The invention: The first simple test for detecting the presence of the venereal disease syphilis led to better syphilis control and other advances in immunology.
The people behind the invention:
Reuben Leon Kahn (1887-1974), a Soviet-born American
serologist and immunologist August von Wassermann (1866-1925), a German physician and bacteriologist
Columbus’s Discoveries
Syphilis is one of the chief venereal diseases, a group of diseases whose name derives from Venus, the Roman goddess of love. The term “venereal” arose from the idea that the diseases were transmitted solely by sexual contact with an infected individual. Although syphilis is almost always passed from one person to another in this way, it occasionally arises after contact with objects used by infected people in highly unclean surroundings, particularly in the underdeveloped countries of the world.
It is believed by many that syphilis was introduced to Europe by the members of Spanish explorer Christopher Columbus’s crew— supposedly after they were infected by sexual contact with West Indian women—during their voyages of exploration. Columbus is reported to have died of heart and brain problems very similar to symptoms produced by advanced syphilis. At that time, according to many historians, syphilis spread rapidly over sixteenth century Europe. The name “syphilis” was coined by the Italian physician Girolamo Fracastoro in 1530 in an epic poem he wrote.
Modern syphilis is much milder than the original disease and relatively uncommon. Yet, if it is not identified and treated appropriately, syphilis can be devastating and even fatal. It can also be passed from pregnant mothers to their unborn children. In these cases, the afflicted children will develop serious health problems that can include paralysis, insanity, and heart disease. Therefore, the understanding,detection, and cure of syphilis are important worldwide.
Syphilis is caused by a spiral-shaped germ called a “spirochete.” Spirochetes enter the body through breaks in the skin or through the mucous membranes, regardless of how they are transmitted. Once spirochetes enter the body, they spread rapidly. During the first four to six weeks after infection, syphilis—said to be in its primary phase—is very contagious. During this time, it is identified by the appearance of a sore, or chancre, at the entry site of the infecting spi-rochetes.
The chancre disappears quickly, and within six to twenty-four weeks, the disease shows itself as a skin rash, feelings of malaise, and other flulike symptoms (secondary-phase syphilis). These problems also disappear quickly in most cases, and here is where the real trouble—latent syphilis—begins. In latent syphilis, now totally without symptoms, spirochetes that have spread through the body may lodge in the brain or the heart. When this happens, paralysis, mental incapacitation, and death may follow.
Testing Before Marriage
Because of the danger to unborn children, Americans wishing to marry must be certified as being free of the disease before a marriage license is issued. The cure for syphilis is easily accomplished through the use of penicillin or other types of antibiotics, though no vaccine is yet available to prevent the disease. It is for this reason that syphilis detection is particularly important.
The first viable test for syphilis was originated by August von Wassermann in 1906. In this test, blood samples are taken and treated in a medical laboratory. The treatment of the samples is based on the fact that the blood of infected persons has formed antibodies to fight the syphilis spirochete, and that these antibodies will react with certain body chemicals to cause the blood sample to clot. This indicates the person has the disease. After the syphilis has been cured, the antibodies disappear, as does the clotting.
Although the Wassermann test was effective in 95 percent of all infected persons, it was very time-consuming (requiring a two-day incubation period) and complex. In 1923, Reuben Leon Kahn developed a modified syphilis test, “the standard Kahn test,” that was
simpler and faster: The test was complete after only a few minutes. By 1925, Kahn’s test had become the standard syphilis test of the United States Navy and later became a worldwide test for the detection of the disease.
Kahn soon realized that his test was not perfect and that in some cases, the results were incorrect. This led him to a broader study of the immune reactions at the center of the Kahn test. He investigated the role of various tissues in immunity, as compared to the role of white blood antibodies and white blood cells. Kahn showed, for example, that different tissues of immunized or nonimmunized animals possessed differing immunologic capabilities. Furthermore, the immunologic capabilities of test animals varied with their age, being very limited in newborns and increasing as they matured.
This effort led, by 1951, to Kahn’s “universal serological reaction,” a precipitation reaction in which blood serum was tested against a reagent composed of tissue lipids. Kahn viewed it as a potentially helpful chemical indicator of how healthy or ill an individual was. This effort is viewed as an important landmark in the development of the science of immunology.
Impact
At the time that Kahn developed his standard Kahn test for syphilis, the Wassermann test was used all over the world for the diagnosis of syphilis. As has been noted, one of the great advantages of the standard Kahn test was its speed, minutes versus days. For example, in October, 1923, Kahn is reported to have tested forty serum samples in fifteen minutes.
Kahn’s efforts have been important to immunology and to medicine. Among the consequences of his endeavors was the stimulation of other developments in the field, including the VDRL test (originated by the Venereal Disease Research Laboratory), which has replaced the Kahn test as one of the most often used screening tests for syphilis. Even more specific syphilis tests developed later include a fluorescent antibody test to detect the presence of the antibody to the syphilis spirochete.
See also Abortion pill; Amniocentesis; Antibacterial drugs; Birth control pill; Mammography; Pap test; Penicillin; Ultrasound.
