Streptococcus pneumoniae: the forgotten microorganism in neonatal sepsis

Early-Onset Neonatal Pneumococcal Sepsis: An Old but Sometimes Forgotten Pathogen

Streptococcus pneumoniae (SP) is an uncommon but potentially serious neonatal pathogen. SP is perceived as a significant cause of mortality and morbidity in infancy; however, there are relatively few cases of neonatal sepsis recorded, with an incidence between 1% and 11%. We aim to report the spectrum of morbidity associated with SP infections in the neonatal period.

Two cases of neonatal SP infection are reported. The first neonate presented with a very early onset of severe clinical disease with bacteremia and pneumonia. She developed severe pulmonary hypertension and needed intensive ventilatory support, including nitric oxide, and vasoactive drugs. An SP serotype 23B was isolated from blood cultures and bronchial secretions as well as from the mother’s vaginal secretions. In the second case, the baby presented with bacteremia and meningitis. He remained hemodynamically stable and did not need respiratory support. Blood and cerebrospinal fluid cultures revealed an SP serotype 8. In both cases, the neonates were treated with vancomycin and cefotaxime. Both mothers remained well and asymptomatic during the perinatal period.

These reported cases emphasize the importance of considering a wide range of microorganisms in the differential diagnosis of early-onset neonatal sepsis. Although uncommon, SP can have different clinical manifestations and cause significant diseases in newborns. Specific preventive measures against early-onset sepsis for this pathogen are yet to be implemented due to the absence of sufficient scientific evidence. For this reason, prompt and aggressive treatment remains the best therapeutic approach.

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.

Early neonatal sepsis: prevalence, complications and outcomes in newborns with 35 weeks of gestational age or more

Objective:

To analyze the incidence, complications, and hospital discharge status in newborns with ≥35 weeks of gestational age with early neonatal sepsis.

Methods:

This is a cross-sectional, retrospective study. Cases of early-onset sepsis registered from January 2016 to December 2019 in neonates with gestational age of 35 weeks or more were reviewed in a level III neonatal unit. The diagnoses were performed based on the criteria by the Brazilian Health Regulatory Agency (Anvisa), and the episodes were classified according to microbiological classification and site of infection. The following complications were evaluated: shock, coagulation disorders, and sequelae of the central nervous system. The conditions at hospital discharge were also assessed. The collected data were analyzed with the descriptive analysis.

Results:

In the period, early neonatal sepsis occurred in 46 newborns, corresponding to 1.8% of all newborns admitted to the neonatal unit, with a prevalence of 4/1,000 live births. Culture confirmed sepsis ocurred in three patients (0.3/1,000 live births), with the following agents: S. pneumoniae, S. epidermidis and S. agalactiae. As to site of infection, there were 35 cases of primary bloodstream infection, seven cases of pneumonia and four cases of meningitis. Most patients (78.3%) had at least one risk factor for sepsis, and all were symptomatic at admission. There were no deaths. Complications occurred in 28.2% of the cases, especially shock (10 cases – 21.7%).

Conclusions:

The prevalence of proven early neonatal sepsis was low. Despite the common occurrence of complications, there were no deaths.

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.