Drug-resistant tuberculosis: an experience from Qatar.

This study was conducted to evaluate the characteristics, treatment outcome and risk factors associated with 223 drug-resistant tuberculosis (DR-TB) cases in the State of Qatar. A descriptive records-based retrospective study was conducted on patients registered at Communicable Disease Centre (CDC), Qatar to all consecutive microbiologically confirmed tuberculosis cases for the period January 2010 - March 2015. Demographic, clinical data, drug-resistance pattern of isolated mycobacteria and treatment outcome was assessed for the patient who completed their treatment in Qatar. Of 3301 patients with positive M. tuberculosis culture were analyzed; 223 (6.7%) were resistant to at least one drug. The overall prevalence of multi-d rug resistant TB (MDR-TB) was 1.2% (n = 38) of patients. A former resident of Indian sub contents was the most common demographic characteristic observed (64.1%). The outcome of treatment was assessed for 85 resistant cases with follow-up after completion of treatment. Cure and relapse rates were 97.6%, and 2.4%, respectively. Drug-resistant TB in Qatar is influenced by migration where the patients were probably infected. Rapid sputum sampling performed in the early stages of the disease, patient isolation, and drug-susceptibility testing should be the standard of care.

Tuberculosis of pancreas, the first case reported from Qatar.

Despite the high prevalence of tuberculosis (TB) in developing countries, primary pancreatic TB is a rare entity. We present a case of pancreatic TB in an immunocompetent patient who was found to have pancreatic mass resembling malignancy. A 40-year-old Indian male presented to the medical emergency room with complaints of abdominal pain and fever for 2 weeks' duration. He had a history of unintentional weight loss of about 20 pounds in the past 2 months. There was no significant history of exposure to TB patient. Family history was unremarkable for any malignancy. On examination, the significant finding was epigastric tenderness. He was thoroughly investigated, his purified protein derivative and QuantiFERON were negative. Chest X-ray was unremarkable. Computed tomography scan abdomen was performed that revealed large heterogenous necrotic mass in the lesser sac likely arising from pancreatic body with possible infiltration of the stomach, left lobe of the liver and encasing celiac vessels and portal vein with multiple peripancreatic and retroperitoneal necrotic lymph nodes. Endoscopic ultrasound with fine-needle aspiration of pancreatic mass was done, biopsy specimen revealed the presence of inflammation with no evidence of malignancy. TB polymerase chain reaction and culture came positive for Mycobacterium tuberculosis. He was started on antituberculosis treatment with isoniazid, rifampicin, pyrazinamide, and ethambutol with a plan to continue for total 6 months. However, follow-up of the patient could not be done as he traveled back to his home country.

Childhood tuberculosis in Qatar.

Childhood tuberculosis (TB) has been long neglected but has gained attention in recent years. In 2012, the World Health Organization annual report included an estimate for childhood TB for the first time, and in the following year, the TB Alliance received a grant from UNITAID (International Drug Purchase Facility) to develop pediatric TB formulations. Qatar is a low-incidence country. In this observational study, laboratory-confirmed cases of TB were analyzed from 2013 to 2015 and included patients aged ⩽14years. Microscopy and GeneXpert MTB/RIF (Cepheid, USA) and MGIT 960 (Becton, Dickinson and Company, USA) automated culture systems were used to confirm cases at the National TB Reference Laboratory, Doha, Qatar. A total of 24 positive cases were identified in this pediatric population, 21 with Mycobacterium tuberculosis complex (MTBC) and three with Mycobacterium other than tuberculosis (MOTT). Out of 21 MTBC cases, 19 were direct polymerase chain reaction (PCR) positive and two were smear and PCR negative but culture positive were later confirmed by PCR. Most of the positive specimens were extrapulmonary from pus and tissues biopsies. While six were from pulmonary, out of that, five were sputum and one was from gastric aspirates. Niacin Strip Test (Becton, Dickinson and Company, USA) was used to identify the Bacillus Calmette-Guérin (BCG) vaccine strains from MTBC infections, and seven patients were infected with BCG. Keeping in mind that there were 500-600 laboratory-confirmed cases of TB in adults, childhood tuberculosis is not a major problem in Qatar. Lack of sensitivity of niacin test due to identification various niacin accumulating BCG strains is documented worldwide, further testing with more stringent molecular methods will certainly increase the number of BCG isolates in this study population.

Increased case finding of tuberculosis from sputum and sputum deposits after magnetic bead concentration of mycobacteria.

Concentration of mycobacteria from sputum by centrifugation prior to acid-fast microscopy increases case finding compared to direct microscopy of the sputum (direct smear). However, centrifugation has to be performed outside the safety cabinet and many laboratories do not have access to a centrifuge. Magnetic bead extraction of the mycobacteria is an alternative method that can be performed in a cabinet with just a magnet. Magnetic TB-Bead (Microsens Medtech Ltd) extraction of mycobacteria from sputum prior to microscopy was compared to direct smear on 78 sputum samples. Microscopy of the TB-Bead extracts identified all of 26 of the direct smear positive samples either with the same microscopy score or, in 19/27 of samples, with an increased microscopy score which aided microscopy detection. In addition, microscopy of the TB-Bead extracts identified 10 additional positive samples compared to direct smear; which represents a statistically significant increase in case finding of 38% (p = 0.002) compared to direct smear. In a separate study, TB-Beads enabled further 4 positive samples to be detected from 30 centrifuged pellets that were originally smear negative; two of these were subsequently found to be positive when the original deposits were reinvestigated by smear microscopy. By concentrating mycobacteria from sputum and sputum deposits, TB-Beads have been demonstrated to increase the number of positive sputum samples which could increase case-finding. The TB-Bead method is simple and rapid and compatible with use within a safety cabinet.