Avian Flu Strain H5N1

� � Jan-15-2009

It is an irony that scientists worldwide are yet to ascertain the details as well as the functioning of the killer avian influenza strain H5N1 virus even five years after it began taking its toll on millions of poultry in Southeast Asia. Avian influenza strain H5N1 is not only an erratic, but also treacherous virus.

Since this lethal virus commenced its cycle of marauding activities in 2003, H5N1 has ravaged through poultry groups across Asia, the Middle East and Africa and at the same time infected and claimed thousands of human lives in these regions and the casualties have been swelling each year. Fortunately, by the end of 2008, the deadly virus seemed to have taken a respite as the year witnessed lesser number of deaths owing to the virus compared to the number of casualties during other years since 2003.

This particular aspect has given rise to curious questions worldwide on whether the spread of H5N1 was on the decline.

Unfortunately, scientists are still in the dark vis-�-vis the coming out of viruses causing influenza, their spread and their jump or soaring from one species to another or the absence of this. Hence, there is no straightforward answer to this query. In fact, the lack of knowledge in this regard, has left scientists involved in researches relating to influenza worldwide grappling for awareness in combating the plague. According to the deputy chief of influenza surveillance and prevention for the U.S. Centers for Disease Control Dr. Tim Uyeki, as of now no one can forecast whether the H5N1 virus will become a human plague in future. Citing the instance of a two-month-old Chinese girl who was recently hospitalized in Hong Kong following an H9N2 contagion, Dr. Uyeki further stated that he was of the view that the virus is definitely a peril to mankind, but not the only hazard.

'Flu fatigue'

As far as the vagueness or lack of adequate information regarding the H5N1 virus is concerned, one thing is transparent and that is the scientific community involved in the study of influenza viruses as well as the public health officials who have been striving to work out a strategy to contain the epidemic seem to be an exhausted lot as all their efforts have yielded little or not result yet. In addition, even a large number of the common public too appears to be fed up over the very mention of the subject. Dr. Keiji Fukuda, head of the World Health Organization's (WHO) global influenza program, is of the view that the above have given rise to a new phrase 'flu fatigue' which has been doing the round in the scientific community as well as the among the public health officials and even common people for the last one year or more.

According to Dr. Fukuda, the deadly virus H5N1 made its first known appearance to marauder the human beings way back in 1997 infecting 18 persons of which six succumbed to the disease caused by the unpredictable virus. While this gave rise to fear and panic both among the health officials as well as the common masses, it also egged the scientists' community to wake up to the need to prepare safeguards from what was described as an emerging epidemic. Dr. Fukuda further said that the first attack of the H5N1 created such a fear that people really could not comprehend the nature and activities of the deadly virus as it has the capability to change itself in any form any moment and cause something fatal. It is this fear that compelled some people to work unbelievably harder to find ways and means to deal with the menace.

A variable virus

But with the passage of time, now it has become obvious that H5N1 has not been functioning on a noticeable schedule. During the peak period in 2006, the virus infected 115 human beings and claimed 79 lives in nine nations during 2006, while both the cases of human infections as well as the number of deaths owing to the killer virus dropped to 88 and 59 respectively in 2007. The human cases further dropped to only 40 and casualties owing to H5N1 were 30 in six countries during 2008. This has only left the experts keep guessing regarding the trend of the virus. They are still unsure whether this gradual decline in human cases as well as the casualty is a long-term change or a short-term problem.

The head of the respiratory virus unit of Britain's Health Protection Agency, Dr. Maria Zambon is of the view that the H5N1 virus possibly functions in a cyclic manner. She says that although only a limited data is available regarding the nature and functions of the H5N1 virus, one needs to be careful keeping in view its long-term developments. Dr. Zambon points out that for many years two different families of influenza B viruses moved freely and in tandem in Southeast Asia recently. While the rest of the world witnessed the spread and contagion of only one family of influenza B virus causing infections, it was only in Southeast Asia that there were two different lineages of the virus. However, after a few years the second lineage of influenza B virus began to spread all over the world and infecting humans like never before.

This trend confused the scientists who were at a loss to ascertain why it took such a long period for the second lineage of the influenza B virus to spread worldwide or what actually led to the rapid spread of this epidemic. According to Dr. Zambon, flu viruses are basically variable and are able to perform different kind of erratic and capricious activities. She cautions that this feature of the influenza viruses make them really dangerous and no one should ever try to undervalue this.

Occurring in cycles or waves

On the other hand, Dr. Michael Osterholm, who is the head of the University of Minnesota's Center for Infestations Disease Research and Prevention, is of the view that many disease-causing microorganisms work in succession or waves. Going by this theory, it is technically doable to assume that a major wave of the influenza virus H5N1 has already affected the poultry and other birds and the viruses that are in circulation now are of lower intensity and doubtful of transmitting the disease to the humans or even if it does, it will not be severe enough so that human cases may be detected. At the same time, Dr. Osterholm adds that although he does not have any evidence to prove this theory of such changes that usually occur over a longer period of time. Cautioning the scientists, Dr. Osterholm says that although people have been trying to assess the contagions and deaths caused by the killer H5N1 influenza virus on a year-to-year basis, the fact is that since the changes take place over a long period of time, they need to assess the menace on a many-year-to-many-year basis.

According to Dr. Keiji Fukuda, no study undertaken on the H5N1 influenza virus has demonstrated that the virus has basically transformed. Hence, he guesses that the decline in human cases and deaths owing to the deadly virus may better be attributed to the change in humans' handling of the menace. Substantiating his view, Dr. Fukuda says that efforts to get rid of diseased poultry have been enhanced and this in turn has reduced the frequency of people coming in contact with the virus in countries that have been using poultry inoculations. In addition, countries affected by the avian flu have taken initiatives to educate their people regarding the dangers of coming in contact with diseased and dying poultry. At the same time, Dr. Fukuda admits that despite the awareness drive, there may be plenty of poor people in these countries who are possibly still consuming the diseased and dead birds instead of culling them right away.

Dr. Uyeki's suggestions

Contrary to Dr. Fukuda's views, Dr. Tim Uyeki has suggested other probabilities that could have led to the decline in the human cases as well as deaths owing to the H5N1 influenza virus. Dr. Uyeki says that as the menace has subsided considerably during 2008, people's attention and concern regarding the fatal affects of the virus too have waned. He has warned that this attitude may lead to slackness in inspections as far as new cases of avian flu are concerned. According to Dr Uyeki, in such circumstances, the physicians would be less inclined to suspect an ailment to be a H5N1 contagion and go for its test. Instead, it is possible that the doctors would attribute the illness to innumerable other probable grounds. He further states that it is possible that the virus has split into numerous diverse line or 'clades' (organisms with common ancestor) or even 'sub-clades' that is likely to make it difficult for examination. In such instances, a positive test may yield negative results in the laboratory if the scientists looking for the sample hereditary substances in the viruses are no longer present in the pathogens.

Ironically, even as the scientists continue to examine the H5N1 influenza virus and keep wondering about its traits, public health officials are increasingly finding it difficult to solve the problems faced by the people.

Meanwhile, despite the abatement in human cases and deaths, the threat of a flu epidemic brought about by H5N1 or H9N2 or any of the other whole host of influenza viruses continue to loom large. From whatever efforts the authorities as well as the scientists have put in, it is evident that even the preliminary work has not been completed. At the same time, it is also true that there is so many other health issues competing for funding in these days of economic distress that has not been possible to address the problem caused by flu adequately.

Dr. Fukuda's concerns

According to Dr. Fukuda, the menace of avian flu caused by H5N1, H9N2 or any other virus has become a major concern for people in the present times. He says that long-term efforts are required to tackle the situation properly and hence cautions the world to be prepared for the outbreak of the next round of the avian flu epidemic. Dr. Fukuda is apprehensive that in view of the temporary abatement in the human cases owing to the avian flu, scientists as well as the people may tend to remove their concentration from the problem and devote their efforts to something that is entirely different. If this really happens, it will be very unfortunate as we will then stand to lose much of the work that has been achieved to combat the menace during the last four years. He emphasizes that if people were to begin all work in this regard from the scratch again, it would not only be akin to acting like Sisyphus of the Greek mythology, but also mean a great loss of time, energy and money. It may be mentioned here that in Greek mythology Sisyphus represents a character that was destined to perform a task that could never be finished.