Kerry Chant

High hepatitis C incidence in new injecting drug users: a policy failure?

Objective: Evidence of ongoing hepatitis C (HCV) transmission among injecting drug users (IDUs) suggests a need for a better understanding of seroconversion characteristics among new IDUs and other vulnerable subgroups. This study aimed to determine incidence of HCV and associated risk factors among new IDUs in Sydney.

Risk behaviors and antibody hepatitis B and C prevalence among injecting drug users in south‐western Sydney, Australia

Background and Aim:  Hepatitis C virus (HCV) infection is now the leading notifiable disease in Australia. The current study aimed to determine the prevalence of HCV and hepatitis B virus (HBV) infection and associated risk behaviors among injecting drug users (IDUs) screened in south‐western Sydney as part of a multisite prospective cohort study.

Varicella‐zoster virus infection in Australia

Objective: To determine the epidemiology of varicella‐zoster virus (VZV) infection in Australia using currently available data sources.

Community-acquired, non-multiresistant oxacillin-resistant Staphylococcus aureus (NORSA) in South Western Sydney.

Summary Community‐acquired oxacillin‐resistant Staphylococcus aureus (ORSA) infections are an emerging problem in the 1990s in Sydney, Australia. Laboratory data pertaining to all specimens that grew S. aureus between 1/1/1990 and 31/12/1999 were analysed. A total of 12,909 isolates of S. aureus were obtained. The proportions that were nonmultiresistant oxacillin‐resistant S. aureus (NORSA) increased from 0.09% in 1990 to 5.5% in 1999. Resistance of NORSA strains to erythromycin was 8.5%, ciprofloxacin 8.4%, tetracycline 13%, rifampicin 0.7%, and fusidic acid 5.3%. A chart review was performed for cases of NORSA infection which occurred 1/1/1998‐3/5/1998. Isolates from these cases underwent E‐test oxacillin MIC testing, mecA determinant PCR, phage typing and pulsed‐field gel electrophoresis. All nine of the patients with NORSA were Polynesians, and all had serious soft tissue infections. Bacteraemia was not seen. Only one patient received vancomycin yet all recovered. Isolates from all nine patients contained the mecA determinant. Oxacillin MICs were 1‐8 mg/l. Strain differentiation with phage typing and pulsed‐field gel electrophoresis showed isolates from eight patients were closely related and were similar to New Zealand WSPP 1 and WSPP 2 strains. Medical practitioners should take specimens for culture and sensitivity from lesions where infection with S. aureus is likely. Empirical treatment of staphylococcal infections in Polynesians needs to cover NORSA. Methods to detect oxacillin resistance need to be robust.

Evaluation of a national surveillance unit

AIM The Australian Paediatric Surveillance Unit (APSU) facilitates national active surveillance of uncommon childhood conditions. This study assessed whether it fulfilled its objectives and satisfied criteria established by the Centers for Disease Control and Prevention (CDC) for evaluating surveillance systems. METHODS Anonymous questionnaires were sent to users of the system, individual studies were reviewed, and data were collected from independent sources. RESULTS Seven hundred and sixty six clinicians, 48 investigators, and 15 public health professionals responded to the questionnaires. Clinicians reported that the APSU was useful, 33% saying information provided by the APSU informed or changed their clinical practice. Most (88%) reported that completing monthly report cards was not a burden. Impact on policy development was limited by suboptimal dissemination of information to public health professionals. Flexibility and timeliness were limited by design. Estimated sensitivity of APSU studies ranged from 92% (congenital rubella) to 31% (drowning/near drowning). Positive predictive value of notified cases was over 70% for most studies. CONCLUSION The APSU fulfils most of its objectives and meets CDC criteria salient to these. Ways in which the APSU could be improved have been identified, as have methodological challenges and limitations in applying CDC guidelines to this type of unit.

A novel hepatitis B vaccination regimen for adolescents: two doses 12 months apart

BACKGROUND Two- and three-dose hepatitis B vaccinations for adolescents are usually administered using dosing schedules of 6 months duration. This does not suit all circumstances. A 12-month schedule would be useful in schools and settings where only annual vaccination is the most practical option. AIM To examine the efficacy of a 12-month dosing interval for two-dose hepatitis B vaccination of adolescents. SUBJECTS Four hundred and fifty-eight healthy first-year high school (Year 7) students. VACCINATION REGIMEN: Engerix-B (GlaxoSmithKline Biologicals) 20 micro g: two doses, 12 months apart. SERUM COLLECTION: #1, same day as first vaccine dose given; #2, >1 month after second vaccine dose. RESULTS Of the 458 children: 15 did not provide serum #1, 17 had prior vaccination, 2 had prior infection, 18 moved, 7 failed to provide serum #2, 12 withdrew (only 1 cited vaccine adverse reactions as the reason). Three hundred and eighty-seven (210 males, 177 females) aged 11.8-14.2 years (mean: 12.9+/-0.42 years) at entry completed both injections 321-381 days (mean: 359+/-10.7 days) apart and supplied serum #2, 30-57 days (mean: 41+/-5.6 days) after the second vaccine dose.Anti-HBs responses: 379 of the 387 subjects (97.9%; 95% CI: 95.9-99.1%) achieved anti-HBs > or =10 mIU/ml (range 10-170,460 mIU/ml, geometric mean concentration (GMC) 4155 mIU/ml-95% CI of mean: 3381-5106 mIU/ml). Sex was the only determinant of anti-HBs concentration (206 males: GMC 3073 mIU/ml-95% CI: 2285-4134 mIU/ml; 173 females: GMC 5944 mIU/ml-95% CI: 4508-7851 mIU/ml; P=0.001). CONCLUSION A high seroprotection rate and GMC were achieved using two 20 micro g doses of Engerix-B administered 12 months apart. These results are similar to those achieved by others using 6-month three- and two-dose regimens in adolescents.

Overseas travel health seminar

Public Health Unit staff are often required to give advice to people planning to travel overseas.