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What is influenza or flu?
Influenza is a viral infection that appears as a sudden onset of fever, aches, and coughing. Elderly people, young children, and those who are already ill are at higher risk of complications.
What is seasonal human influenza?
Many different strains of the influenza virus are found around the world. The viruses that cause annual seasonal epidemics of human influenza undergo minor mutations, which is why an epidemic can take place every year. In the Northern Hemisphere, influenza affects between 5 and 20 percent of the population between autumn and the end of spring, peaking most often in January and February. Prior infection by similar strains can cause some degree of immunity against a new strain. Despite this, many people die of influenza. In Québec, it is believed that between 1,000 and 1,500 people die of influenza per year.
Vaccination is the best way to protect people, reduce the risk of complications, and reduce the impact of the disease (morbidity, mortality, absenteeism). Since the virus changes every year, people must be vaccinated every autumn. The annual vaccine contains the three strains of virus most likely to be spread over the season.
What is avian influenza or flu?
A pandemic is an epidemic on the global scale. An influenza pandemic is caused by a virus that has undergone major changes and is completely different from the seasonal influenza viruses that spread each year. As people have little or no resistance to this virus, they become sick in great numbers, and the number of deaths is accordingly much higher.
To become responsible for a pandemic, a flu virus must:
- be able to infect humans;
- cause high morbidity and mortality;
- spread easily from person to person.
What is an influenza pandemic?
Avian influenza, also known as avian flu or chicken flu, is a contagious viral infection affecting all bird species (poultry, pet birds and wild birds). Since October 2003, avian influenza epizootics (animal epidemics) have been reported in chicken in Asia: Vietnam, Thailand, Japan, South Korea, Cambodia, China, Laos and Indonesia. The virus strain in circulation is H5N1. To deal with these epidemic flare-ups, many countries are currently slaughtering millions of chickens. This measure is the main line of defense to limit the number of new cases.
Other outbreaks caused by avian viruses other than H5N1 are being reported in other parts of the world, including Canada. They are also resulting in massive culls of poultry.
In Canada, low pathogenic and high pathogenic forms of the H7N3 viruses are involved. "Low" or "high" pathogenic refers to the severity of the illness caused by the virus in birds. Note that this is not the same virus as the one currently found in Asia.
Since 1975, low pathogenic avian influenza viruses have been identified in Canada three times. The most recent outbreakwas in Ontario, in 2000. Although the H7N3 virus is not believedto cause illness in humans, all the necessary precautions are being taken to protect people's health, whatever the pathogenic potentialof the virus.
More information is available at:
http://www.oie.int/downld/AVIAN%20INFLUENZA/A_AI-Asia.htm
http://www.inspection.gc.ca/english/anima/heasan/disemala/avflu/avflue.shtml
http://www.info.gov.hk/info/flu/eng/global.htm
What is the link between the human influenza virus and the avian flu?
The avian influenza virus is different from the human influenza virus; it normally attacks only birds, rarely humans. The World Health Organization (WHO) has emphasized that the current avian and human influenza viruses impose the need for increased vigilance because of the possibility of genetic material being exchanged between the viruses. This phenomenon could result in a virus that can be transmitted from one person to another, and in a population with no immunity, this could lead to a pandemic (worldwide epidemic). So far, laboratories have not observed an exchange in genetic material between these viruses.
More information is available at:
http://www.who.int/mediacentre/factsheets/avian_influenza/en/
http://www.who.int/csr/disease/avian_influenza/avian_faqs/en/#whyso
Can avian influenza (avian flu) be transmitted to humans?
Avian influenza rarely causes disease in humans. The mechanism of transmission from birds to humans is poorly understood. Transmission to humans may possibly occur via direct contact with the excrement of contaminated poultry or birds. As yet, there is no evidence of transmission from one human to another.
Vietnam and Thailand have reported human cases of infection with the H5N1 virus. There have been no human cases of H5N1 infection in Québec or Canada.
However, there have been human cases infected with the H7 avian influenza virus in British Columbia. The human health risk remains low. The surveillance and monitoring of all individuals who have been exposed is continuing, and all the precautionary measures are being taken.
More information is available at:
http://www.info.gov.hk/info/flu/eng/global.htm
http://www.phac-aspc.gc.ca/h5n1/index.html
http://www.hc-sc.gc.ca/iyh-vsv/diseases-maladies/avian-aviare_e.html
http://www.hc-sc.gc.ca/dc-ma/index_e.html
http://www.phac-aspc.gc.ca/tmp-pmv/pub_e.html
http://www.who.int/csr/disease/avian_influenza/updates/fr/index.html
I have one or more of the following symptoms: fever, cough, sore throat, muscle aches, eye infection, trouble breathing. What should I do?
Depending on the severity of the symptoms, see your doctor, who will be able to determine the necessary treatment. Many viruses and bacteria can cause these symptoms.
People need to be reassured about avian influenza: There are no cases in humans or in birds currently in Québec. Where it occurs, it only affects birds, except in Asia, where there have been a few human cases in people who were in very close contact with infected birds.
Is there a vaccine against avian flu?
At present, there is no vaccine providing protection against avian influenza. As a precaution, the WHO has taken steps [introduced procedures] for rapid production of a new vaccine.
However, people extensively exposed to poultry infected with the H5N1 strain should be innoculated with the existing vaccines. These are effective against human influenza viruses, and may reduce the likelihood of genetic material being exchanged with avian influenza viruses.
Pharmaceutical companies are getting ready to develop a vaccine against the H5N strain of the avian influenza virus. If the virus should mutate and adapt to inter-human transmission, we would therefore have a head start in producing an efficient vaccine against a mutated virus, which would likely be different from the one now affecting poultry: there is no danger yet, but we are actively getting ready. It would probably take 4 to 6 months to produce a vaccine, if a human strain emerged.
More information is available at:
http://www.who.int/csr/disease/influenza/pandemicvaccines/en/ Should I, or can I, get Tamiflu?
Considering the great demand for Tamiflu, Roche, the company that distributes the antiviral drug, announced that it would be suspending distribution for a limited time to conserve stocks of Tamiflu for needs associated with the influenza (flu) season, to protect people who are most at risk of complications.
Should I get an “oral/nasal mask”?
The current situation does not require widespread wearing of masks. In fact, it is not recommended as a strategy for the general public. It is a public health measure that will be considered only in the case of a pandemic and in certain specific circumstances. Of course, wearing a mask can provide protection for those in contact with sick people.
Is it safe to eat poultry and egg-based products ?
In Québec, it is safe to eat poultry and egg-based products because no cases of avian flu have been reported. The Canadian Food Inspection Agency (CFIA) has imposed restrictions on the import of poultry and unprocessed poultry products from all countries with outbreaks of H5N1. These import restrictions will continue until the situation in Asia has returned to normal.
However, hygiene measures must be followed at all times when handling raw poultry, to avoid transmitting viruses and bacteria, such as salmonella. Ensure that poultry prepared for consumption is thoroughly cooked (juice runs clear and no visible pink meat) to eliminate the risk of infection. Follow normal precautions regarding food storage, handling and preparation.
As a precaution, Health Canada is advising people travelling to countries with outbreaks of avian influenza not to eat poultry, eggs or egg-based products that are not thoroughly cooked.
More information is available at:
http://www.hc-sc.gc.ca/iyh-vsv/diseases-maladies/avian-aviare_e.html I will be traveling to Asia or Europe shortly: should I take any special measures?
It is recommended that travelers to areas where highly pathogenic avian influenza is currently present (Cambodia, China, Indonesia, Thailand, Vietnam, Laos, Russia, Kazakhstan, Mongolia, Turkey, Romania), should, in addition to standard personal hygiene measures:
- Avoid any unnecessary contact with domestic poultry and wild birds.
- Ensure that poultry prepared for consumption is thoroughly cooked (juice runs clear and no visible pink meat) to eliminate the risk of infection.
- Follow normal precautions regarding food storage, handling and preparation.
Which were the main flu pandemics of the 20th century?
The Spanish flu of 1918-1919.
The Asian flu of 1957-1958.
The Hong Kong flu of 1968-1970.
Why are people worried about an influenza pandemic now?
Even though nobody can predict when it will come, everyone agrees that an influenza pandemic is due, for two reasons:
1. Historical data suggest that an influenza pandemic occurs every ten to forty years. As the last pandemic was almost forty years ago, a pandemic is expected during the next few years.
2. The appearance of cases of human influenza caused by the H5N1 avian influenza virus has raised fears of an influenza pandemic.
Could this new H5N1 strain cause a pandemic?
Presently, the virus causing the human cases of avian influenza in Asia does not meet one of the necessary conditions to start a pandemic: it is not known to spread from person to person. To begin a pandemic, this new virus will have to undergo changes – reassortment or adaptive mutation – as described above.
How does an influenza pandemic unfold?
When an influenza pandemic begins, it causes a large number of human influenza cases over two to three months; the numbers then decrease. Next, a second wave of increased numbers of cases arrives a few months later (three to twelve months). The second wave is casused by an additional change in the pandemic strain or by the spread of the disease to populations that were not affected by the first wave.
Will we see the next influenza pandemic coming?
Yes. Monitoring of severe respiratory diseases throughout the world, especially human cases of avian influenza, allow the situation's development to be followed. A network of laboratories is constantly analyzing the agents responsible for these infections.
What effects will the next influenza pandemic have?
It is impossible to predict how intense the next pandemic will be. We do not know the virus's infection rates, i.e. what percentage of the population will contract influenza, nor what groups will be most affected. How can we limit the effects of the next influenza pandemic?
The best way to reduce the impacts of influenza will still be vaccination. We cannot predict which influenza virus will cause a pandemic; it must be clearly identified for an effective vaccine to be produced, since to be effective the vaccine must be close to the pandemic strain. For this reason, the development of a vaccine will be delayed some four to six months.
Antiviral medications can be used to treat influenza, as long as the virus responsible is affected by them. When administered in the first few days of the flu, antivirals reduce the duration and intensity of the symptoms. They can also be administered to those in close contact with someone with influenza in order to help prevent infection. It is clear that there will not be enough antivirals to meet demand.
During the pandemic, public health measures will be available to the population. These measures include health education on means to stem influenza transmission, as well as isolation and quarantine. Additional measures, such as restrictions on public gatherings, could be considered according to the unfolding situation. What measures are in place in Québec and Canada?
Prevention on farms is still the best way to reduce the risk of introducing or spreading disease. The Ministère de l’Agriculture, des Pêcheries et de l’Alimentation has a reminder about the recommended bio-safety rules on its website:
http://www.mapaq.gouv.qc.ca/Fr/Productions/santeanimale/surveillance/maladiesanimales/grippeaviaire/
The Canadian Food Inspection Agency (CFIA) imposes strict regulations on the import of poultry and poultry products. Details of CFIA measures are found at:
http://www.inspection.gc.ca/english/anima/heasan/disemala/avflu/avflufse.shtml
Health Canada has issued recommendations for people planning to travel to Asia. Among other precautions, travellers are advised not to visit markets where live birds are sold. The recommendations are to be found at:
http://www.phac-aspc.gc.ca/tmp-pmv/pub_e.html
http://www.who.int/csr/disease/avian_influenza/en/
Québec's health and social services network is aware of the international situation and has received all the necessary information to rapidly detect symptoms associated with severe respiratory disorders, including severe flu-like syndromes, and to put the necessary measures in place. Other measures such as disease surveillance, infection prevention, laboratory surveillance and emergency preparedness are in place, strengthening our capacity to respond to an epidemic emergency.
In Québec, the Ministère de la Santé et des Services sociaux and the Ministère de l’Agriculture, des Pêcheries et de l’Alimentation are working closely with each other so that they can take fast action if necessary, and prevent harmful consequences for the bird population and public health.
Does the annual flu vaccine protect against the virus that could cause the next influenza pandemic?
No. It only protects against the influenza viruses that are expected to circulate this autumn. If a pandemic were to begin, a vaccine specific to that strain of influenza would be developed.
When do governments intend to use the reserves of antivirals that they have stockpiled?
Antiviral drugs will be available to control (slow) viral transmission in humans as much as possible. They will be administered to target groups.
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More and more, the media is discussing avian influenza and the growing threat of an influenza pandemic. It is important to understand the difference between a pandemic and seasonal flu epidemics.
