[26 January 1998]
Copyright 1998
[Original title:
The Flu: it's not just "for the birds."]
Copyright 1998
By Deborah A. N. Bennu
All Rights Reserved.
Recently, the news has been filled with reports of a deadly new "bird flu." Pet bird owners have been asking, "Will my birds make me sick? What should I do?" Even though the flu should always be treated with respect, one should not worry about "catching" the "bird flu" from pet birds.
Influenza is a virus that can infect many different warm-blooded animals, producing respiratory illness. However, the "flu" virus has developed different variants that are specialized for each species of animal that they infect.
Likewise, animals that are infected by these specialized flu virus variants have developed an immune system that has, over time, detected and successfully fought off these very similar-looking variants. These animals' immune systems are "primed" to detect and destroy their own specialized flu viruses.
Sometimes, an animal can become infected by two different flu variants at the same time. For example, a chicken can become infected with both the human and the chicken flu variants. Even though this is a rare occurrence, it does happen, especially in overcrowded situations where people live with their animals. This is the reason that most of these deadly "new" flu variants arise in China, because many impoverished people live with their animals in crowded, unhygienic conditions.
When two different flu variants infect the same animal, they can "swap" genetic material between themselves. When this "swapping" occurs, it can result in a dramatically altered virus that is frequently unrecognizable by the immune systems of either original host.
And this is where the trouble starts: as you know, the flu can be a very dangerous virus, but usually our immune system is capable of moderating its effects so the result is an unpleasant, but tolerable, illness. However, when the flu virus has "swapped" genetic material with another variant, the resulting virus suddenly has changed its outer "coat" so it cannot be recognized by the immune system. For example, when the human flu virus has the outer coat of the chicken flu virus, the human immune system cannot detect and fight off this virus. Thus, this mutant runs amok and unchecked within the infected person's body, causing serious illness, and even death.
This scenario is how the great flu pandemic of 1919 began. This infamous flu epidemic killed more people than did World War I.
Since the 1920s, we have experienced several other (comparatively minor) flu pandemics, most notably, the swine flu epidemic of 1968, which killed many thousands of people world-wide. America, which enjoys superior medical care, had few swine flu deaths due to the excellent supportive care that was provided to flu victims, and the overall good health of the population. So most of the flu deaths in America were among groups with less efficient immune systems, such as the very old and the very young.
Unlike these other flu variants, the bird flu mutant that recently appeared in Hong Kong does not appear to be very transmissible. This means that it is not as contagious as a typical flu virus. In fact, as of 13 January 1998, when this article was updated, there have not been any confirmed cases of the "bird flu" outside of Hong Kong.
Despite the fact that the bird flu currently is not very contagious, this situation will probably change over time. An additional worry is that Hong Kong is a major hub for air travel, so it can serve as an excellent birthplace for a pandemic. This possibility is the main reason for such concern about this flu mutant.
Another reason for concern is that the flu, like all viruses, cannot be treated with antibiotics. Instead, the victim's immune system must clear the virus from her system. This can be a relatively slow process, sometimes taking as long as 10 days before the victim begins to recover. During this period of time, the patient must be kept well-hydrated and warm, or death may occur.
The mode of transmission is another cause for concern. The flu virus is transmitted either by inhaling air-borne droplets from an infected person's sneezes and coughs, or through direct physical contact. One should always be cautious around a person who is ill with the flu: always avoid putting your fingers on your face, or in your mouth or eyes. Washing your hands with soap and water is sufficient to reduce the likelihood of infection with this virus.
Despite all these dire predictions, one should not worry about pet parrots transmitting the flu to all the humans sharing the household. Animals cannot spontaneously develop the flu. Instead, they must "catch" the flu from another animal. In fact, it is unlikely that the average pet parrot could ever come into contact with any flu virus. The flu is maintained at a low level in fairly large populations where the virus wanders around between hosts within this population. A household that owns one, two, five or even ten healthy parrots does not constitute a large enough population to successfully maintain a flu virus.
[26 January 1998]