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Archives | News Archives 2006: Page 1| 16 June 2005

News Archives: | 2006 | 2005 | 2004 | 2003

• Outbreak of Clostridium difficile infection in a hospital in south east England
  
• Enhanced Tuberculosis Surveillance – final results for tuberculosis cases reported in 2003 in England, Wales, and Northern Ireland
  
• European science academies call for increased co-ordination of activity over infectious diseases
  

Outbreak of Clostridium difficile infection in a hospital in south east England

There has been an outbreak of Clostridium difficile associated disease in an acute hospital in south east England, which is currently under investigation. Laboratory tests have confirmed that many isolates from this outbreak are of type O27, which is unusual in the United Kingdom. C.difficile is a spore-forming anaerobic bacterium that is common in the environment, and is found as part of the normal gut flora in a small percent of the population. When C.difficile is transmitted to vulnerable patients, often the elderly who have been treated with antibiotics, it produces symptoms of varying severity from diarrhoea to severe inflammation of the bowel, which can be life-threatening.

The hospital experienced an increase in C.difficile toxin positive isolates from a background level of between six and eight a month. There were 85 positive tests for C. difficile toxin in the 12 months between April 2003 and March 2004 and this rose to 209 during the following 12 month period. An outbreak was declared in November 2003. Figure 1 shows the course of the outbreak, and it can be seen that a period of control was achieved in mid-2004.

Figure 1 Number of new cases of hospital-acquired C. difficile within the Acute Hospital by month of report: November 2003 to April 2005

Control measures
Specific control measures implemented included the designation of cohort areas within the hospital for the treatment of infected patients, review and implementation of the isolation policy, clear definitions of ’diarrhoea‘ to assist with bed management (use of stool chart – based on Bristol Stool Form Scale), restrictions to patient transfers within the hospital, an increase in the use of disinfectants (containing detergent and hypochlorite) for environmental cleaning, rigorous implementation of hand hygiene using liquid soap and hot water (alcohol gels are used routinely by healthcare staff between treating patients, but only if their hands are not visibly soiled) and the use of protective clothing eg gloves, aprons. The hospital has implemented a restriction on the use of broad-spectrum antibiotics, and this policy has been monitored.

Microbiology
Suspicion that the clinical presentation was changing (increased severity of disease) resulted in referral of isolates to the Health Protection Agency Anaerobe Reference Laboratory for further investigation. Typing revealed that many of the isolates were type O27, previously an unusual type in the United Kingdom. Similar strains belonging to PCR ribotype O27 have been reported recently in Quebec Canada, and across six states of the United States (US). Outbreaks with such a strain in Canada were associated with more severe infection and an increase of the case-fatality ratio (1 ).

Work is underway in the Anaerobe Reference Laboratory to further characterise the UK isolates and compare them with examples of the Canadian and US outbreak strains. Examples of UK isolates of Type O27 have also been sent to CDC Atlanta for comparison of their toxin-liberating capacities in the CDC in vitro toxin assay. Preliminary PFGE and REP-PCR sub-typing investigations performed in the Anaerobe Reference Laboratory have revealed that some of the UK Type O27s examined thus far, while not identical, are closely related to some of the North American isolates.

Investigations in North America have shown that some of the strains observed here are hyper-toxin producers due to a deletion in a toxin regulating gene tcdC that results in a 16 to 20 fold increase in toxins A and B production respectively. It was also revealed that toxins are liberated primarily in the logarithmic growth phase compared to that of comparator strains that liberate toxins mainly in the stationary phase. The strain investigated has been characterised as belonging to toxinotype III which produces the binary toxins A and B, and exhibits resistance to certain new fluoroquinolones. The type O27 isolates from the UK are also hyper-toxin producers with a tcdC gene deletion.

In the meantime, healthcare workers in England and Wales should be alerted to any changes in clinical presentation and the local epidemiology of C. difficile disease, particularly noting any increases in severity of cases, higher mortality than expected, or an increase of cases associated with the use of certain fluoroquinolones In these circumstances, please contact Jon Brazier at the Anaerobe Reference Laboratory, tel: 02920 742378 or 742171 to discuss further typing investigations.

References

1.Pépin J, Valiquette L, Alary M-E, Villemure P, Annick Pelletier A, Forget K, et al. Clostridium difficile-associated diarrhea in a region of Quebec from 1991 to 2003: a changing pattern of disease severity. Can Med Assoc J 2004; 171: 466- 72.

Enhanced Tuberculosis Surveillance – final results for tuberculosis cases reported in 2003 in England, Wales, and Northern Ireland

In 2003, 6837 cases of tuberculosis were reported in England, Wales, and Northern Ireland to the Enhanced Tuberculosis Surveillance system, representing a rate of 12.5 per 100,000 population, compared with 6861 cases and rate of 12.7/100,000 in 2002. Forty-five per cent of all cases were reported in London region, which had the highest tuberculosis rate at 41.3 per 100,000. The rate ranged from 3.3/100,000 to 15.2/100,000 in the other eight English regions, Wales, and Northern Ireland.

Seventy per cent of cases reported were born abroad, and the rate of disease was 23 times higher in people born abroad compared to those born in the United Kingdom (90.1 vs 3.8/100,000).

Fifty-seven per cent of cases reported in 2003 had pulmonary tuberculosis. Between 2000 and 2003, rates of pulmonary tuberculosis have remained unchanged while rates of extra-pulmonary tuberculosis increased (figure 1). A similar trend can be seen in the numbers of tuberculosis notifications (1).

Figure 1. Tuberculosis rates: total and by site of disease (pulmonary vs extra-pulmonary), England, Wales, and Northern Ireland: 2000 - 2003

Final data on tuberculosis cases reported in 2003 to the Enhanced Tuberculosis Surveillance system is available on the Health Protection Agency website at:
<http://www.hpa.org.uk/infections/topics_az/tb/epidemiology/tables.htm#ets> (tables 14-17), and
<http://www.hpa.org.uk/infections/topics_az/tb/epidemiology/figures/figures_menu.htm> (figures 3-11).

The annual report on tuberculosis cases reported in England, Wales, and Northern Ireland in 2003 is due to be published later this year.

References

1. Pulmonary and non-pulmonary notifications, England and Wales , 1982 - 2003. Health Protection Agency website [online] 13 July 2004 [cited 15 June 2005]. Available at:
<http://www.hpa.org.uk/infections/topics_az/tb/epidemiology/figures/figure1.htm>.

European science academies call for increased co-ordination of activity over infectious diseases

Co-ordination across Europe is needed to combat the growing threat of infectious diseases, according to a recently published report from the European Academies Science Advisory Council (EASAC) (1). The report, Infectious diseases – importance of co-ordinated activity in Europe, describes major challenges facing Europe from newly-emerging and long-standing infectious diseases, for example, the threat of new influenza variants, novel microbes such as the SARS agent, resurgent infections such as TB, growing antimicrobial resistance and the continuing threat of bioterrorism. It identifies key issues to resolve in terms of:

• the opportunities for improved disease surveillance and public health infrastructure,
• the basic research agenda,
• support for the pharmaceutical and vaccine industry sectors,
• the needs of developing countries and newer European Union (EU) member states,
• scientific responsibility, and
• public engagement.

EASAC includes representatives from 22 national science academies, and was established in 2001 to provide a means for the national academies of Europe to work together to bring high quality science into EU policy-making. Its task is building science into policy at EU level by providing independent, expert, credible advice about the scientific aspects of public policy issues to those who make or influence policy for the EU.

References

1.European Academies Science Advisory Council. Infectious diseases – importance of co-ordinated activity in Europe. London: The Royal Society, 2005. Available at <http://www.easac.org/publications.htm#pubs>.