Case of the Month - April 2012

A 23 year old HIV-seronegative mother (G2 P2 -1), gave birth to monochorionic, diamniotic twin infants.

The mother had a history of miscarriage at 23 weeks (unknown cause). She was HIV seronegative. She had booked late and was 24 weeks by late ultrasound. The twin pregnancy was treated as an inevitable miscarriage when she went into preterm labour. The mother did not receive intrapartum antibiotics and there was no fetal monitoring.

Twin A was born with Apgars of 8,9 and 9. No resuscitation was necessary. Birth weight was 700g. Liquor was clear. She was assessed as being 27 weeks according to Ballard score and commenced on CPAP. No surfactant was given. Penicillin and gentamicin were commenced according to the protocol for preterm infants. Initial blood tests revealed:

WCC = 5.18 x 109/L; Hb = 15.1 g/dl; plt = 266 x 109/L
C- reactive protein (CRP) = 12 on day 1 and repeat after 12 hours was < 4.
Blood culture was negative after 5 days - Antibiotics were stopped after 3 days.

On day 20 she received ibuprofen to close a patent ductus arteriosus.

On day 22 (gestational age 30 weeks and 1 day) she developed recurrent apnoea.

WCC= 4.27 x 109/L
Neutrophils were 12% with absolute count of 0.51 per mm3
Hb = 11.6 g/dl, nucleated RBCs 18 x 109/L
Plt = 436 x 109 /L
CRP was 114.

She was started on meropenem and vancomycin but was too unstable for lumbar puncture.

Within 6 hours the blood culture grew Gram positive cocci in chains, sensitive to penicillin, ampicillin and erythromycin.

Twin A demised on day 24.

X ray of Twin A

Twin B had Apgar scores of 3, 5 and 8. Birth weight was 820g.
She was estimated to be 29 weeks by Ballard score.
After initial resuscitation she was started on CPAP.

First 2 weeks of life were uneventful. She also received penicillin and gentamicin for the first 3 days. These were stopped after CRP was < 4 and initial blood culture was negative.

On day 17 Twin B started to desaturate.

WCC = 13.8 x 10 9/L
Hb = 13.8 g/dl; platelets =323 x 109/L.
CRP was < 4

Meropenem was started, but stopped after 4 days when the blood culture came back negative.

3 days later a repeat crp was < 4.

On day 25 Twin B developed persistent tachycardia. Penicillin was started. This was just after Twin A had demised.

Penicillin stopped after 2 days as the infant was asymptomatic, CRP was < 4 and blood culture was negative.

On day 33 Twin B again developed desaturations and was admitted to NICU.

WCC= 3.6 x 109/L, neutrophil count = 64%
Hb = 9.2g/dl; Plt = 300 x 109 /L
Blood culture grew Gram positive cocci in chains after 9 hours sensitive to penicillin, ampicillin and erythromycin.
Lumbar puncture : CSF was yellow. P=0; L = 5; RBC= 0. No growth.

Twin B was treated for 14 days with Penicillin. On day 51 Twin B deteriorated again (5 days after stopping penicillin) and was started on meropenem and vancomycin. Blood culture again grew Gram positive cocci in chains sensitive to penicillin, ampicillin and erythromycin. The culture was positive within 4.5 hours suggesting a high bacterial load.

Additional investigations and information: Maternal breast milk was sent twice for culture and was negative. Maternal and Twin B throat swabs were negative for group B streptococcus Mother did not have mastitis.

Xray of Twin B

Both infants had Group B Streptococcus on blood culture.

Question 1: What are the different clinical presentations of Group B Streptococcal infection in infants?

Continue to Answer 1