Case 1: A neonatal zoonosis

CASE A 20-year-old primigravida, who was in the 39th week of gestation, was admitted to the maternity ward in labour. She had been well throughout pregnancy and her antenatal foetal ultrasound scans had shown a normal developing foetus. The amniotic membranes ruptured spontaneously and the liquor was clear. However 15 h following membrane rupture she was still in the first stage of labour. She had developed a fever of 38◦C and the liquor was noted to have become foul smelling. The cardiotocogram did not reveal any signs of foetal distress. In view of evidence of chorioamnionitis she was started on intravenous co-amoxiclav, and was taken urgently to the operating theatre where a female neonate was delivered by an emergency Caesarean section. At birth the newborn was floppy and pale, and needed bag and mask ventilation with oxygen for a few minutes due to a poor respiratory effort. Apgar scores were 7, 8 and 9 at 1, 5 and 10 min, respectively. Following resuscitation she was noted to be tachypnoeic and hypotonic, and was transferred to intensive care. She weighed 3.56 kg (P50th) and her occipitofrontal circumference measured 36 cm (P90th). Her core temperature was 37.5◦C. Blood investigations, including blood cultures, were taken from a peripheral vein at 1 h of age; however, no antibiotics were initiated. Her full blood count showed a total white cell count of 35.6 × 109/l, a neutrophil count of 23 × 109/l, a haemoglobin concentration of 12.3 g/dl with a haematocrit of 36.2% and a platelet count of 301 × 109/l. Her acid base balance and renal function were within normal limits. She required oxygen supplementation via nasal prongs and was given nasogastric feeds. Due to recurrent vomiting and irritability on handling, a chest X-ray and lumbar puncture were performed at 18 h of age. Blood-stained cerebrospinal fluid (CSF) was obtained from the traumatic spinal tap. Biochemical and cytological analyses could not be performed on the small volume of CSF; however, there was sufficient amount that could be sent for culture. Following the lumbar puncture she was started on intravenous co-amoxiclav (30 mg/kg twice daily) and cefotaxime (50 mg/kg twice daily), according to the unit’s standard protocol for treatment of ill newborns with a history of chorioamnionitis at birth, and was supported with intravenous fluids. Her chest X-ray showed clear lung fields with a small right basal pneumothorax, which was treated conservatively. She did not sustain a rise in her Creactive protein taken at 1 h of age and 24 h later. No organisms were cultured from the CSF. However, on the fifth day Gram-negative coccobacilli were isolated from her blood cultures. At this time she was off oxygen and feeding orally, with no further signs of sepsis or cardiorespiratory compromise. Identification of the microorganism isolated from this neonate’s blood was surprising as it is usually found as an oral commensal in cats and dogs. A careful reassessment of the maternal history revealed that two weeks prior to the delivery she had taken care of a puppy for a couple of days. She was not bitten by the dog but was licked several times on the hands. What is the diagnosis?