Key issues in the diagnosis and management of tuberculosis

Risk factors for tuberculosis in older children and adolescents: a matched case-control study in Recife, Brazil

Background

Tuberculosis is a major disease worldwide and most research focus on risk factors for adults, although there is a marked adolescent peak in incidence. The objective of this study was to identify risk factors for tuberculosis in children aged 7 to 19.

Methods

A case control study matched by age with 169 cases and 477 controls. The study population consisted of adolescents and older children from Recife, Brazil. Cases were individuals diagnosed with tuberculosis in the control programme and controls were selected in the neighborhood of cases. Conditional logistic regression was used to identify risk factors.

Results

Cigarette smoking increased by 50% the risk of tuberculosis but that this was not statistically significant (OR = 1.6). Other risk factors were sleeping in the same house as a case of tuberculosis (OR = 31.6), living in a house with no piped water (OR = 7.7) (probably as a proxy for bad living conditions), illiteracy (OR = 3.7) and male sex (OR = 1.8). The increase in risk with living in houses with no piped water was much more marked in males. The proportion of cases of tuberculosis attributed to contact with someone with TB was 38% and to illiteracy, lack of piped water and smoking, 20%.

Conclusion

Household contact with tuberculosis, social factors and male sex play the biggest role in determining risk of TB disease among children and adolescents in the study. We recommend further research on the relationship of cigarette smoking on tuberculosis in adolescents, and on whether the sex differentials are more marked in bad living conditions. Separate studies should be conducted in older children and in adolescents.

Mycobacterium tuberculosis-specific TNF-α is a potential biomarker for the rapid diagnosis of active tuberculosis disease in Chinese population

Interferon-gamma release assays (IGRAs) have proven to be useful to accurately detect Mycobacterium tuberculosis (Mtb) infection, but they cannot reliably discriminate between active tuberculosis (TB) and latent tuberculosis infection (LTBI). This study aims to test whether Mtb-specific tumor necrosis factor-alpha (TNF-α) could be used as a new tool for the rapid diagnosis of active TB disease. The secretion of TNF-α by Mtb-specific antigen-stimulated peripheral blood mononuclear cells (PBMCs) of sixty seven participants was investigated in the study. Our results showed that the total measurement of TNF-α secretion by Mtb-specific antigen-stimulated PBMCs is not a good biomarker for active TB diagnosis. However, we found that calculation of Mtb-specific TNF-α not only distinguish between active and latent TB infection, but also can differentiate active TB from non-TB patients. Using the cutoff value of 136.9 pg/ml for Mtb-specific TNF-α, we were able to differentiate active TB from LTBI. Sensitivity and specificity were 72% and 90.91%. These data suggest that Mtb-specific TNF-α could be a potential biomarker for the diagnosis of active TB disease.

Evaluation of an enzyme-linked immunospot assay for the immunodiagnosis of atypical spinal tuberculosis (atypical clinical presentation/atypical radiographic presentation) in China

Background

Methods

Results

Conclusions

Microbiological diagnosis of spinal tuberculosis

PURPOSE

The purpose of this study was to review the clinical features and diagnosis of spinal tuberculosis cases reported in the literature.

METHODS

A medical literature search in the Medline Pubmed database was undertaken to review tuberculosis spinal infection and extra-pulmonary tuberculosis diagnosis improvement. We introduced the following search items and boolean operators: "spinal infection", "spinal tuberculosis infection", "microbiological diagnosis of spinal tuberculosis" and "spinal tuberculosis PCR." Single cases or series without microbiological diagnosis were rejected. Manuscript language was restricted to Spanish, French, and English versions.

RESULTS AND CONCLUSIONS

Spinal tuberculosis is more common in developing countries and is probably underdiagnosed. Delayed diagnosis is characteristic; it worsens the prognosis and increases morbidity. The microbiological diagnosis is crucial for several reasons. Despite surgical treatment, medical treatment with anti-tuberculous drugs is always necessary. A total of 20-40% of the spinal tuberculosis patients show another locus of infection. Pulmonary location can become a public health problem. Previously treated patients for other tuberculosis locations, incomplete treatments, or poor adherence can change the M. tuberculosis sensitivity pattern. Drug resistance test becomes a major need in the microbiology laboratory. PCR diagnostic techniques advance the diagnosis and increase the sensitivity and specificity rate.