Informing the use of a supplementary immunisation programme for the management of a community cluster of invasive meningococcal disease, Yorkshire, 2022.

OBJECTIVES: To outline the management of a community cluster of serogroup B invasive meningococcal disease (IMD) cases, including key factors for decision making and the choice and implementation of control measures. STUDY DESIGN: Descriptive report of cluster management. METHODS: Subtyping of IMD cases identified a number of potentially linked cases in a defined geographical area. An Incident Management Team (IMT) was convened to coordinate the public health response. A case definition was developed in order to identify further cases within the cluster. RESULTS: Four cases of IMD met the case definition and were initially considered as part of this cluster. Three resided in the same small town, which was the focus for public health management. The IMT agreed that it would be proportionate to instigate additional control measures. The population at higher risk of infection were identified, and a supplementary vaccination programme was rolled out in the community. Over five clinics, 45.6% (639/1401) of the target cohort received at least one dose of the vaccine, with 34.7% (486/1401) receiving both doses. Inequalities in uptake were observed by sex, age and deprivation. CONCLUSIONS: Decision making for public health responses to IMD clusters is complex. Informed by epidemiological evidence, numerous partners engaged in collaborative decision making, which was critical for the effective implementation of the community response. Links between the local authority public health team and the community enabled the use of existing structures and relationships to maximise the number of vaccinations delivered. No further cases of IMD linked to this cluster were identified.

An outbreak of hepatitis A virus infection in a secondary school in England with no undetected asymptomatic transmission among students.

In June 2019 the Health Protection Team in Yorkshire and Humber, England, was notified of cases of hepatitis A virus (HAV) infection in staff at a secondary school. Investigation revealed that an earlier case worked as a food handler in the school kitchen. Indirect transmission through food from the canteen was considered the most likely route of transmission. Cases were described according to setting of exposure. Oral fluid was obtained from students for serological testing. Environmental investigations were undertaken at settings where food handling was considered a potential transmission risk. Thirty-three confirmed cases were linked to the outbreak. All of those tested (n = 31) shared the same sequence with a HAV IB genotype. The first three cases were a household cluster and included the index case for the school. A further 19 cases (16 students, 3 staff) were associated with the school and consistent with indirect exposure to the food handler. One late onset case could not be ruled out as a secondary case within the school and resulted in vaccination of the school population. Five cases were linked to a bakery where a case from the initial household cluster worked as a food server. No concerns about hygiene standards were noted at either the school or the bakery. Oral fluid samples taken at the time of vaccination from asymptomatic students (n = 219, 11-16 years-old) showed no evidence of recent or current infection. This outbreak included household and foodborne transmission but limited (and possibly zero) person-to-person transmission among secondary school students. Where adequate hygiene exists, secondary transmission within older students may not occur.

COVID-19: public health management of the first two confirmed cases identified in the UK.

We report key learning from the public health management of the first two confirmed cases of COVID-19 identified in the UK. The first case imported, and the second associated with probable person-to-person transmission within the UK. Contact tracing was complex and fast-moving. Potential exposures for both cases were reviewed, and 52 contacts were identified. No further confirmed COVID-19 cases have been linked epidemiologically to these two cases. As steps are made to enhance contact tracing across the UK, the lessons learned from earlier contact tracing during the country's containment phase are particularly important and timely.

An outbreak of campylobacteriosis at a hotel in England: the ongoing risk due to consumption of chicken liver dishes.

Despite a sizeable evidence base for the risk of campylobacteriosis associated with eating chicken liver pâté, associated outbreaks continue to occur. In January 2017, six cases of campylobacteriosis reported having eaten a Christmas set-menu meal at the same hotel in North Yorkshire, England on the same day. A retrospective cohort study was undertaken to test the null hypothesis that consumption of individual food items was not associated with an increased risk of illness. There were 19 cases of campylobacteriosis linked to the outbreak; seven confirmed and 12 probable cases. Chicken liver pâté was the food item most strongly associated with illness (P < 0.001) with a corresponding high crude relative risk (12.95). This relationship was supported by multivariable analysis, sensitivity analyses and a clear dose-response relationship. Three cases reported an incubation period of <24 h, consistent with other outbreaks of campylobacteriosis associated with consumption of poultry liver. The findings were suggestive of a single point source exposure with a strong association between the consumption of chicken liver pâté and campylobacteriosis. This outbreak highlights that despite evidence that simple cooking techniques can ensure that all campylobacter are killed during cooking, outbreaks continue to occur. Public and professional awareness needs to be raised through a strategic communication plan to reduce the risk of further outbreaks of campylobacteriosis linked to incorrectly cooked chicken liver dishes.

Inequalities in maternal pertussis vaccination uptake: a cross-sectional survey of maternity units.

Background: This study aims to estimate pertussis vaccine uptake in pregnant women in England, describe timing of vaccine delivery and examine variations in uptake. Methods: Cross-sectional survey of vaccine uptake in women delivering in maternity units in England. Variation in uptake described according to geography, maternal age, ethnicity and parity as reported by the midwife completing the survey. Results: A total of 1325 surveys were returned, 85% of which (1128) contained information about vaccination. Vaccine uptake was 61.8% (95% CI: 56.8-66.5) and was higher in the White British ethnic group than any other (67.7%, 95% CI: 63.5 to 71.5). Uptake was higher outside London (65.3%, 95% CI: 61.1-69.3) than within London (31.0%, 95% CI: 24.9-38.0). Reported uptake was lower in areas of high deprivation, and in women of higher parity, observations that were not statistically significant in the multivariable model. Overall, 74% of women were vaccinated between 28 and 32 weeks. Conclusions: Pertussis vaccine uptake in pregnant women varies significantly across the country and is affected by ethnicity, deprivation and parity. Variations should be addressed through service delivery models designed to reduce potential inequalities in infant protection.

Risk factors for pertussis in adults and teenagers in England.

Pertussis is a vaccine-preventable respiratory infection caused by Bordetella pertussis which can be fatal in infants. Although high vaccine coverage led to prolonged disease control in England, a national outbreak of pertussis in 2011 led to the largest increase in over two decades, including a marked increase in cases aged ⩾15 years. A case-control study in four regions of England was undertaken to investigate risk factors for pertussis in adolescents and adults, specifically employment type and professional and household contact with children. Pertussis cases were laboratory-confirmed and aged ⩾15 years. Controls were recruited through general practitioner nomination. Demographic and risk factor information were collected using an online survey. Multivariable logistic regression was used to estimate independent associations with outcome. Two hundred and thirty-one cases and 190 controls were recruited. None of the four employment variables (social care, education, health sector, patient contact) were significantly associated with pertussis. Professional contact with children aged < 1 year was associated with a significantly reduced odds of pertussis [odds ratio (OR) 0·25, 95% confidence interval (CI) 0·08-0·78, P = 0·017]. Household contact with ⩾1 child aged 10-14 years was associated with significantly increased odds of pertussis (OR 2·61, 95% CI 1·47-4·64, P = 0·001). Occupational contact with very young children was associated with reduced odds of pertussis, probably due to immune boosting by low-level exposures to B. pertussis. Sharing a household with a young adolescent was a significant risk factor for pertussis in adults and older teenagers. The primary focus of the childhood pertussis vaccination programmes is to prevent infant disease. Although evidence is emerging that adolescent vaccination does not provide indirect protection to infants, our results highlight the importance of children aged 10-14 years in pertussis transmission to older adolescents and adults.

Cohort study of a dual-pathogen point source outbreak associated with the consumption of chicken liver pâté, UK, October 2009.

BACKGROUND: In October 2009, a dual-pathogen outbreak of Campylobacter and Salmonella occurred in which 59 cases were identified among guests attending a regional conference in the North of England. The mean symptomatic period was 5.4 days ( confidence intervals: 4.4-6.4), and over 84% of the cases had abdominal pain and diarrhoea. METHODS: A retrospective cohort study was used to investigate the outbreak, and active case-finding was performed through the conference organizers and environmental health officers. A focused questionnaire was distributed to all guests via the event organizers 10 days after the conference. RESULTS: Response rate among guests was 61% (107/175). A cohort study was undertaken, and a strong association was found between illness and consumption of chicken liver pâté, supporting the hypothesis that chicken liver pâté was the most likely cause of the outbreak. CONCLUSION: This is the first mixed pathogen outbreak documented associated with the consumption of chicken liver pâté and adds to the evidence of potential hazards associated with the undercooking of poultry livers. A rapid outbreak investigation with collaboration between several organizations and the venue led to identification of the most probable source.

A practical review of 'containment' during the influenza A (H1N1): an audit of the flu response centre in Yorkshire and the Humber.

BACKGROUND: During the 'containment' phase of the influenza A (H1N1) pandemic 2009, antivirals were used for treatment and prophylaxis. This audit aimed to review the speed of the process involved in delivering antivirals and to assess whether this was likely to have occurred fast enough to be in keeping with the aims of reducing transmission. METHODS: Flu Response Centres in each region were tasked with co-ordinating local delivery and all case data were entered into Fluzone (an electronic case management system). All data between 1 June and 2 July in the Yorkshire and Humber region were reviewed. Forty-eight hours from the onset of illness to treatment and prophylaxis were used as reference standards. RESULTS: The median estimate for the earliest point cases could have received treatment was 2 days (95% CI 2-3 days) and the earliest point contacts of cases could have received prophylaxis was 4 days (95% CI 4-5 days). CONCLUSIONS: The logistical difficulties of delivering 'containment' according to the national algorithms meant there were significant time delays involved and that this was likely to have reduced the effectiveness of the strategy. This would be important to consider if a 'containment' strategy was to be employed in any future emergency.