Pyogenic intraventricular empyema owing to Veillonella parvula in a preterm infant

Anaerobic organisms are an exceptional cause of meningitis in preterm infants.¹Veillonella parvula (V. parvula) is part of the normal flora of the pharynx, gastrointestinal tract, and female genital tract.² 20% of newborns are colonised by V. parvula at 4 weeks of life.³ Meningitis due to V. parvula is exceptional⁴ and only one case has been reported in infants. This was in a 6-week-old boy with a sacral dimple with tethered spinal cord.⁵ We present the first case of primary pyogenic intraventricular empyema caused by V. parvula in a preterm infant.

Male infant born at 29 weeks gestation weighing 1350 g. Born from a fifth pregnancy (3 prior abortions), monitored, with breakthrough bleeding in the first trimester. No urinary or vaginal infection symptoms reported. Normal delivery at 29 weeks. Apgar 8/9. At 36 h of life, the infant had hypovolemic shock secondary to bilateral grade III intraventricular haemorrhage and right frontoparietal periventricular haemorrhagic infarction that evolved into posthaemorrhagic ventriculomegaly, which was treated with serial lumbar punctures. At 19 days of life, he had septic symptoms with poor tolerance of food and abdominal distension, isolating Staph in a haemoculture. Staphylococcus haemolyticus being treated with meropenem. At 41 days of life he was transferred to our Neonatal Intensive Care Unit presenting intermittent fever, tense fontanelle of 4 × 4 cm, a head perimeter of 36 cm that increased 1.5 cm every 2 days and abdominal distension. In the neuroimaging tests (transfontanellar cerebral ultrasound and cerebral MRI) an increase in the size of the ventricular system was observed, more marked in the right ventricle which presented internal material that behaved as hyperintense on the weighted image in diffusion and hypointense on the apparent diffusion coefficient map, and behaved as a mass on the left hemisphere displacing the midline. External drainage was placed in the frontal horn of the right lateral ventricle from which yellowish-green fluid exuded (leukocytes 73,700/microl, PMN 61%, mononuclear 39%, red blood cells 136,000/microl, proteins 1950 mg/dl, glucose 0 mg/dl). No growth was observed in CSF cultures for aerobic bacteria and fungi, but V. parvula T X84005 was identified in 2 CSF samples by means of amplifying and sequencing a fragment of approximately 1500 base pairs of the rRNA gene 16S in 2 CSF samples, using the primers fD1 (5′-AGAGTTTGATCCTGGCTCAG-3′) and rP2 (5′-ACGGCTACCTTGTTACGACTT-3′). The sequences generated were compared with the existing ones in the GenBank database, using the software BIBI (http://pbil.univ-lyon1.fr/bibi), obtaining a similarity of 99.5% with the V. parvula T X84005 sequence. Metronidazole was added for 8 weeks to the meropenem treatment, which had been started at the hospital of origin. In the cerebral MRI prior to discharge, normalisation of the right ventricular system was observed with large cystic encephalomalacia of the ipsilateral cerebral hemisphere.

V. parvula infections are very rare in children. Only rarely do they produce infections of the central nervous system and, to date, had not been reported as a cause of intraventricular infection in preterm infants.

In some of the cases of central nervous system infection due to other anaerobic germs described in newborns, the suspected entry point has been bacteraemia after a necrotising enterocolitis.⁶ In our case, it is likely that the source of the infection was also intestinal after the likely symptoms of necrotising enterocolitis that he had at 19 days of life; although it cannot be ruled out that the bacteraemia had been transmitted vertically from the colonisation of the mother's genital tract or iatrogenically via the lumbar punctures conducted to control the post-haemorrhagic ventriculomegaly.

Based on its rarity, there are no recommendations for the treatment of primary anaerobic intraventricular empyema. Based on the cases reported in adults, CSF drainage was conducted⁷ and treatment with metronidazole and meropenem was administered.⁸

This case illustrates the importance of obtaining aerobic and anaerobic cultures from CSF in cases of premature infants with central nervous system infection, especially if there is a history of necrotising enterocolitis, and emphasises the usefulness of molecular identification methods in infections caused by bacteria which are difficult to culture.