Syphilis

Excerpt

Syphilis is a systemic bacterial infection caused by the spirochete Treponema pallidum. Due to its many protean clinical manifestations, it has been named the "great imitator and mimicker." The origin of syphilis has been controversial and under great debate, and many theories have been postulated regarding this.

The Columbian theory is the most accepted and postulates that syphilis came to Europe in the 1490s when Columbus arrived in Italy from America. After Italy surrendered to the invading French in 1495, this new disease rapidly spread across Europe. The name "syphilis" comes from the work of Girolamo Fracastoro, a noted poet and physician in Verona, Italy. In 1530, he wrote about a shepherd named Syphilus who angered Apollo, causing the god to curse the entire population with the affliction that we now know as syphilis.

Syphilis is a sexually transmitted disease (STD), and humans are its only host. Treponema bacteria are susceptible to heat, cold, and oxygen exposure, so they do not survive long outside the human body. An initial inoculation with as few as 500 to 1,000 bacterial organisms is sufficient for an individual to become infected. The incubation period of syphilis is roughly 3 to 4 weeks and is inversely proportional to the number of inoculated organisms.

The Wasserman test, the first reliable test for syphilis, was developed in 1906. This nontreponemal complement fixation test has since been replaced by newer nontreponemal assays (such as venereal disease research laboratory [VDRL] and rapid plasma reagin [RPR]), which are more reliable.

The untreated infection progresses through 4 stages (primary, secondary, latent, and tertiary) and can affect multiple organ systems, often many years or even decades after the original infection. Syphilis prevalence peaked in 1947, just before the widespread introduction of penicillin, which caused rates to plummet, but recent trends have shown exponentially rising rates.

Today, syphilis remains a contemporary plague that continues to afflict millions of people worldwide, and its incidence is increasing. Its association with the human immunodeficiency virus (HIV) significantly worsens the prognosis and is so prevalent that patients who test positive for either infection should be routinely tested for the other. The cornerstone of eradicating and controlling the disease is early appropriate testing using serologic blood screening with efficient, inexpensive, and widely available nontreponemal tests (VDRL and RPR). Confirmatory testing with a more complex treponemal-specific antibody assay (FTA-ABS, TPPA, and TPHA) is necessary to confirm the diagnosis.

As the clinical manifestations are so varied, clinicians must be constantly aware of the possibility of syphilis in the differential diagnosis of symptoms affecting virtually any bodily organ system and perform appropriate screening serologic testing. Fortunately, the causative organism is still very sensitive to penicillin, but despite this, syphilis remains a major modern global public health challenge as testing and treatment efforts so far have been insufficient to halt its progression and increasing prevalence.