Colonization and infection of mothers and neonates with group B streptococci in three Italian hospitals

Prevalence of early-onset neonatal infection among newborns of mothers with bacterial infection or colonization: a systematic review and meta-analysis

BACKGROUND

Although neonatal infections cause a significant proportion of deaths in the first week of life, little is known about the burden of neonatal disease originating from maternal infection or colonization globally. This paper describes the prevalence of vertical transmission--the percentage of newborns with neonatal infection among newborns exposed to maternal infection.

METHODS

We searched Pubmed, Embase, Scopus, Web of Science, Cochrane Library, and WHO Regional Databases for studies of maternal infection, vertical transmission, and neonatal infection. Studies that measured prevalence of bacterial vertical transmission were included. Random effects meta-analyses were used to pool data to calculate prevalence estimates of vertical transmission.

RESULTS

122 studies met the inclusion criteria. Only seven studies (5.7%) were from very high neonatal mortality settings. Considerable heterogeneity existed between studies given the various definitions of infection (lab-confirmed, clinical signs), colonization, and risk factors of infection. The prevalence of early onset neonatal lab-confirmed infection among newborns of mothers with lab-confirmed infection was 17.2% (95%CI 6.5-27.9). The prevalence of neonatal lab-confirmed infection among newborns of colonized mothers was 0% (95% CI 0.0-0.0). The prevalence of neonatal surface colonization among newborns of colonized mothers ranged from 30.9-45.5% depending on the organism. The prevalence of neonatal lab-confirmed infection among newborns of mothers with risk factors (premature rupture of membranes, preterm premature rupture of membranes, prolonged rupture of membranes) ranged from 2.9-19.2% depending on the risk factor.

CONCLUSIONS

The prevalence of early-onset neonatal infection is high among newborns of mothers with infection or risk factors for infection. More high quality studies are needed particularly in high neonatal mortality settings to accurately estimate the prevalence of early-onset infection among newborns at risk.

Prospective analysis of risk factors associated with group B streptococcal colonisation in neonates born at a tertiary care centre in India

BACKGROUND

Bacterial colonisation of neonates and the birth canal by group B streptococci (GBS) plays a significant role in the development of neonatal infections.

OBJECTIVES

To determine the rate of GBS colonisation in neonates in the first 48 hours of life and to identify the risk factors associated with GBS colonisation.

METHODS

To estimate GBS colonisation, a prospective cross-sectional analysis of 1050 neonates delivered at a tertiary care hospital in India was undertaken. Swabs were taken from the neonates' skin and/or mucus membranes of the external ear canal, anterior nares, umbilicus, throat and ano-rectal sites between 24 and 48 hours of age. Data regarding the various risk factors were collected on a predesigned performa.

RESULTS

338 (32·2%) of 1050 neonates had bacterial colonisation. Escherichia coli (25·9%), was the bacteria most commonly isolated, followed by Staphylococcus aureus (16·3%) and coagulase-negative Staphylococci (CONS) (12·6%). The overall rate of GBS colonisation was 3·23%. Preterm birth, respiratory distress at birth, prolonged rupture of membranes (≧18 hrs), intrapartum antibiotics, underlying medical illness in the mother, prolonged labour, maternal fever and other obstetric complications were identified as significant risk factors associated with neonatal GBS colonisation (P<0·05).

CONCLUSION

Multi-centre and community-based studies in India are recommended to identify the true colonisation rates for GBS, and it is necessary to perform cultures from multiple body sites of neonates in order to obtain an accurate bacteriological evaluation.

Risk of early-onset neonatal infection with maternal infection or colonization: a global systematic review and meta-analysis

BACKGROUND

Neonatal infections cause a significant proportion of deaths in the first week of life, yet little is known about risk factors and pathways of transmission for early-onset neonatal sepsis globally. We aimed to estimate the risk of neonatal infection (excluding sexually transmitted diseases [STDs] or congenital infections) in the first seven days of life among newborns of mothers with bacterial infection or colonization during the intrapartum period.

METHODS AND FINDINGS

We searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, and the World Health Organization Regional Databases for studies of maternal infection, vertical transmission, and neonatal infection published from January 1, 1960 to March 30, 2013. Studies were included that reported effect measures on the risk of neonatal infection among newborns exposed to maternal infection. Random effects meta-analyses were used to pool data and calculate the odds ratio estimates of risk of infection. Eighty-three studies met the inclusion criteria. Seven studies (8.4%) were from high neonatal mortality settings. Considerable heterogeneity existed between studies given the various definitions of laboratory-confirmed and clinical signs of infection, as well as for colonization and risk factors. The odds ratio for neonatal lab-confirmed infection among newborns of mothers with lab-confirmed infection was 6.6 (95% CI 3.9-11.2). Newborns of mothers with colonization had a 9.4 (95% CI 3.1-28.5) times higher odds of lab-confirmed infection than newborns of non-colonized mothers. Newborns of mothers with risk factors for infection (defined as prelabour rupture of membranes [PROM], preterm <37 weeks PROM, and prolonged ROM) had a 2.3 (95% CI 1.0-5.4) times higher odds of infection than newborns of mothers without risk factors.

CONCLUSIONS

Neonatal infection in the first week of life is associated with maternal infection and colonization. High-quality studies, particularly from settings with high neonatal mortality, are needed to determine whether targeting treatment of maternal infections or colonization, and/or prophylactic antibiotic treatment of newborns of high risk mothers, may prevent a significant proportion of early-onset neonatal sepsis. Please see later in the article for the Editors' Summary.

Group B streptococcal infections in a northern region of Italy

BACKGROUND

Group B streptococcus is a leading cause of neonatal bacterial infections. Despite adoption of preventive strategies, cases of infection continue to occur and there is concern that widespread antimicrobial prophylaxis might delay rather than prevent disease onset, increasing the rates of late-onset diseases.

OBJECTIVES

The purpose of this study was to determine the incidence and clinical features of early- and late-onset group B streptococcus disease in a northern region of Italy where a screening-based approach had been proposed.

METHODS

A population-based study was prospectively conducted in Emilia-Romagna, Italy. Infections that occurred during 2003-2005 in infants aged <3 months were analyzed.

RESULTS

Among 112,933 live births, 56 cases of invasive disease (30 early- and 26 late-onset disease) were observed, giving an annual group B streptococcus disease incidence of 0.50 per 1000 live births. Eleven infants with early-onset disease showed no signs of illness or were mildly ill, whereas 19 had moderate-to-severe symptoms, and culture-proven meningitis was found in 2. Risk factors were detected in 12 women. Twenty-two mothers had antenatal screening; 5 were group B streptococcus colonized, but 17 were culture-negative. Prophylaxis was administered in 3 women. Three infants with late-onset diseases were mildly ill, whereas 23 had moderate-to-severe symptoms. Risk factors were found in 7 mothers. Late-onset diseases were clinically more severe than early-onset diseases; meningitis was diagnosed in 12 infants, and 4 of 26 died.

CONCLUSIONS

The incidence of early-onset disease was low. Some early infections were still observed because of negative screening results or missed opportunity for prevention. Late-onset diseases accounted for most meningitis cases and deaths. Strict adherence to protocols and adoption of optimal culture methods would further improve prevention of early-onset disease, but the aim of future strategies should be the prevention of all invasive diseases.

Carriage of group B Streptococcus in pregnant women and newborns: a 2-year study at Perugia General Hospital

OBJECTIVE: To study the prevalence of group B Streptococcus (GBS) colonization in pregnant women and their newborns at Perugia General Hospital. METHODS: The number of mother---child pairs examined was 2300. Vaginal swabs were collected from the mothers at delivery, and auricular and pharyngeal swabs and gastric aspirate from the newborns at birth. Maternal risk factors for GBS disease, including premature delivery, intrapartum fever, prolonged rupture of membranes and multiple births, were evaluated. RESULTS: Maternal and neonatal colonization rates were 11.3% and 4.6%, respectively. GBS was isolated in 41.5% of the neonates born to colonized mothers and in 0.1% of those born to non-colonized mothers. No significant difference was observed in vertical transmission rates in the presence or absence of maternal risk factors. The external auditory canal was the most frequent (93.5%) and heavily colonized body site. Type Ib was the most common serotype among GBS isolates from mothers and babies. C surface protein was not detected in serotype V and VIII isolates, but was frequent in all other serotypes. Early-onset disease was observed in 0.4/1000 live births. CONCLUSIONS: The prevalence of maternal and neonatal colonization at Perugia General Hospital was similar to that obtained in other studies performed in Italy. The external auditory canal was confirmed as the most reliable body site to be sampled for the detection of neonates exposed to maternal GBS colonization.