A new test for diagnosing TB offers a quick and simple alternative to existing three-day methods, according to research published today in the journal Clinical Infectious Diseases.
The study shows that the test, which involves taking three sputum samples from a patient over the course of one day, is just as effective as other more invasive and complicated testing methods, which take three days.
For the new test, patients use a nebuliser to inhale salty water, or hypertonic saline, for twenty minutes. This enables them to produce sputum samples from deep inside the lungs. The samples can then be analysed for traces of mycobacterium tuberculosis, the bacterium which causes most cases of TB.
Other procedures for testing for TB are gastric washing and bronchoscopy with bronchoalveolar lavage. These invasive procedures involve placing tubes in the stomach, to collect samples of mucus swallowed during the night, or the broncial tubes, to try to wash bacteria from infected lung tissue. Patients have to be in hospital for three days to allow these samples to be collected and analysed, delaying the start of treatment.
Such tests are given where patients have symptoms or chest radiography results that suggest the patient might have TB and they are unable to cough up a sputum sample.
The new research, which was carried out by researchers from Imperial College London and Northwick Park Hospital NHS Trust, showed that the new test is just as effective, if not more so, than existing methods for diagnosing TB.
In the 140 people who were examined, use of 3 sputum
specimens correctly detected TB in 39% of the patients. Gastric washing detected TB in 30% of the same patient sample. No additional cases were diagnosed in the 21 patients who underwent bronchoscopy.
Dr Robert Davidson, from the Division of Medicine at Imperial College and the Department of Infection and Tropical Medicine at Northwick Park Hospital NHS Trust, and one of the authors of the research, said: "This is a simple method of ollecting bacteria from individuals with the early stages of TB, and who are unable to cough sputum samples. By doing all the tests in one day, we can start treatment sooner and get patients home sooner. Previously we relied on bronchoscopy or gastric washings, which were uncomfortable for the patient and required a longer stay in hospital. The patient breathing nebulised hypertonic saline feels little or no unpleasant sensation, and it is a very cheap test".
According to the Health Protection Agency, the incidence of TB in the UK is increasing, with around 8,000 new cases a year. Cases in the UK are predominantly confined to the major cities and about 40 per cent of all cases are in London. TB is also a major global problem: an estimated one-third of the world's population - nearly two billion people - are infected. Nine million people a year develop the active disease worldwide, which kills two million each year.
Source: Imperial College London
Related stories:
Cellular senescence a double-edged sword
Scientists have identified a molecular cause behind the ravages of old age and in doing so have also shown how a natural process for fighting cancer in younger persons can actually promote cancer in older individuals. Cellular senescence, the process by which biological cells stop dividing in response to stress or damage to their DNA, was shown to trigger the secretion of proteins that cause inflammation in neighboring cells and tissue. Inflammation is linked to almost every major disease associated with aging, including many cancers.
Genomic signature of colon cancer may individualize treatment
Researchers in the Duke Institute for Genome Sciences & Policy have developed a model for predicting risk of recurrence in early stage colon cancer patients, and have used the model to also predict sensitivity to chemotherapy and targeted therapy regimens.
Researchers identify potential new drug target for chronic leukemia
Researchers at the University of California, San Diego (UCSD) and the Moores UCSD Cancer Center have discovered what could be a novel drug target for an often difficult-to-treat form of leukemia. The investigators have identified a unique "signature" or pattern of a specific family of enzymes in patients with chronic lymphocytic leukemia (CLL), the most common form of adult leukemia.
Researchers identify new leprosy bacterium
A new species of bacterium that causes leprosy has been identified through intensive genetic analysis of a pair of lethal infections, a research team reports in the December issue of the
American Journal of Clinical Pathology.
Carbon Nanotubes Detect Lung Cancer Markers in the Breath
(PhysOrg.com) -- Using an array of nanotube devices, each coated with a different organic material, researchers at the Israel Institute of Technology have developed diagnostic system that may be able to diagnose lung cancer simply by sampling a patient’s breath. The results of this study, which was led by Hossam Haick, Ph.D., appear in the journal
Nano Letters.
Researchers find clue to stopping breast-cancer metastasis
If scientists knew exactly what a breast cancer cell needs to spread, then they could stop the most deadly part of the disease: metastasis. New research from the University of North Carolina at Chapel Hill School of Medicine takes a step in that direction.
Gene chips accurately detect pneumonia in ICU patients on ventilators
Even seasoned doctors have a difficult time diagnosing pneumonia in hospitalized patients breathing with the assistance of a ventilator. That's because a patient's underlying illness often skews laboratory test results and masks pneumonia's symptoms.
Microarray analysis improves prenatal diagnosis
A "chip" or array that can quickly detect disorders such as Down syndrome or other diseases associated with chromosomal abnormalities proved an effective tool in prenatal diagnosis in a series of 300 cases at Baylor College of Medicine, said researchers in a report that appears in the current issue of the journal
Prenatal Diagnosis.