PubMed Health⌕ Search

Biomedical subjects

Mark D Perkins

Publications and source records attributed to Mark D Perkins.

8 recordsLinked to original sources
PubMed2006

Sputum processing methods to improve the sensitivity of smear microscopy for tuberculosis: a systematic review.

In low-income and middle-income countries, direct (unconcentrated) sputum smear microscopy is the primary method for diagnosing pulmonary tuberculosis. The method is fast, inexpensive, and specific for Mycobacterium tuberculosis in high incidence areas. The main limitations of direct microscopy are its relatively low sensitivity, especially in individuals co-infected with HIV, and variable quality of the test in programme conditions. Thus, there is a need to identify methods to improve the sensitivity of microscopy. Physical and chemical sputum processing methods, including centrifugation, sedimentation, and bleach, have been studied and found to show promise. We did a systematic review to assess the ability of different processing methods to improve the sensitivity of microscopy. By searching many sources, we identified 83 studies. Overall, by comparison with direct smears, the results suggested that centrifugation with any of several chemical methods (including bleach) is more sensitive, that overnight sedimentation preceded by chemical processing is more sensitive, and that specificity is similar. There were insufficient data to determine the value of sputum processing methods in patients with HIV infection. Operational studies are needed to determine whether the increased sensitivity provided by processing methods is sufficient to offset their increased cost, complexity, and potential biohazards, and to examine their feasibility.

Bacteriological Techniques↗
PubMed2006

Admitting defeat.

Explore the source record for details and available documents.

AIDS-Related Opportunistic Infections↗
PubMed2003

Serologic diagnosis of tuberculosis using a simple commercial multiantigen assay.

SETTING: Seven primary health clinics and a pulmonary disease specialty clinic in Rio de Janeiro City, Brazil. OBJECTIVE: To evaluate a commercial immunochromatographic test kit (ICT Tuberculosis; AMRAD-ICT; Sidney, Australia) employing five recombinant Mycobacterium tuberculosis proteins for the detection of pulmonary tuberculosis (TB). DESIGN: Serology test results were compared with duplicate sputum microscopy and culture in 277 patients with symptomatic pulmonary disease (243 with pulmonary TB and 34 with nontuberculous disease). An additional 110 healthy control subjects were also tested. RESULTS: The serology test was simple and rapid to perform and detected 64.2% of smear-positive and 46.3% of smear-negative TB patients overall. HIV co-infection was present in 15.3% of TB patients, and serology was much less sensitive (overall 27.6%) in this small group, as was microscopy (13.8%). Specificity of the serology test was 100% in healthy control subjects and 85.2% in the small number of control patients with pulmonary disease, including those with prior TB. Combined with microscopy, serology detected 72.8% of TB patients. CONCLUSION: Depending on the population studied, multiantigen serologic tests for TB may be as sensitive as microscopy, but detect a different and overlapping subset of patients. The use of multiple antigens in this kit increased test sensitivity without significant loss of specificity. Bacille Calmette-Guérin vaccination and tuberculin sensitivity did not affect serology results. Estimating specificity in clinical use will require testing a much larger cohort of symptomatic patients with nontuberculous disease. The TB diagnostic performance of this group of antigens in HIV co-infected individuals was poor.

Adult↗