Neonatal Streptococcus pneumoniae infection: case reports and review of the literature

Changing Incidence of Invasive Pneumococcal Disease in Infants Less Than 90 Days of Age Before and After Introduction of the 13-Valent Pneumococcal Conjugate Vaccine in Blantyre, Malawi: A 14-Year Hospital Based Surveillance Study

BACKGROUND

Invasive pneumococcal disease (IPD) in young infants is uncommon but associated with high morbidity and mortality. Accurate data on the burden of IPD in young infants in low-income countries are lacking. We examined the burden of IPD in infants <90 days old in Blantyre, Malawi over a 14-year period and evaluated the indirect impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on vaccine-serotype IPD (VT-IPD) in this population.

METHODS

We conducted laboratory-based prospective IPD surveillance in infants <90 days of age admitted to Queen Elizabeth Central Hospital in Blantyre between 2005 and 2018, including 7 years pre-PCV13 and 7 years post-PCV13 introduction. IPD was defined as Streptococcus pneumoniae identified by culture from blood or cerebrospinal fluid. Serotypes were determined by multiplex polymerase chain reaction and latex agglutination testing.

RESULTS

We identified 130 cases of culture-confirmed IPD in infants <90 days old between 2005 and 2018. Total IPD incidence was declining before PCV13 introduction. The mean incidence of IPD was significantly lower in the post-PCV13 era. Serotypes 5 (27.8%) and 1 (15.6%) were most prevalent. Even after PCV13 introduction, VTs remained the primary cause of IPD, with serotype 5 accounting for 17.4% and serotype 1 for 13.0% of cases in young infants.

CONCLUSION

Vaccine serotypes 1 and 5 were the main cause of IPD in neonates and young infants, both before and after PCV13 introduction. This suggests incomplete indirect protection with persisting VT carriage across the population despite vaccination in this setting. Alternative vaccine schedules and other vaccine introduction approaches need to be considered to protect this vulnerable population.

PCR for the detection of pathogens in neonatal early onset sepsis

Background

A large proportion of neonates are treated for presumed bacterial sepsis with broad spectrum antibiotics even though their blood cultures subsequently show no growth. This study aimed to investigate PCR-based methods to identify pathogens not detected by conventional culture.

Methods

Whole blood samples of 208 neonates with suspected early onset sepsis were tested using a panel of multiplexed bacterial PCRs targeting Streptococcus pneumoniae, Streptococcus agalactiae (GBS), Staphylococcus aureus, Streptococcus pyogenes (GAS), Enterobacteriaceae, Enterococcus faecalis, Enterococcus faecium, Ureaplasma parvum, Ureaplasma urealyticum, Mycoplasma hominis and Mycoplasma genitalium, a 16S rRNA gene broad-range PCR and a multiplexed PCR for Candida spp.

Results

Two-hundred and eight samples were processed. In five of those samples, organisms were detected by conventional culture; all of those were also identified by PCR. PCR detected bacteria in 91 (45%) of the 203 samples that did not show bacterial growth in culture. S. aureus, Enterobacteriaceae and S. pneumoniae were the most frequently detected pathogens. A higher bacterial load detected by PCR was correlated positively with the number of clinical signs at presentation.

Conclusion

Real-time PCR has the potential to be a valuable additional tool for the diagnosis of neonatal sepsis.

Streptococcus pneumoniae - An Uncommon but Noteworthy Cause of Intrauterine Fetal Demise and Acute Necrotizing Funisitis

Background: Streptococcus pneumoniae (S. pneumoniae) is an uncommon cause of amniotic fluid infection and intrauterine fetal demise. Case report: A 39-year-old G8P2052 presented with preterm premature rupture of membrane at 22 weeks gestation and had a spontaneous vaginal delivery of a neonate who soon expired. Placental examination revealed retroplacental hematoma, acute necrotizing chorioamnionitis, acute three-vessel vasculitis and necrotizing funisitis of the umbilical cord. Postmortem examination demonstrated features of amniotic fluid infection syndrome with blood culture growing S. pneumoniae. Antenatal screening does not typically quantify S. pneumoniae infection, but small series have found vaginal colonization in fewer than 1% of women. Intrauterine or peritoneal infection derives primarily from ascending infection although other routes are hypothetically possible. Intra-amniotic and neonatal infections by S. pneumoniae are associated with high morbidity and mortality. Conclusion: S. pneumoniae should be considered in perinatal death of immature fetus with severe amniotic fluid infection syndrome and acute necrotizing funisitis.

Invasive Pneumococcal Disease in Neonates Prior to Pneumococcal Conjugate Vaccine Use in South Africa: 2003-2008

BACKGROUND

Neonatal invasive pneumococcal disease (IPD) in developing countries is poorly described. We provide a baseline description of neonatal IPD in South Africa, before implementation of the 7-valent pneumococcal conjugate vaccine (PCV7) in 2009.

METHODS

Data from children (age ≤ 2 years) with IPD (pneumococcus identified from a normally sterile specimen) from January 2003 to December 2008 were extracted from a national laboratory-based surveillance database. Clinical and laboratory characteristics of IPD among neonates (0-27 days old) was compared with IPD among young children (≥ 28 days ≤ 2 years). Early-onset IPD (0-6 days old) was compared with late-onset IPD (≥ 7-27 days old). Isolates were serotyped using the Quellung reaction.

RESULTS

Overall 27,630 IPD cases were reported. Of the 26,277 (95%) with known ages, 6583 (25%) were ≤ 2 years of age, of which 4.5% (294/6583) were neonates. The estimated annual incidence of neonatal IPD in 2008 was 5 per 100,000 live births. Fifty-one percent of neonates with IPD presented with early-onset IPD. Case fatality ratios (CFRs) were high in both groups, 31% (28/89) in neonatal IPD versus 26% (614/2383) in non-neonatal IPD (P = 0.18). Among neonates, the meningitis cases (15/37, 41%) were associated with the highest CFR. The 13-valent pneumococcal conjugate vaccine (PCV13) serotypes accounted for 69% (134/194) of neonatal IPD isolates.

CONCLUSIONS

Pneumococcal neonatal disease in South Africa was not uncommon before PCV introduction and is associated with a high CFR. The indirect effect on neonatal IPD of PCV rollout requires further evaluation.

Fulminant early-onset neonatal sepsis due to Streptococcus pneumoniae: Case report and review of the literature

Streptococcus pneumoniae is a rare cause of neonatal sepsis, and it is associated with significant morbidity and a very high fatality rate. The infection is usually acquired intrapartum, from the colonization of the maternal genital tract. Most affected neonates have an early-onset presentation of symptoms, usually within the first 48 hours after birth, which is similar to other causes of neonatal sepsis such as Streptococcus Agalactiae or Escherichia Coli. However, the virulence seems to be higher for Streptococcus pneumoniae, which has in addition a higher infant invasion/ maternal colonization ratio than Streptococcus Agalactiae. Pneumococcal vaccination has not resulted in a significant decline of neonatal cases. Many cases included ours, involved serotypes not present in the vaccine. Other strategies to protect these infants are necessary. We describe a late preterm infant with a fatal, early-onset sepsis caused by Streptococcus Pneumoniae serotype 28 A. Maternal vaginal culture grew the same bacteria.

Early-onset Neonatal Pneumococcal Sepsis: A Fatal Case Report and Brief Literature Review

Sepsis caused by Streptococcus pneumoniae is rare in neonates although associated with high morbidity and mortality. We report a fatal case of invasive pneumococcal disease in a term neonate whose mother was healthy and did not receive any pneumococcal vaccine. Investigation of the infection source yielded negative results. Acquisition of infection through the birth canal was considered unlikely.

Neonatal invasive pneumococcal disease: New Zealand experience in the era of pneumococcal vaccination

BACKGROUND

Invasive pneumococcal disease (IPD) became a notifiable disease in New Zealand in 2008, and in the same year pneumococcal conjugate vaccine (PCV) was added to the childhood immunisation schedule.

DESIGN

This was a retrospective study of IPD in infants aged <90 days reported to the national notifiable disease database, EpiSurv, from 1 January 2009 to 31 December 2013. All cases had Streptococcus pneumoniae isolated from a normally sterile site.

MAIN OUTCOME MEASURES

IPD incidence was calculated for babies aged <90 and <30 days using the number of national IPD cases with a denominator of annual infant live births. Clinical, demographic and outcome data were reviewed for infants aged less than seven days (early onset).

RESULTS

There were 29 cases of IPD in infants aged <90 days and 19 cases in infants aged <30 days. Of the nine early-onset cases, six occurred within the first 48 h. Six of the early-onset cases were infants of NZ Maori ethnicity. One infant died six hours after birth. Three infants developed long-term neurological or respiratory sequelae. Isolates from five of the early-onset cases were S. pneumoniae serotypes not covered by the PCV in use at the time of infection. Maternal vaccination with 23-valent pneumococcal vaccine would have covered 84% (16 of 19) of serotypes responsible for the cases in infants <30 days old.

CONCLUSION

Strategies such as maternal vaccination or accelerated neonatal vaccination may be beneficial to protect neonates at high risk of IPD.

Neonatal infectious diseases: evaluation of neonatal sepsis

Neonatal sepsis remains a feared cause of morbidity and mortality in the neonatal period. Maternal, neonatal, and environmental factors are associated with risk of infection, and a combination of prevention strategies, judicious neonatal evaluation, and early initiation of therapy are required to prevent adverse outcomes. This article reviews recent trends in epidemiology and provides an update on risk factors, diagnostic methods, and management of neonatal sepsis.

Impact of the 7-valent pneumococcal conjugate vaccine on invasive pneumococcal disease in infants younger than 90 days in England and wales

BACKGROUND

Streptococcus pneumoniae is an uncommon but well-recognized cause of invasive bacterial disease in young infants. This study aimed to determine the impact of the 7-valent pneumococcal conjugate vaccine (PCV7) on invasive pneumococcal disease (IPD) in infants aged <90 days in England and Wales and describe their clinical characteristics following PCV7 introduction.

METHODS

Trends in IPD among infants aged <90 days during 1998-1999 through 2009-2010 were analyzed using enhanced national surveillance data. Following PCV7 introduction, clinical information was also obtained for IPD cases in the birth cohorts eligible for vaccination.

RESULTS

Prior to PCV7 introduction, IPD incidence in infants aged <90 days was 13.0 (95% confidence interval [CI], 12.0-14.0) per 100 000 live births and PCV7 serotypes accounted for 44% (154/349) of serotyped isolates. PCV7 introduction resulted in 83% (95% CI, 66%-91%, P < .001) reduction in PCV7 IPD and a declining trend in overall IPD by 2009-2010. Of the 256 cases diagnosed after PCV7 introduction, 23% (n = 60) had been born before 37 weeks' gestation. A third of cases (84/256, 33%) developed IPD in the first 48 hours of life, where 42% (35/84) were premature. Meningitis was diagnosed in 94 infants (37%) and its prevalence increased with age. Case fatality was 7% (18/256) and was higher for meningitis than nonmeningitis cases (adjusted odds ratio, 3.8 [95% CI, 1.2-12.0], P = .024).

CONCLUSIONS

Young infants have benefited from PCV7 through indirect (herd) protection. Given that a third of cases occurred within 48 hours of birth, further studies should focus on risk factors for IPD in pregnancy and strategies to prevent mother-to-child transmission.

Invasive pneumococcal disease in infants younger than 60 days

OBJECTIVE

To review the epidemiology and clinical course of invasive pneumococcal diseases of infants younger than 60 days.

STUDY DESIGN

All Streptococcus pneumoniae strains isolated from blood and cerebrospinal fluid cultures of infants below the age of 60 days during the years 1999-2009 were included in this study. Demographic, clinical, and laboratory data were collected from medical records.

RESULTS

In all, 24 cases of pneumococcal invasive infections were identified. The primary diagnoses were bacteremia without a focus (n = 13), meningitis (n = 6), bacteremia with otitis media (n = 3), and joint infection with bacteremia (n = 2). Only one of the serotypes found is included in the heptavalent pneumococcal conjugated vaccine (PCV7).

CONCLUSIONS

Streptococcus pneumoniae should be considered and treated empirically in infants with suspected invasive bacterial disease during the first 60 days of life. Routine vaccination with PCV7 in not expected to substantially reduce the incidence of invasive pneumococcal disease in Israeli infants of this age as a result of herd immunity.

Streptococcus pneumoniae sepsis in the newborn

BACKGROUND

Streptococcus pneumoniae (SP) is an uncommon cause of neonatal sepsis.

AIMS

To report on the spectrum of morbidity associated with SP infections in the neonatal period.

METHODS

A case series of SP infection in the neonatal period was studied. Maternal and neonatal outcomes were noted.

RESULTS

Four cases of neonatal SP infection are reported, one of which was due to a strain with reduced susceptibility to penicillin. All four cases had very early onset of severe clinical disease with bacteremia and pneumonia. In one case a retrospective diagnosis of meningitis was made as well. Maternal illness was a feature in one of these infants.

CONCLUSIONS

Although less common now than in the pre-antibiotic era, Streptococcus pneumoniae remains a rare but important cause of neonatal sepsis and can mimic early onset Group B streptococcal sepsis. It is unclear whether current infant or adult pneumococcal immunisation programs might influence its incidence in the neonatal period. The potential for strains with reduced susceptibility to β-lactam antibiotics to cause neonatal infection needs to be considered in relevant settings.

A rare case of sepsis in newborn: Streptococcus pneumoniae septicemia

BACKGROUND

Streptococcus pneumoniae is a rare cause of sepsis in the newborn.

CASE

The term baby was admitted on complaint of dyspnea, and antibiotherapy was begun after samples for hemocultures were obtained with the suspicion of sepsis according to the clinical and laboratory data. S. pneumoniae was demonstrated in the vaginal culture of the mother of the patient whose lumbar punction and chest roentgenogram were normal but hemoculture revealed the propagation of S. pneumoniae. The patient, treated with antibiotherapy for 14 days, was discharged without any complications.

CONCLUSION

In preventing the probable complications, it is important to absolutely treat the maternal pneumococcal colonization that can cause severe infections in the newborn and also to treat the newborns even if they are asymptomatic.

Perinatal and Crowding-Related Risk Factors for Invasive Pneumococcal Disease in Infants and Young Children: A Population-Based Case-Control Study

BACKGROUND

Denmark's systems of registry-based data offer a unique opportunity to examine, on a population basis, risk factors for invasive pneumococcal disease (IPD) relating to perinatal and crowding exposures among children. The main objective of this study was to identify the role of familial and day care factors in the risk of IPD among unvaccinated infants and children.

METHODS

A total of 1381 children aged 0-5 years old who experienced IPD were identified from a national surveillance program of IPD in Denmark. Risk factors were assessed in a matched, nested, case-control study that assigned 10 population control subjects to every case patient. Exposure information was obtained from several population-based, person-identifiable Danish registries.

RESULTS

Preterm birth and low birth weight significantly increased the risk of IPD among infants. In infants 0-5 months of age, the risk of IPD was high among infants who had older siblings, compared with infants of the same age who had no older siblings (adjusted rate ratio [aRR], 3.38; 95% confidence interval, 2.11-5.42), whereas the aRR was low (aRR, 0.56; 95% confidence interval, 0.47-0.65) in children aged 6-23 months. Day care attendance, compared with home care, increased the aRR of IPD 0-2 months after enrollment in a day care program (aRR, 2.28; 95% confidence interval, 1.73-3.00), whereas the aRR was 0.70; (95% confidence interval, 0.46-1.06) > or = 6 months after enrollment in children aged 6-23 months.

CONCLUSIONS

During infancy (age, 0-6 months), risk of IPD is associated with low birth weight, presumably because of lower levels of passively acquired maternal antibody. During early childhood, exposure to other young children (either siblings or through day care attendance) is clearly associated with IPD, but natural exposure appears to occur rapidly and confer durable immunity.

Perinatal risk factors for hospitalization for pneumococcal disease in childhood: a population-based cohort study

OBJECTIVE

The objective of this study was to examine the relation of factors that are present at birth to subsequent hospitalization for childhood pneumococcal disease.

METHODS

We conducted a cohort study of all singletons born in 3 counties in western Denmark from 1980 through 2001, using population-based registries to obtain data on pregnancy- and birth-related variables and hospitalizations through age 12. We calculated incidence rates of pneumococcal disease hospitalization overall and within strata of study variables and used Poisson regression to estimate rate ratios for pneumococcal disease hospitalization while accounting for other birth characteristics.

RESULTS

Among 338,504 eligible births, 1052 children were later hospitalized for pneumococcal disease. Pneumonia accounted for most hospitalizations (81.9%). The pneumococcal disease hospitalization rate was highest among 7- to 24-month-olds, followed by 0- to 6-month-olds and 25- to 60-month-olds. The highest rates, typically over 200 hospitalizations per 100,000 person-years, were in 0- to 6- and 7- to 24-month-old children who were born preterm or with low birth weight, a low 5-minute Apgar score, or birth defects. The hospitalization rate was lower for first-born children at 0 to 6 months but not at older ages. At older ages, hospitalization rates were not substantially different for children whose mothers smoked during pregnancy, but at 0 to 6 months, the rate was higher for children of multiparous nonsmokers than for others. Adjusted rate ratios were elevated across all age categories for several variables, including low birth weight, presence of birth defects, and low 5-minute Apgar. For several others, including preterm birth, maternal multiparity, age < or = 20 years, and non-Danish/European Union citizenship, adjusted rate ratios were elevated only for 0- to 6-month-olds.

CONCLUSIONS

This large cohort study of hospitalization for childhood pneumococcal disease clarifies the roles of some gestation and birth factors while raising new questions about how these factors work.

Serious community-acquired neonatal infections in rural Southeast Asia (Bohol Island, Philippines)

OBJECTIVE

To determine the bacterial etiology, clinical presentation and risk factors for outcome of serious community-acquired infections in young infants.

STUDY DESIGN

Infants younger than 60 days, admitted for severe pneumonia or suspected sepsis/meningitis were prospectively evaluated using complete blood count, blood culture, chest radiograph, cerebrospinal fluid (CSF) culture in suspected meningitis. chi2 or Fisher's exact test and stepwise logistic regression were used for analysis.

RESULTS

Thirty-four of 767 enrolled infants had a positive blood or CSF culture. Gram-negative bacteria were more frequent than Gram positive: overall (P=0.004), in those below 7 days of age (P=0.002) and among home deliveries (P=0.012). Case fatality rates were higher among infants below 1 week old (OR 4.14, P<0.001), those with dense (OR 2.92, P<0.001) or diffuse radiographic infiltrates (OR 2.79, P=0.003).

CONCLUSIONS

Gram-negative enteric bacteria are the predominant causes of community-acquired infections in Filipino infants below 2 months old. Age below 7 days and radiographic pneumonia predicted death.

Early-onset neonatal pneumococcal sepsis syndrome

OBJECTIVE

To report two cases of severe early-onset neonatal sepsis due to Streptococcus pneumoniae, including, to our knowledge, the first reported case of sepsis due to penicillin-resistant S. pneumoniae presenting as early-onset neonatal sepsis.

DESIGN

Case reports.

SETTING

A level III military and civilian neonatal intensive care unit.

PATIENTS

Two infants (gestational ages of 38 and 35 wks), both of whom presented shortly after birth with severe septic shock presumed to be due to group B streptococcus.

INTERVENTIONS

Both infants were treated with high-frequency oscillatory ventilation and inhaled nitric oxide, with one infant requiring venoarterial extracorporeal membrane oxygenation.

RESULTS

Cultures of blood specimens from both infants yielded S. pneumoniae. For one infant, antibiotic sensitivity testing demonstrated resistance to penicillin, erythromycin, and trimethoprim/sulfamethoxazole. After treatment, both infants recovered well with normal results of examinations and neural imaging studies at the time of hospital discharge.

CONCLUSIONS

Clinicians should consider S. pneumoniae as a possible cause of fulminant nonresponsive sepsis in neonates. In areas where antimicrobial-resistant S. pneumoniae is prevalent, when culture results are known, or with a clinical course unresponsive to ampicillin, septic infants may require the addition of a penicillinase-resistant antibiotic to their therapeutic regimen until results of antibiotic sensitivity testing are known. Early transfer to a center with extracorporeal membrane oxygenation should be considered for symptomatic neonates.

Twenty year surveillance of invasive pneumococcal disease in Nottingham: serogroups responsible and implications for immunisation

AIMS

To evaluate the incidence, spectrum of clinical manifestations, and outcome of invasive pneumococcal disease (IPD) in children. To determine the major serogroups of Streptococcus pneumoniae responsible for invasive disease and the potential coverage by the new pneumococcal conjugate vaccines.

METHODS

Analysis of prospectively recorded information of all children admitted to two teaching hospitals in Nottingham with IPD between January 1980 and December 1999.

RESULTS

A total of 266 episodes of IPD in children were identified; 103 (39%) were aged <1 year and 160 (60%) <2 years. Major clinical presentations were meningitis in 86 (32%), pneumonia in 82 (31%), and bacteraemia without an obvious focus in 80 (30%). The age specific mean annual incidence rates of IPD overall among children aged <1, <2, and <5 years were 47.1, 37.8, and 20 per 100 000 population, respectively. Mortality rates for children with meningitis and non-meningitic infection were 20% and 7%, respectively. Neurological sequelae following meningitis were documented in 16 (26%) of the 61 survivors assessed. The potential coverage rates in children between the ages of 6 months and 5 years are 84% by the 7-valent, 91% by the 9-valent, and 95% by the 11-valent conjugate vaccines.

CONCLUSION

This study indicates that inclusion of a pneumococcal conjugate vaccine in the primary immunisation programme in the UK would have a considerable effect on the mortality and morbidity associated with IPD.

Vaccines in pregnancy: a review of their importance in Brazil

Neonates and young children remain susceptible to many serious infectious diseases preventable through vaccination. In general, current vaccines strategies to prevent infectious diseases are unable to induce protective levels of antibodies in the first 6 months of life. Women vaccinated during pregnancy are capable of producing immunoglobulin antibodies that are transported actively to the fetus, and maternal immunization can benefit both the mother and the child. With few exceptions, maternal immunization is not a routine, because of the concerns related to the safety of this intervention. Ethical and cultural issues make the studies on maternal immunization difficult; however, in the last decade, the development of new vaccines, which are very immunogenic and safe has reactivated the discussions on maternal immunization. In this paper we present a review of the literature about maternal immunization based on MEDLINE data (1990 to 2002). The most important conclusions are: 1) there is no evidence of risk to the fetus by immunizing pregnant women with toxoids, polysaccharide, polysaccharide conjugated and inactive viral vaccines; 2) most viral attenuated vaccines are probably safe too, but data is still insufficient to demonstrate their safety; therefore these vaccines should be avoided in pregnant women; 3) in Brazil, there is a need for a maternal immunization program against tetanus. Many new candidate vaccines for maternal immunization are available, but studies should be conducted to evaluate their safety and efficacy, as well as regional priorities based on epidemiological data.

Streptococcus pneumoniae infections in the neonate

OBJECTIVE

Streptococcus pneumoniae infections in the neonate (SPIN) are relatively unusual events (1%-11% of neonatal sepsis) but are associated with substantial morbidity and mortality. Previous reports suggest that invasive SPIN is associated with prolonged rupture of membranes, maternal colonization/illness, prematurity, early-onset pneumonia presentation (<72 hours), and high mortality (50%). The aim of this study was to review the current epidemiology and clinical course of SPIN.

METHODS

The US Pediatric Multicenter Pneumococcal Surveillance Group has been prospectively monitoring S pneumoniae infections since 1993 in 8 children's hospitals. For this report, data were gathered retrospectively from the charts of neonates who were 30 days of age and younger and had SPIN from September 1993 to February 2001. All pneumococcal isolates were sent to a central laboratory for serogrouping/typing and susceptibility testing.

RESULTS

Twenty-nine cases of SPIN were identified from a total of 4428 episodes of S pneumoniae infection in children. Sixty-six percent were male, and 55% were white; the mean age was 18.1 day (+/-8.2). Ninety percent of infants were >or=38 weeks' gestation. Two mothers had bacterial infections at delivery; 1 had S pneumoniae isolated from both blood and cervix, and 1 had clinical amnionitis. The primary diagnoses in the neonates were bacteremia (8), meningitis (8), bacteremic pneumonia (4), septic arthritis/osteomyelitis (1), and otitis media (8). Thirty percent of infants with invasive SPIN presented with leukopenia/neutropenia, but this did not predict poor outcome. The infecting pneumococcal serogroups were 19 (32%); 9 (18%); 3 and 18 (11% each); 1, 6, and 14 (7% each); and 5 and 12 (3.5% each). Twenty-six percent of invasive neonatal infections were caused by serogroups 1, 3, 5, and 12, which are not contained in the heptavalent pneumococcal vaccine. In contrast, 6% of invasive nonneonatal disease was caused by these same nonvaccine serogroups. Susceptibility testing demonstrated that 21.4% of isolates were penicillin nonsusceptible and 3.6% were ceftriaxone nonsusceptible. Three (14.3%) neonates with invasive SPIN died; all deaths occurred within 36 hours of presentation. Deaths did not appear to be related to pneumococcal serogroup or susceptibilities.

CONCLUSIONS

Compared with previous studies of neonates with pneumococcal infection, this series showed that infants with SPIN were usually 2 to 3 weeks of age at presentation; likely to be full term; and ill with pneumonia, meningitis, and otitis media. This late-onset presentation was associated with an overall mortality rate of 10.3% (14.3% for invasive disease).

Peripartum transmission of penicillin-resistant Streptococcus pneumoniae

Streptococcus pneumoniae is a rarely recognized cause of neonatal sepsis. We present a recent case of S. pneumoniae bacteremia acquired on the first day of life in a neonate born at 30 weeks of gestation to a mother without prenatal care who had prolonged rupture of the membranes and received intravenous ampicillin prior to delivery. The isolate was resistant to penicillin, with a MIC of the drug of 4 microg/ml. The child responded to a 7-day course of intravenous vancomycin. S. pneumoniae was recovered from the vagina of the mother on a swab culture collected prior to delivery, and isolates from mother and child were confirmed to be identical on the basis of pulsed-field gel electrophoresis. Although neonatal sepsis due to the peripartum transmission of S. pneumoniae is rare, this case highlights the concern that increasing efforts to prevent group B streptococcus neonatal disease may lead to an increase in neonatal infections due to resistant organisms.

Materno-foetal transfer of H. influenzae and pneumococcal antibodies is influenced by prematurity and low birth weight: implications for conjugate vaccine trials

The influence of prematurity and low birth weight (LBW) on transplacental transfer of Haemophilus influenza type B and Streptococcus pneumoniae antibodies was assessed in 213 mothers and their neonates from Gambia. Paired maternal and cord serum samples were tested for specific IgG antibody titres for H. influenza and S. pneumococcus antigens using enzyme linked immunosorbent assay. Prematurity and LBW was significantly associated with reduced placental antibody transfer for these antigens.The reduced materno-foetal transfer of these antibodies in this vulnerable population of babies may further predispose them to more bacterial infections. These findings are of practical importance to the vaccination strategies.

Peritoneal culture alters Streptococcus pneumoniae protein profiles and virulence properties

We have examined the properties of Streptococcus pneumoniae cultured in the murine peritoneal cavity and compared its virulence-associated characteristics to those of cultures grown in vitro. Analysis of mRNA levels for specific virulence factors demonstrated a 2.8-fold increase in ply expression and a 2.2-fold increase in capA3 expression during murine peritoneal culture (MPC). Two-dimensional gels and immunoblots using convalescent-phase patient sera and murine sera revealed distinct differences in protein production in vivo (MPC). MPC-grown pneumococci adhered to A549 epithelial cell lines at levels 10-fold greater than those cultured in vitro.