Risk factors for group B streptococcus early-onset disease: an Italian, area-based, case-control study

Abstract

Purpose: Intrapartum antibiotic prophylaxis (IAP) prevents group B streptococcus (GBS) early-onset disease (EOD). No European study evaluates the relative impact of risk factors (RFs) for EOD after a screening-based strategy and widespread IAP use We aimed to evaluate the risks of EOD in an Italian region where a screening-based strategy for preventing EOD was implemented.

Materials and methods: Cases of EOD born at or above 35 weeks’ gestation were reviewed and matched with controls.

Results: There were 109 cases of EOD among 532,154 live births. Most cases had negative GBS prenatal screening (56/91, 61.5%) and were unexposed to IAP (86/109, 78.9%). At multivariate analysis, GBS bacteriuria (OR = 6.99), positive prenatal screening (OR = 13.7) and maternal intrapartum fever (OR = 188.3) were associated with an increased risk of EOD, whereas intrapartum beta-lactam antibiotics were associated with a decreased risk of EOD (≥4 h: OR = 0.008; <4 h: OR = 0.04). Neonates born to nonfebrile, GBS positive pregnant women, receiving beta-lactam antibiotics had very low probability of EOD, particularly if IAP was adequate.

Conclusions: GBS positive prenatal screening, GBS bacteriuria and intrapartum fever are associated with EOD. Intrapartum beta-lactam antibiotics reduce the probability of EOD in neonates born to nonfebrile mothers.

Keywords:

• Early-onset disease
• GBS screening
• group B streptococcus
• intrapartum antibiotic prophylaxis

Acknowledgements

The authors are really grateful to Professor William Benitz, (Division of Neonatal and Developmental Medicine Lucile Packard Children’s Hospital, Palo Alto, California) who revised the initial draft of this manuscript and gave very valuable suggestions. They also thank the GBS Prevention Working Group of Emilia-Romagna (components are listed below):L. Memo, G. Nicolini (Ospedale San Martino, Belluno); M. Ciccia, A. Bastelli, F. Sandri (Ospedale Maggiore, Bologna); S. Ambretti, M.G. Capretti, L. Corvaglia, A. Dondi, M. Lanari, L. Pasini, L. Ragni, (Policlinico Sant’Orsola, Bologna); A. Albarelli (Ospedale Santa Maria, Borgo Taro); V. Fiorini, C. Giugno, P. Lanzoni (Ospedale B. Ramazzini, Carpi); E. Di Grande, A. Polese (Ospedale Sant’Anna, Castelnuovo Monti); M.C. China, V. Rizzo, M Stella (Ospedale M. Bufalini, Cesena); A. Zucchini (Ospedale Civile, Faenza); L. Malaguti (Ospedale del Delta, Ferrara); M. Azzalli, G. Garani, C. Lama (Ospedale Sant’Anna, Ferrara); S. Nasi, P. Bacchini, G. Fragni (Ospedale di Vaio, Fidenza); P. Baldassarri, R.M. Pulvirenti, E. Valletta, V. Venturoli (Ospedale Morgagni-Pieratoni, Forlì); C. Alessandrini, M.L. Bidetti, S. Storchi Incerti (Ospedale Civile, Guastalla); C. Di Carlo, A. Lanzoni, L. Serra, D. Silvestrini (Ospedale Santa Maria della Scaletta, Imola); A. Berardi F. Facchinetti, F. Ferrari, L. Lugli, C. Venturelli (Azienda Ospedaliera Policlinico, Modena); M. Sarti (Ospedale Baggiovara, Modena); A. Volta (Ospedale Franchini, Montecchio Emilia); I. Dodi, L. Gambini, C. Magnani (Ospedale Policlinico, Parma); B. Guidi (Ospedale Civile, Pavullo); M. Bertelli, G. Biasucci, R. Chiarabini, N. De Paulis, D. Padrini, S. Riboni (Ospedale G. da Saliceto, Piacenza); M.F. Pedna, V. Sambri (Laboratorio Area Vasta Emilia-Romagna, Pievesestina); L. Casadio, F. Marchetti, C. Muratori, G. Piccinini, C. Renzelli (Ospedale Santa Maria delle Croci, Ravenna); S. Amarri, L. Baroni, E. Carretto, S. Fornaciari, G. Gargano, S. Pedori, M. Riva, C. Zuelli (Ospedale Santa Maria Nuova, Reggio Emilia); G. Ancona, S. Bolognesi, I. Papa, G. Vergine, L. Viola (Ospedale Infermi, Rimini); C. Chiossi, R. Pagano, C. Rivi, C. Zanacca (Ospedale Civile, Sassuolo); C. Bonvicini, R. Palmieri (Ospedale C. Magati, Scandiano).

Ethics approval

The study protocol was approved by the ethical committee of the Azienda Ospedaliero-Universitaria of Modena (Italy) (Prot. No 265/17).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Funding Alberto Berardi has received funding from the Agenzia Sanatoria Regione dell’Emilia-Romagna: “Assegnazione e concessione di finanziamenti alle Aziende Sanitarie Regionali per la realizzazione di programmi di interesse regionale a sostegno del Piano Regionale della Prevenzione 2015–2018 C.U.P. n. E43G17000680002”. The remaining authors declare they have no funding source.