The Public Health Agency of Canada continues to closely monitor occurrences of avian influenza A (H5N1) or "bird flu" outbreaks, in humans, in Asia.
The current human outbreak of Avian Influenza A (H5N1) has affected
three countries (Vietnam, Thailand, and Cambodia) and is characterized
by three distinct periods or waves of activity, since late-December 2003,
when human cases were first reported.
Wave
Period
Cases, including death
1
2003-12-26 to 2004-03-10
35 cases, including 24 deaths
2
2004-07-19 to 2004-08-10
9 cases, including 8 deaths
3
2004-12-16 to present
64 cases, including 22 deaths
Vietnam - Human Cases
On June 28th, 2005, the World Health Organization (WHO) reported that
the Ministry of Health in Vietnam has confirmed an additional case of
human infection with H5N1 avian influenza. The case occurred in the northern
province of Ha Tay in May 2005.
Wave 1 - 23 cases, including 16 deaths
Wave 2 - 4 cases, including 4 deaths
Wave 3 - 60 cases, including 18 deaths
To date, Vietnam has reported a total of 87 human cases of avian influenza
infection, including 38 deaths.
Cambodia - Human Cases
Wave 1: nil
Wave 2: nil
Wave 3: 4 cases, including 4 deaths.
To date, Cambodia has reported a
total of 4 human cases of avian influenza infection, all of which have
been fatal.
Thailand - Human Cases
Wave 1: 12 cases, including 8 deaths
Wave 2: 5 cases, including 4 deaths
Wave 3: nil
To date, Thailand has reported a total of 17 human cases
of avian influenza infection, including 12 deaths. The last reported
case in Thailand occurred in October of 2004.
The World Health Organization has developed a chart depicting human case counts by region and time period. The case counts contained within this chart may differ slightly from the cumulative figures reported in past advisories, as case counts have been amended to account for figures recently provided to the WHO from Vietnam.
Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO
Source: World Health Organization
Avian influenza is a contagious
viral infection that can affect all species of birds but can, less commonly,
infect humans.
The first documented infection of humans with an avian
influenza virus occurred in Hong Kong in 1997, when the H5N1 strain
caused severe respiratory disease in 18 humans, six of whom died. The
infection in humans coincided with an epidemic of highly pathogenic avian
influenza virus, caused by the same strain, in Hong Kong's poultry population.
At this time,
there is no vaccine that protects against the avian influenza H5N1 virus.
While the current seasonal flu shot does not protect against the avian
influenza H5N1 virus, immunization with it may be of benefit for travellers
to geographic regions where human cases of H5N1 are being reported.
Individuals who are immunized with the seasonal influenza vaccine are
less likely to contract seasonal influenza. This in turn reduces the likelihood
of an immunized individual becoming infected with both human and avian
forms of influenza at the same time. Should a person be infected with
both viruses at the same time, there is a possibility that the two viruses
could "mix" and
mutate into a new virus that could be spread efficiently and against
which, humans would have no immunity.
Several anti-viral drugs are available
for the prevention and treatment of seasonal influenza in Canada. Although,
none of the anti-viral drugs have been shown to prevent H5N1, studies
done through the WHO Global Influenza Surveillance Network have shown
that the anti-viral Oseltamivir may be effective in the treatment of
H5N1.
Recommendations
As a precautionary measure, it would be prudent that travellers to Thailand, China, Cambodia, Vietnam, South Korea, Japan, Indonesia, and Laos, where avian influenza A (H5N1) outbreaks have been reported, consider the following measures:
The Public Health Agency of Canada advises that travellers to the countries mentioned above, not consume undercooked fowl, raw eggs, or lightly cooked egg products (such as runny eggs). Travellers should ensure that all food products listed above be well cooked before being consumed, as evidence suggests the virus becomes inactive when cooked. While to date there has been no evidence that the virus is transmitted through contaminated food, the above precautionary measure should be followed until further information is available.
Normal precautions regarding food storage, handling and preparation should be followed. Travellers are further advised to maintain high standards of hygiene, including thorough hand washing, particularly after having contacted eggs or undercooked fowl and egg products and to avoid cross contamination with other food products. Using hot, soapy water and lathering for at least 20 seconds is the single most important procedure for preventing infections. This is because disease-causing micro-organisms can frequently be found on the hands. Alternatively, travellers can use waterless, alcohol-based antiseptic hand rinses. If there is visible soiling, hands should be washed with soap and water before using waterless antiseptic hand rinses. If soap and water are unavailable, cleanse hands first with detergent-containing towelettes to remove visible soil.
The Public Health Agency of Canada recommends that travellers avoid unnecessary contact with live fowl. This includes poultry farms as well as markets where live animals such as chickens and ducks are sold, as these animals have been found to be carriers of the avian influenza virus. Travellers should be aware that it is possible for the avian influenza virus to stick to hair and clothing, and may be inhaled. Research has shown that the risk of direct transmission of H5N1 infection from birds to humans is greatest in persons having close contact with live, infected poultry.
Travellers are advised not to bring fowl or egg products from these affected countries into Canada.
Canadian Food Inspection Agency recommendations to prevent the introduction of avian flu into Canada's animal population:
Travellers who have visited a farm while in an affected country should ensure that clothing and footwear worn on the farm are free from soil and manure before entering Canada. Clothing should be laundered and footwear should be disinfected after arrival. More information is available at the Canadian Food Inspection Agency.
As a reminder…
The Public Health Agency of Canada routinely recommends
that Canadian international travellers seek the advice of their personal
physician or travel clinic prior to international travel, regardless
of destination, for an individual risk assessment to determine their individual
health risks and their need for vaccination, preventative medication,
and personal protective measures.
Travellers to geographic destinations
where human cases of H5N1 are being reported are advised to specifically
discuss the topics of seasonal influenza vaccination and the benefit
of carrying Oseltamivir for the treatment of H5N1, as part of an individual
risk assessment with their personal physician or travel clinic.
The
Public Health Agency of Canada recommends, as well, that travellers
who become sick or feel unwell on their return to Canada should seek
a medical assessment with their personal physician. Travellers should
inform their physician, without being asked, that they have been
travelling or living outside of Canada, and where they have been. Additional Information
Information on Avian Influenza from the Public Health Agency
of Canada
FAQ on Avian Influenza.
Archived travel health advisories on avian influenza - Travel
Advisory Archives.
Information on Influenza from the Public Health Agency of Canada
Advisory
Committee Statements
Committee to Advise on Tropical Medicine and Travel
(CATMAT) Statement
on Travel, Influenza, and Prevention
National Advisory Committee on Immunization (NACI) Statement
on Influenza Vaccination for the 2004-2005 Season
Other related information from the Public Health Agency
of Canada
FluWatch weekly
report summarizes influenza surveillance activities in Canada and abroad.
Antivirals
External Sources of Information
For additional information on Avian Influenza A (H5N1) f rom the World
Health Organization (WHO) visit the WHO
Avian Influenza Disease Page
For international reports of the flu, visit the World Health Organization influenza web site
For international reports of infected animals by country, visit the World Organization for Animal Health
