2007, Volume 5, Number 1
Syphilis: Evolution Due to Social Changes Keywords: syphilis, Treponema, social change, sedentism
Abstract
The spiral shaped bacterium Treponema pallidum, translated as “pale turning head”, causes the endemic diseases of the tropics known as pinta, yaws and bejel. Within and outside of the tropics, this same bacterium causes the venereal disease syphilis. Syphilis is present in the archaeological records of Central America, Europe and China. Historical documents go further, suggesting the venereal Treponema bacterium have shared a long history with humans. The corresponding dates of each respective appearance suggest a cross-cultural shift towards a sedentary lifestyle, movement out of the tropical regions, and changes in social practices which result in the form of syphilis we see today.
Background
Non-pathogenic Treponema is a normal part of the human intestinal tract, genital area, and oral cavity. The gum disease gingivitis is a rather benign manifestation of the bacterium. The Treponema bacterium divides asexually through binary transverse fission. More specifically, it grows in volume then cleaves and divides resulting in two identical daughter cells. The outer surface of the bacterium is unique in two respects; it has a high percent of lipids and a relatively low number of protein receptor sites. The human immune system works by recognizing specific protein receptor sites on invading pathogens, then triggering Bcells to produce protein specific antibodies. The four subspecies of Treponema are microscopically identical. On the slide each appears as a slender, white corkscrew against a dark backdrop. Genetically, they share a DNA that is over 95% the same, making penicillin an effective antibiotic against all the “strands”. Due to this genetic and microscopic similarity, subcategories were developed based on the unique manifestations of the disease. It should be noted that within these manifestations, a variety of symptoms and degrees of infection occur, often in relationship to specific environmental changes. Pinta, or the “blue stain disease”, is a childhood infection that often persists into adulthood. It is found in tropical climates and is much less aggressive then the other manifestations of Treponema. The localized infection affects the skins pigmentation, causing blue or white patches to appear. This mild infection lacks the ulcerations that mark the other three subcategories of Treponema. From an evolutionary standpoint, pinta is frequently considered to be the first strand of Treponema that infected the early hunter gatherer societies globally.
Yaws is a common skin infection that occurs in tropical South America. Children are usually infected, developing a mild skin rash that is easily passed to their peers. Children in hot, humid environments have little need for clothes, therefore infection transmits easily without a marked degree of genetic mutation. This strand of Treponema could survive easily on a single host that did little bathing and facilitated distribution, i.e. survival, through a substantial amount of commingling. There is evidence of more aggressive manifestations of this disease that have an especially detrimental effect on the skin, and occasionally affect the bones in the hands or feet. In the more arid regions of the Middle East and southeastern Turkey, the symptoms associated with bejel (endemic syphilis) are found. This environment is considerably less humid and people inhabiting the region tend to wear loose clothes as a means of protection against the sun. Subsequently, this slightly more hostile environment forced the delicate treponema to migrate to a gentler environment on the human body. It sought out areas of the body that are warm, moist, and allow easy conductivity from person to person. Thus infections began to occur in the mucus membranes, specifically the mouth. The physical symptom is a cold sore-like lesion that appears inside or around the mouth. This less conducive environment caused the bejel strand to migrate away from the outermost surfaces of the body. The environment remained somewhat hospitable; the bacterium was not forced to burrow any further into the human body.
Venereal syphilis (Treponema pallidum) is uniquely characterized in the marked stages of progression the disease undergoes. The primary stage consists of a chancre at or near the point of initial exposure that lasts anywhere from ten to fifty days. The rash marking the secondary stage appears approximately six weeks later. After this point, it is fairly typical for the disease to enter a latency stage. This can last from a few weeks to over thirty years, during which time the host is completely asymptomatic. The tertiary stage is the final progression of venereal syphilis. During this time significant cardiovascular and neurological damage occurs. It is also during this stage that bone is damaged in such a marked manner that archaeologists can recognize the victims of venereal syphilis post mortem. Syphilis leaves its distinct mark on the teeth, tibia and cranial bones.
Archaeological Evidence
In 1993, 536 ancient skeletons were excavated and examined at the site of initial Columbus contact with the Dominican Republic. The bones were initially subjected to macroscopic visual examination. If there appeared to be evidence of treponema interacting with the bones, the bones were examined microscopically. Great care was taken to ensure that the bone lesions being examined occurred before death and not due to postmortem weathering or damage. The results suggested that 6-14% of the adult population were suffering from late stage syphilis. No children or adolescents appeared to be affected. The inflicted skeletons exhibited a significant amount of Tibia remodeling, one of the hallmarks of a syphilitic infection.
Hull England was a busy port city in the 1400’s that, like most ports, had a large number of sailors and prostitutes passing through. The cemetery of the large Hull monastery had specific areas excavated in1994. The date of the area being excavated, 1340- 1369, was established through carbon dating of the wood used to build the coffins. In total, 207 relatively complete skeletons were excavated. Of those, Doctor Charlotte Roberts stated that approximately 60% had “classic and convincing” symptoms of tertiary syphilis. The startlingly high percentage of infection has been attributed to the urbaneness of the port city, the intermingling of a variety of cultures (i.e. disease) and the monastery’s supposed role as the city hospital.
Skeletal remains from the 13th century bearing the mark of congenital syphilis have been discovered in Anatolia, or present day Turkey. Turkey has the unique geographic position of being nested between Africa, Europe and Asia. The country has witnessed mass migrations throughout the centuries and was also a major stop on the silk trading route. The skeletal remains of a fifteen-year-old boy exhibiting tertiary symptoms recovered in Anatolia included; darkening of enamel, radial scars on the frontal bones and syphilitis dactylitis. The cranial bones also exhibited gummateous osteomylelitis, or ulceration of the myelin bone covering. Another case of congenital syphilis is evident on the skeleton of a stillborn child born to a French woman during the fourth century. This skeleton also exhibited the cranial abnormalities that are considered markers of syphilis.
The cool, dry climate of Xinin, in the Qinghai province, has also offered up skeletal evidence of syphilitic infections from the Paleolithic era. The archaeological site had a substantial amount of pottery, suggesting a population that was large and sedentary. Altogether, fifteen partial skeletons were discovered. The teeth and cranial bones were not available for examination, but the remainders of the bones were intact. Several of the tibias examined exhibited sclerotic swelling and irregular bone proliferation, suggesting the presence of trepenomas. Due to the lack of teeth or cranial bones, it is difficult to state conclusively if these skeletons had been afflicted with venereal syphilis rather than the bejel strain.
Historical Documentation
Mesoamerican historical documentation, in the form of glyphs, dates back to at least 32 B.C. , though some scholars propose the writing developed as early as 750 B.C. In 1993 linguists translated an Olmec text dating from 159 A.D. The text contained references to the agricultural production of maize, the rise of a king, and of sacrificial ceremonies. All accounts by early European explorers suggest that Mesoamerica was dotted by large cities that would rival any in Europe. Cortes went as far to say that Tenochtitlan was bigger than Paris but the city was remarkably different from its European counterparts. Tenochtitlan housed enormous botanical gardens and a highly efficient waste removal system, unlike its Europeans counterparts who allowed their cities to be overrun by raw sewage and refuse. This evidence supports the idea that many historic Mesoamerican populations were large, stratified and sedentary when they first encountered Europeans. However, though the population density was high, organized waste management was being practiced which effectively kept many diseases at bay. In the instance of Treponema, less virulent strands continued to be passed around the scantily clad populations. During the 1490’s Europe was undergoing several cultural changes as it moved from the Middle Ages into the Renaissance era. These early changes potentially influenced the development of venereal syphilis. Post-plague European populations had fled to the countryside. It was during the 15th century that massive influxes of people began returning to the cities. In addition to this, the devastating plague had caused many people to experience a loss of faith in the churches of the day. Hypothetically speaking, this would lead to increased rates of sexual conduct in a densely populated area, thus increasing the spread of venereal diseases. Another factor that may have inhibited the easy spread of benign Treponmea was changes in European clothing. The trend moved towards fabrics that were heavy and worn in several layers. Granted, the masses may not have had the means to follow fashion very closely but there surely was some trickle down effect. In terms of general increased exposure of Europeans to Treponema, the slave trade from Africa greatly increased. Africans brought with them the benign manifestations of the Treponema bacterium in the form of pinta and bejel. As slaves were subjected to a harsher climate and subsequently heavier clothing, only the strongest strands of this bacterium could survive by migrating to areas of the body more suited for its survival. Prostitution, the migration of people (forced and otherwise) and disease were common. One such migratory disease was called “venereal leprosy”and was treated with mercury. Mercury is a somewhat effective medicine in treating the chancres associated with syphilis, though completely ineffective in treating any symptoms of leprosy.
The historical documentation supporting the presence of venereal syphilis in China dates back to 2637 B.C. It was at this time that the Emporer Hoangty made the decision to release all of his medical records to the general public. He did this in the hopes that the records would benefit the people through increased knowledge of diseases and treatments. Within those documents, symptoms are described in detail that are remarkably similar to syphilis. Mercury was also used as a means of treating the disease in China, further supporting the diagnosis of venereal syphilis.
Conclusion
The Treponema bacterium evolved into the form of venereal syphilis that existed pre-15th century due to cultural changes. Three separate historical societies have left extensive archaeological and historical documents supporting the presence of venereal syphilis on their respective continents during almost simultaneous time periods. The emergence of this disease is marked by an increase of populations living in dense areas. From examination of archaeological evidence of the Mesoamerican population, it appears the benign skin disorder would occasionally mutate into venereal syphilis. It did not reach epidemic status until after missionaries visited the new world. They brought with them clothes, soap and hygiene lessons that “push” the benign treponmoa bacterium out of its environment. In order to survive, the bacterium had to exploit a new niche that was better suited for its nature, thus it began to migrate exclusively into the genitals. Europe experienced a similar situation but due to different social conditions. Europe’s historical population had many sufferers of syphilis, but it was misdiagnosed as leprosy. When the pope allowed all the lepers to return from exile in 1490 he may have unknowingly exposed thousands of people to those suffering from syphilis. When this information is considered alongside the high rates of prostitution, growing slave trade and colder climactic conditions it is easy to see why Europe experienced a syphilis epidemic in the late 1490s.
China was no exception to these rules. As the population grew more sedentary and moved into cooler, semi-arid regions, the common childhood skin affliction of pinta moved with them. More clothing made transmission more difficult, consequently, the bacterium evolved as a means of survival. The stronger strands could burrow deeper into the body, finding the warm, moist areas that facilitated its livelihood. These regions also tend to be gateways into the rest of the human body due to the delicate nature of the genital tissues.
Syphilis needs a large human population to survive, further supporting the theory that it has shared a long evolutionary history with man. This is evident even in this day and age. The densely populated cities in the United States report more cases of syphilis than do rural cities. Due to its long-term evolutionary relationship with humans, it tends to be a disease that takes a long time to become debilitating. In some instances, syphilis can take over thirty years to claim its victim. Life expectancy during the 15th century cross-culturally hovered at the mid-thirties. This could be a contributing factor in the somewhat sparse archaeological evidence of tertiary stage syphilis on the bones. The bacterium Treponema was one of the original hunter-gatherer diseases that ultimately had the ability to keep pace with the rapid evolution of human culture.
WORKS CITED
Cohen, Nathan Mark. Health and the Rise of Civilization. New Haven and London: Yale University, 1989
Davies, Norman. Europe: A History. New York, New York: Oxford University Press, 1996.
Livingstone, Frank B.. “On the Origins of Syphilis: An alternative Hypothesis.” Department of Anthropology, University of Michigan 91(2001): 19.
Mann, Charles G.. 1491. Toronto, Canada: Random House, 2005.
Marshall, Yvonne. “Intro: Adopting a Sedentary Lifestyle in Non-Agricultural Societies.” World Archaeology 38(2)(2006): 153-163.
Oliwenstein, Lori. “Dr. Darwin.” Understanding and Applying Medical Anthropology (1998): 33-37. Rose, Mark. “Origins of Syphilis.” Archaeology 50(1997):
Rothschild, Bruce M.. “First European Exposure to Syphilis: The Dominican Republic at the Time of Columbus Contact.” Clinical Infectious Disease 31(2000): 936-941.