Corporate Banner
Satellite Banner
Molecular & Clinical Diagnostics
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Rapid Test Allows for Earlier Diagnosis of Tuberculosis in Children

Published: Thursday, July 25, 2013
Last Updated: Thursday, July 25, 2013
Bookmark and Share
A new test for diagnosing TB in children detects roughly two-thirds of cases identified by the current culture test, but in a fraction of the time.

The test, known as Xpert MTB/RIF, also detected five times the number of cases identified by examining specimens under the microscope, a preliminary method for diagnosis that is often performed as an initial test, but which must be verified by the culture test. 

Xpert MTB/RIF results from respiratory secretions were ready in 24 hours, on average, compared with an average of more than two weeks for the culture test used in the study, the researchers found.  Previous studies have shown that Xpert MTB/RIF is effective for diagnosing TB in adults and in children with  pronounced symptoms of TB who have been admitted to a hospital.  Diagnosing TB in children is more difficult than diagnosing it in adults, because children tend to have much lower levels of the TB bacteria than do adults.

The results of the current study indicated that the ease and speed of diagnosis would be useful for children seen in clinics in resource-limited countries, which often lack the resources for traditional testing that are available in hospitals.  The test also was able to identify children with drug resistant TB. In addition, the researchers found that Xpert can readily determine when treatment for tuberculosis is not appropriate.  Among children who did not in fact have TB, the results of the Xpert test came back negative for TB with 99 percent accuracy.

Xpert MTB/RIF was developed with funding from the NIH's National Institute of Allergy and Infectious Diseases. Testing of Xpert MTB/RIF in children was funded by NICHD.

Preliminary diagnosis of TB is often made by collecting a sample of lung secretions and examining the sample under a microscope to see if it contains the bacteria that cause TB.    A sample is also sent to a laboratory so the bacteria can be cultured and identified.  It may take as long as six weeks for the culture test to show a positive result.  Because, children have lower levels of infectious bacteria than do adults, it is more difficult to detectthe bacteria under a microscope and to grow it in a culture.  For this reason, accurately diagnosing TB in children has been difficult.

"The availability of this test in primary care settings can help children get appropriate treatment faster," said Lynne M. Mofenson, M.D., of the Maternal and Pediatric Infectious Disease Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH institute that funded the study.  "Looking at a specimen under the microscope, often used for initial diagnosis of TB in adults, is very inaccurate in children." 

The Xpert MTB/RIF test also detects TB strains that are resistant to the drug rifampicin, allowing physicians to more accurately prescribe an appropriate treatment, said Carol Worrell, M.D., also of the NICHD's MPIDB.  This is particularly important in areas where drug-resistant TB is common, such as South Africa.

The World Health Organization estimated that in 2011 there were 500,000 TB cases and 64,000 deaths among those younger than 15 years. 

The study was led by first author Heather J. Zar, M.D., Ph.D., of the University of Cape Town and Red Cross War Memorial Children's Hospital, also in Cape Town, South Africa; and Mark P. Nicol, Ph.D, also of the University of Cape Town and  the South African National Health Laboratory Service at Groote Schuur Hospital, Cape Town. 

The findings appear in The Lancet Global Health.

"There has been a perception amongst health care workers that rapid diagnosis of TB in children wouldn't be possible in primary care, but this study disproves that view, Dr. Zar said.  "Given our results, widespread adoption of rapid testing for TB and drug resistance in children may substantially improve public health without greatly increasing costs."

Dr. Zar and her colleagues collected almost 1500 samples from nearly 400 children who went to a primary care clinic with symptoms of TB.  Collecting the samples -- secretions from the lungs, the nasal passages or both -- requires special equipment and trained clinical staff.  The researchers compared the results from the Xpert MTB/RIF test, examination of samples under a microscope, and from growing the tuberculosis bacteria in laboratory cultures.  Bacterial culture is the most accurate method for diagnosing TB.

Of the 30 TB cases detected by culture, 19 (63 percent) were positive by the Xpert MTB/RIF test on lung or nasal samples, while examining the samples under the microscope turned up only four cases (13 percent).  Adding a second test (of a second lung or nasal passage sample) improved the detection rate for both culture and Xpert MTB/RIF 

In some cases, researchers started TB treatment for children they suspected had TB based on their symptoms.  Xpert MTB/RIF identified seven children who had clinical symptoms of tuberculosis and responded well to treatment for tuberculosis, but whose tuberculosis had not been detected by the tuberculosis culture test.  This might occur when a child is sick with TB, but the bacteria are at especially low levels, or because a sample did not contain enough of the bacteria present in the child's body to appear when cultured, Dr. Mofenson explained.  The total number of cases detected by culture (30 cases) and by XpertMTB/RIF (26 cases) was similar. 

"Because of the global burden of this disease among children, it's vital to make rapid, accurate diagnostic tests available in primary care settings in order to identify the disease and start treatment before children end up in the hospital," said Dr. Worrell.  "NICHD recognizes the value of supporting research to improve the accuracy of TB diagnosis in children, reduce the number of samples required, and make diagnostic tools widely accessible."


Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,400+ scientific posters on ePosters
  • More than 3,700+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Tumor DNA in Blood Reveals Lymphoma Progression
Using an advanced genetic test, researchers were able to detect diffuse large B-cell lymphoma (DLBCL) in blood serum before it could be seen on CT scans.
Tuesday, April 14, 2015
NIH Funds Nine Antimicrobial Resistance Diagnostics Projects
Investigators to develop tools to detect hospital-associated pathogens.
Friday, April 10, 2015
NIH Launches Tool to Advance Down Syndrome Research
Web portal will help approved professionals to plan clinical studies.
Wednesday, January 28, 2015
Sophisticated HIV Diagnostics Adapted For Remote Areas
New tool is low-cost, with no electricity needed.
Tuesday, December 02, 2014
NIH Names New Clinical Sites in Undiagnosed Diseases Network
Four-year, $43 million initiative engages broad expertise in study of mystery conditions.
Wednesday, July 02, 2014
Genetic Disorder Causing Strokes, Vascular Inflammation in Children Discovered
NIH researchers have identified gene variants that cause a rare syndrome of sporadic fevers, skin rashes and recurring strokes, beginning early in childhood.
Thursday, February 20, 2014
NIH, Industry and Non-Profits Join Forces to Speed Validation of Disease Targets
Goal is to develop new treatments earlier, beginning with Alzheimer's, type 2 diabetes, and autoimmune disorders.
Tuesday, February 11, 2014
Speeding Validation of Disease Targets
NIH, industry and non-profits join forces to develop new treatments earlier, beginning with Alzheimer’s, type 2 diabetes, and autoimmune disorders.
Tuesday, February 04, 2014
First Evidence-Based Diagnostic Criteria Published For TMD
The first evidence-based diagnostic criteria have been developed to help health professionals better diagnose temporomandibular disorders, commonly known as TMJ.
Monday, February 03, 2014
Earliest Marker for Autism Found in Young Infants
NIH-funded study finds attention to others’ eyes declines in 2 to 6-month-old infants later diagnosed with autism.
Thursday, November 07, 2013
NIH Announces 15 Clinical and Translational Science Awards
Awards aim to help translate scientific discoveries to improved health.
Tuesday, October 22, 2013
NIH-Funded Study Suggests Brain is Hard-Wired for Chronic Pain
The results, published in the journal Pain, support the growing idea that the brain plays a critical role in chronic pain.
Tuesday, September 17, 2013
NIH Grants to Investigate Disease-Related Variations in Genetic Makeup
Studies focus on underlying susceptibilities in minority populations.
Monday, September 09, 2013
NIH Funds Research to Explore a Cell Communication Process
Researchers will investigate the emerging field of extracellular RNA and its role in human health conditions.
Wednesday, August 14, 2013
Urine Test can Diagnose, Predict Kidney Transplant Rejection
NIH-funded study describes non-invasive alternative to kidney biopsy.
Friday, July 05, 2013
Scientific News
Diagnostic Test Developed for Enterovirus D68
researchers at Washington University School of Medicine in St. Louis have developed a diagnostic test to quickly detect enterovirus D68 (EV-D68), a respiratory virus that caused unusually severe illness in children last year.
Tracking Breast Cancer Before it Grows
A team of scientists led by University of Saskatchewan researcher Saroj Kumar is using cutting-edge Canadian Light Source techniques to screen and treat breast cancer at its earliest changes.
The Light of Fireflies for Medical Diagnostics
EPFL scientists have exploited the light of fireflies in a new method that detects biological molecules without the need for complex devices and high costs.
Could a simple saliva test detect Alzheimer's?
Researchers have presented findings suggesting that a simple, non-invasive diagnostic for Alzheimer's could be within reach.
Cheap Diagnostics with a Portable "Paper Machine"
Scientists have developed a cheap, portable system for point of care diagnostics for a range of infectious diseases, genetic conditions and cancer.
New Variant of Streptococcal Bacteria
Scientists have discovered a new variant of streptococcal bacteria that has contributed to a rise in disease cases in the UK over the last 17 years.
New Insights into “Antenna” of Human Cells
Scientists from the University of Leeds have uncovered the most comprehensive list yet of genes implicated in a group of common inherited diseases.
Discordant NIPT Test Results May Reflect Presence of Maternal Cancer
Results published in Journal of the American Medical Association.
Sperm RNA Test May Improve Evaluation of Male Infertility
To help resolve uncertainty—and guide prospective parents to the right fertility treatments—scientists propose the use of a new kind of fertility test. It involves examining sperm RNA by means of next-generation sequencing.
Optical 'Dog's Nose' Developed to Detect Cancer, Other Diseases
Researchers are using optical spectroscopy to develop a quick, non-invasive “breath test” they believe will have the potential to screen for a variety of diseases, including diabetes, infections and cancers.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!