A 4-week-old Caucasian girl presented to her local accident and emergency department with a one-day history of difficulty breathing. She had been born at 37 weeks gestation by spontaneous vaginal delivery. The pregnancy had been complicated by mild intrauterine growth restriction (weight on the 2nd centile) and maternal genital chlamydia infection at 18 weeks gestation, which had been treated with erythromycin. The delivery was uneventful but she developed respiratory distress at 24 h of age and was admitted to the neonatal unit. The results of investigations undertaken during the early neonatal period are shown in table 1. She was treated with intravenous penicillin and gentamicin for presumed pneumonia, although no organism was isolated. She improved and was discharged from hospital aged 2 weeks. On examination in the A&E the following were noted:

• Temperature 37.5°C

• Pallor

• Respiratory distress

• Oxygen saturation of 88% in air

• Right basal crepitations

• No dysmorphic features

• Weight and head circumference on the 2nd centile.

The chest x ray is shown in figure 1 and the results of blood tests in table 2.

The admitting registrar thought the chest x ray showed right middle and lower lobe pneumonia. In view of the history of maternal genital chlamydia infection, chlamydia pneumonia formed part of the differential diagnosis. Chlamydia IgG and IgM, as well as eye swabs for Chlamydia PCR were therefore sent. As the diagnosis of Chlamydia pneumonia was less likely than typical pneumonia given the full course of treatment her mother had received during pregnancy, she was started on intravenous cefotaxime and gentamicin. Supplementary oxygen was given via a nasal cannula.

COMMENT

• Neonatal chlamydia infection is contracted during parturition. Up to 70% of infants born to mothers with genital chlamydia infection are infected.1

• Conjunctival mucosa is the most commonly infected area, causing ophthalmia neonatorum. This usually …