This is the retyped text of a
Safety Alert from FDA's Center for Devices and Radiological Health.
DEPARTMENT OF HEALTH & HUMAN SERVICES
Public Health Service
Food and Drug Administration
1350 Piccard Drive
Rockville, MD 20860
FDA SAFETY ALERT:
RISKS OF DEVICES FOR DIRECT DETECTION OF
GROUP B STREPTOCOCCAL ANTIGEN
(You are encouraged to copy and distribute this Alert)
March 24, 1997
-
TO:
- Obstetricians
Clinical Laboratory Directors
Neonatologists
Hospital Administrations
Pediatricians
Hospital Risk Managers
Nurse Midwives
Birthing Centers
Purpose
FDA wants to alert you to potentially fatal misdiagnoses when using
test kits to detect
group B streptococcal (GBS) antigen, and to provide guidelines on how to
appropriately use
these tests. GBS disease continues to be a major cause of illness and
death among neonates.
Antigen tests for GBS have produced false negative results from
specimens from pregnant
women and infants with subsequent infant deaths from GBS disease.
GBS antigen tests have also
produced false positive results which may lead to inappropriate antibiotic
therapy and prolonged
hospitalization.
It is important that clinicians understand the limitations of these
devices. Antigen tests are
an adjunct to diagnosis and multiple studies have shown that antigen tests
are NOT an appropriate
substitute for properly performed bacterial culture in the diagnosis of GBS
colonization or
infection1-4.
Guidelines to be Followed
In order to minimize the likelihood of misdiagnosing GBS infection,
we urge that users
adhere to the following guidelines. These guidelines should be distributed
to all appropriate
clinical laboratory personnel, including laboratories in physicians'
offices, and physicians and
nurses who may use or request these tests. (We have asked manufacturers to
notify their
customers of the information in this Alert.)
-
Use in maternity patients
- GBS antigen tests cannot be relied upon to exclude GBS colonization in
a pregnant woman. Negative GBS antigen test results should be confirmed
using selective broth culture which is more sensitive than antigen tests.
-
Use in infants
- The only specimens recommended for testing with these devices
are blood, serum or cerebrospinal fluid. Testing infant urine with
these devices is not recommended.
- These devices should not be used as a substitute for bacteriologic
culture in the diagnosis of GBS septicemia and/or meningitis. A positive
result indicates only the presence of GBS antigen, and not necessarily
the presence of viable organisms. Positive or negative results should be
considered presumptive and confirmed by culture.
Additional Background Information
New information on the prevention of GBS disease is described in the
recent consensus of
the Centers for Disease Control and Prevention (CDC)5, the
American
College of Obstetricians
and Gynecologists6, and the American Academy of Pediatrics7.
This consensus resulted in a
new standard for detecting GBS colonization in pregnant women.
Vaginal/rectal cultures should
be obtained at 35-37 weeks of gestation and be performed using
selective broth media. The
consensus also presented a new algorithm for management of a neonate born to
a mother who
received intrapartum prophylaxis for prevention of early-onset GBS disease.
FDA has informed manufacturers of test kits for detecting GBS antigen
that these devices
must be evaluated according to current CDC recommendations as a condition
for remaining on
the market.
Reporting Adverse Events to FDA
The Safe Medical Devices Act of 1990 (SMDA) requires hospitals and
other user facilities
to report deaths and serious illnesses and injuries associated with the use
of medical devices.
Thus, under the law, an erroneous result from a GBS antigen test kit that
results in a death or
serious illness must be reported. We request that you follow the
procedures established by your
facility for such mandatory reporting.
Even if a report is not mandatory, it would be helpful to report
directly to MedWatch, the
FDA's voluntary reporting program. Submit these reports to MedWatch:
by telephone at 1-800-FDA-1088, by FAX at 1-800-FDA-0178, or by mail to:
MedWatch
Food and Drug Administration
HF-2
5600 Fishers Lane
Rockville, MD 20857
If you have any questions with regard to this Safety Alert, please contact Nancy Pressly,
Office of Surveillance and Biometrics, HFZ-510, 1350 Piccard Drive, Rockville, MD 20850, Fax
301-594-2968, or e-mail nap@cdrh.fda.gov.
Sincerely Yours,
D. Bruce Burlington, M.D.
Director,
Center for Devices and Radiological Health
References:
- Baker, C.J. Inadequacy of rapid immunoassays for intrapartum detection of group B streptococcal carriers. Obstetrics & Gynecology, 88:51-55, 1996.
- Greenberg, D.N., D.P. Ascher, B.A. Yoder, D.M. Hensley, H.S. Heiman
and J.F. Keith, III. Sensitivity and specificity of rapid diagnostic tests
for detection of group B streptococcal antigen in bacteremic neonates.
J. Clin. Microbio., 33:193-198, 1995.
- Perkins, M.D., S. Mirrett and L.B. Reller. Rapid bacterial antigen
detection is not clinically useful. J. Clin. Microbio., 33:1486-1491,
1995.
- Williamson, M., S.H. Fraser and J. Tilse. Failure of the urinary
group B streptococcal antigen test as a screen for neonatal sepsis.
Arch. Dis. Childhood, 73:F109-111, 1995.
- Centers for Disease Control and Prevention. Prevention of perinatal
group B streptococcal disease: A public health perspective.
In Morbidity and Mortality Weekly Report
(MMWR), Recommendations and Reports, Vol. 45, RR-7, May 31, 1996.
Erratum:MMWR, Vol.45, No.31, 1996.
- American College of Obstetricians and Gynecologists. Prevention
of early-onset disease in the newborn due to group B streptococcus.
ACOG Committee Opinion, No. 173, 1996.
- American Academy of Pediatrics. Revised guidelines for prevention
of early-onset group B streptococcal infection. Pediatrics, 99:489-496,
1997.
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