treatment were assessed using non-parametric tests.

RESULTS

Of the 392 participants enrolled, 75 (19%) had DM, 30 (40%) of whom had new DM. Of the 45 participants with known DM, respectively 37 (82%) and 40 (89%) received medication to lower glucose levels at treatment initiation and completion; one participant with new DM initiated glucose-lowering medication during follow-up. The median HbA1c level in participants with known, new and no DM was respectively 10.1% (interquartile range [IQR] 8.3-11.6), 8.5% (IQR 6.7-11.5) and 5.6% (IQR 5.3-5.9) at treatment initiation, and 8.7% (IQR 6.8-11.3), 7.1% (IQR 5.8-9.5) and 5.3% (IQR 5.1-5.6) at treatment completion (P < 0.001). Overall, 5 (12%) with known and 13 (43%) with new DM at treatment initiation had reverted to HbA1c < 6.5% by treatment completion (P = 0.003); the majority of reversions occurred during the first 3 months, with no significant reversions beyond 6 months.

CONCLUSION

HbA1c levels declined with anti-tuberculosis treatment. Repeat HbA1c testing at treatment completion could reduce the risk of misdiagnosis of DM.

Prevalence of dysglycemia and clinical presentation of pulmonary tuberculosis in Western India

SETTING

Pune, India.

OBJECTIVES

To estimate the prevalence and risk factors of pre-diabetes mellitus (DM) and DM, and its associations with the clinical presentation of tuberculosis (TB).

DESIGN

Screening for DM was conducted among adults (age  18 years) with confirmed TB between December 2013 and January 2017. We used multinomial regression to evaluate the risk factors for pre-DM (glycated hemoglobin [HbA1c]  5.7-6.5% or fasting glucose 100-125 mg/dl) and DM (HbA1c  6.5% or fasting glucose  126 mg/dl or random blood glucose > 200 mg/dl or self-reported DM history/treatment) and the association of dysglycemia with the severity of TB disease.

RESULTS

Among 1793 participants screened, 890 (50%) had microbiologically confirmed TB. Of these, 33% had pre-DM and 18% had DM; 41% were newly diagnosed. The median HbA1c level among newly diagnosed DM was 7.0% vs. 10.3% among known DM (P < 0.001). DM (adjusted OR [aOR] 4.94, 95%CI 2.33-10.48) and each per cent increase in HbA1c (aOR 1.42, 95%CI 1.01-2.01) was associated with >1+ smear grade or 9 days to TB detection.

CONCLUSION

Over half of newly diagnosed TB patients had DM or pre-DM. DM and increasing dysglycemia was associated with higher bacterial burden at TB diagnosis, potentially indicating a higher risk of TB transmission to close contacts.

Loss to follow-up and mortality among HIV-infected adolescents receiving antiretroviral therapy in Pune, India

OBJECTIVES

India has the highest number of HIV-infected adolescents in Asia, but little is known about their treatment outcomes. We assessed rates and factors associated with loss to follow-up (LTFU) and mortality among Indian adolescents.

METHODS

The analysis included adolescents (10-19 years old) starting antiretroviral therapy (ART) between 2005 and 2014 at BJ Government Medical College, Pune, India. LTFU was defined as missing more than three consecutive monthly visits. The competing-risks method was used to calculate subdistribution hazard ratios (SHRs) of predictors for LTFU, with death as the competing risk. Cox proportional hazard models were used to identify predictors of mortality.

RESULTS

Of 717 adolescents starting ART, 402 with complete data were included in the analysis. Of these, 61% were male and 80% were perinatally infected, and the median baseline CD4 count was 174 cells/μL. LTFU and mortality rates were 4.4 and 4.9/100-person years, respectively. Cumulative LTFU incidence increased from 6% to 15% over 6 years. Age ≥ 15 years [adjusted SHR (aSHR) 2.44; 95% confidence interval (CI) 1.18-5.02] was a risk factor for LTFU. Cumulative mortality increased from 9.5% to 17.9% over 6 years. World Health Organization (WHO) stages III and IV [adjusted hazard ratio (aHR) 2.26; 95% CI: 1.14-4.48] and an increase in CD4 count by 100 cells/μL (aHR: 0.59; 95% CI: 0.43-0.83) were associated with mortality.

CONCLUSIONS

A third of adolescents had been lost to follow-up or died by follow-up year 6. Older age was a risk factor for LTFU and advanced clinical disease for death. Strategies to improve retention counselling for older adolescents and closer clinical monitoring of all adolescents must be considered.

Impact of maternal hepatitis B virus coinfection on mother-to-child transmission of HIV

OBJECTIVES

Despite high hepatitis B virus (HBV) endemicity in various resource-limited settings (RLSs), the impact of maternal HIV/HBV coinfection on infant health outcomes has not been defined. We aimed to assess the prevalence of HBV coinfection among HIV-infected pregnant women and its impact on HIV transmission and infant mortality.

METHODS

In this study, the seroprevalence of HBV coinfection was determined among HIV-infected pregnant women enrolled in the Six-Week Extended-Dose Nevirapine (SWEN) India trial. The impact of maternal HIV/HBV coinfection on mother-to-child transmission (MTCT) of HIV and infant mortality was assessed using univariate and multivariate logistic regression analysis.

RESULTS

Among 689 HIV-infected pregnant Indian women, 32 (4.6%) had HBV coinfection [95% confidence interval (CI) 3.4%, 5.3%]. HBV DNA was detectable in 18 (64%) of 28 HIV/HBV-coinfected women; the median HBV viral load was 155 copies/mL [interquartile range (IQR) < 51-6741 copies/mL]. Maternal HIV/HBV coinfection did not increase HIV transmission risk [adjusted odds ratio (aOR) 1.06; 95% CI 0.30, 3.66; P = 0.93]. Increased odds of all-cause infant mortality was noted (aOR 3.12; 95% CI 0.67, 14.57; P = 0.15), but was not statistically significant.

CONCLUSIONS

The prevalence of active maternal HBV coinfection in HIV-infected pregnant women in India was 4.6%. HIV/HBV coinfection was not independently associated with HIV transmission.