Bacteraemic Streptococcus pyogenes infection in the peri-partum period: now a rare disease and prior carriage by the patient may be important.

Objectives: To describe the features of invasive peri-partum Streptococcus pyogenes infection as it occurs in current day practice in North Yorkshire.

Methods: The case and laboratory records of all mothers and/or babies with detected S. pyogenes bacteraemia in the Harrogate and Northallerton districts of North Yorkshire (combined catchment population 260 000) were reviewed for the 20 years 1980-99. An additional bacteraemic case occurring recently in the York district was included.

Results: In six recorded episodes, both mother and baby were affected in three, mother only in two and baby only in one. The incidence of detected infection was one such episode per million population per year, one episode per 11 000 live births and one infected baby per 18 000 live births. Maternal features included endometritis, septicaemia, peritonitis, necrotising fasciitis and toxic shock syndrome while, in babies, infection was manifest by stillbirth or septicaemia, cyanosis, jaundice, lethargy and cellulitis.

Conclusion: Peri-partum S. pyogenes infection is rare in North Yorkshire, with a local incidence revealed in this study of 1/million population/year, or 1:11 000 live births. Invasive neonatal infection with S. pyogenes appears to be six times less frequent in this locality than with group B streptococci. Mothers and/or their babies can be affected. Data suggests that some infection is autogenous from streptococci carried in the mother's genital tract. Although data in this setting are currently few, when a mother has suspected invasive group A streptococcal infection we recommend that the newborn child should also receive antibiotics without delay.