We have now moved into the second decade of the AIDS epidemic.
It was 10 years ago this month that the Centers for Disease Control published a short item on an outbreak of a rare form of pneumonia among five homosexual men in Los Angeles, a disease doctors had seen before only in patients with suppressed immune systems.
Since then, 175,000 Americans have been diagnosed with AIDS and more than 110,000 have died. AIDS experts say that another 1 million in this country may be infected with the AIDS virus.
The World Health Organization estimates that 10 million people are infected worldwide, a number, it is further estimated, that will probably grow to 40 million over the coming decade. In some parts of the world, the disease is rampant in the population at large, and in this country the disease has spread far beyond the male gay community.
In observing this grim anniversary, some commentators have noted that, since sexual contact is one way of spreading this disease, the AIDS epidemic signaled the end of innocence about sexuality. But that kind of innocence was relatively recent. Before contraceptives and penicillin, the world knew only too well that sex was not always safe.
Seen another way, the emergence of AIDS may mark the end of another kind of innocence, an innocence about death that was also relatively new but immensely comforting.
With the development and widespread availability of vaccines and antibiotics, many diseases that routinely killed people only a few decades ago were easily prevented or cured.
For a while, until AIDS came along, most Americans felt fairly confident that they were protected from the plagues and epidemics that have periodically attacked the human population.
Strange and frightening outbreaks, such as Legionnaire's disease, were relatively rare and isolated occurrences. And there was hope that scientists would soon find ways to cure or prevent cancer and other well-known lethal diseases.
A decade ago, it was almost possible to dream that untimely deaths from dread diseases would become a distant memory. Certainly, widespread deaths from a new and unimagined virus seemed little more than a science-fiction horror story.
That is no longer the case.
Perhaps the scariest part of the AIDS story is the fact that a previously unknown virus bubbled to the surface, seemingly out of nowhere.
And if it happened once, it could happen again.
It's frightening enough to contemplate the consequences of AIDS; but what if the biological caldron that produced this killer produced a virus even more contagious than HIV?
This possibility is precisely the argument some scientists are now citing to explain why we should care about vanishing rain forests, species becoming extinct and other depredations of the richness of life on earth.
If killer viruses can appear out of nowhere, then we need all the resources we can get to find ways to fight them. And if the diversity of life on this planet can produce killer viruses, it can probably also produce the secrets for fighting them.
One lesson of the AIDS epidemic may simply be that in order to protect our species, we need to protect other forms of life as well. In the end, human life may depend on preserving other forms of life as zealously as we try to protect our own.
Send your comments and questions about death and dying to = Sara Engram, Mortal Matters, The Evening Sun, P.O. Box 1377, = Baltimore, Md. 21278.