TheNSW Immunisation Strategy 2008–2011: how are we doing?

Abstract

Aims: To describe trends in case notification data for vaccine-preventable diseases in NSW for 2009. Methods: Risk factor and vaccination status data was collected from cases through public health unit follow-up. Data from the NSW Notifiable Diseases Database were analysed by: area health service of residence; age; vaccination status; and sub-organism, as appropriate for the period 1991–2009. Results: The incidence of vaccine-preventable disease has declined over time. Outbreaks of measles and pertussis occur in the community, associated with unimmunised groups (measles) or as a result of waning immunity (pertussis). Conclusion: Regular reporting of vaccine-preventable disease surveillance data will help inform control strategies in NSW. This is the first in what is planned to be a series of annual reports on vaccine-preventable disease surveillance in New South Wales (NSW). The objectives of vaccinepreventable disease surveillance are to: detect and investigate outbreaks of vaccine-preventable disease; identify close contacts of patients who may be at risk of infection; identify cases of possible vaccine failure; and understand the epidemiology of vaccine-preventable disease (including the impact of immunisation) to inform the development of prevention strategies. Cases of vaccine-preventable diseasewere defined according to national criteria. Under the NSW Public Health Act 1991, since 1991:medical practitioners have been required to notify patients diagnosed with measles and pertussis; laboratories have been required to notify patients diagnosed with measles, pertussis, rubella, Haemophilus influenzae type b, meningococcal disease, mumps and rubella; and hospital general managers have been required to notify patients diagnosed with measles, pertussis, invasive pneumococcal infections (since 2002),Haemophilus influenzae type b and meningococcal disease, to NSW Health (via public health units). Notifications of Haemophilus influenzae type b, measles, meningococcal disease, pertussis, pneumococcal disease (people aged less than 5 years and 50 years and over) and tetanus prompt public health follow-up according to NSW case definitions and response protocols. Notifications of mumps and rubella are not routinely followed-up by public health units in NSW. Public health unit staff enter data gathered on notified cases into the statewide Notifiable Diseases Database. This report describes trends in surveillance data for vaccine-preventable diseases in NSW. Method Notification data from the NSWNotifiable Diseases Database were reviewed for cases of vaccine-preventable diseases with a date of onset from 1991 to 2009. All rates were calculated using Australian Bureau of Statistics population estimates for the relevant year. Rates are presented as annual rates per 100 000 total population or population in age groups. Risk factor and vaccination status data was collected from cases through public health unit follow-up. In NSW, laboratories provide serotype data for measles, meningococcal and pneumococcal disease. Cases were analysed by place of usual residence according to geographical regions served by the relevant area health service public health unit. Results Haemophilus influenzae serotype b Haemophilus influenzae serotype b (Hib) is a bacillus which may be part of the flora of the upper respiratory tract. The bacteria are spread through contact with droplets from the nose or throat of an infected person, in householdlike settings. Infection can result in invasive disease including meningitis, epiglottitis, septic arthritis, cellulitis and pneumonia. Since 1993, vaccination against Hib has been available and is provided for infants at 2, 4, 6 and 12 months of age. Summary of notified cases The number of notified cases of Hib has decreased significantly in NSWsince the introduction of a vaccine, from 124 in 1993 to six in 2009 (Figure 1). In 2009 two cases were aged less than 12 months, one case was aged 14 years and the remaining cases were aged between 40 and 65 years. Two cases were female and four were male. There were no notified cases of Hib in Aboriginal people in 2009. 10.1071/NB10047 Vol. 21(9–10) 2010 NSW Public Health Bulletin | 197