CDR Weekly
  Search CDR



subscribe to CDR Weekly
Subscribe to CDR

Adobe AcrobatCurrent Issue in PDF format

This site uses Adobe Acrobat

Download here >

 

Final Issue: Volume 16 Number 51

Published on: 21 December 2006

Final Issue in PDF Current Issue in PDF format
PDF format (283 Kb)

News Archives

Last updated: Volume 14, No.1 (PDF file, 100 KB)

Archives | News Archives 2004: Page 1| News 5 January 2004

News Archives: | 2006 | 2005 | 2004 | 2003

Multi-resistant Acinetobacter baumannii: update

 

Information on the nosocomial spread of Acinetobacter baumannii in hospitals in northern France, which resultied in serious infections and possibly associated deaths was published early in December (1). Most of the isolates in France were found to be producing an extended-spectrum B-lactamase, known as VEB-1, that does not destroy carbapenems (and is unrelated to the classical TEM and SHV plasmid-mediated B-lactamases that commonly cause acquired ampicillin resistance). The isolates remained susceptible only to imipenem and colistin (2).

This strain is different from those known to be currently circulating in the United Kingdom (UK), where the critical strains are resistant to carbapenems as well as to multiple other agents. Until recently, carbapenem resistant isolates had been rare in the UK (less than 2% had this resistance in a 50 hospital survey in 2000 [3]), but increasing numbers of carbapenem resistant isolates have since been identified among referrals to the HPA Laboratory of Healthcare Associated Infection and the Antibiotic Resistance Monitoring and Reference Laboratory (ARMRL). One resistant clone has been isolated in more than 30 hospitals in London and south-east England since April 2000. This is highly resistant to B-lactams, fluoroquinolones, and aminoglycosides. Most of the isolates are also resistant to carbapenems, though this resistance has yet to be associated with any identified b-lactamase. In addition to the clone, two strains, each with variants, have been found in London and the south-east with OXA-23 B-lactamase, which can hydrolyse carbapenems. These are consistently carbapenem-resistant, as well as showing broad resistance to other antimicrobials, though variants of one lineage are often still susceptible to tobramycin and amikacin.

The mainstay of treatment of serious infection with these multi-resistant strains of A. baumannii, however unsatisfactory in terms of toxicity and questionable in terms of efficacy, is polymyxin. Sulbactam is active against some carbapenem-resistant acinetobacter strains, but not against the present UK strains. Some strains are susceptible to tetracyclines (minocycline, tigecycline), but effectiveness of these agents in severe acinetobacter infection still needs to be proven.

The possible importation of multi-resistant A. baumannii from the conflict in Iraq in October has also been highlighted (4). Detailed investigations by the HPA Communicable Disease Surveillance Centre have subsequently shown little direct importation from Iraq or subsequent transmission, with most of the multi-resistant strains unlinked to repatriated causalities, and with several of the strains having been in circulation from before the 2003 conflict.

Nevertheless, irrespective of their source, it is clear that multi-resistant acinetobacter are increasingly causing problems generally and, in the light of this, the following actions are being undertaken by the HPA:

In the meantime, microbiologists are asked to report outbreaks of multi-resistant acinetobacter to their regional units of the HPA, under the serious untoward reporting scheme, and to send isolates to the ARMRL for further investigation. ARMRL is happy to confirm and investigate carbapenem-resistant isolates, typically in representatives from outbreaks, but does not seek other resistance types. Please contact Ty Pitt (020 8200 4400 ext 4224) or David Livermore (ext 4223) for further information.

 

 

HPA issues statement on immunisation of children against influenza

 

The Health Protection Agency has issued a joint statement with the Royal College of Paediatrics and Child Health, and The Royal College of General Practitioners. The statement, which emphasises current influenza immunisation recommendations, has been prompted by the low level of vaccine uptake among children covered by the recommendations, given that children seem to be especially susceptible the virus strains circulating this season.

In particular

“Children in the following clinical risk categories, aged 6 months and over, should be offered immunisation against influenza:
1. Any child with compromised lung function, eg BPD. Those with severe asthma, defined as needing long-term oral steroids, should be included.
2. Any child with chronic heart disease.
3. Any child with impaired immunity, either congenital or acquired. This includes all children on immunosuppressive or anti-cancer drugs for whatever reason as well as those on long-term oral steroids.”

The full text of the statement can be found at <http://www.rcgp.org.uk/>.

 

Tuberculosis treatment outcome monitoring: first national results

 

A system to collect information on treatment outcome of all tuberculosis cases reported was implemented in January 2002 on tuberculosis (TB) cases reported in 2001 in England, Wales, and Northern Ireland with the aim of providing information on the national effort in TB control. The first national data from this new surveillance system are now available.

Data were collected following a protocol mainly based on European recommendations about treatment outcome monitoring, published in 1998, but adapted to the United Kingdom (UK) context. As part of enhanced tuberculosis surveillance, a standardised system of data collection has been implemented, collecting information on outcome status one year after start of treatment on all tuberculosis cases reported. The system includes safeguards to ensure the confidentiality of patients and treating physicians.

The analysis on first national results was performed on 5139 TB cases, representing 79% of all the cases reported in England, Wales, and Northern Ireland in 2001. Information on outcome was updated for more than 80% of cases in eight of the 11 regions/countries, in the remaining three regions this varied from 39% to 58%.

Key socio-demographic information on cases with outcome was compared to that on the total number of cases reported in 2001. The cases with outcome data were similar to all TB cases.

Among TB cases whose outcome was determined, 80% were reported to have completed treatment at 12 months. The treatment completion rate was significantly lower in pulmonary cases than in extra pulmonary cases (77% and 84% respectively, p<0.001). Among sputum-smear positive pulmonary cases, the proportion of treatment completion was 78%. Of the 1106 cases who had not completed treatment at one year, 39% had died, 19% were reported to be lost to follow-up, and 18% were still on treatment.

Outcome was found to be strongly associated with age. The proportion of treatment completion decreased in the older age groups (>80% in those aged under 60 years, and <70% in those aged 70 years and over, p<0.001) reflecting the contribution of death in older age. The proportion of cases lost to follow-up in the 10 to 34 years age group was 6.3%, and was higher compared to other age groups (1.3% in those aged under 9 years, and 2.5% for those aged over 35 years, p< 0.001).

These data should be interpreted with caution, as outcome information was not provided for 21% of TB cases reported in 2001. The interpretation of the results will require further analyses and discussion between national, regional, and local levels.

These results show that monitoring of treatment outcome in the UK is feasible. Results from the first year are generally encouraging but the system needs to be strengthened in the light of experience, and efforts hould be directed to increase the proportion of cases on whom outcome is reported. The treatment outcome surveillance protocol is currently being revised. A final report, with more comprehensive details of the results, is being prepared for publication.