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

Join For Free

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 3,300+ scientific posters on ePosters
  • More than 4,900+ 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

Diagnosing Bacterial Infections in Blood Samples
Researchers have diagnosed a bacterial infection from a blood sample in infants.
Wednesday, August 24, 2016
Public Support for National Study
Survey shows the majority of respondents support or show willingness for national precision medicine study.
Thursday, August 18, 2016
NIH Funds Zika Virus Study Involving U.S. Olympic Team
Researchers will monitor potential Zika virus exposure among a subset of athletes traveling to Brazil.
Wednesday, July 06, 2016
Implementation Science Approaches to Reduce Mother-to-Child HIV Transmission
The NIH study will investigate best practices to ease major disease burden in Sub-Saharan Africa.
Friday, July 01, 2016
Some Women With PCOS May Have Adrenal Disorder
Researchers at NIH have found that a subgroup of women with PCOS, a leading cause of infertility, may produce excess adrenal hormones.
Tuesday, June 28, 2016
NIH Sequences Genome of a Fungus
Researchers at the Institute have sequenced genome of human, mouse and rat Pneumocystis that cause life-threatening Pneumonia in immunosuppressed hosts.
Tuesday, April 12, 2016
Children With Cushing Syndrome May Have Higher Suicide Risk
Researchers at NIH have found that depression, anxiety and suicidal thoughts increase after treatment.
Wednesday, March 30, 2016
Couples’ Pre-Pregnancy Caffeine Consumption Linked to Miscarriage Risk
Researchers at NIH have found daily multivitamin before and after conception greatly reduces miscarriage risk.
Friday, March 25, 2016
Researchers Identify Molecule Needed for Sperm Activation
Researchers at NIH have discovered new options for male contraception as well as treatments for infertility resulting from problems with sperm mobility.
Friday, March 18, 2016
A Child’s First Eight Years Critical For Substance Abuse Prevention
Researchers at NIH have released summary of research on early childhood risk and protective factors.
Friday, March 11, 2016
Genomic Signature Shared by Five Types of Cancer
National Institutes of Health researchers have identified a striking signature in tumor DNA that occurs in five different types of cancer.
Monday, February 08, 2016
NIH Unveils FY2016–2020 Strategic Plan
Detailed plan sets course for advancing scientific discoveries and human health.
Thursday, December 17, 2015
$21M Invested in Research Hubs in Developing Countries
The National Institutes of Health and other U.S. and Canadian partners are investing $20.9 million dollars over five years to establish seven regional research and training centers in low- and middle-income countries (LMICs).
Friday, October 09, 2015
Scientists Create World’s Largest Catalog of Human Genomic Variation
An international team of scientists from the 1000 Genomes Project Consortium has created the world’s largest catalog of genomic differences among humans, providing researchers with powerful clues to help them establish why some people are susceptible to various diseases.
Thursday, October 01, 2015
NIH Framework Points The Way Forward For Developing The President’s Precision Medicine Initiative
The NIH Advisory Committee to the Director has presented to NIH Director Francis S. Collins, M.D., Ph.D., a detailed design framework for building a national research participant group, called a cohort, of 1 million or more Americans to expand our knowledge and practice of precision medicine.
Monday, September 21, 2015
Scientific News
AACC 2016 Sees Clinical Chemistry Labs Drive Precision Medicine Offerings
Biomarker assays to enable precision medicine and risk assessment, mass spec-based tests designed for use in clinical labs large and small, and liquid biopsy technology captured the spotlight at the AACC annual meeting.
Diagnosing Bacterial Infections in Blood Samples
Researchers have diagnosed a bacterial infection from a blood sample in infants.
Neurodvelopmental Disorder Cause Linked to SON Gene
A genetic link has been discovered for a previously unxplained neurodevelopmental disorder.
World's Most In-Depth Study to Detect Alzheimer's Disease
A multisite team will see the most thorough and vigorous testing for Alzheimer's ever performed on volunteers.
Personalised Medicine: Dose by Design
Personalised medicine holds the promise of a new approach to healthcare, tailored exactly to our individual needs, as Congenica's Nick Lench discussed on a recent BBC Radio 4 programme.
Misdiagnosis in HCM Tests
Genetic tests for potentially fatal heart anomaly can misdiagnose condition in black Americans.
Computers Better Predict Lung Cancer Type, Severity
Study shows automating the analysis of cancer tissue samples increases the accuracy of tumor classification and patient prognoses.
Examining New Hypotheses for Undiagnosed Patients
UnDx Consortium gathers in San Diego to create new paths to identifying currently undiagnosed illnesses.
Automating Genetic Analysis
Researchers are looking to have computers help perform genetic analysis when scientists study a patient's genome to diagnose a disease.
Understanding Tumor Evolution
Study provides insight into tumor evolution; may point to improved diagnosis and treatment.
Skyscraper Banner

SELECTBIO Market Reports
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
3,300+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,900+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!