Reduction of intrapartum antibiotic prophylaxis by combining risk factor assessment with a rapid bedside intrapartum polymerase chain reaction testing for group B streptococci.

OBJECTIVE: To investigate the impact of administering Intrapartum Antibiotic Prophylaxis (IAP) to laboring women with one or more risk factors for Early Onset Group B Streptococcal neonatal infection (EOGBS) based on the result of a rapid bedside test for Group B Streptococci (GBS). STUDY DESIGN: Quality assessment study. METHODS: Three-hundred-sixty-six laboring women admitted to our maternity ward, with one or more risk factors for EOGBS, were prospectively included. Rectovaginal swab-samples were examined bedside by the GenomEra® GBS Polymerase Chain Reaction (PCR) assay upon admission. Time from administration of IAP to delivery was registered. According to national guidelines, one-hundred-two women mandatorily received IAP independent of the PCR test result fulfilling one of the following three risk factors: prior infant with EOGBS, preterm labor before 35 gestational week, temperature ≥ 38 °C during labor. Women with GBS bacteriuria during current pregnancy, rupture of membranes ≥ 18 h IAP, and preterm labor between 35 and 37 gestational week, received IAP solely if the PCR test was positive. Predictive values were calculated for each risk factor. RESULTS: Previous GBS bacteriuria was strongly associated (PPV = 71%) with a positive GBS PCR test, whilst the corresponding positive percent of ROM > 18 h and of GA 35-37 was only PPV = 16% and 22%, respectively. Seventy-four women, 74/251 (31%), received IAP because they were GBS PCR positive. IAP was thus reduced by about two-thirds compared to the risk-based strategy of offering IAP to all women with one or more risk factors for EOGBS. Two women, 2/254 (0.8%), received inferior care, as they did not receive IAP within the recommended 4 h prior to delivery due to the extra time spend on the test procedure. CONCLUSION: Bedside intrapartum PCR testing of women with risk factors for EOGBS effectively diminishes use of IAP during labor compared to the present risk factor-based strategy alone. In this project, the extra time spend on the PCR test procedure did not lead to noticeable delay in IAP.

A comparison of GenomEra® GBS PCR and GeneXpert ® GBS PCR assays with culture of GBS performed with and without broth pre-enrichment.

This study was designed to compare the performance of GeneXpert® and GenomEra® group B streptococcus (GBS) PCR assays, held up against standard culture of GBS performed with and without broth pre-enrichment. In Denmark, the strategy for preventing early onset GBS infection (EOGBS) is risk factor based. Three hundred and sixty six women fulfilling one or more of the criteria for presence of risk factors for EOGBS were prospectively included. Rectovaginal swab samples were taken intrapartum and tested bed-site by the GenomEra® and the GeneXpert® GBS PCR assays and cultured at the microbiology laboratory using Granada agar plates with and without prior growth of sampling material in selective enrichment broth. Among 366 participants tested intrapartum, 99 were GBS-positive by culture, 95 by GenomEra, and 95 by GeneXpert. Compared with culture, the GenomEra and the GeneXpert performed with a sensitivity of 91.8% and 91.7% and a specificity of 98.1% and 97.3%, respectively. A combined reference standard was established by defining true positives as either culture-positive samples or culture-negative samples where both the GeneXpert and the GenomEra GBS PCR assays were positive. Using this, the sensitivity increased to 92.2% and the specificity to 99.6% for GenomEra and to 92.0% and 96.8% for GeneXpert. The use of selective broth enrichment found only three additional GBS culture-positive samples. The performance of the two PCR methods examined was very similar and close to the findings by culture, and both PCR assays are thus applicable as rapid intrapartum bed-site tests.

Multispacer sequence typing of Coxiella burnetii DNA from removed prosthetic heart valve material discloses first human case of infective endocarditis caused by MST_18.

INTRODUCTION: In Denmark, Q fever has previously been considered a rare and imported disease; however, recent testing of antibodies in cattle as well as humans has indicated that the infection is widespread. A 76-year-old Danish man was diagnosed with infective endocarditis and underwent open surgical aortic valve replacement with insertion of a biological valve. Due to paravalvular leakage, destruction of the aortic annulus, and an aortic root abscess, the patient underwent re-operation 3 weeks later, with replacement of the biological valve and insertion of an aortic prosthetic tube. Despite treatment with various broad-spectrum antibiotic regimes, the patient died 3.5 months after initial hospital admission. METHODS: The causative agent was probed by PCR amplification of bacterial DNA on the removed prosthetic aortic valve using broad range primers targeting the variable regions V1-V3 of the 16S RNA gene. After identification of Coxiella burnetii, multispacer sequence typing (MST) was performed by PCR amplification of 10 intergenic sequences. RESULTS: BLAST analysis of DNA from prosthetic valve material identified a 16S rRNA gene fragment almost identical to the type strain of C. burnetii (462/463 nt). Molecular typing allocated the strain to MST_18. CONCLUSIONS: Molecular methods are increasingly used to characterize isolates and to determine relationships between isolates that cause disease in different contexts and geographical areas. The present case demonstrates that identification and typing of C. burnetii is achievable without access to biosafety level 3 containment and highlights the first molecular characterization of an uncultured strain of C. burnetii causing infective endocarditis.

Risk of adverse pregnancy outcome in women exposed to livestock: a study within the Danish National Birth Cohort.

Maternal infection in pregnancy is a known risk factor for adverse pregnancy outcome, and a number of zoonotic pathogens may constitute a risk to pregnant women and their fetuses. With animal contact as a proxy for the risk of zoonotic infection, this study aimed to evaluate pregnancy outcome in women with self-reported occupational or domestic contact with livestock compared to pregnant women without such contact. The Danish National Birth Cohort collected information on pregnancy outcome from 100 418 pregnant women (1996-2002) from which three study populations with occupational and/or domestic exposure to livestock and a reference group of women with no animal contact was sampled. Outcome measures were miscarriage, very preterm birth (before gestational week 32), preterm birth (before 37 gestational weeks), small for gestational age (SGA), and perinatal death. Adverse reproductive outcomes were assessed in four different exposure groups of women with occupational or domestic exposure to livestock with no association found between exposure to livestock and miscarriage, preterm birth, SGA or perinatal death. These findings should diminish general occupational health concerns for pregnant women with exposures to a range of different farm animals.