Infectious diseases: battling bugs

In the 19th century, scientists discovered that microorganisms were to blame for killer diseases like cholera and tuberculosis, and officials launched public health efforts to provide clean water supplies and waste-disposal systems. By 1900, the incidence of many infectious diseases had declined, but pneumonia, tuberculosis, and diarrhea and enteritis were still the top three causes of death and accounted for one-third of all deaths. (Today, the top three causes of death are heart disease, cancer, and stroke, and 4.5 percent of deaths are attributable to pneumonia, influenza, and HIV.)

Hygiene and disease prevention efforts intensified in the early 1900s, including chlorination of drinking water. Then the 1918 influenza pandemic swept the world, killing 20 million people—including 500,000 in the United States—in less than a year. After the pandemic subsided, infectious disease death rates continued to fall.

The introduction of antibiotics in the 1940s provided a huge boost in the battle against infections, said Barbara Russell, MPH, RN, director of infection control services at Baptist Hospital of Miami and a past president of the Association for Professionals in Infection Control and Epidemiology. Antibiotics saved the lives of people with previously incurable illnesses like streptococcal infections and gonorrhea. More recently, antiviral drugs have led to breakthroughs in the treatment of HIV and other diseases.

The emergence of drug resistance in many organisms is reversing some of the therapeutic miracles of the last 50 years, however. “If we don’t start watching our use of antibiotics, we’ll be back to square one,” Russell warned. “The public has to understand that every time they sneeze, they don’t need an antibiotic.”

Vaccinations: shooting for a healthier population

Childhood vaccination programs have also played a major role in controlling infectious diseases. Vaccinations have also virtually eliminated deadly diseases that were common in the United States earlier in the century, including diphtheria, tetanus, poliomyelitis, measles, mumps, rubella, and Haemophilus influenzae type b meningitis. Smallpox is the only disease that has been eradicated worldwide, thanks to a 10-year campaign involving 33 nations that ended in 1977.

Polio is also on the verge of eradication. But prior to 1955, when the Salk poliovirus vaccine was introduced, there were more than 16,000 polio cases and 1,879 deaths reported a year in the United States. Introduction of the Salk vaccine galvanized national efforts to vaccinate all children against a full range of childhood diseases.

“Vaccines are the most cost-effective thing we can do in medicine. They are inexpensive compared to the diseases they prevent,” said Renee McLeod, MSN, PNP, RN, who chairs the immunizations special interest group for the National Association of Pediatric Nurse Associates and Practitioners and is on the pediatric clinical faculty at Scripps Mercy Hospital in San Diego.

Because many of today’s parents haven’t witnessed the devastation caused by measles, mumps, and polio, they don’t understand the seriousness of such diseases. “Parents think a shot will be worse for their child than the disease it prevents,” McLeod said. Such attitudes are dangerous. “Our world is getting smaller. We still have to deal with those diseases,” she said.

Motor vehicles: safer roads,
cars, and people

The motorization of America is a 20th century phenomenon that’s created new public health challenges. Six times as many people drive today as in 1925, 11 times as many vehicles are on the road, and the number of miles traveled is 10 times higher. Despite this increase in travel, the annual death rate has declined from 18 per 100 million vehicle miles traveled to 1.7 per 100 million vehicle miles traveled—a 90 percent decrease.

Systematic motor vehicle safety efforts began during the 1960s, after Congress defined motor vehicle deaths as an epidemic. Improvements have resulted from engineering improvements to make vehicles and highways safer, as well as personal behavioral changes.

The engineering action that contributed most to reduced deaths and disabilities from vehicle collisions was painting center lines on the roads, said W. Lawrence Daniels, MSN, RN, pediatric nurse practitioner for the Chesapeake, Va., health department and a certified child passenger safety instructor. “It seems very simple to us now, but before the 1950s it wasn’t widespread,” he said. Better lighting and more barriers separating traffic made a difference, too. And vehicles have new safety features, including headrests and shatter-resistant windshields. Changes in driver and passenger behavior—from buckling up to wearing motorcycle helmets—have also made huge differences.

Despite the improvements, vehicle crashes remain the leading cause of injury-related deaths in the United States. For people ages 1 to 24, vehicle-related crashes are the No.1 cause of death.

Heart disease and stroke: identifying the risks

Heart disease has been the leading cause of death since 1921, and stroke has been the third leading cause since 1938. Together they account for approximately 40 percent of all deaths. Even so, our country has made tremendous strides in preventing and treating cardiovascular disease (CVD) in the past 50 years. Since 1950, age-adjusted death rates from CVD have declined 60 percent.

Researchers began intense investigations of CVD in the 1940s. The Framingham Heart Study and other landmark research established the major risk factors of heart disease: high blood cholesterol, high blood pressure, smoking, poor diet, obesity, and physical inactivity. The results were used to launch public health campaigns and education initiatives. During the’70s and ’80s, clinical trials proved the effectiveness of antihypertensive and lipid-lowering drugs.

Much of the public health efforts and scientific research has paid off. The percentage of adults who smoke declined from 42 percent in 1965 to 25 percent in 1995, and the mean blood pressure and cholesterol levels in the population decreased. In addition, there are better methods of diagnosis and treatment of CVD.

The actual number of people dying from heart disease continues to rise, however. “Even with the remarkable progress in fighting heart disease and stroke that has occurred in the last half of the century, cardiovascular disease is still the No.1 cause of disability and death. The fight is not over by any means,” said Lynn Smaha, MD, PhD, president of the American Heart Association. Age-adjusted death rates don’t properly convey the toll CVD continues to take on our population, which contains a higher percentage of older people than ever, Smaha said.

“We realize we have a long way to go,” agreed Swenarski. For example, there has been an increase in the number of teen smokers in recent years, and the decline in adult smokers has leveled off, she said.

Healthier mothers and babies: taking responsibility

Since 1900, infant mortality has decreased 90 percent and maternal mortality has decreased 99 percent. If turn-of-the-century infant death rates had continued, then an estimated 500,000 infants born during 1997 would have died before they reached their first birthday; instead, only 28,000 infants died.

Better hygiene and nutrition, the availability of antibiotics, greater access to health care, and technologic advances in maternal and neonatal medicine have all contributed to the remarkable decline. In the first half of the century, public health and social welfare organizations focused on improving living conditions in urban areas. Greater spacing of children, smaller family size, and better nutritional status of mothers and infants also helped reduce death rates. Milk pasteurization, adopted in 1908, controlled illnesses from contaminated milk supplies.

During the second half of the century, improvements in medical care and the widespread use of vaccines were the main forces behind declining infant mortality. But public health efforts continued to play a role. During the 1990s, there was a decline of more than 50 percent in sudden infant death syndrome rates, attributed to the recommendation that infants sleep on their backs.

“Maternal and child health has always led the way in this nation in the area of prevention,” said Celeste Phillips, EdD, MSN, RN, a women’s healthcare consultant from Santa Cruz, who serves on the board of directors for the Association of Women’s Health, Obstetric, and Neonatal Nurses. Antibiotics, vaccines, and improved nutrition deserve a lot of credit but so do the women who are proactive about their own health and the health of their infants, Phillips said. The majority of women Phillips works with seek out education that goes beyond what they get from their clinic, physician, or nurse-midwife. “To me, that speaks loud and clear for accountability. What women are saying is, I want to do the best thing for myself and my baby,” she said.