Fighting Infectious Disease

Case 17 in the SSVMS Museum of Medical History contains a collection of items that tell the story of how the treatment of infectious diseases has evolved over time. Infectious diseases due to bacteria and viruses have been a major cause of death for humans for thousands of years. The exhibit showcases how the development of various vaccines and antibiotics were responsible for the significant prolongation of the life span of humans.

This improvement has come about only in the recent past. The development of antibiotics for bacterial diseases saves about 200,000 American lives each year and adds 5-10 years to US life expectancy.

Before the development of immunizations for childhood infectious diseases, millions of children worldwide would die every year of complications from diseases like measles, smallpox, diphtheria, and polio. The Centers for Disease Control (CDC) estimates that immunizations save the lives of 4 million children worldwide each year. More than 50 million deaths could be prevented by immunization from 2021 to 2030. The museum has a list of over 46 vaccines developed since the 18th century.

Most vaccines have been developed during the 20th and 21st centuries. Several more vaccines are currently in development.

The very first vaccine developed was for smallpox in 1796. At that time the fatality rate for smallpox was 30%. The vaccine became so successful in preventing disease that in 1980 smallpox was declared eradicated worldwide. No cases have occurred since 1977.

A recent World Health Organization (WHO) study showed that immunization has made the single greatest contribution of any health intervention to preventing early death in infants. Over the past 50 years, global immunization efforts against common childhood infections have saved an estimated 154 million lives, including those of 101 million infants.

The other major development in the fight against infectious diseases was the discovery of antibiotics. Our exhibit focuses on three serious diseases whose outcomes were significantly affected by the development of antibiotics: tuberculosis, syphilis, and acute rheumatic fever. Let us look at each disease in more detail.

Tuberculosis (TB) is a potentially serious bacterial infection. TB has afflicted humans for thousands of years. It primarily attacks the lungs but can affect other organs as well. Every year, 10 million people fall ill with tuberculosis worldwide, with 1.5 million dying. Primarily impacting low- and middle-income countries, TB remains the world's number one killer due to infection. It is estimated that one quarter of the world's population has been infected by TB. However, most infected people do not develop active disease. This population is said to have "latent" infection. People with active infection, especially of the lungs, can potentially transmit the disease to others through the air when they cough.

The museum has several items on exhibit that focus on TB. Before antibiotics were available, the treatment for TB relied mostly on common-sense advice. One was advised to see a doctor, get plenty of rest, eat good food, and seek sunlight and fresh air. To lower the risk of contracting TB, one was also told to avoid intemperance and other excesses, closed spaces, overwork, crowded sleeping conditions, exposure to smoke and dust, and mouth breathing.

Through photographs, our exhibit highlights the use of sanatoriums in the early treatment of TB. These facilities provided patients with the rest, good food, sunlight, exercise, and fresh air recommended before the advent of antibiotics. In the Sacramento area, patients had access to the Colfax Sanatorium and School for Tuberculosis as well as the Weimar Joint Sanatorium. Opening its doors in 1919, the Weimar facility transitioned to a general medical center in the 1950's, finally closing in 1972. There is a video on our museum website that provides further insight into life in a sanatorium.

The exhibit features an example of a surgical device that doctors used to induce a pneumothorax in patients with active TB of the lung. It was used to inject air into the chest cavity, causing an increase in intrathoracic pressure that led to the collapse of the infected part of the lung. This cuts off the oxygen supply to the diseased lung, impeding the growth of the TB bacteria. Following this procedure, patients would often show improvement in their infection.

The population also had to be screened for TB, a process the exhibit illustrates. Technicians would drive mobile X-ray trucks through neighborhoods to administer chest X-rays. They also used a skin test to screen for exposure, placing a small amount of inactivated TB material under the skin with a syringe. If a red bump of a certain minimum size developed at the site of injection after 72 hours, the test was considered positive for exposure to TB. Further evaluation was then required to rule out latent vs. active infection.

The final portion of the TB exhibit features antibiotics that, once developed, allowed doctors to treat and cure many patients.

Case 17 also highlights syphilis, another important infectious disease. Syphilis is thought to have originated in the Americas and been introduced to Europe in the late 15th century, possibly by the crewmen from the ships of Christopher Columbus when they returned home. This sexually transmitted disease caused terrible epidemics across Europe, becoming widely stigmatized and feared. A proverb appeared in the late 1400's concerning syphilis: "For pleasure, a thousand pains." Persons from all walks of life and from every social class were affected, including luminaries like Keats, Oscar Wilde, Casanova, Monet, Paul Gauguin, Vincent Van Gough, Beethoven, Ivan the Terrible, Henry the Ill, Henry the VIII, and Al Capone.

Syphilis can cause severe symptoms, spread rapidly, and be potentially fatal if not treated. It presents in three different stages: the primary sore, the secondary rash, and the tertiary form, where it can spread to various organs. Congenital disease can also occur.

In 1905, researchers found that syphilis was caused by a spirochete called Treponema pallidum. Within a year, Dr. Karl Landsteiner began using dark field microscopy to detect the presence of the syphilis spirochete. A dark field condenser was attached to a regular microscope, allowing a patient sample to be inspected for the bright appearance of the corkscrew-shaped syphilis bacteria. Our exhibit illustrates how this was done.

Early pre-antibiotic treatments for syphilis included many New World plants. Mercury was tried and had some effect, but came with many harmful side effects. Then, in 1908, Dr. Paul Ehrlich discovered that arsphenamine (Salvarsan) was an effective treatment for syphilis. Considered the first modern antimicrobial agent, Salvarsan marked the beginning of the age of chemotherapy for infectious disease, with the discovery also winning Dr. Ehrlich a Nobel Prize in Medicine. A safer arsenic compound, neosalvarsan, was subsequently developed. However, it wasn't until the discovery of penicillin in the 1940's that doctors finally found a safe and effective cure for syphilis.

The discovery of penicillin also led to the end of the rheumatic fever era in the United States. The third infectious disease featured in our exhibit, acute rheumatic fever was the leading cause of death for children in the United States in the 1920's. 100 years ago, more pediatric hospital beds were occupied by children with rheumatic fever and rheumatic heart disease than all other infectious disease combined, according to Dr. Stanford Shulman, a Professor of Pediatrics at Northwestern Medical School.

The major symptoms of acute rheumatic fever include carditis (inflammation of the heart), subcutaneous nodules (lumps under the skin), polyarthritis (aching of multiple joints), chorea (involuntary jerky movements of hands or feet), and erythema marginatum (bright pink or red circular lesions that occur on the skin). These manifestations are due to an autoimmune reaction that occurs after an infection with Group A Streptococcus bacterium. Prior to the antibiotic era, the incidence of acute rheumatic fever was 28.5 cases per 100,000 children; the rate in the US is now much lower, below 2 cases per 100,000 children.

Despite having antibiotics like penicillin available, rheumatic fever still killed more than 3900 people in the US in 2021, with rheumatic heart disease killing an estimated 380,000 people worldwide in the same year. The development of a streptococcal vaccine would be a major advancement toward eradicating rheumatic fever and rheumatic heart disease.

In addition to these discoveries, our exhibit features a shelf containing the bark of the cinchona tree, a natural product found to be useful for treating another common infectious disease: malaria. As discovered by people native to Peru, cinchona tree bark contains quinine, an effective treatment for fevers. Since malaria was a common cause of fever in that part of the world, quinine became the go-to treatment for malaria. The Jesuit priests brought quinine to Europe during the 17th century, where it also found use as a treatment for fevers due to malaria.

We live in a world full of bacteria, viruses, and fungi. Some of these organisms can cause illness and death. Over the past 150 years, human ingenuity has led to the development of antibiotics and vaccines to fend off harmful organisms. The benefits are longer and healthier lives for most of us.

Our infectious disease exhibit includes just a small sample of the many antibiotics developed since Ehrlich's discovery of Salvarsan. As a species, we also have a pretty good record when it comes to developing effective vaccines. It is important for us to continue to support research that leads to new antibiotics and vaccines as new infectious agents can be expected to appear, and existing agents can develop resistance to current treatment regimens.