http://blogs.crikey.com.au/croakey/...-swine-flu-gone-over-the-top-maybe-maybe-not/
Has our response to swine flu gone over the top? Maybe, maybe not?
June 25, 2009 ? 2:35 pm, by Croakey
Given the relative mildness of swine flu, has Australia?s response been appropriate?
It?s a worthy question that will, no doubt, be debated for some time.
In the journal Rural and Remote Health, Dr Alexander Hamilton, a senior resident medical officer at St Vincent?s Hospital in Sydney, puts forward one view. While many believe the response has been excessive ? ?a media storm over a mild illness? ? he considers that Australia?s ?aggressive? response has been appropriate and ?must be commended?.
Over at the Medical Journal of Australia, meanwhile, infectious diseases specialist Dr Sanjaya N Senanayake (from Canberra Hospital and the ANU) is not convinced the response has been justifiable, arguing that it merits review.
He notes that Australia has diverted significant resources, especially at a public health and laboratory level, into investigating and containing this outbreak.
?If these resources are not already overwhelmed, one wonders how they will cope if there is a further rise in swine influenza A cases combined with the work generated by Australia?s ?normal? influenza season,? he writes.
?There has also been some public debate about whether a downgraded response to the outbreak (that would consume fewer resources) would be more appropriate, on the basis that the virus, despite being both novel and infectious, does not seem particularly lethal.?
Dr Senanayake says the virus should not be dismissed as unimportant, however, based on calculations that it may eventually result in around 80 000?200 000 people in Australia being hospitalised, and around 8000 deaths. This compares to annual figures of about 18 000 hospitalisations and 3000 deaths directly or indirectly attributable to seasonal influenza.
Meanwhile, Professor Peter Collignon, an infectious diseases physician and microbiologist at the Australian National University, has filed the following analysis for Croakey:
This current Swine flu virus spreads easily but it only has relatively low virulence (aggressiveness) levels. It causes less serious disease than what we see predicably every year from the spread around the world of new seasonal flu strains.
Going to the ?Protect? phase nationwide in Australia (as now recommended by our Federal Health authorities) means this will be treated as seasonal influenza. This seems to be the most appropriate response based on the available evidence for how this virus acts now or is likely to do in the future. This is effectively, the approach that Canada and most parts of the US have taken.
More than 99% of people who become infected with this virus have had only mild symptoms and fully recover within a few days. (Take a deep breath, Swine Flu?s not that bad). We have been spending too much time monitoring, testing and treating these people. It is the 1% or less, who become moderately to severely ill that we need to quickly identify and treat with antivirals and where necessary antibiotics if they develop bacterial lung infections.
The problem at the moment is that those who are most at risk will have difficulty being seen by healthcare professionals, because too many of the 99% (because of fear, public health directions and other reasons), are in the queue in front of them at doctors? surgeries and emergency departments. Those 99% should just stay at home and recover uneventfully. When people are only slightly unwell but come to healthcare facilities for testing and advice, this also just helps spread the virus
This Swine flu strain is not a ?new? virus, it is just a repackaged H1 strain - variations of which have been circulating and re-infecting people yearly since 1918. This is why so few older people have been infected ? they already have reasonable immunity. Even though young people are the most likely to have little or no immunity to H1 strains, when infected with this swine flu strain, most infections have been very mild.
In the US there is likely to have already been over 300,000 people infected (most undiagnosed). On current data it looks likely that there is less than 1 death for every 10,000 people infected and these deaths are occurring mainly in those with risk factors (diabetes etc).
Some have argued that we need to keep a more aggressive response, re quarantine of those not ill, school closures etc, because second and third waves of infection will occur and then there is a high chance that the virus will have mutated to become more virulent - as they say happened in 1918/19.
Despite these frequent statements, this does not appear to have happened in past with influenza. In general the effect with most viruses is that they usually become less aggressive with time - not more. In any case nearly all those deaths in 1918/19 were due to secondarily bacterial infections (such as pneumonia) rather than the influenza virus itself. (Bacteria, not flu, fatal in past pandemics.)
Antibiotic resistance in bacteria is a continuing and rapidly growing global problem, especially in developing countries. In Australia, we remain much more fortunate with much lower antibiotic resistance rates. We still have a variety of antibiotics (especially injectables) that will work against nearly all strains of bacteria that might cause pneumonia. Thus we would not expect to have very high mortality rates associated with this virus in this country, providing we can readily identify and promptly treat those with complications.
We do need to do things to slow the spread of this virus. This includes cough etiquette, and good general hygiene, especially with our hands. This means using alcohol hand rub and soap and water, masks on occasion and other general infection control measures, such as staying at home and away from school and work if you are unwell. With a virus of such low comparative virulence it is very doubtful however that closing schools and keeping people away from school and workplaces in home quarantine when they are asymptomatic, is an appropriate response.
When we have a virus of relatively low virulence such as this Swine Flu strain, we need also to ensure that any new vaccine it is as safe as possible and only given to those where the risks of disease outweigh the risks of the vaccine. This takes time and appropriate very large safety trials. In the 1970s in the US there was great concern in when a new form of swine flu developed. A new vaccine was rapidly developed and then given to over 40 million people. The expected ?swine flu? epidemic however never occurred. There was however a relatively rare side-effect from the vaccine that lead to an excess (in about 1 per 100,000 vaccine recipients) of Gilluiane-Barre Syndrome - a form of ascending neurological paralysis.
We need to reconsider how we approach this virus (and other strains that might develop in the future).
Flu strains every year cause proportionately more illness and deaths than this swine flu strain is likely to do in Australia. The implementation of stricter controls via the different phases of a Pandemic plan, should only be adopted when a new influenza strain looks likely to arrive in Australia that is both hyper-virulent AND spreads easily. We now know that this is not the case for this Swine flu strain as it is not particularly virulent.
The very early approach of most of the US and Canada, to treat this as seasonal influenza, seems a more appropriate current response than our prolonged and ultimately futile attempts at containment in many Australian States.
We need to continue to monitor the situation, but only change our response from seasonal influenza if the virus changes in its virulence.
Has our response to swine flu gone over the top? Maybe, maybe not?
June 25, 2009 ? 2:35 pm, by Croakey
Given the relative mildness of swine flu, has Australia?s response been appropriate?
It?s a worthy question that will, no doubt, be debated for some time.
In the journal Rural and Remote Health, Dr Alexander Hamilton, a senior resident medical officer at St Vincent?s Hospital in Sydney, puts forward one view. While many believe the response has been excessive ? ?a media storm over a mild illness? ? he considers that Australia?s ?aggressive? response has been appropriate and ?must be commended?.
Over at the Medical Journal of Australia, meanwhile, infectious diseases specialist Dr Sanjaya N Senanayake (from Canberra Hospital and the ANU) is not convinced the response has been justifiable, arguing that it merits review.
He notes that Australia has diverted significant resources, especially at a public health and laboratory level, into investigating and containing this outbreak.
?If these resources are not already overwhelmed, one wonders how they will cope if there is a further rise in swine influenza A cases combined with the work generated by Australia?s ?normal? influenza season,? he writes.
?There has also been some public debate about whether a downgraded response to the outbreak (that would consume fewer resources) would be more appropriate, on the basis that the virus, despite being both novel and infectious, does not seem particularly lethal.?
Dr Senanayake says the virus should not be dismissed as unimportant, however, based on calculations that it may eventually result in around 80 000?200 000 people in Australia being hospitalised, and around 8000 deaths. This compares to annual figures of about 18 000 hospitalisations and 3000 deaths directly or indirectly attributable to seasonal influenza.
Meanwhile, Professor Peter Collignon, an infectious diseases physician and microbiologist at the Australian National University, has filed the following analysis for Croakey:
This current Swine flu virus spreads easily but it only has relatively low virulence (aggressiveness) levels. It causes less serious disease than what we see predicably every year from the spread around the world of new seasonal flu strains.
Going to the ?Protect? phase nationwide in Australia (as now recommended by our Federal Health authorities) means this will be treated as seasonal influenza. This seems to be the most appropriate response based on the available evidence for how this virus acts now or is likely to do in the future. This is effectively, the approach that Canada and most parts of the US have taken.
More than 99% of people who become infected with this virus have had only mild symptoms and fully recover within a few days. (Take a deep breath, Swine Flu?s not that bad). We have been spending too much time monitoring, testing and treating these people. It is the 1% or less, who become moderately to severely ill that we need to quickly identify and treat with antivirals and where necessary antibiotics if they develop bacterial lung infections.
The problem at the moment is that those who are most at risk will have difficulty being seen by healthcare professionals, because too many of the 99% (because of fear, public health directions and other reasons), are in the queue in front of them at doctors? surgeries and emergency departments. Those 99% should just stay at home and recover uneventfully. When people are only slightly unwell but come to healthcare facilities for testing and advice, this also just helps spread the virus
This Swine flu strain is not a ?new? virus, it is just a repackaged H1 strain - variations of which have been circulating and re-infecting people yearly since 1918. This is why so few older people have been infected ? they already have reasonable immunity. Even though young people are the most likely to have little or no immunity to H1 strains, when infected with this swine flu strain, most infections have been very mild.
In the US there is likely to have already been over 300,000 people infected (most undiagnosed). On current data it looks likely that there is less than 1 death for every 10,000 people infected and these deaths are occurring mainly in those with risk factors (diabetes etc).
Some have argued that we need to keep a more aggressive response, re quarantine of those not ill, school closures etc, because second and third waves of infection will occur and then there is a high chance that the virus will have mutated to become more virulent - as they say happened in 1918/19.
Despite these frequent statements, this does not appear to have happened in past with influenza. In general the effect with most viruses is that they usually become less aggressive with time - not more. In any case nearly all those deaths in 1918/19 were due to secondarily bacterial infections (such as pneumonia) rather than the influenza virus itself. (Bacteria, not flu, fatal in past pandemics.)
Antibiotic resistance in bacteria is a continuing and rapidly growing global problem, especially in developing countries. In Australia, we remain much more fortunate with much lower antibiotic resistance rates. We still have a variety of antibiotics (especially injectables) that will work against nearly all strains of bacteria that might cause pneumonia. Thus we would not expect to have very high mortality rates associated with this virus in this country, providing we can readily identify and promptly treat those with complications.
We do need to do things to slow the spread of this virus. This includes cough etiquette, and good general hygiene, especially with our hands. This means using alcohol hand rub and soap and water, masks on occasion and other general infection control measures, such as staying at home and away from school and work if you are unwell. With a virus of such low comparative virulence it is very doubtful however that closing schools and keeping people away from school and workplaces in home quarantine when they are asymptomatic, is an appropriate response.
When we have a virus of relatively low virulence such as this Swine Flu strain, we need also to ensure that any new vaccine it is as safe as possible and only given to those where the risks of disease outweigh the risks of the vaccine. This takes time and appropriate very large safety trials. In the 1970s in the US there was great concern in when a new form of swine flu developed. A new vaccine was rapidly developed and then given to over 40 million people. The expected ?swine flu? epidemic however never occurred. There was however a relatively rare side-effect from the vaccine that lead to an excess (in about 1 per 100,000 vaccine recipients) of Gilluiane-Barre Syndrome - a form of ascending neurological paralysis.
We need to reconsider how we approach this virus (and other strains that might develop in the future).
Flu strains every year cause proportionately more illness and deaths than this swine flu strain is likely to do in Australia. The implementation of stricter controls via the different phases of a Pandemic plan, should only be adopted when a new influenza strain looks likely to arrive in Australia that is both hyper-virulent AND spreads easily. We now know that this is not the case for this Swine flu strain as it is not particularly virulent.
The very early approach of most of the US and Canada, to treat this as seasonal influenza, seems a more appropriate current response than our prolonged and ultimately futile attempts at containment in many Australian States.
We need to continue to monitor the situation, but only change our response from seasonal influenza if the virus changes in its virulence.
