Albert H. Adriaanse

Epidemiology of neonatal group B streptococcal disease in the Netherlands before and after introduction of guidelines for prevention

Objectives: (1) To describe the epidemiology of neonatal group B streptococcal (GBS) disease over five years (1997–2001) in the Netherlands, stratified for proven and probable sepsis and for very early (<12 h), late early (12 h – <7 days) and late (7–90 days) onset sepsis. (2) To evaluate the effect of the introduction in January 1999 of guidelines for prevention of early onset GBS disease based on risk factors. Methods: Data on cases were collected in collaboration with the Dutch Paediatric Surveillance Unit and corrected for under-reporting by the capture-recapture technique. Results: Total incidence of proven very early onset, late early onset and late onset GBS sepsis was 0.32, 0.11 and 0.14 per 1000 live births, respectively, and of probable very early onset, late early onset and late onset GBS sepsis was 1.10, 0.18 and 0.02 per 1000 live births, respectively. Maternal risk factors were absent in 46% of the proven early onset cases. Considerably more infants with proven GBS sepsis were boys. 64% of the infants with proven very early onset GBS sepsis were first borns compared with 47% in the general population. After the introduction of guidelines the incidence of proven early onset sepsis decreased considerably from 0.54 per 1000 live births in 1997–8 to 0.36 per 1000 live births in 1999–2001. However, there was no decrease in the incidence of meningitis and the case fatality rate in the first week of life. The incidence of late onset sepsis also remained unchanged. Conclusion: After the introduction prevention guidelines based on risk factors there has been a limited decrease in the incidence of proven early onset GBS sepsis in the Netherlands. This study therefore recommends changing the Dutch GBS prevention guidelines.

Semmelweis: the combat against puerperal fever

Groups A and B streptococci are of great significance in the history of obstetrics. Group A streptococci were a great threat to the puerperium, especially in the 19th century, when homebirth was replaced by institutional birth in lying-in hospitals. The history of the rise and fall of puerperal fever is indeed a tragedy. Some people, like Semmelweis, who brought new and important evidence based findings were not believed by their fellow obstetricians, an attitude that spoiled thousands of innocent lives. Even today group A streptococci, though seldom, may be the cause of puerperal sepsis. Group B streptococci are widespread and may cause sepsis and important lifelong morbidity or mortality of the newborn. Obstetricians today try to establish cost-effective prophylactic measures during labor to prevent these neonatal infections.

Neonatal early onset group B streptococcal infection. A nine-year retrospective study in a tertiary care hospital.

Retrospectively, morbidity and mortality of neonatal early onset group B streptococcal (GBS) infection were established. Risk factors and prognostic factors were determined. Between 1985 and 1993, 78 patients with early onset GBS disease were identified. The overall mortality rate was 23%. In 60 of 73 cases (82%) at least one of the investigated risk factors was present. Low birth weight was not an independent risk factor. Outcome of 44 of 60 survivors (73%) at the age of at least one year was obtained. Almost 30% of them had sequelae. The most important were spastic disorders and delayed psychomotor development. In 42% of patients with symptoms of GBS-infection within six hours after birth sequelae occurred. There were no sequelae among patients with symptoms after 6 hours. All 9 severely brain damaged infants showed symptoms shortly after birth. Mortality and adverse outcome rate were higher in infants with low gestational age or low 5 minute Apgar scores. Early treatment resulted in less mortality, but not in less sequelae. GBS-sepsis still causes significant mortality and leaves a substantial number of survivors damaged. Alertness to GBS-infection, even in the absence of risk factors, remains crucial for early treatment and good outcome.

Strategy to prevent neonatal early-onset group B streptococcal (GBS) disease in the Netherlands

Early-onset group B streptococcal (GBS) infection can be prevented by intrapartum antibiotic prophylaxis. In the USA the effectiveness of this strategy was demonstrated after the introduction of formal guidelines in 1996. In Europe prevention strategies for early-onset GBS infection have not been implemented universally. In 1998 the Dutch Society of Paediatrics and the Dutch Society of Obstetrics and Gynaecology posted conjoint guidelines for the prevention of early-onset GBS disease based on currently available knowledge and the local situation. These guidelines will be discussed in this overview.

Sensitivity of intrapartum group B streptococcal screening and in vitro comparison of four rapid antigen tests.

OBJECTIVES To evaluate the sensitivity of intrapartum screening for group B streptococcal (GBS) colonization and to compare 4 rapid GBS antigen tests in vitro. DESIGN Two swabs of the lower vagina of 769 parturients were taken; one swab was cultured, the other was frozen at -70 degrees C until antigen testing with the Group B Strep Test (Quidel) of the culture positive samples was performed. The Quidel test was then compared with 3 other rapid GBS antigen tests in vitro: Wellcogen Strep B (Wellcome Diagnostics), Slidex méningite Strepto B (bioMérieux) and ICON Strep B (Hybritech). The supernatant of 29 GBS cultures in Todd-Hewitt broth was tested in bacterial concentrations of 10(6), 10(7), and 10(8) Colony-forming Units (CFU)/ml, respectively. RESULTS Lower vagina GBS carrier rate was 13.4% (103/769) and heavy colonization (growth density 3 and 4 on blood agar plates) was found in 5.2% (40/769). The Group B Strep Test detected 11% (11/103) of GBS carriers, with a sensitivity for heavy colonization of 25% (10/40). In vitro none of the tests scored positively with a concentration of 10(6) CFU/ml, while with 10(7) CFU/ml the enzyme immunoassay tests (Quidel, Hybritech) were more sensitive (McNemar test, P < 0.05) than the latex agglutination tests (Wellcome Diagnostics, bioMérieux). CONCLUSIONS Although in vitro the enzyme immunoassay tests are more sensitive than the latex agglutination tests, sensitivity in vivo is too low to recommend the use of rapid antigen tests for general screening.

Using a new HPV detection system in epidemiological research: change of views on cervical dyskaryosis?

UNLABELLED The prevalence of human papillomavirus (HPV) rises with increasing histological severity of neoplasia, more cigarettes smoked per day and higher lifetime number of sexual partners in women with cervical dyskaryosis. Recently, the highly sensitive SPF10 primers and Inno-LiPA (line probe assay) HPV prototype research assay became available for the detection and typing of HPV. BACKGROUND using this system, we challenged the previously reported findings. STUDY DESIGN the study group comprised 304 women referred because of abnormal pap smears in whom a histological diagnosis was made. Data on the lifetime number of sexual partners and smoking behaviour were obtained by questionnaire. HPV analysis was performed on cervical scrapes obtained at the enrollment visit. RESULTS oncogenic HPV was found in 288 (95%) women. A total of 86 (30%) out of these 288 women disclosed multiple types. HPV 16 occurred significantly less often in multiple infections than was expected on the basis of chance alone. The grade of neoplasia was significantly associated with the presence of oncogenic HPV, and this association depended on the presence of HPV type 16. No association was found between grade of neoplasia and the presence of multiple HPV types. Neither the lifetime number of sexual partners nor smoking were associated with oncogenic HPV, the five most frequent HPV types separately or the presence of multiple types. CONCLUSION we conclude that the association between the detection of HPV and the epidemiological risk factors, as found with the GP5/6 PCR in the past, could not be confirmed when using SPF10 PCR primers and LiPA HPV genotyping. We suggest that the number of sexual partners and smoking may be determinants of high HPV viral load rather than determinants of the presence of HPV per se.

Significance of Gram's stain in rapid intrapartum screening for maternal carriership of group B streptococcus.

Objective: Group B streptococcus (GBS, Streptococcus agalactiae) is an important cause of neonatal sepsis. Prevention is possible by intrapartum screening for maternal GBS carriership and antimicrobial treatment of colonized women with risk factors during labor. The conflicting results of diagnostic performance are reported both for the newly developed rapid GBS antigen tests and Grams stain. Methods: The value of Grams stain in GBS screening was investigated prospectively in 1,020 women. Intrapartum Grams stains of the cervix from these women and of the introitus from 510 of them were compared with cultures of the cervix, introitus, and anorectum in a semiquantitative way. Results: The sensitivities of the cervical and introital Grams stains were 25% and 31%, respectively, and the specificities 99% and 98%, respectively. Higher sensitivities (52% and 44%, respectively) were found in heavily colonized parturients. No significant influence of rupture of the membranes was detected. There was a poor correlation between the number of gram-positive cocci in the Grams stain and the growth density. Conclusions: We do not recommend the routine use of the Grams stain for intrapartum GBS detection because of both the limited sensitivity and positive predictive value.