An outbreak of Salmonella typhimurium 108/170 at a privately catered barbeque at a Sydney sports club.

An outbreak of gastrointestinal illness was identified among attendees at a large community barbeque at a Sydney sports club on 30 January 2009. A retrospective cohort study was initiated, and attendees were identified through hospital emergency department gastroenteritis presentations, snowball recruitment through known cases, responders to linguistically specific press, and those returning to the venue the next week. A symptom and food history was collected from attendees, and stool samples were provided for microbiological investigation. An environmental investigation and trace back of implicated foods was also undertaken. Attendance estimates at the barbeque ranged from 100 to 180, and the food was prepared by a family that was not registered as a food business. Seventy one of the 87 attendees identified met the case definition. Thirty attendees (42%) had laboratory confirmed Salmonella Typhimurium phage-type 108/170, all with the same multilocus variable number of tandem repeat analysis typing. Burden of illness was high with 76% of cases seeking medical attention and 18% admitted to hospital. Microbiological evidence confirmed that a number of food items were contaminated with Salmonella Typhimurium 108/170, with the raw egg mayonnaise used in a Russian salad being the most likely primary food vehicle (adjusted odds ratio=10.3 [95% confidence interval 1.79-59.5]). Further, having Russian salad on the plate even if it was not consumed increased the relative risk of illness, thus suggesting that other food items may have been contaminated when they came into contact with it on the plate. This Salmonella outbreak highlighted the risks associated with the improper handling of food in private residences, which are then sold at a large public event.

Risk factors and seroprevalence of markers for hepatitis A, B and C in persons subject to homelessness in inner Sydney.

OBJECTIVE: To determine the seroprevalence of hepatitis A, B and C and the prevalence of risk factors for blood-borne infections in persons subject to homelessness attending a medical clinic in inner Sydney. METHOD: During 2003-05, 201 clients were enrolled in a prospective study to determine the acceptance, completion rates and immunogenicity of the standard vaccination schedule for hepatitis A and B. On enrolment, clients completed a risk factor assessment questionnaire and undertook pre-vaccination serological screening for hepatitis A, B and C. RESULTS: Forty-five per cent (85/188) of clients were positive for anti-HCV antibodies; 32% (60/189) showed evidence of past infection with HBV (anti-HBc); and 48% (89/189) were positive for anti-HAV antibodies. It was not uncommon for clients to have multiple markers of hepatitis. A past history of injecting drug use was significantly associated with markers for hepatitis B and C; age predicted presence of anti-HAV. A verbal history of infection appeared more reliable for hepatitis C, but considerably less so for hepatitis A and B. CONCLUSION: Persons subject to homelessness are at risk of blood-borne infection. The seroprevalence of markers for hepatitis B and C are higher than in the general population. IMPLICATIONS: Despite the high proportion of clients with serological markers for hepatitis A and B, at least 69% of clients could potentially benefit from hepatitis A and/or B vaccination.

Epidemic infectious syphilis in inner Sydney--strengthening enhanced surveillance.

OBJECTIVE: To report the results of a 2001-04 enhanced syphilis surveillance program in south-eastern Sydney and a subset of cases from the Sydney Sexual Health Centre (SSHC). METHODS: For all laboratory syphilis notifications, a questionnaire was sent to the referring doctor requesting demographic data, clinical information about disease classification and the presence of symptoms. Sex of partner/s and HIV status were collected from a subset of cases seen at SSHC. RESULTS: During 2001-04, 1,275 syphilis notifications were received and 1,112 (87%) were able to be classified as 361 (28%) cases of infectious syphilis, 221 (17%) non-infectious syphilis and 530 (42%) treated syphilis. From mid 2002, an increase in the number of infectious syphilis notifications was noted. Of the 361 cases of infectious syphilis, most were in men (348, 97%). From a subset of 47 cases of infectious syphilis from SSHC, 43 (91%) were in gay men and nine (21%) had concurrent HIV infection. CONCLUSIONS: Inner Sydney has recently experienced a rapid increase in infectious syphilis affecting a defined population: men, aged 30-39, English speaking and Australian born. These results support recent reports of outbreaks among men who have sex with men, but without routine collection of additional risk factors control programs may be misguided. IMPLICATIONS: In light of the review of the NSW Public Health Act 1991, it is recommended that reducing barriers to the collection of HIV status and sex of sexual partners in de-identified syphilis notifications be explored as a matter of urgency.

Getting it right--the Australian Childhood Immunisation Register and immunisation rates in south-eastern Sydney.

OBJECTIVES: To assess the completeness of ACIR data for south-eastern Sydney children at 12 to < 15 months of age and to develop strategies to improve rates. METHODS: We surveyed children aged 12 to < 15 months listed as overdue on the ACIR011A report, December 2001, by contacting the last immunisation provider or the parents. RESULTS: From the 470 children listed as overdue, 162 children were systematically selected to form the study group. Seventeen were lost to follow-up and results are available for 145 children. Eighty children were up to date (69, encounter forms incorrect or not sent; 11, vaccinated overseas) and 11 children had moved overseas. Fifty-four children were overdue (30, provider error due to incorrect Haemophilus influenzae type b (Hib) schedule or Hib vaccine omitted; 18 did not complete schedule; 6 conscientious objectors). CONCLUSIONS: Our study indicates that between 6-9% of children on the register were likely to be overdue, whereas the ACIR011A report identified 19%. Failure of immunisation providers to correctly complete, or send encounter forms to the ACIR was the main reason for this discrepancy. Migration and failure to record overseas vaccination were also factors. IMPLICATIONS: Public health units should develop good working relationships with immunisation providers to assist and encourage immunisation and the completion and submission of encounter forms. A quarterly review, using the third dose assumption, of all children aged 12 to < 15 months identified on the ACIR011A report as overdue for immunisation may be an effective way for public health units to increase apparent rates for their area.

Men who have sex with men, infectious syphilis and HIV coinfection in inner Sydney: results of enhanced surveillance.

UNLABELLED: Background The resurgence of infectious syphilis in men who have sex with men (MSM) has been documented worldwide; however, HIV coinfection and syphilis reinfections in MSM in inner Sydney have not been published. METHODS: For all laboratory syphilis notifications assessed as a newly notified case or reinfection, a questionnaire was sent to the requesting physician seeking demographic data and disease classification. Sex of partner and HIV status were collected for all infectious syphilis notifications in men received from 1 April 2006 to March 2011. RESULTS: From April 2001 to March 2011, 3664 new notifications were received, 2278 (62%) were classified as infectious syphilis. Infectious syphilis notifications increased 12-fold from 25 to 303 in the first and last year respectively, and almost all notifications were in men (2220, 97.5%). During April 2006 to March 2011, 1562 infectious syphilis notifications in males were received and 765 (49%) of these men were HIV-positive and 1351 (86%) reported a male sex partner. Reinfections increased over time from 17 (9%) to 56 (19%) in the last year of the study and were significantly more likely to be in HIV-positive individuals (χ(2)=140.92, degrees of freedom= 1, P=<0.001). CONCLUSION: Inner Sydney is experiencing an epidemic of infectious syphilis in MSM and about half of these cases are in HIV-positive patients. Reinfections are increasing and occur predominantly in HIV-positive men. Accurate surveillance information is needed to inform effective prevention programs, and community and clinician education needs to continue until a sustained reduction is achieved.

A community outbreak of cryptosporidiosis in sydney associated with a public swimming facility: a case-control study.

In February, 2008, the South Eastern Sydney Illawarra Public Health Unit investigated an outbreak of cryptosporidiosis within the south east region of Sydney, Australia. Thirty-one cases with laboratory-confirmed cryptosporidiosis and 97 age- and geographically matched controls selected by random digit dialling were recruited into a case-control study and interviewed for infection risk factors. Cryptosporidiosis was associated with swimming at Facility A (matched odds ratio = 19.4, 95% confidence interval: 3.7-100.8) and exposure to household contacts with diarrhoea (matched odds ratio = 7.7, 95% confidence interval: 1.9-31.4) in multivariable conditional logistic regression models. A protective effect for any animal contact was also found (matched odds ratio = 0.2, 95% confidence interval: 0.1-0.7). Cryptosporidium hominis subtype IbA10G2 was identified in 8 of 11 diagnostic stool samples available for cases. This investigation reaffirms the importance of public swimming pools as potential sources of Cryptosporidium infection and ensuring their compliance with water-quality guidelines. The protective effect of animal contact may be suggestive of past exposure leading to immunity.

Q fever cholecystitis in an unvaccinated butcher diagnosed by gallbladder polymerase chain reaction.

Acalculous cholecystitis has been described in association with Q fever. We describe the first known case of Q fever cholecystitis diagnosed by polymerase chain reaction on gallbladder tissue. The presence of Coxiella burnetii genome in the diseased gallbladder tissue argues for direct involvement of the organism in the pathogenesis of Q fever cholecystitis.

Vaccination against hepatitis A and B in persons subject to homelessness in inner Sydney: vaccine acceptance, completion rates and immunogenicity.

OBJECTIVES: To determine acceptance, completion rates and immunogenicity of the standard vaccination schedule for hepatitis A (HAV) and B (HBV) in persons subject to homelessness. METHODS: A convenience sample of clients (n=201) attending a medical clinic for homeless and disadvantaged persons in Sydney was enrolled. Serological screening for HAV and HBV was undertaken. An appropriate vaccination program was instituted. Post-vaccination serology determined serological response. RESULTS: Although many clients had serological evidence of past infection, at least 138 (69%) clients had the potential to benefit from vaccination. For hepatitis A and B vaccinations, completion rates were 73% (73 of 100 clients) and 75% (69 of 92 clients), respectively; after vaccination, protective antibody was found in 98.2% (56 of 57) and 72% (36 of 50) of clients, respectively. CONCLUSION: A successful vaccination program can be mounted with a vulnerable population. We consider a clinic with a well-established history of acceptance and utilisation by the target group; a low staff turnover and regular clientele; inclusion of vaccination as part of routine client care; and counselling (part of pre- and post-serological testing) essential components in achieving good vaccination completion rates.