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A screening test (GBS-Test) for urogenital carriage of group B streptococci
Volume 157 Number 2
ghani and Ansari' reported a case of a ruptured right external iliac artery aneurysm secondary to drug abuse in a pregnant patient. This led to an intrauterine fetal death and significant maternal morbidity. A series of 50 nonpregnant patients with mycotic aneurysms has been reported from our institution. 2 Local pain, swelling, bleeding, and symptoms of vascular insufficiency were the most common presenting complaints. A pulsatile, indurated mass with an associated bruit was present in nearly all cases, with the femoral artery being the most frequently involved site. Approximately 80% of the patients were adequately treated with simple ligation and excision, but the remaining 20% required bypass or amputation. Resistant S. aureus was isolated from more than three quarters of the cases. A thorough history and physical examination are necessary in patients who abuse drugs intravenously, with special attention given to complaints referred to injection sites and extremities. Careful palpation for fluctuance or pulsations and auscultation for bruits is essential for the diagnosis of an underlying abscess or aneurysm. Arteriograms should be liberally used for confirmation. Operation for this condition during pregnancy presents potential fetal risks including anesthetic complications, hypotension from supine positioning, and decreased placental perfusion from operative blood loss. The delay in surgical treatment may result in aneurysmal rupture with maternal hypotension, decreased placental perfusion, and possibly fetal death.' The effect of second-stage valsalva maneuvers
Mycotic aneurysms in pregnancy
may increase the risk of aneurysmal rupture, although there is little evidence to confirm this. At all gestational ages, the risk of operation to the undelivered fetus must be weighed against delaying definitive treatment. It is difficult to formulate a management scheme on the basis of this limited experience; however, the following guidelines would appear appropriate: (1) Leaking or expanding aneurysms require immediate operation irrespective of gestational age. If viable, the fetus should be monitored during operation and the attending obstetrician prepared to perform a cesarean delivery for fetal indications. (2) Aneurysms diagnosed during the first and second trimesters should be surgically treated. (3) Near term, attempts at conservative management awaiting fetal maturity should be considered, with delivery prior to operation. (4) Careful attention to bacterial isolates and resistance patterns is necessary to optimize antibiotic therapy. With early diagnosis and intensive surgical-obstetric management, the excessive morbidity of this condition in pregnancy may be minimized. We wish to acknowledge the expert technical assistance of Suellen]. Pence. REFERENCES l. Dirghani JK, Ansari MR. Rupture of mycotic aneurysm
during pregnancy: another hazard of drug abuse. Henry Ford Hosp J 1982;30:93. 2. Johnson JR, Ledgerwood AM, Lucas CE. Mycotic aneurysm: new concepts in therapy. Arch Surg 1983; 118:577.
A screening test (GBS-Test) for urogenital carriage of group B streptococci Karen Christensen, M.D., Ph.D., and Pout Christensen, M.D., Ph.D.
Lund, Sweden A commercial kit for the detection of group B streptococci (GBS-Test) is described. The test is based on orange pigment production after 2 days' incubation at 3r C. It showed a 100% specificity and a sensitivity superior to that of a conventional selective broth method. (AM J OssTET GYNECOL 1987;157:341-2.)
Key words: Group B streptococci, pregnancy, screening
From the Fdeon Science Park. Received for publication july 22, 1986; revised February 4, 1987; accepted March 12, 1987. Reprint requests: Dr. Karen K. Christensen, Fdeon Science Park, S-22370 Lund, Sweden.
Recently, a successful prevention program for the majority of early-onset group B streptococcal infections was described, based on screening during pregnancy.' The present paper describes a new commercial kit 341
342
Christensen and Christensen
August 1987 Am J Obstet Gynecol
Table I. Comparison of a conventional selective method and the GBS-Test for detection of group B streptococci in the urethra, cervix, and rectum
Site of collection of specimen
Urethra Cervix Rectum All specimens
No. of specimens containing group B streptococci per No. collected
No. of tests positive for group B streptococci
Sensitivity (%)
No. of tests positive Day 1
58/200 53/200 29/100
53 46 25
91 87 86
57 48 21
140/500
124
89
126
(GBS-Test*) which is suitable for the detection of group B streptococci during pregnancy. The test consists of a tube containing 1.5 ml of broth. Each specimen to be investigated for group B streptococci was obtained with a cotton-tipped swab, which was then whisked out in the broth. The tube was capped and incubated for 2 days at 37° C. On days 1 and 2, tubes were inspected for orange pigmentation, indicating the presence of group B streptococci. With this technique, 500 urogenital specimens were evaluated, 200 from the urethra, 200 from the cervix, and 100 from the rectum. All specimens were transported in Stuart medium within 24 hours of collection. Each specimen was whisked out in 1 ml of ToddHewitt broth at a temperature of 4° to 8° C. Two sterile cotton swabs were then dipped simultaneously in the broth; one of them was used for selective broth medium isolation of group B streptococci, and the other was used for detection of these bacteria with the GBS-Test. When a GBS-Test was positive but no ~-hemolytic streptococci had been detected on the blood agar plate, new attempts were made to isolate the bacteria from the Todd-Hewitt broth, by use of the selective method. The results of the "second look" were not included in the data given for the selective method (Table 1). The sensitivity of the conventional method was 91% for the urethra, 87% for the cervix, and 86% for the rectum (Table 1). The respective figures for the *Patent pending.
CBS-Test
Conventional selective method
I
Day2
Sensitivity(%) Day 1
58 49 25
98 91 72
132
90
I
Day 2
100 92 86 94
GBS-Test were 100%, 92%, and 86% after 2 days of incubation. No false positive results were recorded with the GBS-Test (specificity = 100%). All of 14 group B streptococcal strains isolated from cerebrospinal fluid or blood of newborn infants gave positive results with the GBS-Test, 13 after 24 hours' incubation and the fourteenth strain after 42 hours' incubation. The data thus demonstrated that the GBS-Test was at least as reliable as a conventional selective method used for detection of group B streptococci at bacteriologic laboratories. Although it does not appear to be quicker than conventional methods, the test permits diagnosis of group B streptococci at the doctor's office. The simple handling and easy reading of the test and a cost below 6 dollars for two tubes (that is, one screening occasion) has radically changed the cost-benefit ratio in favor of routine screening for group B streptococci during pregnancy. When this test is combined with prophylactic antibiotics in selected patients at risk,' we now have access to an instrument that can prevent a substantial part of early-onset group B streptococcal infections in newborn infants. REFERENCE 1. Boyer KM, Gotoff SP. Prevention of early-onset neonatal group B streptococcal disease with selective intrapartum chemoprophylaxis. N EnglJ Med 1986;314:1665-9.
ghani and Ansari' reported a case of a ruptured right external iliac artery aneurysm secondary to drug abuse in a pregnant patient. This led to an intrauterine fetal death and significant maternal morbidity. A series of 50 nonpregnant patients with mycotic aneurysms has been reported from our institution. 2 Local pain, swelling, bleeding, and symptoms of vascular insufficiency were the most common presenting complaints. A pulsatile, indurated mass with an associated bruit was present in nearly all cases, with the femoral artery being the most frequently involved site. Approximately 80% of the patients were adequately treated with simple ligation and excision, but the remaining 20% required bypass or amputation. Resistant S. aureus was isolated from more than three quarters of the cases. A thorough history and physical examination are necessary in patients who abuse drugs intravenously, with special attention given to complaints referred to injection sites and extremities. Careful palpation for fluctuance or pulsations and auscultation for bruits is essential for the diagnosis of an underlying abscess or aneurysm. Arteriograms should be liberally used for confirmation. Operation for this condition during pregnancy presents potential fetal risks including anesthetic complications, hypotension from supine positioning, and decreased placental perfusion from operative blood loss. The delay in surgical treatment may result in aneurysmal rupture with maternal hypotension, decreased placental perfusion, and possibly fetal death.' The effect of second-stage valsalva maneuvers
Mycotic aneurysms in pregnancy
may increase the risk of aneurysmal rupture, although there is little evidence to confirm this. At all gestational ages, the risk of operation to the undelivered fetus must be weighed against delaying definitive treatment. It is difficult to formulate a management scheme on the basis of this limited experience; however, the following guidelines would appear appropriate: (1) Leaking or expanding aneurysms require immediate operation irrespective of gestational age. If viable, the fetus should be monitored during operation and the attending obstetrician prepared to perform a cesarean delivery for fetal indications. (2) Aneurysms diagnosed during the first and second trimesters should be surgically treated. (3) Near term, attempts at conservative management awaiting fetal maturity should be considered, with delivery prior to operation. (4) Careful attention to bacterial isolates and resistance patterns is necessary to optimize antibiotic therapy. With early diagnosis and intensive surgical-obstetric management, the excessive morbidity of this condition in pregnancy may be minimized. We wish to acknowledge the expert technical assistance of Suellen]. Pence. REFERENCES l. Dirghani JK, Ansari MR. Rupture of mycotic aneurysm
during pregnancy: another hazard of drug abuse. Henry Ford Hosp J 1982;30:93. 2. Johnson JR, Ledgerwood AM, Lucas CE. Mycotic aneurysm: new concepts in therapy. Arch Surg 1983; 118:577.
A screening test (GBS-Test) for urogenital carriage of group B streptococci Karen Christensen, M.D., Ph.D., and Pout Christensen, M.D., Ph.D.
Lund, Sweden A commercial kit for the detection of group B streptococci (GBS-Test) is described. The test is based on orange pigment production after 2 days' incubation at 3r C. It showed a 100% specificity and a sensitivity superior to that of a conventional selective broth method. (AM J OssTET GYNECOL 1987;157:341-2.)
Key words: Group B streptococci, pregnancy, screening
From the Fdeon Science Park. Received for publication july 22, 1986; revised February 4, 1987; accepted March 12, 1987. Reprint requests: Dr. Karen K. Christensen, Fdeon Science Park, S-22370 Lund, Sweden.
Recently, a successful prevention program for the majority of early-onset group B streptococcal infections was described, based on screening during pregnancy.' The present paper describes a new commercial kit 341
342
Christensen and Christensen
August 1987 Am J Obstet Gynecol
Table I. Comparison of a conventional selective method and the GBS-Test for detection of group B streptococci in the urethra, cervix, and rectum
Site of collection of specimen
Urethra Cervix Rectum All specimens
No. of specimens containing group B streptococci per No. collected
No. of tests positive for group B streptococci
Sensitivity (%)
No. of tests positive Day 1
58/200 53/200 29/100
53 46 25
91 87 86
57 48 21
140/500
124
89
126
(GBS-Test*) which is suitable for the detection of group B streptococci during pregnancy. The test consists of a tube containing 1.5 ml of broth. Each specimen to be investigated for group B streptococci was obtained with a cotton-tipped swab, which was then whisked out in the broth. The tube was capped and incubated for 2 days at 37° C. On days 1 and 2, tubes were inspected for orange pigmentation, indicating the presence of group B streptococci. With this technique, 500 urogenital specimens were evaluated, 200 from the urethra, 200 from the cervix, and 100 from the rectum. All specimens were transported in Stuart medium within 24 hours of collection. Each specimen was whisked out in 1 ml of ToddHewitt broth at a temperature of 4° to 8° C. Two sterile cotton swabs were then dipped simultaneously in the broth; one of them was used for selective broth medium isolation of group B streptococci, and the other was used for detection of these bacteria with the GBS-Test. When a GBS-Test was positive but no ~-hemolytic streptococci had been detected on the blood agar plate, new attempts were made to isolate the bacteria from the Todd-Hewitt broth, by use of the selective method. The results of the "second look" were not included in the data given for the selective method (Table 1). The sensitivity of the conventional method was 91% for the urethra, 87% for the cervix, and 86% for the rectum (Table 1). The respective figures for the *Patent pending.
CBS-Test
Conventional selective method
I
Day2
Sensitivity(%) Day 1
58 49 25
98 91 72
132
90
I
Day 2
100 92 86 94
GBS-Test were 100%, 92%, and 86% after 2 days of incubation. No false positive results were recorded with the GBS-Test (specificity = 100%). All of 14 group B streptococcal strains isolated from cerebrospinal fluid or blood of newborn infants gave positive results with the GBS-Test, 13 after 24 hours' incubation and the fourteenth strain after 42 hours' incubation. The data thus demonstrated that the GBS-Test was at least as reliable as a conventional selective method used for detection of group B streptococci at bacteriologic laboratories. Although it does not appear to be quicker than conventional methods, the test permits diagnosis of group B streptococci at the doctor's office. The simple handling and easy reading of the test and a cost below 6 dollars for two tubes (that is, one screening occasion) has radically changed the cost-benefit ratio in favor of routine screening for group B streptococci during pregnancy. When this test is combined with prophylactic antibiotics in selected patients at risk,' we now have access to an instrument that can prevent a substantial part of early-onset group B streptococcal infections in newborn infants. REFERENCE 1. Boyer KM, Gotoff SP. Prevention of early-onset neonatal group B streptococcal disease with selective intrapartum chemoprophylaxis. N EnglJ Med 1986;314:1665-9.