Featured Research

from universities, journals, and other organizations

Traditional 'heel stick' test is not an effective screening tool for CMV in newborns

Date:
April 13, 2010
Source:
NIH/National Institute on Deafness and Other Communication Disorders
Summary:
The heel-stick procedure, a routine screening test for several metabolic and genetic disorders in newborns, is not effective in screening for cytomegalovirus (CMV) infection, a leading cause of hearing loss in children, says a new study.

A routine screening test for several metabolic and genetic disorders in newborns, the heel-stick procedure, is not effective in screening for cytomegalovirus (CMV) infection, a leading cause of hearing loss in children, according to research published in the April 14 online issue of the Journal of the American Medical Association.

About 20,000-30,000 infants are born infected with CMV each year, 10-15 percent of whom are at risk for eventually developing hearing loss.

The study, funded by the National Institute on Deafness and Other Communication Disorders (NIDCD), one of the National Institutes of Health, is part of a multicenter research project headed by the University of Alabama at Birmingham that is seeking to find the most effective screening test for CMV infection in newborns. The standard method for detecting CMV infection in newborns is labor-intensive and not conducive to a widespread screening program.

"The heel-stick test is a simple test that is already being used to screen for other diseases in newborns across the United States, so it seemed like a good candidate for a possible universal screening program for CMV," said James F. Battey, Jr., M.D., Ph.D., director of the NIDCD. "However, these findings show us that, at least with current technologies, the heel-stick test should not be used as a primary newborn screening tool for CMV."

CMV is the most common infection passed from a mother to her unborn child. The vast majority of CMV-infected babies show no initial symptoms, and many babies will never develop health problems. But in some CMV-infected babies, serious problems can develop over time. Hearing loss is the most common deficit to emerge later on. The earlier doctors can identify CMV infection, the better they can monitor a child's hearing. If signs of hearing loss are present, appropriate intervention should be provided as soon as possible.

Between March 2007 and May 2008, the researchers analyzed dried blood samples obtained using the heel-stick procedure from babies born at the University of Alabama at Birmingham, and six other participating medical centers across the United States. The heel-stick procedure involves pricking a newborn's heel, drawing a small amount of blood, and placing the blood on filter paper to dry so that it can be analyzed for several diseases, including hypothyroidism and sickle cell disease.

To test for CMV infection, the researchers removed the babies' DNA from the filter paper and then used a common molecular diagnostic technique to quickly and efficiently detect whether any CMV DNA was mixed in. The procedure, called real-time polymerase chain reaction, or PCR, uses special molecules, called primers, to seek out a tell-tale portion of CMV DNA and churn out lots of fluorescent copies of that segment so it can be easily detected. For the initial group of babies, the researchers used a single set of primers targeting one section of CMV DNA. As the study progressed, they added a second primer set targeting an additional section in hopes of increasing accuracy, or sensitivity, of the test.

The team also compared their results to the standard method of detecting CMV in newborns. CMV rapid culture is a highly effective procedure that uses saliva or urine instead of dried blood samples to make the identification. The rapid culture method is labor-intensive and requires a tissue culture facility on site, so it would be difficult to adapt this technology to a widespread screening program.

Many studies have found that dried blood spot PCR is able to identify babies with congenital CMV infection, so some researchers have suggested that it be used for a universal screening program. However, none of the earlier studies compared dried blood spot PCR results to the rapid culture method and therefore could not determine if the PCR procedure was as good as the standard or if it fell short and missed truly infected babies or falsely identified babies as being CMV-infected when they were not infected.

In this study, 20,448 babies were screened, 92 of whom were confirmed to have congenital CMV infection. The rapid culture method identified 91 of the 92 infants, for nearly 100 percent sensitivity. For the 11,422 infants who were screened with the single-primer PCR assay derived from dried blood spots, only 17 out of 60 infected children were identified, a 28.3 percent sensitivity. Of the 9,026 infants who were screened with the two-primer PCR method, 11 out of 32 infected children were identified, a sensitivity of 34.4 percent.

"In order to be included as part of a screening test, the minimum sensitivity should be at least 95 percent," said Suresh Boppana, M.D., a co-principal investigator on the study with Karen Fowler, Ph.D., both of whom are with the University of Alabama at Birmingham. "Our findings indicate that dried blood spot PCR will only detect 30-40 percent of babies with CMV infection. More than half of babies who are infected would be missed."

The researchers are now assessing whether analysis of saliva samples using real-time PCR technology can do a better job than dried blood spots when compared with the rapid culture method. They believe that the use of saliva may be beneficial since babies with congenital CMV infection are known to have a lot of virus in their saliva, compared to the blood, where amounts can vary depending on when the infant was infected during development. In addition, saliva samples require minimal processing and are noninvasive.

Other participating institutions are Saint Peter's University Hospital, New Brunswick, N.J.; University of Mississippi Medical Center, Jackson; Carolinas Medical Center, Charlotte, N.C.; University of Pittsburgh and the Children's Hospital of Pittsburgh; University of Texas Southwestern Medical Center, Dallas; and University of Cincinnati and Cincinnati Children's Hospital Medical Center.


Story Source:

The above story is based on materials provided by NIH/National Institute on Deafness and Other Communication Disorders. Note: Materials may be edited for content and length.


Journal Reference:

  1. Suresh B. Boppana; Shannon A. Ross; Zdenek Novak; Masako Shimamura; Robert W. Tolan, Jr; April L. Palmer; Amina Ahmed; Marian G. Michaels; Pablo J. Sanchez; David I. Bernstein; William J. Britt; Karen B. Fowler; for the National Institute on Deafness and Other Communication Disorders CMV and Hearing Multicenter Screening (CHIMES) Study Dried Blood Spot Real-time Polymerase Chain Reaction Assays to Screen Newborns for Congenital Cytomegalovirus Infection. Dried Blood Spot Real-time Polymerase Chain Reaction Assays to Screen Newborns for Congenital Cytomegalovirus Infection. JAMA, 2010;303(14):1375-1382 [link]

Cite This Page:

NIH/National Institute on Deafness and Other Communication Disorders. "Traditional 'heel stick' test is not an effective screening tool for CMV in newborns." ScienceDaily. ScienceDaily, 13 April 2010. <www.sciencedaily.com/releases/2010/04/100413170652.htm>.
NIH/National Institute on Deafness and Other Communication Disorders. (2010, April 13). Traditional 'heel stick' test is not an effective screening tool for CMV in newborns. ScienceDaily. Retrieved July 24, 2014 from www.sciencedaily.com/releases/2010/04/100413170652.htm
NIH/National Institute on Deafness and Other Communication Disorders. "Traditional 'heel stick' test is not an effective screening tool for CMV in newborns." ScienceDaily. www.sciencedaily.com/releases/2010/04/100413170652.htm (accessed July 24, 2014).

Share This




More Health & Medicine News

Thursday, July 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com
Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Doctor At Forefront Of Fighting Ebola Outbreak Gets Ebola

Newsy (July 24, 2014) Sheik Umar Khan has treated many of the people infected in the Ebola outbreak, and now he's become one of them. Video provided by Newsy
Powered by NewsLook.com
Condemned Man's US Execution Takes Nearly Two Hours

Condemned Man's US Execution Takes Nearly Two Hours

AFP (July 24, 2014) America's death penalty debate raged Thursday after it took nearly two hours for Arizona to execute a prisoner who lost a Supreme Court battle challenging the experimental lethal drug cocktail. Duration: 00:55 Video provided by AFP
Powered by NewsLook.com
China's Ageing Millions Look Forward to Bleak Future

China's Ageing Millions Look Forward to Bleak Future

AFP (July 24, 2014) China's elderly population is expanding so quickly that children struggle to look after them, pushing them to do something unexpected in Chinese society- move their parents into a nursing home. Duration: 02:07 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins