Obstetric and Neonatal Invasive Meningococcal Disease Caused by Neisseria meningitidis Serogroup W, Western Australia, Australia

Three mother-baby pairs with invasive meningococcal disease occurred over 7 months in Western Australia, Australia, at a time when serogroup W sequence type 11 clonal complex was the predominant local strain. One mother and 2 neonates died, highlighting the role of this strain as a cause of obstetric and early neonatal death.