HEALTH / PUBLIC HEALTH
Are we ready for the avian flu pandemic?
The WHO has warned that India would likely be hit if a bird-flu pandemic breaks out because India has large numbers of domestic ducks and the country is along major bird migratory routes originating in the East.
notes a few positive elements in India's readiness, but finds that much more is needed to avert disaster.
01 December 2005 -
The avian influenza or bird flu has been in the news for some time now. From time to time we come to learn of how a parrot died of the deadly H5N1 strain of the influenza virus in UK or how migratory birds have been dying in large numbers in Siberia or China. Side by side we also get sporadic news of a human being dying of this flu in Indonesia or in Vietnam. Experts have also been talking of the threat of a global influenza epidemic (or pandemic) and there is news of how Tamiflu (an influenza medicine) stocks are being sold out in many countries.
All of us are familiar with influenza having had influenza more than once in our childhood. Influenzas are usually characterized by fever, sore throat or cough, running nose and red eyes. Ordinary flu is self limiting and gets cured in about a week, whether you take medicine or not. From our childhood, most of us may also remember having been told that if you take medicines you will get cured in one week, otherwise it will take seven days for you to get okay. (Translated from a common Hindi saying that goes dawai loge tho ek saptah, dawai nahi loge tho saat din!
Why is there such a hue and cry over such a simple and common ailment?
Influenza is caused by the influenza virus. There are many kinds of influenza virus, and those which affect human beings usually get transmitted through droplet infection or through the respiratory tract. While in most cases 'flu' is relatively mild, it can also assume severe forms. This is particularly so when the influenza virus is a new one. As a rule, most of us have developed some kind of immunity over the years to the common influenza virus. Even then, the very young or old, or those whose immune system is not robust may suffer complications from the common influenza virus as well. A particularly severe influenza pandemic occurred in 1918 (called the Spanish flu) when an estimated 40 million people died all over the world due to the disease. There have been two other flu pandemics in the last century in 1957 and 1968 (the Asian flus), which took a lesser toll of lives.
Why the concern about bird flu?
According to the WHO, a flu pandemic occurs when three conditions are satisfied. First, a new influenza virus must emerge in the human population to which everyone is susceptible, second, it must be easily transmitted from one person to another and finally it should be able to cause serious illness. It is based on these three criteria that there is concern that the avian flu that has emerged in Southeast Asia may well transform itself into the next flu pandemic.
The avian flu that is in the news is a contagious disease that commonly occurs in birds and sometimes in humans and pigs. It is caused by a type A influenza virus and many are now familiar with its specific type -- H5N1. The disease may occur in a mild form or a severe form. It may start as a mild illness but after some months, due to changes in the virus, the disease may become serious and rapidly kill nearly all the affected birds. Hence the name, Highly Pathogenic Avian Influenza (HPAI). The present avian flu epidemic is severe. It is affecting domesticated poultry (chicken, turkey and eggs from infected birds) plus ducks, pigs, tigers and human beings in some countries.
This avian flu virus is (currently) not easily transmitted from birds to humans and all the persons whose death has been due to avian flu came in close contact with infected birds. Humans get infected from handling the birds or any material which is contaminated by the bird faeces. The virus may enter the respiratory tract by a simple act like rubbing your nose using your hand which may have held poultry.
From 1997, when this current virus was first described in Hong Kong, till 14 November, a total of 126 human beings were affected and 64 succumbed.
The number of fatalities may not be of pandemic proportions, but there are a couple of things happening to the virus in the last
eight years that has caused experts to raise the alert.
First, the virus is changing its virulence or ability to infect. Earlier it caused disease in poultry, but did not cause the disease
in wild ducks. Ducks were asymptomatic carriers. But now, these ducks are dying in large numbers. There is evidence that wild birds and mammals are also dying in large numbers from this virus. Cats, which were earlier thought immune to the disease have also been found to be affected. There is also suspicion of human to human transmission in a few cases. All this clearly points to the fact that the virus is changing its character. The ability of a virus to change its character is itself well known. It does this either by mutation or by reassortment (incorporating human genetic material which will make virus replication in human beings easier).
Dr Samlee Plianbangchang, WHO Regional Director for the South-East Asia Region has warned, "The threat of a pandemic is very real. It is no longer a question of if it will occur. It is now only a question of when." He also pointed out that two of three pre-requisites to start any influenza pandemic have already been met. These are the emergence of a new virus to which all are susceptible and that the new virus is able to replicate and cause disease in humans. The third pre-requisite, which has not yet happened, is the ability of the new virus to be transmitted efficiently among humans (i.e. human to human.)
Should we be worried in India?
India is recovering from a badly managed Japanese Encephalitis (JE) outbreak this year which hit U.P. and Bihar. Considering that JE has been around in the country for over twenty five years (i.e. it is not new), and JE prevention and control measures are better known, the recurring failure in arresting JE each year does not bode well for the country. However it would be worthwhile to review the current state of vulnerability and preparedness.
Early warning and detection
While India does have a system of disease notification, influenza is currently not among the list of notifiable diseases. Notifiable diseases have to be reported to health authorities by the attending doctor, so there is a check on both incidence and spread.
U.P. mismanaging JE epidemic
While cases of bird flu have been found in Europe, the epicentre of the disease continues to be in Southeast Asia and there have been reports of avian, animal and human infection from China, Vietnam, Cambodia, Thailand, Malaysia, Korea, Lao PDR and Japan. While Vietnam and Cambodia are reasonably far away, the Tibet autonomous region of China or Thailand are not, and migratory birds do not respect international borders. With winter setting in, birdwatchers across the country are eagerly waiting for the migratory birds.
The WHO has warned that India would likely be hit if a bird-flu pandemic breaks out because India has large numbers of domestic ducks and there are major bird migratory routes from Mongolia, China and Tibet across the country. In October, there were reports of a large number of migratory birds from China dying at the Kulik Sanctuary 500 kilometers north of Kolkata. Though there has been no confirmation of avian flu in this case, it points to the vulnerability to infection from migratory birds. According to news reports, testing of migrating bird populations have begun in West Bengal and Orissa for the disease.
The WHO says there are five steps to deal with a flu pandemic which are as follows:
1. Reduce opportunities for human infection
2. Strengthen the early warning system
Phase: Emergence of a pandemic virus
3. Contain or delay spread at the source
Phase: Pandemic declared and spreading internationally
4. Reduce morbidity, mortality, and social disruption
5. Conduct research to guide response measures
Poultry raising has been spreading rapidly as a home or small scale industry in India. It is not surprising that chicken prices have been stable for a long time. What this means is that there are many opportunities for human infection in India from infected domestic birds. The culture of protective practices is very low in India. In agriculture for e.g., it is common to find farmers spraying deadly insecticide without any protection or for labourers to handle harmful chemicals with bare hands. Similarly, it is difficult to imagine that thousands of poultry keepers around the country will shift to more protective practices in handling these birds like using overalls, facemasks or even washing their hands repeatedly, even if the information reached them.
What must India do?
Culling of birds has been an important way of containing the infection within bird populations once infection has been detected. While this sounds an easy public health solution, it has tremendous economic ramifications. During the JE epidemic, the U.P. state government dragged its feet over the simple act of relocating piggeries away from human populations. To cull millions of chickens worth crores of rupees, which will affect the lives of tens of thousands of rural poultry farmers is going to be a very difficult political choice which political leaders and bureaucrats will delay for as long as possible.
(1 crore = 10 million.)
Effective early warning systems will require the coordination between a number of departments for example animal husbandry, forest and health as well as institutions like the Bhopal-based High Security Animal Disease Laboratory, the Pune based National Institute of Virology and the Bareilly based Indian Veterinary Research Institute. The Bhopal institute has claimed to have developed an easier way of testing for the avian flu virus from bird-droppings. The Pune based institute has also developed a simpler test kit. But the advantages of India's scientific readiness and enterprise may be blunted by bureaucratic red-tapism.
Containing or delaying the epidemic at source will require early detection of the disease, isolation of the cases to prevent further spread, and quick treatment of the people affected in order to control public panic. While India has a system of disease notification, influenza is currently not among the list of notifiable diseases. Notifiable diseases have to be reported to health authorities by the attending doctor so that there is a check on both the incidence and spread.
Also people who have the greatest possibility of contracting the disease from poultry can be assumed to be from rural India where most of the poultry farms are located. Public health systems in large parts of rural India are in a very poor state and a large number of people in many states prefer to consult private or even informal health care providers. Without a largescale effort to involve these providers in the influenza control programme it is difficult to imagine that they will on their own notify the authorities.
It is already time that special task forces be set up under the supervision of the Chief Medical Officers at each district to spread information about the disease and to monitor all suspicious cases of influenza. However no such action has been taken as yet. It has been reported that the Health Minister Dr Anbumani Ramadoss is holding weekly meetings with senior officials to review the situation. The one good sign is that the Minister is concerned. At a recent interview in Guwahati he did mention that the government would take all steps to deal with the disease. Still, even Ramadoss has agreed that with its limited infrastructure and large population India will not be able to cope with a bird flu outbreak among humans.
There are a number of manufacturers like Ranbaxy and Cipla who can quickly produce the drug if India invokes the compulsory licensing prerogative under WTO rules. But producing the drug is a long distance from getting the drug on time to the rural poor, who will be at high risk.
Patents Law implications for health
Skeptical of compulsory licensing
If the epidemic cannot be contained, the only way to deal with the disease is to reduce mortality, morbidity and social disruption. (Morbidity refers to the sickness and debility caused by a disease as compared to mortality which is death.) At present the only effective medicine Tamiflu is prohibitively expensive. While western countries and Japan are stockpiling the medicines, India cannot afford to do so with the pitiful budget that is allotted to medicines within the overall inadequate health budget.
However the one area where India may have a advantage compared to many other countries is the manufacture of the anti-influenza medicine. The patent for the anti-influenza drug Tamiflu is currently held by the Swiss drug maker Roche. Under the current WTO regime, a country can invoke the Compulsory Licensing clause to manufacture a patented drug in case of emergencies. If India chooses to use this prerogative, there are a number of manufacturers like Ranbaxy and Cipla who can quickly produce the drug. But producing the drug is a long distance from getting the drug on time to the rural poor, who will certainly be the population which will be the worst affected. At present the Government of India has stock of 20,000 doses which have been supplied by WHO.
The recently announced National Rural Health Mission includes the control of communicable diseases as part of its agenda.
The NRHM provides a framework for initiating a coordinated response, though it is still in its infancy. The flu epidemic is still some
way off, though how far away no one can predict. With all the advance warning about the bird flu, health authorities now need to quickly put in place a composite plan with the help of WHO. This must not only involve responses to cases when they occur but also equip the whole health care delivery system, both public and private, to work together so that the history of the last century's pandemics is not repeated.