News Archives |
Volume 4 No 37; 17 September 2010
- Increase in Salmonella Typhimurium DT8 in 2010 linked to duck eggs
- Dengue fever in France
- Continuing progress reported in prevention and control of HCAIs
Increase in Salmonella Typhimurium DT8 in 2010 linked to duck eggs
This report presents the conclusions of investigations carried out following an upsurge in cases of non-travel related gastro-intestinal illness caused by Salmonella Typhimurium Definitive Phage Type (DT) 8 in England and Northern Ireland in late summer 2010.
In July 2010, the Health Protection Agency's LabBase Exceedance Reporting System reported an increase in the number of Salmonella enterica isolates being typed as Salmonella Typhimurium definitive phage type (DT) 8. Microbiological and epidemiological investigations were initiated by the Centre for Infections Department of Gastrointestinal, Emerging and Zoonotic Infections (GEZI). The Salmonella Reference Laboratory (SRU), Laboratory of Gastrointestinal Pathogens (LGP) confirmed that isolates were fully susceptible to the LGP panel of antimicrobial drugs. The SRU had reported 66 cases of S. Typhimurium DT8 in 2010 up to and including week 36 (see figure) (compared to 34 and 47 in 2008 and 2009 respectively). Most cases were male (40, 61%) and 26 were female. Isolates have been submitted from Northern Ireland and most regions in England (see table), with predominance in the South East and North West . No cases were reported from Wales. The cases range in age from 0 to 80 years; with an average age of 46 (median 46) years. Two cases are known to have been hospitalised, with one death reported (although at present it is uncertain whether the death is directly related to the Salmonella infection).
The GEZI Epidemiological Services Team coordinated and conducted epidemiological and trace back investigations. Detailed food histories collected from 21 cases during July and August known not to have travelled outside the UK. These revealed that 14 (67%) had eaten duck products: duck eggs (11); duck liver pate (2); and duck meat (1).
Follow up of supply chains of duck eggs consumed by cases of S. Typhimurium DT8 infection found that the eggs came from a variety of sources, ie from local small retailers, farms or at market places. Duck eggs contaminated with the outbreak strain were collected from a patient's home and investigations by the Food Standards Agency also revealed evidence of S. Typhimurium DT8 further up the duck egg supply chain. The Republic of Ireland has also reported an outbreak of S. Typhimurium DT8 associated with duck eggs in 2010 [1,2].
Regional distribution of fully sensitive Salmonella Typhimurium DT8 cases, England and Northern Ireland, January - September 2010Region |
Reports in 2010 |
|---|---|
East of England |
8 |
London |
3 |
North East |
4 |
East Midlands |
1 |
North West |
10 |
South East |
15 |
South West |
8 |
West Midlands |
5 |
Yorkshire and The Humber |
4 |
Northern Ireland |
8 |
Wales |
0 |
Total |
66 |
Epidemic curve of fully sensitive Salmonella Typhimurium DT8 reports, England and Northern Ireland, January - September 2010 (n=66) 
Maintaining high hygiene standards for the production of duck eggs can be more difficult than it is for hens. The presence of open water troughs, naturally moist faeces, earth floors and straw bedding can lead to difficulties maintaining low moisture levels in bedding and effective disinfection between flocks. Eggs are laid in nests in the straw bedding and this may lead to contamination if Salmonella is present in the flock. Advice on improved biosecurity, hygiene and vaccination is provided to duck farmers if S. Typhimurium DT8 is found on the premises.
Consumers and caterers need to be aware that a ll eggs, including duck eggs, may occasionally be contaminated with Salmonella and follow advice provided by the Food Standards Agency in order to reduce the risk of infection [3,4]. Eggs should be cooked thoroughly and good hygiene practices, such as washing hands, utensils and preparation surfaces after handling or using duck eggs.References
1. Health Protection Surveillance Centre, Ireland. Nationwide Salmonella Typhimurium DT8 outbreak linked to duck eggs. Disease Surveillance Report of HPSC, Ireland, 11(5), May 2010. Available at: http://ndsc.newsweaver.ie/epiinsight/yjgisj9h2px1d27jpionwl.
2. Food Safety Authority of Ireland. Largest outbreak in recent years linked to Salmonella in duck eggs. Available at: http://www.fsai.ie/14092010.html.
3. Food Standards Agency. Eggs. Available at: http://www.eatwell.gov.uk/healthydiet/nutritionessentials/eggsandpulses/eggs/
4. Food Standards Agency. Eggs - Advice for caterers. Available at: http://www.food.gov.uk/foodindustry/caterers/eggs/.
On 13 September 2010, the Ministry for Health and Sport in France reported the first confirmed case of autochthonous (locally acquired) dengue fever on the French mainland [1]. The case resided in Nice, in the department of Alpes-Maritimes in southern France, and developed symptoms in August. The case had not travelled abroad or received any blood transfusions before onset of illness and has now fully recovered. At present no further cases have been reported.
This is the first autochthonous case of dengue fever to be reported in mainland Europe since 1928 when outbreaks were reported in Greece [2]. Although this is an extremely rare event, it is not unexpected, as a large number of imported cases of dengue are reported in France and the mosquito vector, Aedes albopictus, is well established in southern France. However, A. albopictus is a less efficient vector of dengue than A. aegypti, which is the vector responsible for the majority of dengue outbreaks worldwide, therefore the risk of a larger outbreak occurring is thought to be low at this time [3]. Epidemiological and entomological surveillance within Alpes-Maritimes has been strengthened and vector control measures in the area around where the case is resident have been implemented.
In the UK, around 150 imported cases of dengue fever are reported each year; most are associated with travel to South East Asia, the Caribbean and Latin America. Health professionals who suspect a case of dengue fever should send appropriate samples for testing (with full travel and clinical history) to the HPA Special Pathogens Reference Unit.
The risk of travellers acquiring dengue fever in France is very low but all travellers should practise mosquito bite avoidance when visiting countries where mosquitoes are present. Aedes mosquitoes bite in the day, particularly around dawn and dusk. More information about mosquito bite avoidance is available on the NaTHNaC website.
For more information about dengue fever, please see the dengue pages of the HPA website.
References
1. Le Ministère de la Santé et des Sports. Premier cas autochtone isolé de dengue en France métropolitaine 13 septembre 2010 [in French]. [Accessed 17 September 2010]. Available at: http://www.sante-sports.gouv.fr/premier-cas-autochtone-isole-de-dengue-en-france-metropolitaine.html.
2. European Centre for Disease Prevention and Control (ECDC). Dengue fever in France, 16 September 2010. [Accessed 17 September 2010].
3. ECDC threat assessment 16 September 2010 [Accessed 17 September 2010].
Continuing progress reported in prevention and control of HCAIs
The success of the Department of Health's (DH) multi-faceted programme for the reduction of healthcare-associated infections (HCAIs), and related mortality, from their peaks between 2003 and 2006 has been considerable and sustained.
Annual infection rates for MRSA bacteraemia have been reduced by 75% from their peak in 2003/04 - when 7,700 MRSA bacteraemias were reported - to 1,898 in 2009/10 [1]. A similar scale of reduction was achieved in respect of Clostridium difficile infections (CDI ): since their peak in 2006/07 when - although reporting was at the time limited to over-65 year-olds - there were 55,681 infections, which were reduced to 25,604 by 2009/10, when infections in all people over two years of age were included. Parallel reductions had been achieved in HCAI-related mortality: deaths in which MRSA had been reported to have been an underlying cause fell from a peak of 480 in 2006 to 133 in 2009, and deaths in which CDI was an underlying cause fell from a peak of 3875 in 2007 to 1510 in 2009 [2].
The latest annual review (for 2009/10) of Health Protection Agency activities related to HCAI prevention and control in NHS acute trust hospitals in England, and to the monitoring of antimicrobial resistance throughout the UK, has been published on the HPA website [3]. Highlights of the report, Healthcare-associated infections and antimicrobial resistance: 2009/10, are:- there was a 35% year-on-year reduction in MRSA bacteraemia cases reported in 2009/10: 1,898 cases of compared with the previous year when 2,935 cases were reported;
- in the same period, there was a 29% reduction in CDI cases reported: 25,604 cases compared with the previous year when 36,095 cases were reported;
- monthly reports of mandatory surveillance data, along with quarterly and annual tables, were introduced;
- the e-Bug project, to support teaching in schools, was launched in September 2009;
- a web-based data capture system to record cases of MRSA and CDI is being redesigned to help NHS trusts submit data and use it more effectively.
Most recently, the HPA's latest quarterly commentary on data generated by the mandatory surveillance of HCAIs in NHS acute trust hospitals in England, covering April-June 2010, has also been published on the HPA website, confirming the continuing, significant reductions in overall reports of both MRSA bacteraemia and CDI, both year-on-year and compared with the previous quarter. MRSA reports in April-June 2010 were reduced by 13% compared to the January-March 2010, from 482 to 419; and CDI reports were reduced by 6% compared with the previous quarter, from 482 to 419 (see the routine reports section of this issue of HPR [4]).
Future developments
The DH is applying a new rolling programme of annual "objectives" to performance management relating to HCAI prevention and control in order to further reduce infection rates and HCAI-related mortality. Reductions achieved to date had been most dramatic in Trust-apportioned cases of infection (those presumed to have been acquired in hospital) whereas the "other infections" category, those that may have been acquired outside hospital, have been less marked, suggesting that in future greater efforts will have to be made in primary care and other community settings [2].
The DH's programme is expected to address the different risk factors that may apply to different patient populations through its developing programme of HCAI prevention and control measures, including among other measures: the screening for MRSA of all hospital admissions from the start of 2011 and the expected extensions of mandatory reporting to include other infection categories, as has been recommended by the government's Advisory Committee on Antimicrobial Resistance and Healthcare Associated Infections (ARHAI) [5]. A session at last week's HPA annual conference at Warwick University [6] included presentations about HCAI prevention, control and surveillance arrangements in the Devolved Administrations where, in some cases mandatory reporting requirements are more extensive than in England.
References
1. MRSA bacteraemia and C. difficile mandatory reports 2009/10, HPR 4(28), 16 July 2010.
2. "Zero tolerance - the clinical challenges ahead", presentation by the Department of Health's inspector for microbiology and infection control, Dr Brian Duerden, at the national conference, "Reducing HCAIs 2010 - a transformation process: embedding the culture of patient safety", Wednesday, 8 September 2010, London, organised by GovToday.
3. HPA. Healthcare-associated infections and antimicrobial resistance: 2009/10. HPA website: Home > Publications > Infectious diseases > Antimicrobial and healthcare associated infections.
4. HPA. "Quarterly epidemiological commentary: mandatory MRSA bacteraemia and C. difficile infection (up to April-June 2010)", September 2010 (PDF, 515 KB). HPA website: Infections A-Z > Clostridium difficile > Epidemiological Data > Clostridium difficile Mandatory Surveillance > Quarterly Epidemiological Commentaries.
5. DH. Report on HCAI surveillance priorities - recommendations for HCAI surveillance in England, 25 March 2010, DH website.
6. See: www.hpa-events.org.uk/hp2010 > Programme >Wednesday-15-SEP-2010 > Quality and improvements in healthcare associated infections > Prevention and control of HCAIs: making a difference (0900-1035).