Quest Diagnostics Health Trends(TM) Report shows declines vary widely by
state
MADISON, N.J., Oct. 25 /PRNewswire-FirstCall/ -- The largest study of
rotavirus laboratory data developed since an oral rotavirus vaccine was
introduced in the U.S. in early 2006 shows that cases of rotavirus infection
have decreased significantly, suggesting the vaccine is preventing infection
in infants and young children. The latest Quest Diagnostics Health Trends(TM)
Report also provides evidence for the first time that cases of infection
decreased in children up to the age of six, suggesting that herd immunity may
have reduced rates of infection in children age two and over who were unlikely
to have been vaccinated. However, the report shows that while cases of
infection decreased nationally, rates varied by state, indicating possible
geographic differences in use of the vaccine.
Rotavirus is the most common cause of severe, dehydrating gastroenteritis
among infants and young children worldwide, and one of the leading causes of
emergency department visits, physician visits and hospitalizations of children
in the United States.
The findings were presented today by Jay M. Lieberman, M.D., medical
director, infectious diseases, Quest Diagnostics Incorporated (NYSE: DGX) at
the Joint Meeting of the 48th Interscience Conference on Antimicrobial Agents
and Chemotherapy (ICAAC) and the 46th Annual Meeting of the Infectious Disease
Society of America (ISDA) in Washington, D.C. The Quest Diagnostics Health
Trends(TM) Report is the largest assessment of rotavirus laboratory-test
results since the Advisory Committee on Immunization Practices of the U.S.
Centers for Disease Control and Prevention recommended routine vaccination in
August 2006 for infants at 2, 4, and 6 months of age.
The analysis was performed on de-identified diagnostic test results from
September 2003 through June 2008 from data of more than 132,000 patients in
the Quest Diagnostics database.
The analysis showed a 76 percent reduction in positive test results during
the most recent peak season, December 2007 through June 2008, compared to the
three years before the rotavirus vaccine was available, December 2003 to June
2006. In addition, the positivity rate (the number of individuals who test
positive in proportion to the total number of tests taken) decreased 70
percent during the study period.
"Our analysis suggests that the oral rotavirus vaccine has been highly
effective at reducing the incidence of rotavirus. Our findings reinforce
those from a preliminary report issued by the CDC earlier this year.
Considering the toll this disease has traditionally taken on children and
their families each year in the U.S., this is exciting and welcome news for
physicians and parents," said Dr. Lieberman. "Our report also may have
important implications for public health efforts in developing parts of the
world, where rotavirus tragically is a frequent cause of childhood death."
Rotavirus causes severe acute gastroenteritis among infants and young
children, often resulting in high fever, vomiting and diarrhea. Rotavirus
accounts for more than half a million deaths of children under the age of five
each year worldwide. In the U.S., the disease causes fewer deaths annually (an
average of 20 to 60), but remains a substantial cause of morbidity, resulting
in approximately 410,000 physician visits, 205,000 to 270,000 emergency
department visits, and 55,000 to 70,000 hospitalizations. Rotavirus infection
represents a significant drain on resources, with estimates of $1 billion in
societal costs nationally. In the U.S. rotavirus activity follows a distinct
winter-spring seasonal pattern.
Decline in Rotavirus Varies Among States
The analysis showed a reduction in rotavirus positivity rates in all 43
states and Puerto Rico that had submitted at least 100 lab specimens during
the pre-vaccine period. Some states experienced greater declines than others,
which likely reflect differences in vaccine uptake. The majority of states
reduced the incidence of rotavirus, as indicated by positivity rates, by more
than 60 percent. However, there was substantial variability, with states such
as Delaware, North Carolina, and Alabama each experiencing declines of more
than 95 percent, while in Washington, Nebraska, New Mexico, and Arizona, the
declines were less than 35 percent.
"While our data does not provide insight into why rates of infection
varied geographically, we know that multiple factors determine how quickly new
vaccines are adopted by physicians, parents and public health agencies," said
Dr. Lieberman. "We suspect that much of the variability we see in our data is
related to such differences in vaccine uptake. Our analysis suggests the need
for further research into the factors influencing uptake and its implications
for public health policy."
Herd Immunity Benefits Nonvaccinated Children
The analysis showed that the sharpest decline in positive rotavirus test
results, approximately 83 percent, occurred in children younger than 12 months
of age, the age group most likely to have been vaccinated. However, the
analysis also showed a dramatic decline in positive test results in older
children (ranging from 67 to 75 percent), including children ages two to six.
Because children older than two years of age in the U.S. are unlikely to have
been vaccinated, these data suggest a herd immunity phenomenon, which occurs
when enough individuals are vaccinated so as to reduce transmission of a
virus, thereby providing some protection to unvaccinated individuals.
"Herd immunity is a significant favorable outcome of a successful
vaccination program because it means that even unvaccinated individuals may be
benefiting from widespread use of a vaccine," said Dr. Lieberman. "Our
analysis provides evidence for the first time that unvaccinated children may
also be reaping the benefits of the rotavirus vaccine. Herd immunity is
particularly valuable to newborns and other young infants who have not yet
started or completed their vaccine series."
Study Methodology
The Quest Diagnostics Health Trends(TM) Report, "Decline in Rotavirus
Cases in the U.S. After Licensure of a Live, Oral Rotavirus Vaccine," is based
on an analysis of more than 132,000 rotavirus antigen detection test results
(by antigen-capture enzyme immunoassay, or EIA) performed from December to
June at all Quest Diagnostics regional laboratories, during the period of
December 2003 to June 2008. The results were extracted from the Quest
Diagnostics Information Data Warehouse (IDW), the largest private database of
clinical laboratory tests results in the United States. IDW contains
information on all clinical test results reported by Quest Diagnostics
laboratories in the United States, and includes data from all 50 states, the
District of Columbia, and Puerto Rico. The database includes information on
the ordering physician, patient, tests ordered, and results reported, and data
are handled in a HIPAA-compliant manner. The study utilized only
de-identified testing data that did not contain any patient- or
physician-identifiable health information.
In the study, the pre-vaccine period was defined as the three seasons
before vaccine* licensure (December through June 2003-2004, 2004-2005, and
2005-2006). The post-vaccine period was defined as the most recent peak
season, December 2007 through June 2008. (The December 2006-June 2007 season
was a "transition" year, with limited vaccine use in young infants in the
months immediately after the vaccine became available.) In the pre-vaccine
period, Quest Diagnostics performed an average of 27,625 tests for rotavirus
annually, of which 7,162 (26 percent) were positive. By contrast, of the
21,873 tests conducted by Quest Diagnostics in the post-vaccine period, only
1,703 (7.8 percent) were positive - a 76.2 percent reduction in the total
number of positive tests (p<0.001). Declines in the number of positive test
results during the post-vaccine period were seen in all age groups (ranging
from 67.3 percent to 83.2 percent), including children over the age of two.
The greatest decline was among children less than 12 months old.
The rate of test positivity decreased from an average of 26 percent during
the pre-vaccine period to 7.8 percent in the post-vaccine period, representing
a 70.0 percent reduction (p<0.001). Positivity rates declined across age
groups (59.0 percent to 76.4 percent), including children over two, with the
greatest decline among children less than 12 months old.
Quest Diagnostics Health Trends(TM)
Quest Diagnostics maintains the largest private clinical laboratory data
warehouse in the United States. Consisting of data on more than 1.1 billion
patient encounters since January 2000, the database provides laboratory
information on the vast majority of conditions and diseases affecting
Americans today. Quest Diagnostics provides these data to health plans to
help manage the health of their members. Quest Diagnostics Health Trends(TM)
Reports are designed to identify and track disease and wellness benchmarks to
inform patients, health professionals and policymakers about the current
status of the nation's health.
About Quest Diagnostics
Quest Diagnostics is the world's leading provider of diagnostic testing,
information and services that patients and doctors need to make better
healthcare decisions. The company offers the broadest access to diagnostic
testing services through its network of laboratories and patient service
centers, and provides interpretive consultation through its extensive medical
and scientific staff. Quest Diagnostics is a pioneer in developing innovative
new diagnostic tests and advanced healthcare information technology solutions
that help improve patient care. Additional company information is available
at: www.questdiagnostics.com.
The statements in this press release that are not historical facts or
information may be forward-looking statements. These forward-looking
statements involve risks and uncertainties that could cause actual results and
outcomes to be materially different. Certain of these risks and uncertainties
may include, but are not limited to, competitive environment, changes in
government regulations, changing relationships with customers, payers,
suppliers and strategic partners and other factors described in the Quest
Diagnostics Incorporated 2007 Form 10-K and subsequent SEC filings.
* Rotavirus vaccine, live, oral, pentavalent (RotaTeq(R), Merck & Co.,
Inc., Whitehouse Station, New Jersey)
SOURCE Quest Diagnostics
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