Streptococcus pneumoniae (pneumococcus) is a microorganism with high morbidity in children, especially when related with the respiratory tract (in the form of pneumonia) and as a focus of infection in the otorhinolaryngological region (otitis). The most severe complication of pneumococcal infection is invasive pneumococcal disease, be it either as sepsis or meningitis. In the neonatal period, these forms of presentation of pneumococcal infection (pneumonia, sepsis or meningitis) are relatively infrequent but they are related with high morbidity and mortality.

In the neonatal period, pneumococcal sepsis may have an early or late onset. The transmission of the germ in these cases is not clear, and 2 possible forms are described: vertical by vaginal colonization of pneumococcus, and horizontal due to local infections or infections by non-vaccine serogroups.

We present a case of early neonatal infection due to vertical transmission of S. pneumoniae.

The patient is a 2-day-old newborn who had been born at full term and with proper birth weight. There was no obstetrical history of interest (water had broken spontaneously and less than 8h before the birth, vaginal–rectal exudate culture for Streptococcus agalactiae [SGB] was negative, previous infection by toxoplasmosis, negative HBV, past rubella infection) who was brought to our neonatal unit due to continuous loud crying, irritability, and whining.

On physical examination, we observed: poor general state, apparent illness, continuous crying. Lung auscultation revealed: overall hypoventilation with disperse rhonchus. Constant wheezing that was audible without a stethoscope. Cardiac auscultation was normal. The examination of other organs showed no significant findings.

During the first few hours after admittance, the patient presented a declining general condition, with tachypnea, increased whine, and fever of 38.6°C.

Hemogram showed 6800 leukocytes per microliter with left shift (1% metamyelocytes and 6% rod neutrophils) and an infection rate of 0.2. The white, red, and platelet series were normal. Coagulation was normal. Blood biochemistry was normal: sodium 129meq/L, C-reactive protein 384mg/L, and procalcitonin 0.22ng/ml. Cerebrospinal fluid (CSF) showed normal cytochemistry. Urine testing was negative. In addition, blood, CSF, and urine sample were taken for culture.

Chest radiography showed: bilateral interstitial infiltrate with less aeration of the right lung and an image of right retrocardiac alveolar infiltrates.

Empirical intravenous antibiotic treatment was initiated with ampicillin and gentamycin, antipyretics, and plasma therapy.

On the third day, the culture results came back negative both in the urine and CSF, while the blood culture was positive for S. pneumonia. The antibiotic treatment was changed to cefotaxime, according to the antibiogram.

After the blood culture results and as the setting was not epidemiologically compatible, the vaginal culture of the mother was repeated, which came back positive for S. pneumoniae 5 days later.

The baby was discharged from the hospital 15 days later after completing antibiotic treatment, with a normal physical examination and diagnosis of early-onset neonatal sepsis due to S. pneumoniae.

Currently, according to the study by the Grupo de Hospitales Castrillo, SGB is the etiological agent that most frequently causes sepsis by vertical transmission (33.3%), followed by Escherichia coli (32.3%) and Listeria monocytogenes (7.1%), but the incidence of S. pneumoniae is not registered because it is low.1 Studies in the United States estimate an incidence of 1%–10% of all neonatal sepsis.2

S. pneumoniae is not part of the usual vaginal flora, and the incidence of its colonization in pregnant women is exceptional (0.03%–0.75% of cases).3 Strategies for the prevention and treatment of SGB are also effective for infections caused by S. pneumoniae.

In Spain, there are 16 published cases of neonatal pneumococcal disease4–6: 14 with early-onset4–6 and 2 with late-onset.6 Our case was of the early disease type.

The administration of heptavalent pneumococcal vaccines over recent years, and most recently the 10- and 13-valent types (including the 7F, 3, and 6A serotypes, which are an important cause of invasive pneumococcal disease worldwide), has reduced the transmission of diseases due to pneumococcus in the general population (from 50–100 to 9 cases for every 100000 people) and, consequently, the incidence of neonatal invasive pneumococcal disease has decreased.

Vaccination during the third trimester of gestation could be a measure to follow in the future, although there are no conclusive studies that currently confirm this.1