Misery knows no boundaries
By MARC RINGEL, MD

When Grandma was in the hospital dying, it was hard to get Grandpa to visit her, no matter that they'd been happily married for over 60 years. He was deathly afraid of hospitals-had been since the great influenza epidemic of 1918-1919, to which he'd lost his mother, a sister and a niece. Grandpa, a mere teenager, had laid near death in the Chicago Infectious Disease Hospital during the epidemic, with a view out his window of the constant stream of hearses picking up bodies from the morgue on the ground floor below. He never got over his belief that hospitals were where people went to die. He had cheated fate once early in life and he wasn't going to risk it again if he could help it.

      That mother of all epidemics was a pandemic (from the Greek roots pan-, meaning all and -demos, meaning people). It killed 30 to 40 million people worldwide and indelibly traumatized many millions more, including my grandfather.

      A combination of circumstances made the flu season of 1918-1919 so deadly. First, there was a particular new mutation of the influenza virus. Every year, new varieties of the flu bug enter the human community, usually from Asia, where people and domesticated animals have been crowded together for millennia. Viruses that inhabit chickens, ducks, pigs and other animals intermingle with viruses that infect humans, producing novel combinations of surface proteins, different enough to slip by immune defenses targeted against the infectious particles that caused previous epidemics. You need a new flu shot every year to prepare your body to fight off the influenza virus clothed in this season's style of winter coat.

      The germ that caused the pandemic of 1918-1919 was very different from the ones that had infected humans in the preceding years, so human immune systems had little cross-reactivity, based on previous epidemics, to provide clues for that season's battle against the latest version of the influenza virus. Of course, this was before the time when flu shots could provide the antigenic ³hints² that prime the immune response to the latest bug coming out of Asia.

      Then there was World War I. During that war, hundreds of thousands of men were jammed together in miserable, unsanitary trenches, arrayed across bits of contested ground against their enemy, who lived under the same horrible conditions. You couldn't design a better environment for spreading a respiratory illness such as influenza. As is often the case, more soldiers died of infectious diseases in that war than of bullet and shrapnel wounds.

      Most infections that have been around humans for a long time have ³learned² to be moderate. If a bug is to survive for the long haul, it will generally do better if it doesn't make its victims too sick. When an infection lays you up, you're not on your feet-at the workplace, school, subway, or movie theater-to spread germs and perpetuate the disease's existence. Over time, hosts learn to tolerate bugs, while bugs learn not to make hosts too sick.

      Not so in the trenches. The soldiers didn't need to get up and walk around to spread the influenza virus. They couldn't walk around. This situation favored a more virulent bug, one that could multiply as rapidly as possible, perhaps killing the host, but producing so many copies of itself that it could just about ooze from person to person on the battlefront. Once unleashed, the virus made no distinctions, leaving military and civilian, man and woman, young and old dead in its wake. A combination of microbial genetics and social conditions paved the way for the great influenza epidemic of 1918-1919 and the subsequent great hospital phobia of Jack Epstein, my grandfather.

      The story of HIV is similar. A virus-pretty benign to its host simian population in central Africa-mutated enough to jump to humans, causing a disease called AIDS, first diagnosed on June 5, 1981. As a new infectious agent in humans, HIV hadn't had the opportunity to co-evolve with this host into a chronic, low-grade infection.

      Without treatment, HIV kills virtually everybody it infects within a few years. However, social conditions in Africa have been such that this deadly opportunist has stayed in play. Due to poverty and social upheaval, many African men have been forced to move away from their families for large parts of the year, eking out a living in urban areas and sending a small surplus home to support wife and children. Prostitution has become rampant, as it tends to be where men are separated for long periods from their families and where women are deprived of other opportunities to earn a living. Though the life expectancy of one HIV-infected prostitute might not be very great, it is still plenty long enough to spread the infection to tens or hundreds of her clients.

      Conditions that favor transmission of this deadly disease have also occurred in the homosexual and IV drug using communities in the United States. In the days before HIV treatment and widespread understanding of the risks of unsafe sex, though the life expectancy of an HIV-positive gay man may not have been great, he still had the opportunity to infect many partners if he were a member of the hyper-promiscuous sub-population that was part of the gay scene in every urban area. Likewise, an IV drug abuser, by sharing needles and syringes, could spread the infection to many ³buddies² before succumbing to AIDS.

      The combination of infectious agent and social conditions must be taken into account as we try to understand the newest scourges to break upon our shores. First there's smallpox and anthrax. They're the same old deadly pathogens, the former a virus, the latter a bacillus. It's the context in which these infections can spread that makes them so scary. Desperate terrorists, sociopaths and immoral national leaders make these threats real.

      How about West Nile virus? A right wing nut friend of mine claims that the virus came to the United States from Iran, via Cuba. (Before the end of the cold war he used to attribute all things unhealthy to Russia, including AIDS.) I don't think he's right. West Nile is a virus, native to Africa, that got into North America's mosquitoes, birds and mammals, no doubt as an unintended result of increased international travel and commerce. At this time, minimizing the disease's impact centers around protecting against the mosquitoes that carry the virus.

      Then there's monkeypox that has struck humans because a few of us have chosen to adopt prairie dogs and Gambian giant rats. Keeping exotic pets introduces new diseases into human populations. Fortunately, domesticating unusual animals is not nearly so hazardous nor widespread a social phenomenon as would be found in World War I battlefield trenches, central African ghettoes, gay bathhouses or drug shooting galleries.

      SARS is another new disease. Once again, internationalization is to blame for its appearance in the United States. In the days before airplane travel, SARS would have probably been limited to a few cities in South Asia or, at most, to much of Asia. The disease almost certainly would not have reached other continents.

      Fortunately, a wonderfully vigilant international public health community, in cooperation with scientists wielding the super-potent tools of molecular biology-all of them tied together by the Internet-were able to identify, within weeks of its appearance, the new highly-infectious coronavirus that causes the deadly illness and halt its spread before it had infected very many people. Here's yet another set of social conditions to keep in our sights: the resources needed to support a vigorous international and national public health community, a well-connected coterie of epidemiologists and microbiologists, and governments that actually listen to such experts.

      Sure, the future is scary. As the pace and flavor of contact between human and animal populations and exchange between humans from different parts of the world accelerate, we will see more new, sometimes deadly, infectious diseases. Controlling them will take not just good science, but good politics. We must not shortchange public health institutions, neither their funding nor their influence. And we must strive for justice, because justice leads to health-and now, more than ever, our health depends on the wellbeing of every other human on the planet.

      Marc Ringel, MD, is a family practitioner and writer based in Greeley, Colorado. Marc is writing a book on the interplay of healing, medicine and technology, and another based on his Nexus column.