Preliminary investigation of a significant national Cryptosporidium exceedance in the United Kingdom, August 2023 and ongoing.

Routine laboratory surveillance has identified an unprecedented and ongoing exceedance of Cryptosporidium spp. across the United Kingdom, notably driven by C. hominis transmission, since 14 August 2023. Information from 477 reported cases in England and Wales, followed up with a standardised exposure questionnaire as of 25 September 2023, identified foreign travel in 250 (54%) of 463 respondents and swimming in 234 (66%) of 353 cases. A significant, common exposure has not yet been identified in first analyses.

National public health response to an outbreak of toxigenic Corynebacterium diphtheriae among asylum seekers in England, 2022: a descriptive epidemiological study.

BACKGROUND: In July, 2022, an increase in diphtheria cases caused by toxigenic Corynebacterium diphtheriae (C diphtheriae) was reported among asylum seekers arriving by small boats to England. Rising case numbers presented challenges for case and contact management in initial reception centres, prompting changes to national guidance and implementation of population-based control measures. This study aimed to describe the outbreak of toxigenic C diphtheriae among asylum seekers arriving by small boats to England during 2022 by use of national surveillance data. METHODS: We undertook a descriptive epidemiological analysis of cases of toxigenic C diphtheriae among asylum seekers arriving by small boats to England during 2022, incorporating genomic sequencing data, antibiotic susceptibility testing results, and epidemiological data obtained through the UK Health Security Agency's national enhanced surveillance programme. Health Protection Teams conducted risk assessments, and operational data (including details regarding offer and uptake of antibiotics and vaccinations) were obtained from National Health Service partners supporting the intervention programme. FINDINGS: In 2022, C diphtheriae isolates from 86 asylum seekers arriving by small boats were submitted to the National Reference Laboratory for confirmation and testing. Toxigenic C diphtheriae was confirmed for 72 (84%) cases and one individual with typical diphtheritic lesions but from whom no C diphtheriae was isolated from clinical swabs was also included as a probable case, resulting in 73 cases of diphtheria. 71 (97%) were male, 39 (53%) were younger than 18 years, and 36 (49%) presented with cutaneous diphtheria. The prevalence of diphtheria was highest among Afghans (1·3%) compared with all other nationalities (<0·1%). Local antibiotic susceptibility testing identified six cases with a macrolide resistant strain. INTERPRETATION: The increase in diphtheria coincided with a high volume of asylum seekers arriving by small boats to England during 2022, and subsequently increased clinical awareness of the disease among this population. Long-term disruption to vaccination programmes in origin countries along with barriers to accessing health care along migrant routes puts asylum seekers arriving by small boats at risk of disease. With arrivals expected to continue in 2023, the UK Health Security Agency has recommended continuation of population-based control measures in England until October, 2023, subject to ongoing review. FUNDING: The UK Health Security Agency.

Factors associated with delay in treatment initiation for pulmonary tuberculosis.

BACKGROUND: Delays in treatment initiation for tuberculosis (TB) may lead to worse clinical outcomes and increased transmission. We aimed to determine factors associated with treatment delays, to guide public health action. METHODS: We extracted data on clinical characteristics and documented potential barriers to treatment from all pulmonary TB cases with clinical case review data from 2011 to 2015 and linked these to TB surveillance data. We described the distribution of delays from symptom onset to first presentation ("presentation delay") and from presentation to treatment ("healthcare delay"). We calculated time ratios (TRs) to determine the association between sociodemographic and clinical factors and delay outcomes. RESULTS: Median presentation delay was 30 days (interquartile range (IQR) 11-72 days). Language barriers were associated with 40% longer presentation delay (TR 1.40, 1.01-1.94). Median healthcare delay was 40 days (IQR 13-89 days), and mostly consisted of the time taken before deciding to refer to TB specialists (median 26 days, IQR 4-73 days). Shorter healthcare delay was associated with positive sputum smear (TR 0.58, 0.47-0.70), UK residency <2 years (TR 0.47, 0.32-0.67), male sex (TR 0.74, 0.60-0.91) and secondary care referral (TR 0.63, 0.51-0.78). CONCLUSIONS: Our findings support continued initiatives to enable access to care for migrant populations to minimise presentation delay. Multifaceted approaches to increase clinician awareness of TB clinical presentations, to implement systems enabling early case recognition, to maximise the yield from sputum smear investigations and to ensure rapid diagnosis of smear negative cases are required to achieve further TB control.

Molecular diagnostics and the public health management of legionellosis.

In 2009-2010, we investigated four legionella cases notified over an 8-month period in two adjacent villages in South East England. Molecular techniques enabled us to conclude that three of the cases had distinct infections. The absence of an adequate respiratory sample in one case necessitated epidemiological investigations to exclude a potential common environmental source of further infections. One of the cases had spent a part of their incubation period in a country in South East Asia. DNA-sequence-based typing of their isolate showed it to be of the Legionella pneumophila serogroup 1 (LP1) DNA-sequence type (ST) 481. Intriguingly, the only other two ST 481 isolates in the European Working Group for Legionella Infections database were among Dutch travellers to the same country in 2003 and 2006. This case makes clear the value of molecular diagnostics and the importance of obtaining adequate clinical specimens. The potential future uses for typing data are discussed.

A large point-source outbreak of Salmonella Typhimurium phage type 9 linked to a bakery in Sydney, March 2007.

This report describes the investigation and public health response to a large point-source outbreak of salmonellosis in Sydney, Australia. The case-series investigation involved telephone interviews with 283 cases or their guardians and active surveillance through hospitals, general practitioners, laboratories and the public health network. In this outbreak 319 cases of gastroenteritis were identified, of which 221 cases (69%) presented to a hospital emergency department and 136 (43%) required hospital admission. This outbreak was unique in its scale and severity and the surge capacity of hospital emergency departments was stretched. It highlights that foodborne illness outbreaks can cause substantial preventable morbidity and resultant health service burden, requiring close attention to regulatory and non-regulatory interventions.

Audit of post-exposure treatment to prevent lyssavirus infection in Sydney South West Area Health Service, 2005-2007.

OBJECTIVES: To describe the profile of people who received post-exposure treatment to prevent lyssavirus infection in Sydney South West Area Health Service between 2005 and 2007 and to assess treatment compliance with the current NSW Health protocol. METHODS: Thirty-eight public health files and a subset of 11 medical records were reviewed to collect demographic, exposure and treatment information for the period. RESULTS: Twenty-nine (76%) potential Lyssavirus exposures occurred overseas. Nine potential exposures occurred within Australia; eight of these resulted from a bat bite or scratch. Thirteen (34%) of all potential exposures resulted from handling an animal. CONCLUSION: Many potential exposures were the result of a bite or scratch from a domesticated animal; the animal's survival or health status was not routinely recorded. While all people who commenced post-exposure treatment completed the prescribed course, this was often not within the stipulated timeframe.

Investigation of an outbreak of acute illness in a school group visiting Sydney, September 2006.

OBJECTIVE: We describe the investigation into an outbreak of acute illness in approximately 40 people attending Darling Harbour in Sydney during a school music camp. METHODS: We used three methods, including the Public Health Realtime Emergency Department Surveillance System, to obtain information on the food and travel history of the group and symptoms of the cases rapidly. RESULTS: Forty-five cases of gastroenteritis were identified in people on the bus trip. Most dates of onset of illness were obtained from triage text fields in the NSW Public Health Real Time Emergency Department Surveillance System, and were verified through medical record review and interviews. No causative agent was identified. CONCLUSION: The investigation suggested person-to-person transmission rather than a point source, and demonstrates how the NSW Public Health Real Time Emergency Department Surveillance System can assist with case finding in public health investigations.

Vibrio cholerae O1 El Tor cluster in Sydney linked to imported whitebait.

Three cases of cholera in women aged 71, 72 and 84 years were notified in November 2006 in Sydney, New South Wales. This is the first reported cluster of cholera in Australia for over 30 years, and was an unusual outbreak in patients with no history of recent travel to cholera-endemic areas. A food trace-back investigation found that the only exposure common to all cases was consumption of raw whitebait imported from Indonesia. This outbreak demonstrates that the practice of eating raw whitebait does occur in Australia, albeit in the process of taste-testing uncooked fritter batter. All three patients were undergoing long-term therapy with proton-pump inhibitors, which may have contributed to their susceptibility to the disease. A review of importation practices of food from cholera-endemic regions may be required to prevent future transmission.

Impact of ambient air pollution on gestational age is modified by season in Sydney, Australia.

BACKGROUND: The effect of individual pollutants and the period(s) during pregnancy when pollutant levels are likely to have most impact on preterm birth is not clear. We evaluated the effect of prenatal exposure to six common urban air pollutants in the Sydney metropolitan area on preterm birth. METHODS: We obtained information on all births in metropolitan Sydney between January 1, 1998 and December 31, 2000. For each birth, exposure to each air pollutant was estimated for the first trimester, the three months preceding birth, the first month after the estimated date of conception and the month prior to delivery. Gestational age was analysed as a categorical variable in logistic regression models. RESULTS: There were 123,840 singleton births in Sydney in 1998-2000 and 4.9% were preterm. Preterm birth was significantly associated with maternal age, maternal smoking, male infant, indigenous status and first pregnancy. Air pollutant levels in the month and three months preceding birth had no significant effect on preterm birth after adjusting for maternal and infant covariates. Ozone levels in the first trimester of pregnancy and spring months of conception and sulphur dioxide were associated with increased risks for preterm births. Nitrogen dioxide was associated with a decreased risk of preterm births. CONCLUSION: We found more protective than harmful associations between ambient air pollutants and preterm births with most associations non-significant. In view of these inconsistent associations, it is important to interpret the harmful effects with caution. If our results are confirmed by future studies then it will be imperative to reduce Sydney's already low air pollution levels even further.

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.

Effect of a chemical manufacturing plant on community cancer rates.

BACKGROUND: We conducted a retrospective study to determine if potential past exposure to dioxin had resulted in increased incidence of cancer in people living near a former manufacturing plant in New South Wales, Australia. During operation, from 1928 to 1970, by-products of the manufacturing process, including dioxin and other chemical waste, were dumped into wetlands and mangroves, discharged into a nearby bay and used to reclaim land along the foreshore, leaving a legacy of significant dioxin contamination. METHODS: We selected 20 Census Collector Districts within 1.5 kilometres of the former manufacturing plant as the study area. We obtained data on all cases of cancer and deaths from cancer in New South Wales from 1972 to 2001. We also compared rates for some cancer types that have been associated with dioxin exposure. Based on a person's residential address at time of cancer diagnosis, or at time of death due to cancer, various geo-coding software and processes were used to determine which collector district the case or death should be attributed to. Age and sex specific population data were used to calculate standardised incidence ratios and standardised mortality ratios, to compare the study area to two comparison areas, using indirect standardisation. RESULTS: During the 30-year study period 1,106 cases of cancer and 524 deaths due to cancer were identified in the study area. This corresponds to an age-sex standardised rate of 3.2 cases per 1,000 person-years exposed and 1.6 deaths per 1,000 person-years exposed. The study area had a lower rate of cancer and deaths from cancer than the comparison areas. The case incidence and mortality due to lung and bronchus carcinomas and haematopoietic cancers did not differ significantly from the comparison areas for the study period. There was no obvious geographical trend in ratios when comparing individual collector districts to New South Wales according to distance from the potential source of dioxin exposure. CONCLUSION: This investigation found no evidence that dioxin contamination from this site resulted in increased cancer rates in the potentially exposed population living around the former manufacturing plant.