Highlights included:

• a slight increase in Haemophilus influenzae type b (Hib) notifications compared to the previous three years, with a number of cases in older, vaccinated children, and adults
• an increase in invasive meningococcal disease (IMD) –with a total of 91 cases notified. This follows increases in 2015 (n=71) and 2016 (n=44), largely driven by increased cases caused by serogroup W. Serogroup B continued to be the predominant strain in NSW (n= 43), followed by cases of serogroup W (n=19) and serogroup y (n= 16). Cases caused by serogroup C continue to be rare in NSW (n=5) following introduction of meningococcal C vaccine at 12 months of age on the National Immunisation Schedule in 2003.
• an increase in invasive pneumococcal disease, with 694 cases notified, an increase from the previous year (543). Children under five years accounted for 86 notifications of IPD up from 63 notifications in 2016. The severe influenza season experienced by NSW may have had a direct impact on the number of notifications as pneumococcal pneumonia is often a secondary complication of influenza infection
• thirty cases of measles, an increase compared to 2016 (n=18), resulting in several small outbreaks associated with importations from overseas. All but one importation was from countries in South East and South Asia. The majority of cases were unvaccinated (70%), with four cases (13%) in children too young to have received their first dose under the National Immunisation Schedule
• twice as many mumps cases (n=127) compared to 2016 (n= 67). While the infection remains uncommon in NSW, periodic increases in notifications are occurring every four to five years. Eighty two per cent of cases occurred in individuals 15 years and older, with 18% of cases reported as fully vaccinated for age
• a steady decline in pertussis (whooping cough) notifications to 5274 cases, with 82% of these occurring in persons over 5 years old. Of the 942 cases reported in children less than 5 years of age, 80% were fully vaccinated for age. NSW Health continued to offer free pertussis vaccine to all pregnant women, preferably at 28 weeks gestation, to reduce the risk of pertussis in the early weeks of life
• a single case of tetanus, in an unvaccinated child aged between 5 and 9 years.​