The phenotypic methods of smear microscopy, culture and indirect drug susceptibility testing (DST) remain the 'gold standard' diagnostics for tuberculosis (TB) in 2015. However, this review demonstrates that genotypic methods are in the ascendancy. Current-generation nucleic acid amplification tests (NAATs) are important supplementary tests for the rapid direct detection of (multidrug-resistant) TB in specific clinical settings. Genotypic detection is already the preferred method of detecting rifampicin and pyrazinamide resistance. Next-generation NAATs able to detect about 10 colony forming units/mL of sputum could replace culture as the initial test for detecting TB. Whole genome sequencing could also plausibly replace phenotypic DST but much work is required in method standardisation, database development and elucidation of all resistance gene determinants. The challenge then will be to rollout these increasingly complex and expensive diagnostics in the low-income countries where TB is prevalent.
The impact of latent tuberculosis infection (LTBI) on health and wellbeing is not well understood. This review aims to evaluate the health and wellbeing of individuals with LTBI. A systematic literature search was performed to assess studies reporting patient-reported outcomes in LTBI management including health-related quality of life (HRQoL), health utilities, disease burden and experience of individuals with LTBI. A pooled analysis was performed to estimate the effect of LTBI on HRQoL.A total of 4464 studies were screened, of which 13 eligible articles describing nine unique studies were included for review. The HRQoL of individuals with LTBI and without tuberculosis (TB) infection were comparable, and better than patients with active TB disease. However, individuals with LTBI reported poorer mental health compared with individuals without TB infection (mean difference -4.16, 95% CI -7.45- -0.87; p=0.01). Qualitative studies suggest the presence of fear, anxiety and stigma in individuals with LTBI.This review highlights potential psychosocial challenges in individuals with LTBI despite the absence of clinical symptoms. While their quality of life was marginally affected, this could be evidence to support LTBI management in preventing TB re-activation and the severe consequences of active TB disease that affect all domains of HRQoL.
During recent years, extensive development has been made to improving vaccines for tuberculosis. This is due to the presence of genome sequences of diverse mycobacterial species and Mycobacteroum tuberculosis (M. tuberculosis) isolates which has led to advances in the characterization of genes and antigens of M. tb and better realization of protective immune responses to the disease in both animals and humans. This review summarizes vaccine types, reasons for variable efficacy of BCG, latest advances in tuberculosis vaccine development and major vaccine design strategies.
Objectives: Tuberculosis remains a common infection and is often associated with non-specific constitutional symptoms or laboratory investigations regardless of site of manifestations. This study compares the profiles of abdominal tuberculosis (ATB) and pulmonary tuberculosis (PTB).
Methods: Patients with ATB (n=34, male-21, mean age 43.3 ± 16.0 years) diagnosed over a nine year period were identified from the National Tuberculosis registry and retrospectively reviewed. Comparisons were made with patients treated for PTB (n=163).
Results: The most commonly affected sites were the ileocecal regions, peritoneum and hepatobiliary system. Common clinical presentations were abdominal pain (61.8%), anorexia (44.1%), weight loss (55.9%), fever (41.1%) and abdominal distension (29.4%). Four patients had concomitant active PTB. Compared to PTB, patients with ATB had significantly lower serum haemoglobin (11.6 ± 2.4 vs. 12.6 ± 2.0 gm/dL, p=0.036) and higher rate of adverse events of antituberculous treatment (50% vs. 15.4%, p<0.001). There were no difference in prevalence of constitutional symptoms (fever, weight loss and anorexia), platelet level, albumin, total protein and erythrocyte sedimentation rate. Importantly, there was no difference in the treatment
response. More patients with ATB and concomitant active PTB had reported weight loss (100% vs. 36.7%, p=0.017).
Conclusion: There are differences in the profiles of ATB and PTB. Awareness of such differences can help to improve the understanding and management of this infection.
The last few years have witnessed intense research on vaccine development against tuberculosis. This has been driven by the upsurge of tuberculosis cases globally, especially those caused by multi-drug-resistant Mycobacterium tuberculosis strains. Various vaccine strategies are currently being developed which can be broadly divided into the so-called living and non-living vaccines. Examples are attenuated members of the M. tuberculosis complex, recombinant mycobacteria, subunit proteins and DNA vaccines. Given current developments, we anticipate that recombinant BCG and DNA vaccines are the most promising. Multiple epitopes of M. tuberculosis may need to be cloned in a vaccine construct for the desired efficacy to be achieved. The technique of assembly polymerase chain reaction could facilitate such a cloning procedure.
The overall incidence of clinical pulmonary tuberculosis in the University of Malaya students was found to be 3.15 per cent. This higher incidence of clinical tuberculosis is in keeping with the general morbidity and mortality figures of tuberculosis in the general public. Among students who were originally enrolled as inactive cases 26.5 per cent developed activity while in university and required treatment. No significant difference was found in the incidence and rate of reactivation of disease in students of various races. No student was obliged to quit studies permanently on account of the breakdown