Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Dartmouth study reveals flaws in screening for TB; Cases in 3rd world HIV patients may go undetected


New findings from a Dartmouth Medical School collaboration in Tanzania may alter assumptions about the diagnosis of tuberculosis in HIV-infected people, and prompt a major change in way TB testing is routinely done in the developing world.

Writing in the journal, "Clinical Infectious Diseases," researchers found that while the co-existence of HIV and TB is well-known, traditional screening methods for TB are allowing significant number of cases of subclinical, active tuberculosis to go undetected. In apparent response to the these findings, the international physicians’ group, Médecins Sans Frontières (Doctors Without Borders), has recommended that all HIV/AIDS patients receive the more sensitive and accurate TB culture test used in the Tanzania research project.

This latest research was reported by investigators in the DARDAR Health Study, a collaboration between Dartmouth Medical School and the Muhimbili University College of Health Sciences in Dar Es Salaam, Tanzania. C. Fordham von Reyn, MD, Chief of the Section of Infectious Disease and International Health at Dartmouth-Hitchcock Medical Center, is the leader of the DARDAR project and author of the new study with Lillian Mtei MD, and other colleagues in Tanzania.

"Our study team found that when we used the same comprehensive diagnostic approach to tuberculosis available in industrialized countries 15% of HIV-infected patients in Tanzania had previously unrecognized active tuberculosis," von Reyn said. "These findings emphasize the importance of improving the availability of TB diagnostic tests in the developing world."

In the developing world, TB is the leading cause of death among people with HIV infection. Thus, diagnosis and proper treatment of TB is a critical component of HIV treatment in these regions. Unfortunately, HIV infection can actually make TB more difficult to diagnose, creating additional challenges for health workers.

The DARDAR team, working from their clinic in Tanzania, tested HIV-positive subjects with traditional skin testing for TB and physical exams, followed by chest x-rays and microscopic examination of sputum samples. They then preformed cultures of these samples, incubating them in a controlled lab environment a procedure used widely in the industrialized countries, but typically not available or recommended in resource poor countries . In 10 cases sputum culture was the only positive test. These patients with "subclinical" tuberculosis denied symptoms when they were first examined and had normal chest x-rays.

"…Previously undiagnosed tuberculosis was common, often asymptomatic, and difficult to detect on the basis of a single evaluation," the authors reported. In addition the authors noted that the HIV-infected patients with subclinical tuberculosis had a much better prognosis than previously observed, perhaps due to earlier diagnosis and treatment. Failure to diagnose an subclinical case of active TB and treat with standard multiple drug treatment could result in improper single drug treatment for latent TB, which has the potential to induce TB drug resistance.

The findings are important because existing standards for detection of TB rely on using cough as the indication for screening, with chest x-ray as the screening method. "Our study demonstrates that neither cough nor chest radiography would have identified the 10 subjects (in the study) with subclinical tuberculosis," write the authors.

In an accompanying editorial in the same issue, Dr. David L. Cohn said the findings serve "as a reminder of the complexity of tuberculosis in HIV-infected patients in high-burden countries. This study … presents a potential new challenge for the diagnosis of subtle tuberculosis in asymptomatic patients and it may have implications with regard to treatment decisions."

In the wake of the study, Médecins Sans Frontières issued an advisory from its South Africa office, urging patients to insist on the sputum culture test if traditional TB skin and X-ray tests come back negative.

Deborah Kimbell | EurekAlert!
Further information:

More articles from Studies and Analyses:

nachricht Rutgers-led innovation could spur faster, cheaper, nano-based manufacturing
14.02.2018 | Rutgers University

nachricht New study from the University of Halle: How climate change alters plant growth
12.01.2018 | Martin-Luther-Universität Halle-Wittenberg

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>