[Evaluation of three rapid methods for intrapartum detection of group B streptococcus].
OBJECTIVE
The goal of this study was to evaluate three methods for rapid group B streptococcus (GBS) intrapartum vaginal detection.


METHODS
In 330 women, at risk of delivering an infant with GBS disease, vaginal exudates were collected and a culture performed. The following rapid tests were also performed: 1) Equate Strep B immunoassay in 133 samples. 2) Icon Strep B immunoassay in 192 samples. 3) Co-agglutination with Phadebact Strep B, with a previous incubation (> 4 hours) of the vaginal swabs in Lim Group B Strep broth, in 88 samples. In some patients, two of these methods were performed simultaneously.


RESULTS
GBS was detected in 37 women (11.2%) by culture. The sensitivity of Equate Strep B was 47%, Icon Strep B was 35% and co-agglutination with Phadebact Strep B was 38%. The specificity was 91%, 99% and 100% for each one of these methods. PPV 44%, 90% and 100%, respectively and NPV 92%, 91% and 90%, respectively.


CONCLUSIONS
In conclusion, none of these methods was shown sensitive enough to be used for the routine detection of GBS. Therefore, in order to know the GBS carrier status and prevent its vertical transmission, the practice of vaginal culture during late pregnancy is mandatory.
Andreu Domingo
A
A
Servicio de Microbiología, Hospitals Vall d'Hebron, Barcelona.
Saleedo Abizanda
S
S
Heredia Prim
F
F
González Morlans
J
J
Bartolomé Comas
R M
RM
Cabero Roura
L
L
D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007229:Infant Welfare; D007231:Infant, Newborn; D018445:Infectious Disease Transmission, Vertical; D007743:Labor, Obstetric; D011247:Pregnancy; D013290:Streptococcal Infections / Q000209:etiology* / Q000382:microbiology / Q000635:transmission*; D013292:Streptococcus agalactiae / Q000472:pathogenicity*; D014621:Vagina / Q000382:microbiology