Group A and Group B Strep Screening, Changes to Protocol

Beginning Tuesday, January 14, 2014, the University of Iowa Hospitals and Clinics Microbiology Laboratory will begin performing Group A and B Streptococcus screening using the Illumigene nucleic acid amplification platform.  This has significant but different impacts on each test as follows:

Group A Strep (GAS) screens:

  1. A pharyngeal swab using a single Eswab is required, delivered to Microbiology (6006 BT).  GAS screening and followup culture will both be done from the single Eswab.  This replaces our old protocol, where a Culturette swab was delivered to Specimen Receiving and one Eswab was delivered to Microbiology.
  2. GAS screening will typically take approximately 20 minutes longer on average but will detect approximately 2.5 times the number of GAS cases previously detected by rapid Strep testing.

Group B Strep (GBS) Screens:

  1. Collection of swabs for GBS screens will not change.
  2. Positive GBS screens will be finalized approximately 24 hrs. more rapidly than before.
  3. Because the Illumigene test replaces culture, isolates will not be immediately available for susceptibility testing for penicillin-allergic patients unless requested up front.  Ordering in Epic has been designed to facilitate obtaining susceptibility testing for penicillin allergic patients.  In case the need for susceptibility testing is appreciated later, all GBS enrichment broths will be held for 7 days.

The Epic codes for these tests are as follows:

Group A Strep:
O103409 Group A Streptococcus with reflex to culture (Inpatient)
O103411 (Outpatient)

Group B Strep:
O103412 Group B streptococcus with reflex to culture (Inpatient)
O103414 (Outpatient)

There is a checkbox within the GBS screen for ordering susceptibility testing on penicillin-allergic patients and a reminder within the GBS result in Epic that susceptibility testing can still be ordered even after a screening result is reported out.

Questions concerning this broadcast can be directed to Bradley Ford, MD, PhD, Associate Medical Director of Microbiology, (ext. 6-2990,