The increasing healthcare burden of enteric fever in a low-incidence setting.

OBJECTIVES: Enteric fever carries appreciable morbidity in non-endemic settings, particularly in returned travelers. This study aimed to characterize the healthcare burden of enteric fever in a low-incidence setting and to identify risk factors and opportunities for preventative interventions. METHODS: Analysis of a retrospective case series from a tertiary pediatric center (2015-2019), augmented by public health notification and microbiological laboratory data (2018-2019), from Western Sydney, Australia, a region with frequent travel links to South Asia. RESULTS: Eighty-nine (89) patients were diagnosed with enteric fever, including 43 children with complete demographic and travel data. Enteric fever cases increased over time (by 4.9 % per year) and incidence was three times higher in the pediatric population (<15 years old) compared to adults. Travel to India and visiting friends and relatives (VFR) travel were risk factors. Few children received enteric fever vaccination prior to travel, as pre-travel advice most commonly was not sought. CONCLUSIONS: Children visiting relatives in high-incidence countries are increasingly at risk for enteric fever, particularly when travelling to South Asia. Targeted health advice to travelers visiting friends and relatives is warranted to mitigate the healthcare burden of enteric fever in low-incidence settings.

Socioeconomic disadvantage and engagement with digital contact tracing for COVID-19 in Western Sydney: A secondary analysis of surveillance data.

OBJECTIVE: COVID-19 outcomes were highly inequitably distributed in Australia and worldwide. The digitalisation of public health interventions offers resource-efficiency and increased capacity for pandemic responses, but risks excluding the elderly and disadvantaged, reinforcing existing inequalities. Despite this, there has been little evaluation of the determinants of uptake of digital contact tracing. This paper describes the use of digital contact tracing for COVID-19 in a population in metropolitan Sydney and the determinants of engagement in this population. METHODS: Routinely collected surveillance data for residents of Western Sydney Local Health District, returning a positive SARS-CoV-2 result between 1st August 2021 and 12th February 2022, were extracted including responses to a digital contact tracing questionnaire. Individual records were linked to area-level socioeconomic indices of disadvantage. Descriptive analyses explored characteristics of non-responders and geospatial variation. Logistic regression was undertaken to evaluate the effect of age, sex and socioeconomic disadvantage on the odds of response. RESULTS: Of the 133 055 individuals included, 130 645 (98%) were issued a digital contact tracing questionnaire, and 106 432 (81%) responded. Odds of responding were lower in males (odds ratio: 0.79), individuals aged 80+ (odds ratio: 0.17) and the most disadvantaged communities (odds ratio: 0.32). CONCLUSIONS: Digital data collection for contact tracing was a scalable and efficient tool in the context of the Western Sydney Local Health District COVID-19 response. However, older people and individuals in disadvantaged communities were less likely to engage. IMPLICATIONS FOR PUBLIC HEALTH: Responses to future pandemics should leverage the resource-efficiency of digital interventions but should avoid compounding existing health inequalities.

Rapid on-site molecular Point of Care Testing during influenza outbreaks in aged care facilities improves antiviral use and reduces hospitalisation.

OBJECTIVE: Western Sydney Local Health District (WSLHD) measured the utility and validity of rapid molecular point-of-care testing (POCT) in aged care facilities (ACFs) experiencing influenza-like illness (ILI) outbreaks against routine laboratory testing. METHODS: A descriptive epidemiological study into 82 respiratory outbreaks reported across 63 ACFs within WSLHD supporting approximately 6,500 residents aged ≥65 years and staffed by ∼6,500 employees, from 1 August 2018 to 31 December 2019. RESULTS: WSLHD Public Health Unit performed on-site testing at 27 ACF outbreaks (34%), while 53(66%) ACFs conducted only routine laboratory testing. The Xpert®Xpress Flu/RSV molecular PCR provided a sensitivity and specificity of 100%. Those with on-site testing, antiviral prophylaxis was prescribed at 75% of facilities within 24 hours of testing, as opposed to 32% of those using laboratory testing (p<0.01). There were 24 of 181 ACF residents hospitalised in the POCT group compared to 76 of 357 in the laboratory-only group (OR=0.57; p=0.02). CONCLUSIONS: On-site ACF testing is reliable and practical for early identification of influenza, enabling timely use of antiviral treatment and prophylaxis, and was associated with decreased hospitalisation. PUBLIC HEALTH IMPLICATIONS: Enhanced respiratory surveillance and on-site testing should be strongly considered as part of routine management of respiratory outbreaks in ACFs and may reduce outbreak severity.

Outbreaks of Human Metapneumovirus in Western Sydney Aged-Care Facilities in 2018.

Background: Human metapneumovirus (hMPV), first described in 2001, is a cause of acute respiratory tract infection in the elderly, with symptoms ranging from mild to severe, including pneumonia, but outbreaks are rarely described. Methods: Between 1 July and 31 December 2018, there were three outbreaks of Influenza-like Illness (ILI) where hMPV was the primary pathogen observed, among 64 aged-care facilities (ACFs) in Western Sydney. These outbreaks were investigated by the Western Sydney Local Health District (WSLHD) Public Health Unit (PHU); multiplex polymerase chain reaction (PCR) testing was performed on nasopharyngeal swabs collected by the ACF. Results: hMPV was the main causative pathogen in three outbreaks (27, 28, and 15 symptomatic cases, respectively) in late winter and early spring. Fifty-five residents and 15 staff cases (70 total cases) were identified; hMPV was detected in 12 of 63 specimens submitted. Of the cases in residents, eight were hospitalised (8/63; 15%), including five with confirmed hMPV and a further one epidemiologically linked to a positive case. Six residents died (6/63; 11%) during the hMPV outbreaks; four of these had laboratory-confirmed hMPV, with a further case epidemiologically linked to a hMPV case, with a primary diagnosis of pneumonia/viral pneumonia. The sixth death was not epidemiologically linked, nor did this case exhibit any respiratory symptoms during the outbreak; however, it was reported in line with public health guidelines. Conclusion: A major challenge in 2018 was the incompleteness of testing for, and awareness of, hMPV as a viral cause of ILI by facilities, laboratories, and emergency departments, which generally opted for rapid testing for influenza and RSV only. There is no licensed vaccine or approved treatment for hMPV, so efficient infection control measures are most important.

Salmonella Paratyphi A infection: implications for public health management of extra-intestinal presentations - case study of a neck abscess.

ABSTRACT: This study explores the implications of unusual presentations of Salmonella enterica subsp. enterica ser. Paratyphi (S. Paratyphi) infection for public health management, through a literature review and case study. In 2016, a 36-year-old male presented with a five-day history of right sided painful neck swelling, coryza and a two-day history of fevers after arriving in Australia from India nine weeks earlier. S. Paratyphi A was isolated from a fine needle aspirate sample. A descriptive epidemiological review was performed of confirmed cases of S. Paratyphi notified in New South Wales between 2008 and 2017. S. Paratyphi was isolated in blood and/or faecal samples in 247 cases (98.4%). Only four specimens (1.6%) were from a focal site. A literature review of extraintestinal infections of S. Paratyphi A or B was performed. Of the 41 such cases reported, 16 (39%) had a clear history of a prior gastroenteritis and/or febrile illness, or information suggested this was highly likely. No preceding gastroenteritis or febrile illness occurred in 15 (37%) of the cases. Information was reviewed and presented with a public health lens, valuable for 'evidence-informed' public health risk assessment of contacts and exposures related to these types of S. Paratyphi infection. S. Paratyphi infection usually presents as an enteric fever illness. Our case illustrates the variable nature of infectious diseases and the importance of laboratory testing in obtaining a diagnosis. S. Paratyphi can have unusual presentations, which may require adjustment in the public health management of the case. Public health staff should keep an open mind when investigating possible sources and assessing risk. In Western Sydney, this disease is largely associated with residents travelling to high-incidence countries to visit family and friends, and receiving family visits from these countries. The increasing number of cases of S. Paratyphi (prior to COVID-19) in Western Sydney and the importance of awareness of the risk of enteric fever to travellers to endemic regions is highlighted.

Epidemiologic Evidence for Airborne Transmission of SARS-CoV-2 during Church Singing, Australia, 2020.

An outbreak of severe acute respiratory syndrome coronavirus 2 infection occurred among church attendees after an infectious chorister sang at multiple services. We detected 12 secondary case-patients. Video recordings of the services showed that case-patients were seated in the same section, up to 15 m from the primary case-patient, without close physical contact, suggesting airborne transmission.

Detailed characterisation of the tuberculosis epidemic in Western Sydney: a descriptive epidemiological study.

Traditional tuberculosis (TB) epidemiology reports rarely provide a detailed analysis of TB incidence in particular geographic locations and among diverse population groups. Western Sydney Local Health District (WSLHD) has one of the highest TB incidence rates in Australia, and we explored whether more detailed epidemiological analysis could provide a better overview of the local disease dynamics. Using multiple relevant data sources, we performed a retrospective descriptive study of TB cases diagnosed within the WSLHD from 2006 to 2015 with a specific focus on geographic hotspots and the population structure within these hotspots. Over the study period nearly 90% of Western Sydney TB cases were born in a high TB incidence country. The TB disease burden was geographically concentrated in particular areas, with variable ethnic profiles in these different hotspots. The most common countries of birth were India (33.0%), the Philippines (11.4%) and China (8.8%). Among the local government areas in Western Sydney, Auburn had the highest average TB incidence (29.4 per 100 000) with exceptionally high population-specific TB incidence rates among people born in Nepal (average 223 per 100 000 population), Afghanistan (average 154 per 100 000 population) and India (average 143 per 100 000 population). Similar to other highly cosmopolitan cities around the world, the TB burden in Sydney showed strong geographic concentration. Detailed analysis of TB patient and population profiles in Western Sydney should guide better contextualised and culturally appropriate public health strategies.

Monitoring tuberculosis contact tracing outcomes in Western Sydney, Australia.

Treatment of latent tuberculosis infection (LTBI) is an important component of strategies to achieve global tuberculosis (TB) elimination, but implementation is rarely monitored. This is a retrospective review of TB contact tracing outcomes at one of the busiest TB clinics in Australia, measured against the Centre for Disease Control and Prevention performance indicators. In total, 45 of 53 (85%) pulmonary TB cases had 171 close contacts, of whom 139 (81%) were evaluated with a tuberculin skin test (TST); 58 of 139 (42%) were positive at baseline. Among 57 close contacts of 16 sputum smear-positive TB cases, the elicitation, evaluation, initiation of LTBI treatment and completion rates were 93%, 86%, 14% and 100%, and among 114 close contacts of 37 sputum smear-negative pulmonary TB cases 81%, 83%, 16% and 89%, respectively. Of 79 contacts with an initial negative TST, 19 of 47 (40%) demonstrated TST conversion when retested; 5 of 19 (26%) were offered LTBI treatment. Four secondary TB cases were identified. One incident TB case developed a pleural effusion 5 months after TST conversion, despite LTBI treatment. Apart from young children, LTBI treatment was inconsistently initiated in household TB contacts. Safe and pragmatic treatment options, as well as functional monitoring frameworks, are essential to improve LTBI treatment implementation.

Seven Salmonella Typhimurium Outbreaks in Australia Linked by Trace-Back and Whole Genome Sequencing.

Salmonella Typhimurium is a common cause of foodborne illness in Australia. We report on seven outbreaks of Salmonella Typhimurium multilocus variable-number tandem-repeat analysis (MLVA) 03-26-13-08-523 (European convention 2-24-12-7-0212) in three Australian states and territories investigated between November 2015 and March 2016. We identified a common egg grading facility in five of the outbreaks. While no Salmonella Typhimurium was detected at the grading facility and eggs could not be traced back to a particular farm, whole genome sequencing (WGS) of isolates from cases from all seven outbreaks indicated a common source. WGS was able to provide higher discriminatory power than MLVA and will likely link more Salmonella Typhimurium cases between states and territories in the future. National harmonization of Salmonella surveillance is important for effective implementation of WGS for Salmonella outbreak investigations.

Towards public health surveillance of intensive care services in NSW, Australia.

OBJECTIVES: Outbreaks of known and novel pathogens causing very severe illness increase the risk to public health in a globalised community and alarm the public. Intensive care units (ICUs) may be an underused setting for public health surveillance. This study investigates the electronic Record for Intensive Care (eRIC), an electronic clinical information and management system being developed for New South Wales ICUs, and its surveillance opportunity offerings. METHODS: The surveillance benefits being introduced by the eRIC were evaluated through consultation with stakeholders and the eRIC program team. The consultation process involved providing stakeholders with background information about the eRIC system. Based on the consultation, a draft data and information model for surveillance was developed. The model was evaluated using guidelines from the US Centers for Disease Control and Prevention. RESULTS: Population health stakeholders confirmed that the eRIC offers an appealing surveillance data source for pathogens and other hazards causing severe illness. Suggested application of the surveillance included, for known hazards, seasonal and pandemic influenza, enterovirus 71, Murray Valley encephalitis virus, enterohaemorrhagic Escherichia coli 0104:H4 and parechovirus. The proposed surveillance model uses syndromic rather than specific-cause surveillance. It may offer greater timeliness and sensitivity than relying on reporting of diagnoses of specific pathogens. Five syndromes derived from clinical pathways in the eRIC are proposed: severe acute respiratory disease, severe acute neurological disease, sepsis or septicaemia, jaundice or hepatitis, and acute renal failure. CONCLUSION: New intensive care clinical information systems offer a largely untapped resource for continuous, mainstream, rapid ICU surveillance of severe illness. A continuous, mainstream, rapid ICU surveillance facility that will readily adapt to emergency situations would be a valuable resource for protecting population health. This study establishes a firm basis on which ICU surveillance can be developed.

Narrative review of strategies by organizations for building evaluation capacity.

Program evaluation is an important source of information to assist organizations to make "evidence-informed" decisions about program planning and development. The objectives of this study were to identify evaluated strategies used by organizations and program developers to build the program evaluation capacity of their workforce, and to describe success factors and lessons learned. Common elements for successful evaluation capacity building (ECB) include: a tailored strategy based on needs assessment, an organizational commitment to evaluation and ECB, experiential learning, training with a practical element, and some form of ongoing technical support within the workplace. ECB is a relatively new field of endeavor, and, while existing studies in ECB are characterized by lower levels of evidence, they suggest the most successful approaches to ECB are likely to be multifaceted. To build the level of evidence in this field, more rigorous study designs need to be implemented in the future.

The changing epidemiology of measles in an era of elimination: lessons from health-care-setting transmissions of measles during an outbreak in New South Wales, Australia, 2012.

INTRODUCTION: In countries where measles is rare, health-care-setting transmissions remain problematic. Australia experienced its largest measles outbreak in 15 years in 2012 with 199 cases reported nationally; 170 cases occurred in the state of New South Wales (NSW) with symptom onset between 7 April and 29 November 2012. METHODS: A descriptive study was conducted using measles case data obtained from metropolitan Sydney local health districts in NSW in 2012. Characteristics of measles source and secondary cases were described. Details of health-care presentations resulting and not resulting in measles transmission were also analysed. RESULTS: There were 168 confirmed and two probable cases resulting in 405 documented health-care presentations. Thirty-four secondary cases acquired in health-care settings were identified, including 29 cases resulting from 14 source cases and 5 cases whose source could not be identified. Health-care-acquired cases accounted for 20% of all cases in this outbreak. Source cases were more likely to be of Pacific Islander descent (P = 0.009) and to have had more presentations before diagnosis (P = 0.012) compared to other cases. The percentage of presentations to emergency departments was higher for presentations that resulted in transmission compared to those that did not (71.4% and 37.6%, respectively, P = 0.028). There were no significant differences between transmission and non-transmission presentations with respect to presence of rash and infection control measures (P = 0.762 and P = 0.221, respectively), although the power to detect these differences was limited. Rash was reported at 66% of the presentations. CONCLUSION: Development of and adherence to protocols for the management of patients presenting to hospitals with fever and rash will minimize secondary transmission of measles.

Use of a prohibition order after a large outbreak of gastroenteritis caused by norovirus among function attendees.

INTRODUCTION: In May 2011, an outbreak of acute gastroenteritis occurred among guests attending two functions (Function A and B) at a local function centre in Sydney, Australia. The Sydney South West Public Health Unit and the New South Wales (NSW) Food Authority sought to determine the cause of the outbreak and implement control measures. METHODS: A retrospective cohort study was planned. A complete guest list was unavailable, so guests who could be contacted were asked to provide details of other guests. Attendee demographics, symptom profile and food histories were obtained using a standard response questionnaire. Stool samples were requested from symptomatic guests. The NSW Food Authority conducted a site inspection. RESULTS: Of those interviewed, 73% of Function A guests and 62% of Function B guests were ill, with mean incubation times of 27 and 23 hours respectively. Diarrhoea was the most common symptom. Three stool samples and four environmental swabs were positive for norovirus. One food handler reported feeling ill before and during the functions. A prohibition order was used to stop food handlers implicated in the outbreak from preparing food. DISCUSSION: This outbreak strongly suggests transmission of norovirus, possibly caused by an infected food handler. Regulatory measures such as prohibition orders can be effective in enforcing infection control standards and minimising ongoing public health risk.

A large point-source outbreak of Salmonella Typhimurium linked to chicken, pork and salad rolls from a Vietnamese bakery in Sydney.

INTRODUCTION: In January 2011, Sydney South West Public Health Unit was notified of a large number of people presenting with gastroenteritis over two days at a local hospital emergency department (ED). METHODS: Case-finding was conducted through hospital EDs and general practitioners, which resulted in the notification of 154 possible cases, from which 83 outbreak cases were identified. Fifty-eight cases were interviewed about demographics, symptom profile and food histories. Stool samples were collected and submitted for analysis. An inspection was conducted at a Vietnamese bakery and food samples were collected and submitted for analysis. Further case ascertainment occurred to ensure control measures were successful. RESULTS: Of the 58 interviewed cases, the symptom profile included diarrhoea (100%), fever (79.3%) and vomiting (89.7%). Salmonella Typhimurium multiple-locus-variable number tandem repeats analysis (MLVA) type 3-10-8-9-523 was identified in 95.9% (47/49) of stool samples. Cases reported consuming chicken, pork or salad rolls from a single Vietnamese bakery. Environmental swabs detected widespread contamination with Salmonella at the premises. DISCUSSION: This was a large point-source outbreak associated with the consumption of Vietnamese-style pork, chicken and salad rolls. These foods have been responsible for significant outbreaks in the past. The typical ingredients of raw egg butter or mayonnaise and pate are often implicated, as are the food-handling practices in food outlets. This indicates the need for education in better food-handling practices, including the benefits of using safer products. Ongoing surveillance will monitor the success of new food regulations introduced in New South Wales during 2011 for improving food-handling practices and reducing foodborne illness.