Epidemics: yesterday, today ... and tomorrow.

epidemic (ep-e-dem'-ik): An outbreak of disease that attacks many people at about the same time and may spread through one or several communities.

Strange black swellings under the skin were often the first sign. Victims sweated, coughed, spit blood, and died within days. "This is the end of the world," wrote one observer.

Terror, panic, and despair seemed to rule the world. "Father abandoned child, wife husband, one brother another," wrote a chronicler of the times, "for this plague seemed to strike through the breath and sight. And so they died. And no one could be found to bury the dead for money or friendship.... And I, Angolo di Tura, called the Fat, buried my five children with my own hands."

The year was 1348. The "Black Death," the most terrible epidemic in European history, killed an estimated 20 million people, or one-third of Europe's total population. Before the Black Death, the city of Paris held 100,000 citizens. After, there were only 50,000 people.

True, that was long ago. And what could such epidemics have to do with your life at the high-tech end of the 20th century?

More than you think.

Epidemics (we used to call them "plagues") aren't history. They happen all too often in today's world, too. Did you know, for instance, that cases of bubonic plague (the same "Black Death") are still reported on every continent? Medical bulletins from Asia and Africa regularly report outbreaks of bubonic plague, cholera, and other diseases. And a current epidemic--AIDS or HIV infection--is changing lives and lifestyles around the globe.

In the early years of this century, Americans fell ill (and often died) in epidemics of many infectious diseases: influenza, diphtheria, measles, tuberculosis, meningitis, scarlet fever, polio, and others. During the winter of 1918-1919, 20 million people around the world died in an influenza epidemic--spread, in part, by soldiers coming home "safe" from World War I. More recently, your parents or grandparents may remember summers in the 1940s and 1950s when children weren't allowed to swim or go to the movies for fear of spreading the polio infection that crippled thousands of children.

Effective vaccines and antibiotics (almost all developed during the past 40 or 50 years) have helped us control many infectious diseases. But those diseases have not disappeared. Today, doctors and medical researchers say we face the possibility that some of those "old time" diseases are on the way back and may be resistant to treatment with the drugs usually used against them.

How do epidemics start? What can the world do to control them? And what can you do to keep yourself safe?

How Epidemics Begin

Epidemics involve infectious or communicable diseases--illnesses that can spread from person to person. (Cancer, asthma, and diabetes are examples of noninfectious diseases; you cannot "catch" them from someone else.) Infectious diseases are caused by bacteria, viruses, and other microorganisms called pathogens. Pathogens are spread in three primary ways:

* by PEOPLE: Many infectious diseases are spread when an infected person coughs, sneezes, or handles objects that are handled by other people. Colds, influenza, measles, mumps, tuberculosis, and pneumonia are spread in this way. Some infections are transmitted by direct contact with an infected area on another person's body. Some skin infections and STDs (sexually transmitted diseases) spread this way.

* by ANIMALS: Insects, wild animals, and even household pets can spread infectious disease. Fleas can carry bubonic plague to both rats and humans. Mosquitoes spread the infection of malaria, yellow fever, and other diseases by carrying blood from an infected person to a healthy person. Ticks can spread a variety of diseases, from typhus to Lyme disease. And infected mammals (rats, cats, dogs, rabbits, squirrels, etc.) and birds can spread a number of serious diseases. (Recently, a few bubonic plague cases in the Southwest were reportedly traced to pet cats who had come in contact with infected rats.)

* by NONLIVING SOURCES: Some pathogens can survive on nonliving objects: clothes, bedding, silverware, and other things handled by sick people. Contaminated food, milk, or water supplies can cause widespread illness, too. One example: Bacteria in undercooked hamburgers caused serious illness and a few deaths in the Pacific Northwest last year.

In this country, person-to-person contact is the source of most infectious disease, including those that turn into community epidemics. Marcia sits near Lucas in class. She has the beginnings of the flu--and her coughing spreads the infection to him. Lucas shares a room with his little brother, who catches it, too--and passes it along in a sneeze to...well, you get the idea.

Some infectious diseases are more difficult to pass from one person to another. (We'll talk more about that later.) But for now, let's look at ways to break the chain of infection--to stop epidemics before they start, or to "contain" them before they do even more damage.

Fighting the Spread of Infection

Fighting to break the chain of infection isn't a job for superheroes. All of us can play a part: doctors and other health professionals, parents, teachers, public health officials...and you, too.

What can be done? Immunization programs that reach everyone are a good start. (In recent years, public health officials have worried about the growing number of children who don't get their shots.) Parents, teachers, and health "pros" can teach younger people ways to try to prevent infection: frequent handwashing, a healthy diet, and exercise. We can all work to keep our local environment clean (reducing rat, mosquito, and tick populations). And we can vow to do all we can to avoid the world of drugs and alcohol--where bad choices, confusion, and disease walk hand in hand.

Clear and Present Danger: AIDS

The global AIDS epidemic (yes, it is now considered a pandemic) presents some special dangers to all of us.

Number one, of course, is that there is no cure--and no vaccine--for this still-fatal disease, which is caused by the HIV (human immunodeficiency virus). Research goes on, but public health officials don't seem to think a vaccine will be ready soon.

More than 170,000 Americans have died of AIDS, and more and more cases are resulting from sexual activity and intravenous (IV) drug use, says a new report from the surgeon general. Worldwide, the numbers are even scarier. North America accounts for only 10 percent of the global AIDS infections. Fully 70 percent of the world's people infected with HIV live in Sub-Saharan Africa (the region below North Africa's deserts). There, nearly 8 million men and women are infected, plus nearly 1 million children.

If there's any good news about AIDS, it is that researchers know a great deal about this virus. They have developed tests to protect the blood supply, and have been able to develop many medications that help people with AIDS live longer.

AIDS is different from many other epidemic diseases because it is not transmitted through air or water, or by casual contact with other people. You can't catch AIDS from a sneeze, from food, or from sharing classroom or living space with someone who has AIDS.

HIV infection is mainly spread by sexual contact with an infected person or by needle-sharing among injecting drug users.

How can you stay safe? Don't shoot drugs, and be sexually abstinent. AIDS is a growing problem for American teens of both sexes.

What Does the Future Hold?

Back in the 1940s and 1950s, some doctors liked to say that the modern world had "eliminated" this or that disease. But the truth is, the tiny organisms that cause infectious disease never quite disappear--and from time to time, new diseases turn up to complicate the picture.

What do health experts worry about these days? They worry about AIDS, of course. They worry about the number of tuberculosis (TB) cases--after nearly 50 years of considering this disease all but conquered. And there are other emerging threats, one example being the small but frightening outbreaks of hantavirus disease, which killed soldiers during the Korean War and now has been identified in parts of the United States.

Doctors and researchers are also worried about new "drug-resistant" strains of infection that can't be treated by many existing antibiotics. Medical experts say we must put more money into research for new drugs to combat these "changed" forms of pneumonia, influenza, TB, streptococcus, and other infections.

We've made more progress in this century against epidemic diseases than ever before in history. But there are plenty of important battles left to fight--and you can play your part by learning how to do everything you can to keep yourself (and the people you love) healthy and safe.

For More Information

Abbott Laboratories Dept. 383-DC, Bldg. AP6D2 Attn: Health Pamphlets One Abbott Park Road Abbott Park, IL 60004

Pamphlets: "AIDS: The New Epidemic" (available in both English and Spanish), "Rubella Immunization: The Next Generation Depends on It," single copy of each free with self-addressed, stamped business-size envelope for each pamphlet.

The National Institute of Allergy and Infectious Diseases Office of Communications Bldg. 31, Room 7A-50 Bethesda, MD 20892

Reprint: "Defiant Diseases" from Medical World News, June 25, 1990, Fact Sheet: "Tuberculosis," Pamphlet: "HIV Infection and AIDS," single copy of each free.

American Lung Association 1740 Broadway New York, NY 10019-4374

Pamphlets: "Facts About Tuberculosis," "TB--What You Should Know," single copy of each free.

American Social Health Association Dept. PR26 P.O. Box 13827 Research Triangle Park, NC 27709

Pamphlet: "For Teens," $1 to cover postage and handling. National STD Hotline [phone].

EPIDEMICS: A Historic Timeline

1348 to Present

The bubonic plague conquered Egypt in 541. Centuries later it devastated Europe and Asia; in 1994, cases were reported in India.

1918-1919

During a worldwide influenza epidemic, patients in a U.S. Army hospital wore masks.

1924-1965

Dr. Albert Schweitzer dedicated more than 40 years of his life to healing in Africa

1954

Dr. Jones Salk, who developed the polio vaccine, gives it to a young patient

1962

Rubella virus was first isolated

AIDS virus first identified in 1984

1987

AIDS victim Ryan White went to court to protest being kept out of school.

1994

Outbreak of cholera in Rwanda

The Term-inator: Getting the Names Right

What's the difference between an epidemic and a pandemic? And what if someone says a disease is endemic?

When an epidemic spreads to populations throughout the world, it is considered a "pandemic." For instance, the same type of influenza can be causing chills and fever in people from Peking to Paris to Pittsburgh. A disease is called "endemic" if the infection exists permanently in a particular region or population. Malaria is a constant worry in parts of Africa, for example. In Sub-Saharan Africa (the region below the deserts of North Africa), nearly 8 million men and women are infected with the HIV virus that causes AIDS--and so are more than 1 million children. AIDS is now considered endemic in Africa: a continuing and permanent threat to the general population.

The Real "Conquistador"

Cortez? Pizarro? Well, yes, those are the usual names in the history books. But many historians agree that the real "conqueror" of the Aztecs, Incas, and other Native American tribes was...epidemic disease.

Smallpox was the first conquistador, killing much of the native population but not the Europeans, who remained healthy while the natives died. Why? Because Europeans who survived into adulthood had already survived smallpox and many other diseases--and were immune.

Calling the Shots

Recommended Immunizations

Have you had all the shots you need to protect yourself? Here's the recommended immunization schedule for children in the United States:

Age:             Vaccine:

2 months         DPT--a combined vaccine for diphtheria,
                 pertussis (whooping cough), and tetanus

2 months         polio, HiB (influenza B)

4 months         second DPT and HiB

6 months         third DPT

12-15 months     third HiB

15 months        MMR--a combined vaccine for German
                 measles (rubella), measles, mumps

18 months        DPT booster, polio booster

4-6 years        second DPT and polio boosters, second
                 MMR (according to CDC)

11-12 years      second MMR (according to American
A                Academy of Pediatrics)

14-16 years      diphtheria and tetanus booster (and
                 every 10 years thereafter)

These are the basics. But you may want or need other types of shots at specific times in your life.

The Centers for Disease Control and Prevention (CDC) recommends:

* Older adults and persons with diabetes or other chronic diseases get flu shots every autumn. The shot is short-term protection--not permanent--against the type of influenza "going around" that year.

* Doctors can give injections of antibodies from the blood of infected persons as short-term protection for people who have already been exposed to hepatitis, measles, rabies, or tetanus.

* Travelers to certain parts of the world may need inoculation against diseases such as typhoid, cholera, and plague. One of the most common diseases travelers get is hepatitis A, which is a danger for people traveling to Mexico and the Caribbean, South and Central America, Africa, and Asia. Treatment with antibodies (called immune globulin) can protect you for three to five months.

He's Having a Cow, Man

Sometimes the discovery that stops an epidemic happens because one person is brave enough to do something. That's what happened in the late 1700s with English country doctor Edward Jenner.

In Jenner's small hometown, no mother or father thought of their children as "safe" (or likely to reach adulthood) until they had survived smallpox. But many country people believed that one group was safe from smallpox--the young girls who tended milk cows. They often caught a minor disease called cowpox (symptoms were sores on the hands), but never seemed to come down with smallpox.

Jenner paid attention to these country tales. Jenner was pretty sure that the dairy maids were "immune" to smallpox because they already had had cowpox. To test this idea, he scraped matter from the hand of a dairy maid and placed it in two small cuts on the arm of a healthy 8-year-old boy, James Phipps--who then caught cowpox. Forty-eight days later, Jenner put smallpox matter into James' arm.

The boy did not contract smallpox.

Jenner was hailed as a hero around the world for his quick-witted invention of the first vaccination (the word comes from the Latin vacca or "cow"). Smallpox vaccination became standard treatment around the world--including in the New World, where Spanish missionaries brought the vaccine to Europeans and Native Americans.

Modern vaccines contain dead or extremely weakened strains of disease-causing pathogens. When taken into the body, vaccines trigger a reaction from the immune system, which produces substances called antibodies, that exist to fight infection from one specific disease-causing pathogen. A single dose of some vaccines creates a lifelong immunity; other vaccines require multiple doses or regular "boosters" to remain effective.