A state-wide information campaign during a pertussis epidemic in New South Wales, 2010.

Pertussis notifications increased dramatically in New South Wales in 2008, exceeding the rates in previous epidemic years. A state-wide, multi-faceted campaign was launched in March 2009 to provide information about pertussis prevention. A population-based survey was conducted using a Computer Assisted Telephone Interviewing facility to assess the effectiveness of sending letters to households with young infants. A representative sample of 1,200 adults across all 8 area health services was interviewed between July 2009 and September 2010, with responses weighted against the state population. Many respondents (39.7%) reported receiving the letter, while fewer (29.6%) reported receiving an adult pertussis booster in the last year, mostly in response to General Practitioner advice (40.4%). Letter receipt was associated with the uptake of an adult pertussis booster in the past 12 months by respondents (OR 5.8; 95%CI 4.1, 8.2) and other adults in the household (OR 5.1; 95%CI 3.5, 7.5), as well as knowledge about pertussis prevention. Health providers remain crucial for vaccination decision making; however letters may have contributed to an increased uptake of pertussis booster vaccination and knowledge. Health authorities may consider mailing households in future pertussis epidemics as a component of a wider communication strategy.

Case-control study of risk factors for hospitalization caused by pandemic (H1N1) 2009.

We conducted a case-control study to identify risk factors for hospitalization from pandemic (H1N1) 2009 virus infection among persons >16 years of age in Sydney, Australia. The study comprised 302 case-patients and 603 controls. In a logistic regression model, after adjusting for age and sex, risk factors for hospitalization were pregnancy (odds ratio [OR] 22.4, 95% confidence interval [CI] 9.2-54.5), immune suppression (OR 5.5, 95% CI 2.8-10.9), pre-existing lung disease (OR 6.6, 95% CI 3.8-11.6), asthma requiring regular preventive medication (OR 4.3, 95% CI 2.7-6.8), heart disease (OR 2.3, 95% CI 1.2-4.1), diabetes (OR 3.8, 95% CI 2.2-6.5), and current smoker (OR 2.0, 95% CI 1.3-3.2) or previously smoked (OR 2.0, 95% CI 1.3-3.0). Although obesity was not independently associated with hospitalization, it was associated with an increased risk of requiring mechanical ventilation. Public health messages should give greater emphasis on the risk for severe disease among pregnant women and smokers.

Staff immunisation: policy and practice in child care.

AIM: The aims of this study were to determine the level of knowledge among child-care centre directors regarding the National Health and Medical Research Council (NHMRC) recommendations for the immunisation of child-care workers, the extent to which this knowledge was translated into practice and any organisational barriers to the development and implementation of staff immunisation policy. METHODS: A cross-sectional survey, conducted in August 2006, in which a postal questionnaire was sent to a random sample of 784 NSW child-care centres. Centre directors were asked to complete the questionnaire on immunisation knowledge, policy and practice for the centre. A multivariate logistic-regression model was used to identify factors independently associated with centres with an immunisation policy for staff and centres that offered to pay all or part of the cost of vaccination of staff. RESULTS: Directors from 437 centres participated in the study for a response rate of 56%. Of these, 49% were aware of the NHMRC recommendations, and 57% had a staff immunisation policy in place. In the logistic regression model, centres with a written immunisation policy for staff were more likely to be aware of the NHMRC guidelines and offer long day care services. Centres that offered to pay all or part of the cost of immunisation for staff were more likely to be aware of the NHMRC guidelines, offer other child-care services and not operate for profit. Barriers to staff immunisation were related to the implementation of policy and included cost, time and access to information. CONCLUSIONS: The level of awareness of specific staff immunisation recommendations was relatively low. The transition of knowledge to policy was encouraging, although implementation of policies requires further commitment.

NSW Annual Vaccine-Preventable Disease Report, 2009.

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.

Review of the 2008-2009 pertussis epidemic in NSW: notifications and hospitalisations.

In 2008 and 2009 increased numbers of pertussis notifications were reported in NSW. During the epidemic period, the pertussis notification rate was 2.7 times higher than the previous 5-year average. Rates of pertussis notifications and hospitalisations were highest among infants aged less than 1 year across all years studied. Compared to previous years, the notification rate for children aged 1-4 years increased dramatically and was particularly striking for children aged 3 years with notifications exceeding those for infants in 2009. Changes in testing practices during the epidemic period, including a significant increase in the use of polymerase chain reaction, may account for some of the relative increase in size of the 2008-2009 outbreak compared with previous outbreak years.

Pandemic (H1N1) 2009 influenza in NSW: an overview of the public health response.

In April 2009, a new influenza A virus, pandemic (H1N1) 2009 influenza, was identified in Mexico and the United States of America. The NSW response was co-ordinated by the Public Health Emergency Operations Centre through an incident control structure that included planning, operations and logistics teams with designated roles and responsibilities for the public health response. The emphasis of public health action changed as the pandemic moved through three response phases: DELAY, CONTAIN and PROTECT. This article describes the NSW public health response to the 2009 influenza pandemic from the perspective of the NSW Department of Health.

Investigation of equine influenza transmission in NSW: walk, wind or wing?

OBJECTIVES: An outbreak of equine influenza occurred in New South Wales in 2007. In addition to the local spread of the disease between bordering properties, windborne spread over several kilometres had been postulated as a possible method of transmission in this outbreak. This study aimed to describe potential modes of transmission for a property infected with equine influenza where no apparent epidemiological links to other infected properties were reported. METHODS: A semi-structured questionnaire was administered to owners of affected properties. The questionnaire collected detailed transmission-risk information, including personnel movements, equipment sharing, and horse and other animal movements. RESULTS: Interviews with property owners from one geographic area suggested the potential for birds and other animals - rather than wind - to facilitate transmission of equine influenza. CONCLUSION: This study described the potential for mechanical spread of equine influenza. Further research, including laboratory testing of bird plumage following contact with infected horses, may be useful to confirm the possibility of avian fomite transmission.

Gonorrhoea enhanced surveillance for indigenous status and risk factors in the south-eastern Sydney population

Background: Gonorrhoea incidence is increasing in the Australian population. As a laboratory notifiable disease in NSW, information is not routinely available on indigenous status, sexual preference or other risk factors for infection. We conducted a 12-month pilot of enhanced surveillance in south-eastern Sydney in order to assess the feasibility of gathering this additional information. Methods: For each notification in a south-eastern Sydney resident with a 2013 specimen date, we sent a letter and questionnaire to the requesting doctor seeking additional demographic and risk factor information. Results: Of 1,341 questionnaires sent, 1,073 (79.5%) were returned, and men comprised 947 (88.3%). Indigenous status was provided for 1,009 (94.1%) cases, with seven (0.7%) identified as Aboriginal or Torres Strait Islander. Most men (83%) but a minority of women (19%) had same sex partners (p<0.001). Whilst 70% of men reported acquisition from a casual partner, only 46% of women thought they had acquired infection from a casual partner. Conclusions: The high response rate and completeness of indigenous status were strong features of this enhanced surveillance pilot which also provided valuable information on sexual preference and other risk factors for infection. However, gathering of this information was very labour intensive for both clinical and public health staff.

Parental Tdap boosters and infant pertussis: a case-control study.

BACKGROUND: Although recommended for almost a decade, evidence for field effectiveness of vaccinating close adult contacts of newborn infants against pertussis ("cocooning") is lacking. We evaluated the impact of a government-funded cocoon program during a pertussis epidemic in New South Wales, Australia. METHODS: We matched all New South Wales laboratory-confirmed pertussis cases aged <4 months with onset between April 1, 2009, to March 30, 2011 to controls from the state birth register by date of birth and area of residence. Parental vaccine receipt was by self-report, with a subset verified. Parents were considered "immunized" if vaccinated ≥4 weeks before case symptom onset. The effectiveness of parental immunization (versus neither vaccinated) was quantified as (1 - odds ratio) × 100%. RESULTS: Case households had fewer immunized mothers (22% vs 32%) or fathers (20% vs 31%) but were more likely to include additional and older children. After adjustment, when both parents met our definition of immunized, risk of pertussis at<4 months of age was reduced by 51% (95% confidence interval 10% to 73%). Maternal vaccination prepregnancy and an immunized father reduced the risk by 51% (95% confidence interval 0% to 76%). CONCLUSIONS: Timely parental pertussis boosters provided significant protection. Evidence of protection from maternal vaccination prepregnancy is biologically plausible, and more precise data on the magnitude and duration of this is important for future policy recommendations.

NSW Annual vaccine-preventable disease report, 2011.

AIM: To describe the epidemiology of selected vaccine-preventable diseases in NSW for 2011. METHODS: Data from the NSW Notifiable Conditions Information Management System were analysed by: local health district of residence, age, Aboriginality, vaccination status, and organism, where available. Risk factor and vaccination status data were collected by public health units for case-patients following notification under the NSW Public Health Act 1991*. RESULTS: Outbreaks of measles and pertussis were reported in 2011, associated with unimmunised groups for measles, and a variety of factors for pertussis. Notification rates for other selected vaccine-preventable diseases remained stable. CONCLUSION: Vaccine-preventable diseases are generally well controlled in NSW. However, pertussis remains an important public health issue. To prevent measles high population vaccination coverage, including vaccination in risk groups, is essential.

EpiReview: Measles in NSW, 2002-2011.

Measles has been eliminated in NSW for more than a decade; however outbreaks associated with international travel do occur. This EpiReview describes the epidemiology of measles in NSW from 2002-2011. A total of 281 cases of measles were notified during the period, an average annual notification rate of 0.41 notifications per 100 000 population (range: 0.06-1.25). There were 139 hospitalisations recorded with a measles diagnosis in the 10-year reporting period, corresponding to a rate of 0.20 hospitalisations per 100 000 population. Of the 80 measles virus specimens genotyped, five genotypes were identified: D9 (38%), D8 (24%), D4 (16%), D5 (14%) with H1 identified less frequently (9%). No single genotype was associated with local transmission across successive years. To sustain good measles control, children should be vaccinated against measles on time through routine childhood immunisation, and all young adults who travel internationally should be vaccinated. Clinician awareness remains important in the early identification and control of measles to avoid further transmission during outbreaks and to enable the timely implementation of public health measures.

NSW annual vaccine-preventable disease report, 2010.

AIMS: To describe trends in case notification data for vaccine-preventable diseases in NSW for 2010. METHODS: Risk factor and vaccination status data were collected from cases through public health unit follow-up. Data from the NSW Notifiable Conditions Information Management System (NCIMS) were analysed by: local health district of residence; age; vaccination status; and sub-organism, where available. RESULTS: Outbreaks of measles and pertussis were notified in 2010, associated with unimmunised groups (measles) or as a result of waning immunity (pertussis). CONCLUSION: With the exception of pertussis, most vaccine-preventable disease notifications remain low in NSW. Ensuring high levels of vaccination for travellers is important to prevent future outbreaks of vaccine-preventable disease, particularly measles.