Survey of neonatal unit outbreaks in North London: identifying causes and risk factors.

BACKGROUND: This survey was undertaken after a number of neonatal unit (NNU) outbreaks were reported to the North London health protection teams (HPTs). AIM: To determine the diversity of the outbreaks, ascertain potential sources and contributing factors, and identify the investigative procedures followed and control measures implemented. METHODS: Using a structured questionnaire, information from the HPT database was collected for all NNU outbreaks reported between January 2010 and February 2011. FINDINGS: Ten outbreaks were identified from seven hospitals in 14 months. There was one para-influenza outbreak, seven Staphylococcus aureus [including six meticillin-resistant S. aureus (MRSA)] outbreaks, and two Gram-negative outbreaks. Potential sources of transmission identified for the MRSA outbreaks were healthcare worker (HCW)-assisted transmission (N = 2) and mother-to-baby transmission with onward HCW-assisted transmission (N = 3). An environmental source with onward HCW-assisted transmission was documented for one of the Gram-negative outbreaks. Interventions included patient screening and enhanced cleaning (N = 10), isolating/cohorting affected neonates (N = 9), barrier nursing (N = 6), staff movement restrictions (N = 5), hand hygiene audits (N = 4), staff screening (N = 4), household contact screening (N = 3) and environmental sampling (N = 3). Potential contributing factors included inadequate staffing levels, cluttered unit, inadequate sterilization of communal milk-expressing equipment and inappropriate follow-up of MRSA results. CONCLUSION: This survey determined the diversity of NNU outbreaks in North London, and highlighted the importance of a multi-faceted approach to outbreak control. These data will assist in the development of clinical standards for the prevention, control and reporting of NNU outbreaks, and guidance for best practice in NNUs.

No evidence of transmission from an acute case of hepatitis A in a foodhandler: follow-up of almost 1,000 potentially exposed individuals, London, United Kingdom, April 2012.

Identification of acute hepatitis A virus (HAV) infection in a foodhandler in a London hotel led to a large incident response. We identified three potentially exposed groups: hotel staff who had regularly consumed food prepared by the case and shared toilet facilities with the case, patients who shared the same hospital ward as the case and hotel guests who consumed food prepared by the case. We arranged post-exposure HAV vaccination for all 83 potentially exposed hotel staff and all 17 patients. We emailed 887 guests advising them to seek medical care if symptomatic, but did not advise vaccination as it was too late to be effective for most guests. Through the International Health Regulations national focal points and the European Union Early warning and response system (EWRS), we communicated the details of the incident to public health agencies and potential risk of HAV transmission to international guests. Potentially exposed hotel staff and guests were asked to complete an online or telephone-administered questionnaire 50 days following possible exposure, to identify any secondary cases. Survey response was low, with 155 responses from guests and 33 from hotel staff. We identified no secondary cases of HAV infection through follow-up.

Retrospective analysis of whole genome sequencing compared to prospective typing data in further informing the epidemiological investigation of an outbreak of Shigella sonnei in the UK.

The aim of this study was to retrospectively assess the value of whole genome sequencing (WGS) compared to conventional typing methods in the investigation and control of an outbreak of Shigella sonnei in the Orthodox Jewish (OJ) community in the UK. The genome sequence analysis showed that the strains implicated in the outbreak formed three phylogenetically distinct clusters. One cluster represented cases associated with recent exposure to a single strain, whereas the other two clusters represented related but distinct strains of S. sonnei circulating in the OJ community across the UK. The WGS data challenged the conclusions drawn during the initial outbreak investigation and allowed cases of dysentery to be implicated or ruled out of the outbreak that were previously misclassified. This study showed that the resolution achieved using WGS would have clearly defined the outbreak, thus facilitating the promotion of infection control measures within local schools and the dissemination of a stronger public health message to the community.

From containment to community: Trigger points from the London pandemic (H1N1) 2009 influenza incident response.

OBJECTIVE: In the UK, during the first wave of pandemic (H1N1) 2009 influenza, a national 'containment' strategy was employed from 25 April to 2 July 2009, with case finding, treatment of cases, contact tracing and prophylaxis of close contacts. The aim of the strategy was to delay the introduction and spread of pandemic flu in the UK, provide a better understanding of the course of the novel disease, and thereby allow more time for the development of treatment and vaccination options. STUDY DESIGN: Descriptive study of the management of the containment phase of pandemic (H1N1) 2009 influenza. METHODS: Analysis of data reported to the London Flu Response Centre (LFRC). RESULTS: The average number of telephone calls and faxes per day from health professionals before 15 June 2009 was 188, but this started to rise from 363 on 12 June, to 674 on 15 June, and peaked on 22 June at 2206 calls. The number of cases confirmed [by pandemic (H1N1) 2009 influenza specific H1 and N1 polymerase chain reaction] in London rose to a peak of 200 cases per day. There were widespread school outbreaks reporting large numbers of absences with influenza-like illnesses. Activity in the LFRC intensified to a point where London was declared a 'hot spot' for pandemic (H1N1) 2009 influenza on 19 June 2009 because of sustained community transmission. The local incident response was modified to the 'outbreak management phase' of the containment phase. CONCLUSIONS: The sharp rise in the number of telephone calls and the rise in school outbreaks appeared to be trigger points for community transmission. These indicators should inform decisions on modifying public health strategy in pandemic situations.

Hepatitis A outbreak in an Orthodox Jewish community in London, July 2010.

A cluster of hepatitis A cases in the Orthodox Jewish community in London, United Kingdom in July 2010 has triggered extensive contact tracing and vaccination. Two primary cases imported from a common source in Israel and three secondary cases have resulted in immunisation of over 900 contacts to date. Rapid response by local public health, primary care services and a dedicated community health team, and active hepatitis A vaccination rather than immunoglobulin treatment were used to avert a larger outbreak.

Assessing public health risk in the London polonium-210 incident, 2006.

OBJECTIVES: Mr Alexander Litvinenko died in a London hospital on 23 November 2006, allegedly from poisoning with the radionuclide polonium-210 ((210)Po). Associated circumstances required an integrated response to investigate the potential risk of internal contamination for individuals exposed to contaminated environments. STUDY DESIGN: Descriptive study. METHODS: Contaminated locations presenting a potential risk to health were identified through environmental assessment by radiation protection specialists. Individuals connected with these locations were identified and assessed for internal contamination with (210)Po. RESULTS: In total, 1029 UK residents were identified, associated with the 11 most contaminated locations. Of these, 974 were personally interviewed and 787 were offered urine tests for (210)Po excretion. Overall, 139 individuals (18%) showed evidence of probable internal contamination with (210)Po arising from the incident, but only 53 (7%) had assessed radiation doses of 1mSv or more. The highest assessed radiation dose was approximately 100mSv. CONCLUSIONS: Although internal contamination with (210)Po was relatively frequent and was most extensive among individuals associated with locations judged a priori to pose the greatest risk, a high degree of assurance could be given to UK and international communities that the level of health risk from exposure to the radionuclide in this incident was low.

A fatal case of Lassa fever in London, January 2009.

In January 2009, the eleventh [corrected] case of Lassa fever imported to the United Kingdom was diagnosed in London. Risk assessment of 328 healthcare contacts with potential direct exposure to Lassa virus - through contact with the case or exposure to bodily fluids - was undertaken. No contacts were assessed to be at high risk of infection and no secondary clinical cases identified.