Long COVID in a highly vaccinated but largely unexposed Australian population following the 2022 SARS-CoV-2 Omicron wave: a cross-sectional survey.

OBJECTIVE: To estimate the prevalence of long COVID among Western Australian adults, a highly vaccinated population whose first major exposure to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was during the 2022 Omicron wave, and to assess its impact on health service use and return to work or study. STUDY DESIGN: Follow-up survey (completed online or by telephone). SETTING, PARTICIPANTS: Adult Western Australians surveyed 90 days after positive SARS-CoV-2 test results (polymerase chain reaction or rapid antigen testing) during 16 July - 3 August 2022 who had consented to follow-up contact for research purposes. MAIN OUTCOME MEASURES: Proportion of respondents with long COVID (ie, reporting new or ongoing symptoms or health problems, 90 days after positive SARS-CoV-2 test result); proportion with long COVID who sought health care for long COVID-related symptoms two to three months after infection; proportion who reported not fully returning to previous work or study because of long COVID-related symptoms. RESULTS: Of the 70 876 adults with reported SARS-CoV-2 infections, 24 024 consented to contact (33.9%); after exclusions, 22 744 people were invited to complete the survey, of whom 11 697 (51.4%) provided complete responses. Our case definition for long COVID was satisfied by 2130 respondents (18.2%). The risk of long COVID was greater for women (v men: adjusted risk ratio [aRR], 1.5; 95% confidence interval [CI], 1.4-1.6) and for people aged 50-69 years (v 18-29 years: aRR, 1.6; 95% CI, 1.4-1.9) or with pre-existing health conditions (aRR, 1.5; 95% CI, 1.4-1.7), as well as for people who had received two or fewer COVID-19 vaccine doses (v four or more: aRR, 1.4; 95% CI, 1.2-1.8) or three doses (aRR, 1.3; 95% CI, 1.1-1.5). The symptoms most frequently reported by people with long COVID were fatigue (1504, 70.6%) and concentration difficulties (1267, 59.5%). In the month preceding the survey, 814 people had consulted general practitioners (38.2%) and 34 reported being hospitalised (1.6%) with long COVID. Of 1779 respondents with long COVID who had worked or studied before the infection, 318 reported reducing or discontinuing this activity (17.8%). CONCLUSION: Ninety days after infection with the Omicron SARS-CoV-2 variant, 18.2% of survey respondents reported symptoms consistent with long COVID, of whom 38.7% (7.1% of all survey respondents) sought health care for related health concerns two to three months after the acute infection.

Successful Control of an Onboard COVID-19 Outbreak Using the Cruise Ship as a Quarantine Facility, Western Australia, Australia.

Onboard quarantining has been only partially effective to control outbreaks of coronavirus disease on cruise ships. We describe the successful use of the ship as a quarantine facility during the response to the outbreak on the MS Artania, which docked in Western Australia, Australia. The health-led 14-day quarantine regime was based on established principles of outbreak management and experiences of coronavirus disease outbreaks on cruise ships elsewhere. The attack rate in the crew was 3.3% (28/832) before quarantine commencement and 4.8% (21/441) during quarantine on board. No crew members became symptomatic after completion of quarantine. Infection surveillance involved telephone correspondence, face-to-face visits, and testing for severe acute respiratory syndrome coronavirus 2. No serious health issues were reported, no response staff became infected, and only 1 quarantine breach occurred among crew. Onboard quarantine could offer financial and operational advantages in outbreak response and provide reassurance to the shore-based wider community regarding risk for infection.

Prevalence of microcephaly in an Australian population-based birth defects register, 1980-2015.

OBJECTIVES: To describe the prevalence and characteristics of microcephaly in a geographically defined Australian population. DESIGN, SETTING AND PARTICIPANTS: Descriptive epidemiological study of microcephaly cases ascertained by the Western Australian Register of Developmental Anomalies, 1980-2015, defining microcephaly as an occipito-frontal head circumference below the third percentile or more than two standard deviations below the mean sex- and age-appropriate distribution curve. MAIN OUTCOME MEASURES: Microcephaly prevalence (per 10 000 births) was calculated for cases with known and unknown causes, and by demographic characteristics. Temporal trends were analysed, and prevalence ratios (PRs) and 95% CIs calculated for Aboriginal and non-Aboriginal births. RESULTS: For births during 1980-2009 (ie, with at least 6 years' follow-up and therefore complete case ascertainment), 416 cases were identified, a prevalence of 5.5 per 10 000 births (95% CI, 4.95-6.02), or 1 in 1830 births. There was no significant temporal trend in prevalence (P = 0.23). Most cases were in live-born children (389, 93.5%), and other major birth defects were diagnosed in 335 of the affected children (80%). Prevalence was higher in Aboriginal births (PR, 4.5; 95% CI, 3.55-5.73). A cause of microcephaly was identified in 186 cases (45% of cases), and more often for Aboriginal (64 cases, 70%) than non-Aboriginal births (122 cases, 38%). The most frequent known cause of microcephaly in Aboriginal births was fetal alcohol spectrum disorder (FASD; 11 per 10 000 births); monogenic (0.68 per 10 000) and chromosomal conditions (0.59 per 10 000 births) were the most common causes in non-Aboriginal births. CONCLUSIONS: These data provide a baseline for prospective surveillance of microcephaly. We identified a high proportion of cases without known cause, highlighting the need for clinicians to carefully investigate all possibilities, including emerging infections. FASD is an important cause of microcephaly in the Aboriginal population.

Predictors of uptake of influenza vaccination--a survey of pregnant women in Western Australia.

BACKGROUND: Pregnant women are at increased risk of complications following influenza infection. Vaccination is the most effective preventive strategy. This survey aimed to determine the levels of uptake of influenza vaccine in pregnant women in Western Australia (WA), the proportion of women offered vaccination as part of antenatal care, and women's attitudes toward influenza vaccination in pregnancy. METHODS: Computer assisted telephone interviews were conducted with 416 randomly selected women who were pregnant during the 2012 influenza vaccination season. RESULTS: Influenza vaccination coverage was 23%. Predictors of vaccination included believing that vaccination is safe for the infant, having been recommended vaccination by an antenatal care provider, and attending a general practitioner for most antenatal care. The majority (74%) of unvaccinated women reported that they would have the vaccine if their antenatal care provider recommended it. DISCUSSION: General practitioners lead the way in antenatal influenza vaccination in WA. Vaccination coverage can be improved if recommending and offering influenza vaccination becomes a routine part of antenatal care.

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.

Delusions of Certainty: Commercial Vessel COVID-19 Risk Stratification.

Since the World Health Organization's (WHO's) pandemic declaration on March 11, 2020, coronavirus disease 2019 (COVID-19) outbreaks have occurred on numerous maritime vessels and the containment measures, travel restrictions, and border closures continue to make it increasingly difficult for ship operators world-wide to be granted pratique, conduct trade, and conduct crew changes.Knowledge of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) circulating on-board a ship prior to its arrival has significant implications for the protection of shore-based maritime workers (ie, pilots, stevedores, and surveyors), the broader community, and trade. A useful approach is a graded assessment of the public health risk. The Western Australia (WA) experience and associated observed pitfalls in implementing the prediction equation for the potential presence of SARS-CoV-2 on-board based on five COVID-19 outbreaks on commercial and cruise vessels during 2020 is described.Despite best efforts, the qualitative and quantitative predictors of SARS-CoV-2 circulating on-board commercial vessels are failing to deliver the required certainty, and to date, the only accepted method of ascertaining the presence of SARS-CoV-2 remains the real-time reverse transcription polymerase chain reaction (rRT-PCR) testing reported by an accredited laboratory.Based on legal or regulatory requirements, germane processes, underpinned by robust and auditable processes and procedures, must be put in place to inform the risk assessment of SARS-CoV-2 circulating on-board vessels.

The Healthy Crew, Clean Vessel, and Set Departure Date Triad: Successful Control of Outbreaks of COVID-19 On Board Four Cargo Vessels.

BACKGROUND: A variety of infectious diseases can cause outbreaks on board vessels, with both health and economic effects. Internationally, Coronavirus Disease 2019 (COVID-19) outbreaks have occurred on numerous cruise and cargo vessels and the containment measures, travel restrictions, and border closures continue to make it increasingly difficult for ship operators world-wide to be granted pratique, effect crew changes, and conduct trade. An effective outbreak management strategy is essential to achieve the outcome triad - healthy crew, clean vessel, and set departure date - while maintaining the safety of the on-shore workers and broader community and minimizing disruption to trade. This report describes the principles of COVID-19 outbreak responses on four cargo vessels, including the successful use of one vessel as a quarantine facility. METHODS: Established principles of management and the experiences of COVID-19 outbreaks on cruise ships elsewhere informed a health-lead, multi-agency, strict 14-day quarantine (Q) regime based on: population density reduction on board; crew segregation; vessel cleaning and sanitation; infection risk zones, access, and control measures; health monitoring; case identification and management; food preparation and delivery; waste management control; communication; and welfare and security. FINDINGS: Sixty-five crew were diagnosed with Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection (range 2-25; attack rate 10%-81%; 15 asymptomatic). No deaths were recorded, and only one crew was hospitalized for COVID-19-related symptoms but did not require intensive care support. Catering crew were among the cases on three vessels. All non-essential crew (n-EC) and most of the cases were disembarked. During the vessel's Q period, no further cases were diagnosed on board, and no crew became symptomatic after completion of Q. The outbreak response duration was 15-17 days from initial decision.No serious health issues were reported, no response staff became infected, and only two Q protocol breaches occurred among crew. INTERPRETATION: Despite increasing risk of outbreaks on cargo vessels, maritime trade and crew exchanges must continue. The potential consequences of COVID-19 outbreaks to human life and to trade necessitate a balanced response. The principles described can offer health, financial, operational, and safety advantages.

SARS-CoV-2 infections among Australian passengers on the Diamond Princess cruise ship: A retrospective cohort study.

BACKGROUND: Prolonged periods of confined living on a cruise ship increase the risk for respiratory disease transmission. We describe the epidemiology and clinical characteristics of a SARS-CoV-2 outbreak in Australian passengers on the Diamond Princess cruise ship and provide recommendations to mitigate future cruise ship outbreaks. METHODS: We conducted a retrospective cohort study of Australian passengers who travelled on the Diamond Princess from 20 January until 4 February 2020 and were either hospitalised, remained in Japan or repatriated. The main outcome measures included an epidemic curve, demographics, symptoms, clinical and radiological signs, risk factors and length of time to clear infection. RESULTS: Among 223 Australian passengers, 56 were confirmed SARS-CoV-2 positive. Forty-nine cases had data available and of these over 70% had symptoms consistent with COVID-19. Of symptomatic cases, 17% showed signs and symptoms before the ship implemented quarantine and a further two-thirds had symptoms within one incubation period of quarantine commencing. Prior to ship-based quarantine, exposure to a close contact or cabin mate later confirmed SARS-CoV-2 positive was associated with a 3.78 fold (95% CI, 2.24-6.37) higher risk of COVID-19 acquisition compared to non-exposed passengers. Exposure to a positive cabin mate during the ship's quarantine carried a relative risk of 6.18 (95% CI, 1.96-19.46) of developing COVID-19. Persistently asymptomatic cases represented 29% of total cases. The median time to the first of two consecutive negative PCR-based SARS-CoV-2 assays was 13 days for asymptomatic cases and 19 days for symptomatic cases (p = 0.002). CONCLUSION: Ship based quarantine was effective at reducing transmission of SARS-CoV-2 amongst Australian passengers, but the risk of infection was higher if an individual shared a cabin or was a close contact of a confirmed case. Managing COVID-19 in cruise ship passengers is challenging and requires enhanced health measures and access to onshore quarantine and isolation facilities.

Influenza outbreaks during World Youth Day 2008 mass gathering.

Influenza outbreaks during mass gatherings have been rarely described, and detailed virologic assessment is lacking. An influenza outbreak occurred during World Youth Day in Sydney, Australia, July 2008 (WYD2008). We assessed epidemiologic data and respiratory samples collected from attendees who sought treatment for influenza-like illness at emergency clinics in Sydney during this outbreak. Isolated influenza viruses were compared with seasonal influenza viruses from the 2008 influenza season. From 100 infected attendees, numerous strains were identified: oseltamivir-resistant influenza A (H1N1) viruses, oseltamivir-sensitive influenza A (H1N1) viruses, influenza A (H3N2) viruses, and strains from both influenza B lineages (B/Florida/4/2006-like and B/Malaysia/2506/2004-like). Novel viruses were introduced, and pre-WYD2008 seasonal viruses were amplified. Viruses isolated at mass gatherings can have substantial, complex, and unpredictable effects on community influenza activity. Greater flexibility by public health authorities and hospitals is required to appropriately manage and contain these outbreaks.

Lessons from the NSW laboratory response to pandemic (H1N1) 2009 influenza.

Procedures undertaken by NSW Health in the laboratory response to pandemic (H1N1) 2009 influenza were reviewed to assist planning for a future infectious disease emergency. Laboratory plans developed prior to the pandemic sought rapid detection of pandemic virus in the early phases of the pandemic response until demonstration of widespread community transmission, followed then by limited testing when indicated clinically. As planned, the laboratory response was based on the Pandemic Influenza Management System with a web-based outbreak management tool, NetEpi, as the single public health database used for cases and test results. This was found to be effective for tracking specimens and results, and enhanced the public health response. The sustained large volume of community testing during this mild pandemic had an adverse effect on the timely delivery of priority results.

An epidemiological investigation into an outbreak of rash illness among methadone maintenance clients in Australia.

In late 2004, NSW Health received several reports of a serious desquamating rash among clients of the methadone program. We sought to identify the extent and likely cause of this outbreak. We initiated active surveillance for cases throughout Australia, a survey of dosing points in NSW, and a case control study of clients receiving methadone syrup (MS) at two clinics. Between October 2004 and March 2005, 388 cases were identified, largely in NSW. The dosing point survey found almost all cases were clients prescribed MS (attack rate 4.5%). In multivariate analysis of data from dosing points that dispensed MS, use of take away doses or location of the dosing point in greater western Sydney were associated with illness. In the case control study, MS injection, use of street MS, high doses of MS, frequent takeaway doses, or use of benzodiazepines were associated with illness. Testing found no abnormality in associated batches of MS. Batches of MS temporally associated with the outbreak were quarantined from use and the outbreak subsided. While a direct causal link could not be established, available evidence suggests that a contaminant may have caused the outbreak. Epidemiological analyses are important for assessing concerns about product safety following marketing approval.

Zika Virus: What Have We Learnt Since the Start of the Recent Epidemic?

Zika is a viral disease transmitted mainly by mosquitoes of the genus Aedes. In recent years, it has expanded geographically, changing from an endemic mosquito-borne disease across equatorial Asia and Africa, to an epidemic disease causing large outbreaks in several areas of the world. With the recent Zika virus (ZIKV) outbreaks in the Americas, the disease has become a focus of attention of public health agencies and of the international research community, especially due to an association with neurological disorders in adults and to the severe neurological and ophthalmological abnormalities found in fetuses and newborns of mothers exposed to ZIKV during pregnancy. A large number of studies have been published in the last 3 years, revealing the structure of the virus, how it is transmitted and how it affects human cells. Many different animal models have been developed, which recapitulate several features of ZIKV disease and its neurological consequences. Moreover, several vaccine candidates are now in active preclinical development, and three of them have already entered phase I clinical trials. Likewise, many different compounds targeting viral and cellular components are being tested in in vitro and in experimental animal models. This review aims to discuss the current state of this rapidly growing literature from a multidisciplinary perspective, as well as to present an overview of the public health response to Zika and of the perspectives for the prevention and treatment of this disease.

Infection of transjugular intrahepatic portosystemic shunt devices: three cases and a review of the literature.

During the past decade, transjugular intrahepatic portosystemic shunting (TIPS) has become accepted as an alternative to the surgical shunt procedure for controlling the complications of portal hypertension, yet few data exist regarding infectious complications. The records of all patients who underwent a TIPS procedure during 1992-2000 at a single university teaching hospital were analyzed retrospectively to determine the rate and type of infections that occurred. A search of the English-language literature on the subject was conducted, and the findings were compared with our experience. Three cases of TIPS stent infection were identified out of 180 procedures performed during a 9-year period, resulting in an overall rate of infection of 1.7%. One of the patients was cured, and the other 2 died. A total of 21 cases of TIPS infection were identified from the literature search. A need exists for a standardized case definition for TIPS infection, and one is proposed.

Pandemic (H1N1) 2009 influenza vaccination coverage in Western Australia.

OBJECTIVE: To assess pandemic (H1N1) 2009 influenza vaccination coverage in Western Australians, up to 31 January 2010. DESIGN, SETTING AND PARTICIPANTS: Vaccination data for Western Australians aged 10 years and older were obtained from two sources: the WA Pandemic Influenza Vaccination Database (PIVD; which collected reports of pandemic influenza vaccinations from vaccination providers statewide) for the period 30 September 2009 to 31 January 2010, and the WA Health and Wellbeing Surveillance System (HWSS; a continuous population-based telephone survey) for the period 1 December 2009 to 31 January 2010. Data from the PIVD was used to input vaccination coverage estimates for at-risk subpopulations not assessed in the HWSS interviews. MAIN OUTCOME MEASURES: Vaccination coverage of Western Australians aged 10 years and older and of subgroups targeted by the national pandemic (H1N1) 2009 influenza vaccination campaign. RESULTS: A total of 171,789 pandemic influenza vaccinations were reported to the PIVD by 31 January 2010 and 88% of these were administered by 1 December 2009. Based on HWSS data, vaccination coverage of persons aged 10 years and older was 14.5% (95% CI, 12.6%-16.6%) and of persons aged 18 years and older was 15.3% (95% CI, 13.3%-17.6%). Based on PIVD data, coverage in adults ranged from 10.3% in pregnant women to 52.8% in health care workers. CONCLUSIONS: Our estimate of pandemic influenza vaccination coverage in the adult population of WA is comparable to the national estimate of 19%, but it did not reach levels considered sufficient to interrupt community transmission. Future influenza vaccination programs should target groups at increased risk of severe influenza, such as pregnant women.

Blessings in disguise: public health emergency preparedness for World Youth Day 2008.

Mass gatherings, such as World Youth Day (WYD) 2008 in Sydney, provide an opportunity for public health workers to gain emergency management experience. Communicable disease (mainly influenza) among pilgrims was the major public health issue during WYD. Public health workers also identified environmental health issues, resulting in hazard reduction measures being made to reduce falls. Other public health issues highlighted include training, communication, surge capacity, and health education. Lessons learned from planning WYD mass accommodation could be applied to emergency accommodation in the case of evacuation.

Salmonella typhimurium phage type 170 in a tertiary paediatric hospital with person-to-person transmission implicated.

Nosocomially-acquired salmonellosis is uncommonly reported in Australia. We report a cluster of gastroenteritis caused by Salmonella Typhimurium phage type 170 (STm 170) centred on a tertiary paediatric hospital in Sydney, New South Wales from 8 to 19 May 2004. A total of 12 children had STm 170 isolated from faecal specimens. Of the 12 cases, seven were acquired in hospital and five in the community. The mean age of the cases was 4.1 years (range: 2 months to 11.2 years). We conducted a case series investigation to generate hypotheses regarding the cause of this outbreak. Standardised interviews with cases' parents were conducted to identify potential exposures including in recently consumed food. An environmental investigation mapped the food preparation and storage areas, movements of staff caring for cases, relative case-bed locations, and duration of stay in these locations. Five of the seven hospital-acquired cases were immunocompromised with a history of prolonged and/or multiple hospital admissions. We found that STm 170 was probably brought into the hospital by a community-acquired case and spread to other in-patients through person-to-person transmission by hospital staff and/or patients. This study emphasises the importance of stringent compliance with hospital infection control practices at all times.