Travel-associated lineages and unique endemic antimicrobial-susceptible lineages of Neisseria gonorrhoeae predominate in Western Australia.

In Australia, gonococcal isolates are monitored for antimicrobial susceptibilities. In Western Australia (WA), gonorrhoea notification rates increased by 63 % between 2013 and 2016, with the steepest increase occurring between 2015 and 2016, before stabilizing at this higher baseline between 2017 and 2020. This increased prevalence was associated with antimicrobial-susceptible (AMS) lineages. To understand the provenance of these isolates causing gonorrhoea in WA, whether they were introduced or expanded from endogenous lineages, 741 isolates were collected in 2017 and characterized by both iPLEX typing and whole genome sequencing (WGS). Antibiograms and genocoding of the isolates revealed that AMS isolates were most prevalent in the remote regions, while the urban/rural regions were characterized by antimicrobial-resistant (AMR) isolates. iPLEX typing identified 78 iPLEX genotypes (WA-1 to WA-78) of which 20 accounted for over 88 % of isolates. WA-10 was the most frequently identified genotype in the urban/rural regions whilst WA-29 was the most frequently identified genotype in the remote regions. Genotypes WA-38, WA-52 and WA-13 accounted for 81 % (n=36/44) of the azithromycin-resistant N. gonorrhoeae (AziR) isolates. A representative isolate of each iPLEX genotype and AMR biotype was whole genome sequenced and analysed using MLST, NG-MAST and NG-STAR, and the novel core genome clustering Ng_cgc_400 typing scheme. Five predominant Bayesian population groups (termed BPG-1 to 5) were identified in the study collection. BPG-1 and BPG-2 were associated with AMS isolates from the remote regions. BPG-1 and BPG-2 were shown to be unique to the remote regions based on a minimum spanning tree against 4000 international isolates. AMS isolates in urban/rural regions were dominated by international lineages. AziR and Cef DS (decreased susceptibility to ceftriaxone) was concentrated in three urban/rural genomic groups (BPG-3, 4 and 5). Azithromycin minimum inhibitory concentrations (0.5-16 mg l-1) correlated with the accumulation of mtrR mutations or/and the fraction of 23S rRNA C2611T mutated copies. The majority of isolates in BPG-3, 4 and 5 could be correlated with known AMR lineages circulating globally and nationally. In conclusion, the surge in AMS isolates in WA in 2017 was due to importation of international AMS lineages into urban/rural regions, whilst the local AMS lineages persisted largely in the remote regions. Bridging between the urban/rural and remote regions was relatively rare, but continued surveillance is required to prevent ingress of AMR strains/lineages into the remote regions of WA.

Early diagnosis of HIV among men who have sex with men in Western Australia: impact of a peer-led sexually transmissible infection testing service.

UNLABELLED: Background In July 2010, the Western Australian AIDS Council established the 'M Clinic', a peer-led STI testing service for MSM. This study describes trends in HIV notifications among MSM in WA from 2004 to 2013, particularly the impact of the M Clinic on newly acquired HIV diagnoses. METHODS: The number and proportion of MSM HIV cases with newly acquired infection were compared for the 2004-2006, 2007-2009 and 2011-2013 time periods. Data from 2010 were excluded as the M Clinic opened in July 2010. RESULTS: Between the 2004-2006 and 2007-2009 periods, the number of MSM with newly acquired HIV increased by 50% (23 to 33 cases) and the number of newly acquired cases as a proportion of all new HIV diagnoses among MSM increased from 27% to 35% (30% increase) (P=0.25). In the 2011-2013 period, the number of newly acquired HIV cases among MSM more than doubled to 70 cases and comprised 53% of all new HIV diagnoses among MSM (P<0.05). Of the 70 newly acquired HIV cases in the 2011-2013 period, 30% (n=21) were diagnosed at the M Clinic. CONCLUSIONS: The proportion of MSM HIV notifications that were newly acquired increased between 2004 and 2013 in WA, with the greatest increase seen after the M Clinic commenced operation. A peer-led approach to HIV testing should be considered in order to achieve early diagnosis and treatment of HIV among MSM.

Aboriginal and non-Aboriginal sexually transmitted infections and blood borne virus notification rates in Western Australia: using linked data to improve estimates.

BACKGROUND: National notification data for sexually transmitted infections (STIs) and blood borne viruses (BBVs) continue to have a high proportion of missing data on Indigenous status, potentially biasing estimates of notification rates by Aboriginality. We evaluated the use of data linkage to improve the accuracy of estimated notification rates for STIs and BBVs in Aboriginal and non-Aboriginal groups in Western Australia. METHODS: STI and BBV case notifications in Western Australia received in 2010 were linked with administrative health data collections in Western Australia to obtain additional data on Indigenous status. STI and BBV notification rates based on the pre- and post-linkage data among Aboriginal and non-Aboriginal groups were compared. RESULTS: Data linkage decreased the proportion of notifications with unknown Indigenous status by 74% from 10.2% to 2.7%. There was no significant difference in disease-specific age-adjusted notification rate ratio estimates based on pre-linkage data and post-linkage data for Aboriginal people compared with non-Aboriginal people. CONCLUSION: Our findings suggest that reported STI and BBV disease-specific age-adjusted notification rates for 2010 in Western Australia are unlikely to be significantly biased by excluding notifications with unknown Indigenous status. This finding is likely to be dependent on recent improvements in the reporting of Indigenous status in notification data in Western Australia. Cost-effective and systematic solutions, including the better use of existing data linkage resources, are required to facilitate continued improvement in the completeness of reporting and accuracy of estimates for notifiable STIs and BBVs in Australia by Aboriginality.

Improvement in antenatal testing for sexually transmissible infections and blood-borne viruses in Western Australian hospitals, 2007 to 2010.

OBJECTIVE: Antenatal testing for specified sexually transmissible infections (STIs) and blood-borne viruses (BBVs) is recommended by the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG). In 2007, the Department of Health, Western Australia (DoHWA) issued an operational directive (OD) recommending universal testing for chlamydia and additional testing for women in the STI endemic regions of Western Australia (WA). To assess adherence to these guidelines, seven WA public hospitals were audited. DESIGN AND SETTING: Demographic details and testing information of the last 200 women who gave birth immediately before 30 June 2007 (baseline audit) and 30 June 2010 (follow-up audit) were obtained from each hospital's antenatal records. RESULTS: Data from 2718 women who delivered at ≥36 weeks' gestation were analysed (baselinen=1353; follow-upn=1365). Testing at the first antenatal visit in accordance with the guidelines improved over time (RANZCOG: 68-74%; χ(2)-test = 13.96, d.f.=1, P<0.001; DoHWA OD: 12-40%; χ(2)-test = 279.71, d.f.=1, P<0.001). Retesting at 28-36 weeks' gestation in the STI endemic regions improved for chlamydia (3-10%; χ(2)-test = 17.40, d.f.=1, P<0.001) and gonorrhoea (3-7%; χ(2)-test=6.62, d.f.=1, P<0.05), but not for syphilis or HIV. Chlamydia prevalence was 3% and 8% among nonAboriginal and Aboriginal women, respectively. CONCLUSION: The proportion of women delivering in WA public hospitals who had antenatal STI and BBV tests improved after publication and promotion of the OD.

Syphilis epidemiology and public health interventions in Western Australia from 1991 to 2009.

OBJECTIVES: To describe the epidemiology of congenital and infectious syphilis during 1991-2009, examine the impact of public health interventions and discuss the feasibility of syphilis elimination among Aboriginal people in Western Australia (WA). METHODS: WA congenital and infectious syphilis notification data in 1991-2009 and national infectious syphilis notification data in 2005-2009 were analysed by Aboriginality, region of residence, and demographic and behavioural characteristics. Syphilis public health interventions in WA from 1991-2009 were also reviewed. RESULTS: During 1991-2009, there were six notifications of congenital syphilis (50% Aboriginal) and 1441 infectious syphilis notifications (61% Aboriginal). During 1991-2005, 88% of notifications were Aboriginal, with several outbreaks identified in remote WA. During 2006-2009, 62% of notifications were non-Aboriginal, with an outbreak in metropolitan men who have sex with men. The Aboriginal:non-Aboriginal rate ratio decreased from 173:1 (1991-2005) to 15:1 (2006-2009). CONCLUSIONS: These data demonstrate that although the epidemiology of syphilis in WA has changed over time, the infection has remained endemic among Aboriginal people in non-metropolitan areas. Given the continued public health interventions targeted at this population, the limited success in eliminating syphilis in the United States and the unique geographical and socioeconomic features of WA, the elimination of syphilis seems unlikely in this state.

Chronic disease and hospitalisation for pandemic (H1N1) 2009 influenza in Indigenous and non-Indigenous Western Australians.

Indigenous and non-indigenous Western Australians with pandemic (H1N1) 2009 influenza (pH1N1) infection were compared for risk factors, influenza vaccination history, symptoms, use of antiviral medications, and hospitalisation. Data were collected systematically on 856 notified cases with laboratory confirmed pH1N1 infection during the first 10 weeks of pH1N1 virus transmission in Western Australia in 2009. Indigenous people with pH1N1 were approximately 3 times more likely to be hospitalised and were more likely to have a range of underlying medical conditions and be smokers, compared with non-Indigenous cases. Age (P < 0.001) and the presence of two or more co-morbidities (P < 0.001) were independent predictors of hospitalisation, while Indigenous status was not, indicating that higher pH1N1 hospitalisation rates in Indigenous Australians during the 2009 winter season were attributable to the higher prevalence of underlying chronic disease. These results underscore the need to ensure that influenza vaccination is delivered as widely as possible among those with chronic health conditions.

Epidemiology of syphilis in Australia: moving toward elimination of infectious syphilis from remote Aboriginal and Torres Strait Islander communities?

OBJECTIVE: To describe the epidemiology of infectious syphilis among Aboriginal and Torres Strait Islander (Indigenous) people in Australia. DESIGN AND SETTING: We assessed trends in national infectious syphilis notification rates from 2005 to 2009 using Poisson regression, with a focus on geographic and demographic differences by Indigenous status. We compared Indigenous and non-Indigenous rate ratios over the study period and summarised the annual changes (summary rate ratio). MAIN OUTCOME MEASURES: Crude notification rates and summary rate ratios by Indigenous status, jurisdiction, sex, age group and area of residence. RESULTS: From 2005 to 2009, in the Indigenous population, there was a substantial decline in the notification rate for infectious syphilis nationally; as well as in the following subgroups: females, 15-29 year olds, and people living in outer regional and remote areas in the Northern Territory and Queensland. In contrast, there was a significant (P < 0.001) upward trend in the notification rate in the non-Indigenous population nationally; as well as in males, in people aged 20 years and over, and in residents of metropolitan and regional areas, New South Wales, Queensland, South Australia, Victoria and Western Australia. The highest summary rate ratios were seen in remote/very remote areas (86.33; 95% CI, 57.45-129.74), in 15-19 year olds (64.65; 95% CI, 51.12-81.78), in females (24.59; 95% CI, 19.73-30.65), and in Western Australia (23.89; 95% CI, 19.82-28.82). CONCLUSION: These data demonstrate that Australia has two distinct patterns of infectious syphilis: a substantially declining occurrence in Indigenous remote communities and an increasing incidence in males residing in urban and regional areas. Given the decline in notification rates in Indigenous remote communities, now might be the right time to move toward eliminating infectious syphilis from Indigenous communities.

A prolonged mumps outbreak among highly vaccinated Aboriginal people in the Kimberley region of Western Australia.

OBJECTIVE: To describe a prolonged outbreak of mumps in the Kimberley region of Western Australia in 2007-2008. DESIGN: Descriptive analysis of all mumps cases notified to the WA Notifiable Infectious Diseases Database for the period 1 July 2007 to 30 June 2008. MAIN OUTCOME MEASURES: Notified cases of mumps by patients' place of residence, age, Indigenous or non-Indigenous ethnicity, vaccination status and method of diagnosis. RESULTS: 84% (153/183) of mumps notifications in WA over the study period occurred in the Kimberley region or were directly linked to Kimberley cases. Median age of patients was 18 years (range, 2-63 years), and 54% of patients were aged less than 20 years. Almost all (92%) were Australian Aboriginal people; 67% (102/153) had received at least one dose of mumps vaccine, and 52% had received two doses. The highest notification rate (1816 cases per 100,000 population) was in the Aboriginal 15-19-years age group, and 92% of these patients had received at least one dose of mumps vaccine. Almost all outbreak cases (94%) were laboratory confirmed. Genotyping was performed on 20 mumps virus isolates: all were genotype J. CONCLUSION: A prolonged outbreak of mumps occurred in a well defined, highly vaccinated, predominantly young Aboriginal population in the remote Kimberley region of WA. This outbreak raises questions about the effectiveness and scheduling of the current vaccine (which is genotype A-derived), especially for Aboriginal people. Surveillance of circulating mumps virus genotypes and neutralisation studies will help in evaluating the protection provided by the current vaccine against genotypically different strains.

An increase in overseas acquired HIV infections among heterosexual people in Western Australia.

BACKGROUND: There has been a recent increase in the number of heterosexually acquired HIV infections among non-Aboriginal people in Western Australia (WA), which has not been reported in other Australian jurisdictions. This report describes the epidemiological features of this increase. METHODS: A descriptive analysis was conducted of newly diagnosed HIV infections among non-Aboriginal WA residents notified to the Department of Health from 2002 to 2006. Analysis outcomes included demographics, exposure categories, and place of HIV acquisition. RESULTS: From 2002 to 2006, 258 new HIV diagnoses were notified among non-Aboriginal WA residents. Over this period, the number of notifications increased from 41 cases in 2002 (2.2 cases/100 000 population) to 66 cases in 2006 (3.4 cases/100 000 population). Overall, 107 (42%) of the cases were heterosexually acquired, and the annual number increased threefold from 2002 to 2006 (12 to 36 cases, respectively). Of these cases, 64 (60%) were male and 43 (40%) were female. The majority (89%) of male cases acquired HIV overseas, mostly in countries other than their region of birth; South-east Asia was the most common place of acquisition reported. Over half (56%) of the female cases acquired HIV overseas, mainly in their region of birth (83%), and sub-Saharan Africa was the most common place of acquisition. CONCLUSION: There has been a recent increase in heterosexually acquired HIV infections among male and female WA residents, many of whom reported acquiring HIV overseas. Safe sex campaigns in WA should continue to reinforce safe sex messages among people travelling overseas.

Characteristics of HIV diagnoses in Australia, 1993-2006.

OBJECTIVE: To describe recent trends in the diagnosis of HIV infection in Australia. METHODS: National HIV surveillance data from 1993 to 2006 were analysed with a focus on geographic differences by HIV exposure route and late presentation (HIV within 3 months of a first AIDS-defining illness or a CD4 count of less than 200 cells muL(-1)). RESULTS: In 1993-99, the number of HIV diagnoses declined by 32%, and then increased by 39% from 1999 to 2006. From 2000 onwards, rates increased significantly in Victoria, Queensland, South Australia and Western Australia. The most frequently reported routes of HIV exposure were male to male sex (71%) and heterosexual contact (18%), and the population rate of diagnoses have increased in both categories. Among the cases reported as heterosexually acquired (n = 2199), 33% were in people born in a high-prevalence country and 19% in those with partners from a high-prevalence country. Late presentation was most frequent in heterosexually acquired infections in persons who had a partner from a high-prevalence country: 32% compared with 20% overall. CONCLUSIONS: Recent increases in annual numbers of HIV diagnoses in Australia underline the continuing need for HIV-prevention programs, particularly among men having male to male sex. Early diagnosis and access to care and treatment should also be emphasised, as a substantial proportion of people with HIV infection are unaware of their status until late in the course of disease.

HIV diagnoses in Australia: diverging epidemics within a low-prevalence country.

OBJECTIVE: To describe recent trends in the diagnosis of HIV infection in Australia. DESIGN AND SETTING: Analysis of national surveillance system data for 1993-2006. MAIN OUTCOME MEASURES: Number and population rate of new HIV diagnoses by year, exposure route and demographic characteristics. RESULTS: Between 1993 and 2006, 12 313 new diagnoses of HIV infection were reported in Australia. From 1993 to 1999, the annual number of diagnoses declined by 32% from 1056 to 718, and then increased by 31% from 763 in 2000 to 998 in 2006. Between 2000 and 2006, diagnosis rates significantly increased in Victoria, Queensland, South Australia and Western Australia. The most frequent route of HIV exposure was male-to-male sex, accounting for 70% of diagnoses. Heterosexual contact accounted for 18% of cases, with just over half of these people born in or having a sexual partner from a high-prevalence country. Exposure by injecting drug use remained infrequent. CONCLUSIONS: The number of HIV diagnoses has risen in the past 7 years, but not in New South Wales, which has long had the highest rates. The differences in rates between states/territories are likely to be due to divergent trends in sexual risk behaviour in men having male-to-male sex, which remains the predominant route of HIV transmission in Australia. There is a need for effective, innovative and evidence-based programs for HIV prevention, particularly among men having male-to-male sex.

Fulfilling prophecy? Sexually transmitted infections and HIV in Indigenous people in Western Australia.

OBJECTIVE: To compare trends and rates of HIV and sexually transmitted infections in Indigenous and non-Indigenous people of Western Australia. DESIGN AND SETTING: Analysis of WA notification data for chlamydia, gonorrhoea, and primary and secondary syphilis in 2002, and for HIV infections from 1983 to 2002. MAIN OUTCOME MEASURES: Rates of HIV and sexually transmitted infection by Indigenous status. RESULTS: In 2002, there were 3046 notifications for chlamydia, 1380 for gonorrhoea and 64 for syphilis. When information on Indigenous status was available, Indigenous people accounted for 41% of chlamydia and 76% of gonorrhoea notifications, with Indigenous:non-Indigenous age-standardised rate ratios of 16 (95% CI, 14-17) and 77 (95% CI, 67-88), respectively. Indigenous people accounted for 90.6% of syphilis notifications (age-standardised Indigenous:non-Indigenous rate ratio, 242 [95% CI, 104-561]). From 1985 to 2002, HIV notification rates for non-Indigenous people in WA declined and rates for Indigenous people increased. From 1994 to 2002, there were 421 notifications of HIV infection in WA residents, 52 (12.4%) in Indigenous people and 369 (87.6%) in non-Indigenous people. Indigenous people accounted for 39% and 6.2% of all notifications in WA females and males, respectively. The Indigenous:non-Indigenous rate ratios were 18 (95% CI, 12-29) for females and 2 (95% CI, 1-3) for males. CONCLUSIONS: Indigenous Western Australians are at greater risk of HIV transmission than non-Indigenous people. Strategies to prevent further HIV infection in Indigenous Australians should include control of sexually transmitted infections.