TB across the globe (2). Tuberculosis in India--the past and prospects for the future

Accuracy of Xpert® MTB/RIF in diagnosing extrapulmonary tuberculosis in Indian children

Background Diagnosing extrapulmonary tuberculosis (EPTB) can be challenging because of a variety of presentations. We assessed the accuracy of the Xpert MTB/RIF assay in diagnosing EPTB in children. Methods Of the 255 children diagnosed to have tuberculosis (TB) who underwent testing by the Xpert MTB/ RIF assay at the TB clinic from December 2014 to April 2017, 182 had EPTB and were included in the study. The diagnostic accuracy, specificity and sensitivity of the Xpert assay were calculated with Mycobacterium growth indicator tube (MGIT) as a reference standard. Results Lymph node TB was present in 58 (32%) children, 37 (20%) had neurological TB, 36 (20%) had bone TB, 31 (17%) had pleural TB, 15 (8%) had abdominal TB, 2 (1%) had abscess, 2 (1%) had congenital TB and disseminated TB was seen in 1 (0.4%) child. Xpert MTB/RIF assay was positive in 84 (46.2%) patients. The sensitivity and specificity of the Xpert MTB/RIF assay were 72% and 72.04%, respectively. Compared to MGIT, a kappa coefficient of 0.44 shows moderate agreement between the Xpert assay and MGIT. The sensitivity of Xpert MTB/RIF assay in abdominal TB, bone TB, lymph node TB, neurological TB and pleural TB was 50% (15%-85%), 72.7% (15.9%- 86.9%), 80.8% (62.1%-91.5%), 75% (50.5%-90%) and 25% (4.6%-70%), respectively. The specificity of abdominal TB, bone TB, lymph node TB, neurological TB and pleural TB was 83.3% (43.7%-97%), 69.2% (42.4%- 87.3%), 55.2% (37.6%-71.6%), 85% (64%-94.8%) and 82.6% (62.9%-93%), respectively. Forty-seven (26%) patients had drug-resistant TB (DR-TB), of which 15 (8%) were rifampicin-resistant (RR), 2 (1%) were polyresistant, 14 (8%) had multi-DR (MDR), 15 (8%) had pre-extremely DR (XDR) and 1 (1%) had XDR-TB. Of the 15 patients with MDR-TB, Xpert MTB/RIF assay detected only 10 (71%) as RR (p=0.06). Of the 15 pre-XDR cases, Xpert MTB/RIF detected only 8 (53%) as RR (p=0.02). Conclusion Xpert MTB/RIF assay is useful in the diagnosis of EPTB. It shows good concordance with MGIT. However, it may be negative in patients with DR-TB.

Clinical and biochemical profile of tuberculosis in patients with liver cirrhosis

INTRODUCTION

There is paucity of data on tuberculosis and antituberculous therapy (ATT) induced hepatotoxicity in patients with chronic liver disease.

AIM

To study demographic, clinical characteristics of tuberculosis, pattern of drug induced liver injury and treatment responses to ATT in patients with liver cirrhosis.

MATERIAL AND METHOD

All cases of liver cirrhosis diagnosed with tuberculosis (TB) between January 2010 and June 2013 were enrolled. Drug induced liver injury (DILI) was defined as follows (1) an aspartate aminotransferase (AST)/alanine aminotransferase (ALT) value exceeding 3 times the normal upper limit if the baseline level was normal (<40 IU/L), or an AST/ALT exceeding 2 times the baseline level if the baseline level was abnormal and an absolute increase in serum bilirubin >2 mg/dl from baseline.

RESULTS

Sixty seven patients had confirmed TB with underlying cirrhosis and formed the study group. The mean age was 52 ± 12 years and M:F ratio was 57:10. Mean Child Turcotte Pugh (CTP) score 8.5 ± 1.5 (CTP A:B:C:7:44:16). The sites of TB included: pulmonary (25, 37%); pleural effusion (10, 16%) peritoneal (19, 29%); chest lymph nodes (3, 4%); liver (1, 1.5%); intestines (3, 4%), vertebra (3, 4%), brain (1, 1.5%) and disseminated (2, 3%). Thus, extrapulmonary TB was more common in the cirrhotic patients as compared to pulmonary TB. Patients with Child's status A (n = 7) received 4 drugs (R: rifampicin, H: Isoniazid, E: ethambutol, Z: pyrizinamide) and could tolerate well even during follow up without any drug induced toxicity. In rest of patients commonest regimen followed was combination of drugs (RHEO, n = 32) followed by RHE (n = 11). DILI occurred in 35% started with either RHEO, HEO and REO. Median time of onset of DILI was 12 days (4-34) days. There was no DILI related death during hospital stay or follow up.

CONCLUSIONS

Extrapulmonary TB is common in patients with cirrhosis and DILI is common in Child B and C with combination of rifampicin and isoniazid regimen.

Exploratory qualitative study for community management and control of tuberculosis in India

Tuberculosis (TB) is a major public health problem in India which accounts for nearly one-fifth of the global TB burden. Though India has been gaining success in eliminating TB, the disease still kills 1000 people daily. It is of prime importance to control the TB situation in India. Motivated by the need to explore factors influencing TB, a qualitative study was conducted with 14 doctors and key TB informants in India over a period of one month involving face-to-face interviews. The interviewees came from diverse backgrounds and vocations, thus providing a rich data on varied issues in controlling the spread of TB in India for enhanced patient care. The data was coded and analyzed. The findings suggest the need to address mental and social well-being of the TB patients through three main themes, namely, Alerts, Care and Education, in order to control the TB situation in India.

Spoligotyping of Mycobacterium tuberculosis isolates from patients with pulmonary tuberculosis in Mumbai, India

Tuberculosis remains a major health problem in India, with 2 million new cases and 421,000 deaths each year. In this paper, we describe the spoligotyping results of 216 Mycobacterium tuberculosis culture isolates from patients with pulmonary tuberculosis in Mumbai, India. As spoligotyping data from India have rarely been described until now, and as there is limited information on the major circulating clades of M. tuberculosis, the data obtained were also compared to an international spoligotype database (SpolDB4) that contained patterns from 22,546 isolates from more than 100 countries. Eighty-four (39%) of the isolates were definitively marked as orphan strains, indicating the paucity of such data from India. The remaining 132 isolates clustered among 59 shared types; among these, 42 shared types were already present in the database, 17 were newly created, and 5 of them were specifically reported from Mumbai. A total of 9 major types in this study clustered 32% of the isolates. At the phylogenetic level, 30% of the isolates belonged to the Central Asian families CAS1 and CAS2, of the major genetic group (MGG) 1, 29% to MGG 2 and 3 families (spacers 33-36 missing) and 17% to the ancestral East African Indian (EAI) family. Finally, nearly 10% of the isolates belonged to the W-Beijing family in a broad sense, also in the MGG 1 group. In conclusion, historic clones of the MGG 1 group of M. tuberculosis are responsible for roughly 60% of all tuberculosis cases in Mumbai. Together with the fact that organisms presumably of European descent (such as the Haarlem family) were only rarely found, our observations suggest that tuberculosis in Mumbai, India is essentially caused by historical clones of tubercle bacilli undergoing active circulation due to uncontrolled demography, high prevalence of the disease, and a paucity of resources.