Viruses are versatile and adapt quickly. There are many types, and new ones form all the time. The bird flu virus seems far away, bit it may already be in the United States. The Government has stockpiled vaccine, but that is not enough: each of us must optimize our immune system.
The Common Thread Between AIDS, Mad Cow Disease, SARS, Tami Flu, and Avian Influenza
Virus attacks are not new to most of us. Many who are now concerned about avian influenza have lived with threats of similar diseases for years. We have always found ways to manage risks from pathogens, and bird flu is unlikely to be different. A virus may cause a variety of symptoms. Some humans and animals may harbor these germs without any visible sign of illness, while others become seriously sick and even die. Fever, cough, pain and muscular weakness are early signs of bird flu virus. These symptoms may occur in both birds and humans, and bird flu may be fatal to both. It spreads between avian species and from birds to humans through saliva, nasal discharge, and bird feces. No virus can exist for any length of time without living tissue to feed upon. Any discharge of body fluids from an infected animal or a person can be a source of infection.
How virus infections spread
It is not common for an avian virus to jump to a human, though this has happened regularly during the last 2 years. Transmission of an avian virus from one person to another is even rarer, but cannot be ruled out altogether. International travel imposes the risk of virus transmission between nations and communities. Countries where people live with birds pose a threat of an avian influenza pandemic. The World Health Organization or WHO has been engaged in a massive effort during the past three years to contain the spread of avian influenza within affected pockets of Asia. The disease has not appeared in the United States as yet, but since visits by Americans to affected areas and visits by people from affected parts of Asia to the United States cannot be stopped, there remains a sizeable danger of avian influenza reaching our shores. It is likely that there are carriers in our midst already.
The limits of a vaccine based approach
We read a great deal about work in progress to develop a vaccine to combat the bird flu, and are accustomed to rolling up our sleeves for flu shots. However this approach works better for bacteria and for larger organisms than it can for any virus. Every virus has an innate ability to adapt and change form. The pathogenic types that infect humans may well have their origins in lower life forms. The main kinds of human flu virus are probably related to their close cousins from the avian world. Natural immunity and some modern therapeutic forms of intervention can boost immunity, or can act by attacking the causative virus. However neither of these approaches provides certain protection against virus attack, for the pathogens are able to adjust and survive through every adversity.
There is a fairly standard method to prepare a vaccine to guard against a virus attack, but the limitation is that the vaccine will not work against a modified form that the virus can quickly assume. Stable immunity builds up over generations. People who live in isolation gradually evolve powers of resistance to combat known virus forms prevalent in their environment. This system of protection becomes vulnerable as soon as people move to a new environment or once a new pathogen is introduced in their midst. A flu shot certainly helps against one type of virus, but can be entirely useless when the virus mutates or if a new virus is introduced in to the environment. Do not count on a bird flu vaccine alone to keep the bug away!
The relative advantage of most US citizens
Most of us do not live so near living birds that we are likely to come in touch with their bodily discharges. Hence the chances of direct spread of the bird flu virus to us is relatively low. Most of us eat well, exercise often, wash our hands and cover our coughs. We may take such simple things for granted, but they have played huge roles in keeping SARS, encephalitis and other illnesses away from our shores. These diseases have brought much misery to people who do not enjoy the social benefits that come with our material prosperity. This is not an absolute situation: travelers from affected parts of Asia could introduce the bird flu virus to the United States. Professionals from our neighborhoods have occasion to visit and work in virus affected parts of the world, and may return as silent carriers, if not afflicted outright by contagious spread.
It is likely that the avian influenza virus does exist in some parts of the US, though it has fortunately kept an invisible profile until now. The authorities deserve credit for observing quarantine and hygiene without variation all over the many potential points of entry in to the country. It is likely that the original virus that lives in birds, and that has attacked humans in Asia, hides in our continent in slightly modified form. The genetic pattern of the human flu virus which does hit us each winter is very similar to that of the bug that causes the bird flu. Americans need to be vigilant and to monitor the movement and spread of the avian influenza virus. The US has an active role in the international effort to contain infection, disease and fatalities due to the highly potent pathogen.
How doctors can prevent their patients from virus attack
Your primary care physician can monitor changes in your immunity through blood counts of both types of lymphocytes. There are specific serological tests that can be used to detect early stages and small doses of infection. These tests should be ordered when a person has been in physical contact with diseased animals or with people who could be carriers. There is an obvious element of guess-work in deciding which patients need tests for bird flu virus, but a visit to an affected country or a guest from such a place could be sufficient reason to get differential blood counts updated. There is some anti viral medication that can treat animals and people affected by a virus, but there is no proven remedy against the changes of form for which the entire virus world is infamous.
It follows that an annual and comprehensive medical evaluation is a universal requirement. People who do have insurance, and those who travel to countries where people live in close proximity to animals, are particularly vulnerable to attack, though they may not show any obvious symptoms for a long time. There are certain medical conditions such as diabetes and some cancers in which powers of resistance to infection are compromised. A doctor has the skills and experience to be able to detect early signs of viral infection and to manage them in time. Medical records of lymphocyte counts and details of past anti-viral medication are very useful in dealing with cases of fever, muscular weakness and respiratory distress: patients and parents have roles to play in ensuring that doctors have full and accurate access to such information.
Awareness of the nature of virus attack and how it spreads can help prevent outbreaks.
It may sound rude to discuss the importance of washing soiled hands, covering coughs and using gloves when handling any body discharge or fresh meat, but it bears repetition to state that no virus can live without the support of living animal or human tissue. Discharge from the nose, eyes and mouth as well as feces are the established routes of infection transfer for the bird flu virus. The particle size is such that it is barely visible even to the most powerful microscope; hence even the slightest slip is enough for a virus to find a new host. Any animal or a person, who shows first signs of the avian influenza virus attack, has to be quarantined immediately. It has to be kept in mind that it takes a few days for a person of average health to show symptoms after infection. Therefore an animal or a bird or a human being that has come near another one of these life forms that is infected, has to be treated as a suspect and watched as well.
Doctors, nurses and technicians who treat people and animals with the bird flu often fall prey to the attack themselves. This shows the highly infectious nature of the pathogen. It is also a pointer to the fact that sharing a closed room or air conditioned or heated interiors with unknown and large numbers of people and pets should be a cause for concern and for extra precautions. Aircraft, trains, offices and all crowded public places are potential foci of infection. The risk is much lower when close-knit communities congregate; conversely, red flags must be hoisted when exotic bodies drop in. This calls for a whole new etiquette in international settings, because necessary medical precautions can easily be construed as being rude and even discriminatory.
Why epidemiology is against the third world
The bird flu virus has lived in the innards of wild birds for centuries; there have been no signs of harm. However birds reared for their meat or as pets in human dwellings, fall sick and often die when exposed to this virus. Chickens and ducks are especially vulnerable. A bird virus is normally happy to live within the bodies of its normal host species, but can jump across and enter human bodies when there are plenty of them nearby. This is especially the case when a bird is terminally ill and close to death or freshly slaughtered. Interviews with people, especially children who have suffered from a bird flu attack, will generally establish that they have handled sick birds shortly before they fell ill.
Communities that live amongst animals including birds are in danger of a contagious virus outbreak. This has happened in Asia during the recent past. Communities in both rural areas and poor sections of cities share their dwellings with cattle. Chickens and ducks roam free, leaving children and adults exposed to their droppings. Handling living birds and cooking their fresh meat involves serious risk. Social habits are difficult to change and hence the threat of an epidemic in parts of Asia looms large. Poor nutrition can reduce immunity because the body has inadequate resources to produce white corpuscles in adequate numbers and of the right type. Malnutrition becomes a deadly threat when combined with close contact with domesticated animals. Children are especially vulnerable. This explains why some Asian children are vulnerable to encephalitis and rotavirus, though these diseases are virtually unknown in the West.
Problems in containing a pandemic
The nature of a virus allows it to mutate without warning. It works rather like a safe-breaker, trying to crack the code that each body uses to create new cells. It can replicate with dazzling speed once it has deciphered any one individual’s genetic code. The avian influenza virus concentrates on the lungs of its host, and quickly spreads to all parts of the respiratory system. Saliva, sputum, nasal discharge and even tears may be rich in pathogen counts, and spread infection amongst other birds in a flock or a pen. A virus is opportunistic and will not hesitate to try and colonize other life forms in the vicinity. Most humans and animals have sophisticated defense mechanisms that counter threat from any virus. A virus has the ability to live stealthily in a body with powerful defenses and wait for a chance to cross over to another that may be weakened by poor diet and other diseases.
Ease of infection transfer, the ability of individuals to harbor a virus without apparent symptoms and speed of replication are the three primary factors that lead to a sudden and explosive outbreak in a community. Poor hygiene and living habits exacerbate the problem, and make containment in an emergency very difficult. Quarantine is not practical on a large scale. Asian authorities have resorted to mass slaughter of suspect birds and other animals until now, but the prospects of large numbers of human carriers and victims are disturbing for people everywhere. Aircraft and the global economy are legacies of our times that enable and cause large-scale and continuous transfer of people between areas infected with bird flu virus, and other parts of the world. People arriving at ports of entry and showing signs of fever and severe respiratory distress can be screened and isolated, but there could be plane loads of carriers who appear healthy, and who arrive ever hour of the day, and spread the virus. Most wild birds that use North America for transit during autumn and spring live in the Arctic and South America, but species from the heart of Asia are also found amongst them. Bird migration is a natural wonder deserving the most assiduous conservation, but it is a threat and potential source of infection where their reserves and haunts are near human dwellings, poultries, dairies and hog farms and ranches.
Controlled air flow can be contagious!
Though the bird flu virus has reared its head amongst impoverished rural people with poor hygiene habits until now, one cannot ignore the potential for sudden spread amongst other sections of international society. Consider that the smallest particle of discharge from any orifice in a head may have sufficient inoculums of avian influenza virus to threaten innocent lives. The indefinite gap between infection transfer and its detection makes effective surveillance almost impossible. Open air, adequate space for people at all times and clean habits keep the probability of infection low. However those of us who have to take long aircraft flights and those who commute in packed trains are at risk. Those who work in popular banks, busy medical institutions and shopping malls are also vulnerable. Working dogs at offices with air-conditioning and heating are a hazard, to say nothing of an exotic avian pet, gifted from abroad! It helps, in terms of keeping bird flu at bay, if you are an introvert and keep social interaction to a minimum!
The risk rises exponentially as Americans travel back and forth between other countries. China is a major concern with a considerable number of avian influenza episodes. India, now an important destination for business people from the US, has the world’s highest recorded child mortality from encephalitis and rotavirus. The pathogens that cause these terrible illnesses are different from bird flu, but it is possible that people in India are carriers of air borne infective agents against which people in the US have poor resistance. Christopher Columbus is said to have brought new bugs to North America in his ships and through his crews. Native Indians were decimated by such intrusion, as their immune systems had never encountered these organisms before. This unfortunate phenomenon now hangs over our heads as a sword that can repeat history in fearsome manner! Nations and people have lived with threats of international transfer of infection since the days of intrepid explorers. We now encounter such danger every time an aircraft or a ship brings people from lands of the bird flu to the United States.
A frightening lesson from mad cow disease
The prion is a new addition to the rogue’s gallery of infection agents. Unlike a virus that cannot survive outside a living body, prions may lodge in dead meat for unknown periods, and strike even after flesh has been cooked. Cases of mad cow disease have brought this frightening matter to light. Bird meat has been known to contain bacteria, fungi and protozoa. These pathogens are relatively easy to control through the use of chemical biocides. However an infection threat from bird meat has seemed unlikely until now, since the animals are dressed, cooked and eaten hours if not days after slaughter. What if a chicken leg, breast or other part contains prions? Our knowledge of prions in birds is sketchy. The implications of consuming meat of diseased birds are simply not known. Prions are associated with fatal diseases in big game such as deer, and have been discovered in fish as well. Where will all this end?
Mad cow disease has changed meat production and its international trade forever. Each animal that shows signs of nerve defect or brain damage is isolated. Preceding generations are traced as a matter of abundant precaution. Countries are careful not to source beef from foreign sources where monitoring and quarantine practices are suspect. Logically, we should extend these measures to poultry, piggeries and fish farms. However the logistics are daunting, and how can you tell if a fish feels a bit under the weather anyhow? The situation in most of Asia is more complicated: animals are allowed to roam free, taken to graze and slaughtered without effective regulation. US Customs do not allow people arriving from abroad to bring in edible substances, but how can such conditions be universally enforced? Can we make sure that every backpack is free of that sandwich, or that meals left unconsumed in an airliner do not make their way to a soup kitchen?
Living with the fear of infectious disease
It will not be productive to describe infection threat any further. Suffice it for us to conclude that life at ground zero faces threats of epidemic outbreaks. Avian influenza is not the only unwanted gift that we may unwittingly receive from another country! What should you do?
1. Keep your immune system in top condition. Balanced nutrition and regular exercise should normally be adequate to keep both types of lymphocytes within the normal range.
2. Remember that high blood sugar, radiation and chemical therapy for cancer and inappropriate diet make you especially vulnerable to virus infection.
3. Review your blood counts and encounters with people exposed to viral infection with your doctor, so that specific tests and treatment can start as soon as possible.
4. Avoid places with closed air circulation, especially when people with productive coughs, colds, fever and labored breathing are around. This applies to animals of all kinds, including working dogs and pets. Be especially careful in aircraft and crowded trains to stay away from people who are ill, and try and have them wear masks.
5. Do not eat any animal flesh from abroad or from wild life reserves. Quarantine animals that appear to be ill and everyone who you know has come in contact with such animals.
A virus behaves like a thief. It is always ready for an opportunity to enter your body, may use disguise and live within undetected. It adapts itself to prey and plays hide and seek with the lymphocytes that are supposed to police your body. Remember that you can never let your guard slip, because criminals do not give up! Think of every virus as a thief and the steps you need to take will be easier to keep in mind!