Thursday 25 September 2008
Epidemiological updates
Scientific Advances
Public Health Developments
Meetings and workshops
Request for Contributions
Epidemiological updates
Seasonal Influenza – Global Status - Southern Hemisphere
WHO publishes regularly updates on global influenza activity at the following website: http://www.who.int/csr/disease/influenza/en/.
The latest bulletin was published on 12th September, covering weeks 35–36. It recorded that in the southern hemisphere, the overall influenza activity declined except for Australia where local activity was reported, and New Zealand where a widespread outbreak was reported. Activity was low in the rest of the world.
In Australia influenza activity was local with influenza A and B co-circulating
In New Zealand influenza activity remained widespread with influenza B viruses predominating and A(H3) co-circulating. The majority of B viruses detected were from the B/Victoria linege.
Seasonal Influenza – European Status
Text updated from: European Influenza Surveillance Scheme (EISS) Inter-season Electronic Bulletin
During the inter-season period over the summer, EISS produces a bulletin every two weeks as a low-level monitoring of human influenza activity in Europe based only on virological data. The inter-seasonal bulletin will be produced between week 21-39, and the integrated epidemiological and virological surveillance of influenza will be resumed from week 40/2008. The next EISS update for weeks 38-39 will be published by the end of October 2008.
Very sporadic influenza activity in Europe
Summary: Influenza virus detections occur very sporadically in Europe. In week 36/2008, there was no detection and in week 37 there was only one detection reported. Out of 11 countries reporting the geographical spread indicator in week 36-37/2008, 10 countries reported no influenza activity and England reported sporadic activity.
In week 36-37/2008, Out of a total of 137 investigated specimens in Europe only one influenza virus (type A not subtyped) was detected in England from a non-sentinel specimen.
There have been no reports of unusual influenza activity in Europe at a community level (i.e. in a region or local area such as a city, county or district) since week 16/2008.
Background: The Inter-season Electronic Bulletin presents and comments influenza activity based on virological data reported to EISS. In weeks 36/2008 and 37/2008, a total of 14 countries reported virological data to EISS. The Inter-season Electronic Bulletin will be published between week 21/2008 and week 39/2008.
The spread of influenza virus strains and their epidemiological impact in Europe are being monitored by EISS in collaboration with the WHO Collaborating Centre in London (United Kingdom) and the European Centre for Disease Prevention and Control in Stockholm (Sweden).
Full interactive EISS interseasonal bulletin including maps and graphs by country and informative links in the text
National/regional bulletins in Europe and other bulletins from around the world
Links to general information from EISS:
General information on EISS, including background, membership and information on citing the EISS bulletin
Definitions of epidemiological indicators used by EISS
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Seasonal Influenza – Antiviral Resistance
Resistance to oseltamivir (Tamiflu) in some European influenza virus samples
EU data updated 24th September– Global data 20th August 2008
In late January 2008, antiviral drug susceptibility surveillance of seasonal influenza viruses was carried out in Europe (the EU-EEA-EFTA countries) by the EU-funded VIRGIL network. The National Influenza Centres revealed that some of the A (H1N1) viruses circulating this season (winter 2007-8) are resistant to the antiviral drug oseltamivir through mutation at position 274 in the viral neuraminidase gene.
Analysis of 2898 A(H1N1) viruses from 25 European (European Union, EEA/EFTA) countries isolated between November 2007 and late July 2008 (data archived on August 6th) showed that 704 were resistant to oseltamivir, but retained sensitivity to zanamivir and amantadine. The data are shown as a figure with a linked table.
The proportion of A(H1N1) viruses that are oseltamivir resistant varied significantly across Europe. The highest proportion of resistant viruses to date have been in Norway where 184 (67%) of the 273 samples are resistant to oseltamivir, whereas no resistant viruses have been detected in five of the 25 countries.
Surveillance in previous years by the Virgil Project found <1% of circulating viruses to be resistant The predominant influenza A viruses in Europe in winter 07/08 were A(H1N1) viruses, antigenically similar to the A/Solomon Islands/3/2006 virus included in the 2007/08 N Hemisphere vaccine. As the season progressed influenza B viruses started to circulate and then predominated. There was only limited circulation of other influenza A in Europe. Further details on country to country virus distribution this season are available on the European Influenza Surveillance Scheme (EISS) weekly update as well as in Influenza News.
Following the observation of a high level of resistance to oseltamivir in the A(H1N1) viruses circulating in Norway, the Norwegian authorities notified their EU partners and the World Health Organization (WHO) of this situation at the end of January. The Norwegian Public Health Institute also published an advisory to doctors and the public. The country with the second highest proportion is now Belgium (53%) followed by France with 231 (47%) of 496 specimens showing the marker for oseltamivir resistance. This is then followed by the Netherlands and Luxembourg with proportions of 27% and 26% respectively. There is no evidence that the appearance of these new viruses are related to use of oseltamivir which is currently seemingly not widely prescribed in most European countries. ECDC is now working with the manufacturer and national authorities to gather more information on routine oseltamivir use in Europe.
Experts from the European Centre for Disease Prevention and Control (ECDC), the European Commission, the European Influenza Surveillance Scheme and the World Health Organization (WHO) are currently assessing the significance of the data from the EISS VIRGIL network. An interim European risk assessment has been published by ECDC and comments on this are welcomed to influenza@ecdc.europa.eu.
Global surveillance started immediately after the detection in Europe and is being coordinated by WHO, and evidence has been found of similarly resistant viruses in North America and the Far East. All data including that on the WHO web-site are updated at monthly intervals at present.
The latest global data were posted on August 20th and now WHO is showing data separately for the 2007/8 winter season (Last Quarter 2007 to March 2008) and the 2008 season (Table 1 Second Quarter 2008 to August 20th). At the global level the most recent notable finding was from South Africa where now all 107 influenza A/H1N1 specimens gathered since the start of the second Quarter 2008 showed the marker of resistance. Their findings have been confirmed by WHO Collaborating Centres. To date there have been 136 specimens influenza A/H1N1 specimens tested from WHO’s Africa Region but only nine of these have shown the markers of resistance apart from those from South Africa. Other significant national proportions of A/H1N1 specimens for the Southern Hemisphere or Equatorial regions showing resistance for which there are data are from Australia (10 out of 10), Chile (4 out of 13), Argentina (2 out of 5) and the Hong Kong Region of China 97 out of 483 (17%). These are the first of these viruses reported from the Southern Cone of South America.
Looking back to the earlier period (Quarter 4 2007 to end of Quarter 1 2008 equivalent to the Northern Hemisphere winter season where there are data on more than 50 specimens the results are: the Russian Federation 45%, (58 of 128), Canada 26% (127 of 486), United States 12% (126 of 1026), Japan 3% (44 of 1652), Hong Kong 12% (98 of 797), Australia 4% (3 of 83), Madagascar (none of 59), Korea (none of 99%) and New Zealand (none of 88). As well as the WHO monthly table. WHO is publishing less frequent analytic summaries on the WHO web-site. WHO also published regular summaries on influenza in the world. The last of these was published in late July. These data are interesting because they firstly indicate that these A(H1N1) viruses are not going away and also that they seem to be following the pattern suggested for A(H3N2) viruses of spreading eventually to even the Southern Cone of South America.(1)
Although sporadic low level transmission of drug resistant viruses may have taken place since 1999 when the Neuraminidase Inhibitor drugs first were licensed, the 07/08 winter season is the first time there has been widespread and sustained transmission of such viruses in the community. Similar viruses have been seen before, but usually following treatment. Such viruses previously have not been able to readily transmit and have rapidly disappeared. Clinical experience in Norway and elsewhere suggests that people who become ill with an oseltamivir resistant strain of A(H1N1) have a similar spectrum of illness to those infected with “normal” seasonal influenza A which can cause severe disease or death in vulnerable people (older people, those with debilitating illnesses and the very young). This is now being investigated in national studies and international studies coordinated by ECDC.
At this stage the significance of these findings remains uncertain. The emergence of drug resistance in the context of limited drug use is unexpected, and the extent of future circulation is difficult to predict. ECDC, WHO, EISS, VIRGIL and authorities in the member states are undertaking intensive surveillance and progress will be reported through this and other relevant web-pages. A summary of the arrangements for the EU EEA & EFTA Countries is on the ECDC web-site this is also available in a pdf version as a briefing for policy makers in the EU and EEA/EFTA Member States.
(1) Russell C, Jones T, Barr I et al The global circulation of seasonal influenza A (H3N2) viruses Science 2008; 320 340-
AVIAN INFLUENZA
There are fluctuating reports in the media of influenza A(H5N1) and other avian influenza infections in birds and humans. ECDC monitors these carefully as part of its epidemic intelligence work. However without laboratory confirmation ECDC only rarely mentions these media reports in this output.
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AVIAN INFLUENZA – HUMAN HEALTH
There are no new human cases of avian influenza A(H5N1) reported by WHO since 10th September 2008
Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO (10/09/2008)
H5N1 avian influenza: timeline of major events (10/09/2008)
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AVIAN INFLUENZA – ANIMAL HEALTH – TOGO
24th September 2008
The OIE has reported 1 poultry outbreak of A(H5N1) infection in a farm in Maritime region. From the 6500 susceptible birds, there were 4131 infected cases with 100% apparent case fatality. Investigations are ongoing and control measures have been implemented.
See:
OIE raport of AI case in Togo, including location map (24/09/2008)
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Scientific advances
SCIENTIFIC ADVANCES –SEASONAL INFLUENZA – VACCINES
Effectiveness of Maternal Influenza Immunization in Preventing Maternal
Effectiveness of Maternal Influenza Immunization in Mothers and Infants
Zaman K. et al
The New England Journal of Medicine 2008 Sep 17
Description: In this randomized blinded study carried out in Bangladesh 340 pregnant women were randomly assigned to receive in pregnancy either inactivated influenza vaccine (influenza vaccine group) or a 23-valent pneumococcal polysaccharide vaccine (control group). Mother and infants were then followed intensely for six months after birth with observation for illness in the mother and child and laboratory testing for serological evidence of infection. This work was part of a larger study investigating the immunogenicity and safety of pneumococcal vaccine given sequentially to mothers and infants. No significant adverse events were noted in association with either immunisation. The researchers found that among the 159 infants whose mothers received influenza vaccine there were only 6 laboratory confirmed influenza infections, as compared with 16 among the 157 infants whose mothers were in the control group. This is compatible with a vaccine effectiveness of 63% (95 % CI of 5 to 85%). In addition the influenza immunised group experienced a 29% (95 % CI 7 – 46%) reduction in infant respiratory illnesses with fever, and a 42% (95 % CI 18% - 59%) reduction in the rate of infant clinic visits. Among the mothers, there was a reduction in the rate of respiratory illness with fever of 36% (95 % CI 4-57%). There was no effect on diarrhoeal disease. It was estimated that 100 maternal influenza vaccinations of mothers prevented 7 and 14 cases of respiratory infection with fever in the mothers and babies respectively. The study also showed that the virus was circulating for at least 10 of the fifteen months of observation.
ECDC comment (25/09/08): This is an elegant study which, by comparing two vaccinations in mothers, overcomes effects that might be due to non-specific stimulation. The results are impressive and makes a strong case for immunising pregnant women to protect their own and their babies health. What needs to be done now is to undertake health economic studies to determine how these interventions rank against other uses of resources in less resourced countries. A useful by-product is demonstrating that influenza is a health burden in tropical countries. Although there are few data on this, these seem to suggests that influenza is circulating more continuously there than in temperate zones. (1) WHO is running a programme to expand vaccine use and production in poorer parts of the world. (2)
1) Viboud C, Alonso WJ, Simonsen L. Influenza in tropical regions. Plos Med 2006; 3(4): e89.
2)WHO Global pandemic influenza action plan to increase vaccine supply. WHO Geneva Immunization, Vaccine and Biologicals. Epidemic and Pandemic Alert and Response. September 2006. http://www.who.int/csr/resources/publications/influenza/
WHO_CDS_EPR_GIP_2006_1/en/index.html
Comment to influenza@ecdc.europa.eu
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Public Health Developments
P.H. DEVELOPMENTS –SEASONAL INFLUENZA-VACCINES
WHO recommends composition of influenza virus vaccines for use in the 2009 southern hemisphere influenza season.
Description: Following a meeting to review the recent strains of viruses circulating in the Southern Hemisphere in its influenza season (April to September 2008) the recommended composition of the influenza vaccine for the 2009 season (southern hemisphere, winter) was announced by the World Health Organization this week.
It is recommended that vaccines for use in the 2009 influenza season (southern hemisphere winter) contain the following: — an A/Brisbane/59/2007 (H1N1)-like virus;*
— an A/Brisbane/10/2007 (H3N2)-like virus;**
— a B/Florida/4/2006-like virus.#
* A/South Dakota/6/2007 (an A/Brisbane/59/2007-like virus) is a current vaccine virus used in live attenuated vaccines.
** A/Brisbane/10/2007 and A/Uruguay/716/2007 (an A/Brisbane/10/2007-like virus) are current vaccine viruses.
# B/Florida/4/2006 and B/Brisbane/3/2007 (a B/Florida/4/2006-like virus) are current vaccine viruses.
Compared to 2007-08 season for the southern hemisphere the current recommended composition of influenza virus vaccines has changed in one virus strain. The A/Solomon Islands/3/2006 (H1N1)-like virus component has been replaced with A/Brisbane/59/2007 (H1N1)-like virus. The other two recommended strains remain the same as last year.
The recommendation and summary report are also available on the WHO web at:
http://www.who.int/csr/disease/influenza/recommendations2009south/en/index.html.
ECDC comment (25/09/08): This process of strain examination takes place under the charge of WHO’s Global Influenza Programme.(1,2) Recommendations have to be made speedily to allow time for vaccines to be produced in time by industry for the coming season. This recommended change in the Southern hemisphere’s recommended strains means they are now the same for both the Southern and Northern hemispheres.
1) ECDC Influenza News The science and practicalities of making recommendations for the composition of influenza vaccines
2) Gerdil C. The annual production cycle for influenza vaccine. Vaccine 2003; 21: 1776-9.
Comment to influenza@ecdc.europa.eu
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P.H. DEVELOPMENTS –PANDEMIC INFLUENZA-ANTIVIRAL RESISTANCE
Timeline for the emergence of oseltamivir resistant influenza A(H1N1) 2007-8
With the help of its partners (1) ECDC is constructing a time-line of the more significant events and publications surrounding the emergence and dissemination of these viruses. This is very much a work in progress and ECDC welcomes comments and additions which should be sent to influenza@ecdc.europa.eu The Time line which will be update periodically.
Information and data in the time line were provided by the European Influenza Surveillance Scheme http://www.eiss.org/index.cgi and the VIRGIL Project http://www.virgil-net.org/ ECDC would like to thank all countries, virologists, clinicians and others for contributing data.
Funding for the VIRGIL project comes from the European Union FP6 Research Programme http://ec.europa.eu/research/health/influenza/proj13_en.html and EISS is supported by ECDC. Laboratories in EISS contribute to the Global Influenza Surveillance Network
managed by WHO
Comment to influenza@ecdc.europa.eu
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Meetings and workshops
International Ministerial Conference on Avian and Pandemic Influenza, Sharm el-Sheikh, Egypt. 24-26 October 2008.
This meeting organised by the Government of Egypt is the sixth in a series of high level meetings that began in Washington in October 2005, followed by Beijing (January 2006), Vienna (June 2006) Bamako (December 2006) and Delhi (November 2007). The Delhi meeting established a Road Map for countries to progress AI prevention and pandemic planning during 2008.
The Ministerial meeting in Egypt is supported by many bodies including the European Union, United Nations, WHO, United States international aid (USAID), the World Bank, the two major global animal health organisations (OIE & FAO) and the African Union. The focus is to assess the current epidemiological situation and progress since Delhi, and review the effectiveness of the strategies applied and remap the way forward in global avian and pandemic flu preparedness and response for 2009. A group from the UN Development programme (UNDP) is in the process of preparing a report for the meeting. Its last report is available at http://www.undg.org/docs/8097/12-18-07-UN-WB-AHI-Progress-Report-final.doc
A web-site for the conference in Egypt has now been activated http://www.imcapi2008.gov.eg/
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International symposium on viral respiratory disease surveillance. Seville, Spain 25-27th March 2009. International Society for Influenza and other Respiratory Virus Disease (ISIRV)
Conference information can be found at http://www.isirv.org
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Contributions Requested
The ECDC influenza project team very much welcomes potential contributions to these web updates from EU/EEA member states particularly concerning public health developments and scientific published papers. This includes publications in non-English languages. These should be sent, preferably with a web-link, to influenza@ecdc.europa.eu. If drawing to our attention a non-English language article for development, a short summary in English is appreciated. However, this is not essential because of its multi-national staff, ECDC can cope with most languages from within the EU.