• Oseltamivir resistant influenza A(H1N1) virus in the UK, 2008/09 – an update

• Annual Evidence Update on Diagnosing HIV/AIDS

• Confirmed rabies case in puppy in Malawi
  

 

Oseltamivir resistant influenza A(H1N1) virus in the UK, 2008/09 – an update

Following the recently reported, first UK oseltamivir resistant influenza A case (H1N1) in the 2008/09 season [1], several further cases have been detected. From week 36/08 up to 19 November 2008, twelve of the 13 influenza A(H1N1) isolates detected in England have been found to be resistant to oseltamivir. All these cases are from the south west of England. Two oseltamivir resistant influenza A(H1N1) cases have also been detected in Scotland. All the H1N1 cases from England remain sensitive to zanamivir and amantadine and are antigenically similar to the H1N1 reference strain A/Brisbane/59/2007, which is included in this season's influenza vaccine.

Since the start of the current 2008/09 flu season, between weeks 40/08 and 46/08, sporadic laboratory-confirmed influenza infections have been detected across the UK including 58 influenza A(H3), 13 influenza A(H1), 57 influenza A (not subtyped) and three influenza B viruses [2]. Although clinical indicators of influenza activity remain below base-line levels throughout the UK, a recent trend of increasing levels in these indicators is apparent.

The oseltamivir resistant cases are focused in one geographical area of England. Most cases, where age is known, have occurred in the 20-29 year age group. Investigation of the cases by the Avon, Gloucestershire and Wiltshire Health Protection Unit, in collaboration with HPA South West and HPA Centre for Infections, is continuing. There is no evidence of any increased morbidity in these cases to date.

It remains too early to predict which strain(s) of influenza virus will predominate this season. The Agency will continue to monitor closely the characteristics of circulating isolates including drug susceptibility. It remains important that respiratory samples are taken from suspected influenza cases, and that outbreaks of acute respiratory illness are investigated. Respiratory samples confirmed as influenza virus positive should be forwarded to the HPA Centre for Infections Respiratory Virus Unit for culture and anti-viral testing.

Efforts should continue to encourage people in the CMO-defined influenza risk groups to take up the recommendation of seasonal influenza vaccination [3].

Influenza virus detections across Europe remain low so far in this season. Oseltamivir-resistant influenza A(H1N1) isolates have also been reported in a small number of other countries. Oseltamivir-resistant influenza A(H1N1) viruses emerged last season in association with the H274Y mutation, which confers resistance to oseltamivir, but not to zanamivir. By the end of the 2007/08 season, 26 of 34 reporting European countries had reported H1N1 oseltamivir resistance and, in the UK, 38 out of 347 (11%) were found to be oseltamivir resistant [4, 5]. The epidemiological evidence from the 2007/08 season suggested no reported increase in morbidity associated with these confirmed oseltamivir-resistant cases.

References
1. HPA. Identification in the UK of the first oseltamivir resistant-influenza virus (H1N1). Health Protection Report [serial online] 2008, 2(43): news, 24 October 2008. Available at:
http://www.hpa.org.uk/hpr/archives/2008/news4308.htm#ah1n1.

2. Weekly HPA influenza report, week 46. http://www.hpa.org.uk/web/HPAwebFile/HPAweb_C/1226478484902.

3. DH. PL CMO (2008)3, PL CNO (2008)2, PL CPHO (2008)1: The influenza immunisation programme 2008/09. http://www.dh.gov.uk/en/Publicationsandstatistics/Lettersandcirculars/Professionalletters/
Chiefmedicalofficerletters/DH_083812

4. European Centre for Disease Prevention and Control. Antivirals and antiviral-resistant influenza - resistance to oseltamivir (Tamiflu) in some influenza A(H1N1) virus samples. ECDC website [online] September 2008 [cited 24 October 2008]. http://ecdc.europa.eu/Health_topics/influenza/antivirals.html

5. WHO. Influenza A(H1N1) virus resistance to oseltamivir. 13 October 2008. http://www.who.int/csr/disease/influenza/h1n1_table/en/index.html.

Annual Evidence Update on Diagnosing HIV/AIDS

The Infections Specialist Library (ISL) [1] is hosting the first Annual Evidence Update on Diagnosing HIV/AIDS (also known as "national knowledge week") from 24 November to 7 December 2008, which encompasses World AIDS day on 1 December 2008. The event is held in collaboration with the Sexual Health Programme Board and the National Library for Public Health.

The focus of the event is the diagnosis of HIV and the importance of early diagnosis that benefits both the individual - through much improved prognosis - and the community - through reduced onward transmission of HIV.

A comprehensive collection of peer-reviewed publications is being brought together on an Evidence Update webpage [2], including several commentaries, written by experts in the field, that elaborate on the recently released guidelines on guidelines for HIV testing [3].

ISL is a single portal to evidence-based medical knowledge on infections, based at the Health Protection Agency Centre for Infections, having strong links with many partner organisations, professional groups and charities. It aims to provide access to the best available evidence on prevention, treatment and investigation of infections.

References
1.http://www.library.nhs.uk/infections/

2.Diagnosing HIV Annual Evidence Update 2008 homepage, http://www.library.nhs.uk/infections/Page.aspx?prv=y&pagename=HIVAEU.

3. BHIVA/BASHH/BIS. UK National Guidelines for HIV Testing 2008. Available at: http://www.britishinfectionsociety.org/documents/GlinesHIVTest08.pdf. See also: New guidelines on HIV testing in high-prevalence areas. Health Protection Report [serial online] 2008, 2 (38): news. Available at: http://www.hpa.org.uk/hpr/archives/2008/news3808.htm#sophid .

Further information
Further information about SLI, including subscription to its newsletter, can be obtained by emailing to: isl@hpa.org.uk.

Confirmed rabies case in puppy in Malawi

The HPA has been involved in contact tracing following a case of confirmed rabies in a puppy that may have been in contact with UK travellers at a backpacker lodge in Lilongwe, Malawi, East Africa. Up to 75 UK travellers are thought to have stayed at the lodge in late October and early November and the Agency has advised that those who had any contact with the animal during this period should seek medical advice.

An HPA press release (containing full details of the case) [1] reminds travellers that, outside of western Europe, a rabies vaccination may be recommended for travel to some countries, especially developing countries where rabies is common in animals.

Reference
1. HPA press release, Confirmed rabies case in puppy in Malawi, 21 November 2008.

Further information
Healthcare professionals and members of the public can find detailed information about travel health (including country-specific advice) from the National Travel Health Network and Centre (NaTHNaC), http://www.nathnac.org/, or the Fit for Travel website, http://www.fitfortravel.nhs.uk/