Week 2- Columbian Exchange (Syphilis) Flashcards
What was the Columbian Exchange?
The exchange of goods, ideas, and disease between the Old and New World
List 4 subspecies of treponeme and the disease they cause
T. pallidum ssp. pallidum: syphilis
T. pallium ssp. pertenue: yaws
T. pallidum ssp. endemicum: Bejel/ endemic syphilis
T. pallidum ssp. carateum: pinta
What are the characteristics of treponemes?
bacteria, spirochete shape, microaerophilic, cannot be grown in vitro, too small to be seen with regular microscope
How is syphilis transmitted?
Direct penetration; sexually or transplacentally
What are the characteristics and symptoms of primary syphilis?
chancre (painless ulcer at site of infection), local lymphadenopathy, highly infectious, usually resolves in 1-6 weeks
What are the characteristics and symptoms of secondary syphilis?
- occurs several weeks after chancre appears, may last for weeks/months, infectious
- lymphadenopathy, malaise, generalized rash (unique in that its also on soles/palms)
- about 25% of untreated cases have reccurent disease in 1-2 yrs
What are the characteristics and symptoms of latent syphilis?
- latency can occur between any stage
- only clinical sign is serology
- unlikely to be infectious at this time
What are the characteristics and symptoms of tertiary syphilis?
- about 30% of untreated cases progress to this stage
- occurs 1-20+ years after primary infection
- clinical signs: gummas (tumor like lesions that can affect any tissue)
- nuerosyphilis; affects CNS and brain, cardiac syphilis: affects heart
What are the characteristics and symptoms of congenital syphilis?
- can be transmitted during any stage, the most likely during secondary
- clinical signs may not be present at birth but include: stillbirth, neurological impairment, deafness, blindness, bone deformities
How is yaws (T. pallidum ssp. pertenue) transmitted?
direct penetration (contact with lesions)
What are the clinical signs of yaws?
Early: initial papilloma/nodule at the site of the infection, swelling of skin with no visible fluid, painless, lasts 3-6 months
Late: disfigurement of nose and bones, thickening of skin on palms/soles
How is Bejel (T. pallidum ssp. endemicum) transmitted?
direct penetration (using contaminated eating utensils)
What are the clinical signs of Bejel (endemic syphilis)?
Primary/Secondary: oral lesions
Late: gummas (skin, bones, nasopharynx affected)
How is pinta (T. pallidum carateum) transmitted?
Direct penetration (contact w/ lesions)
What are the clinical signs of pinta?
early: initial papilloma @ site of infection, enlarged plaques, lasts months-years
late: areas of hyper-pigmentation/ depigmentation
* no cases since 1979
How did syphilis spread throughout Europe?
- mercenaries from Spain went with French army to invade Naples and brought syphilis with them (1495), mercenaries likely picked it up in brothels
- from Naples, syphilis spread throughout Europe
- worth noting there are 2 main theories on how/when syphilis first got to Europe
What is the Columbian theory?
- Columbus’ voyage (1493) brought syphilis back from the New World, spread it to brothels in Spain, then spread through Europe
- possible mutated into VD after reaching Europe (not sure); selection pressures in Hispaniola were different (clothing, sexual practices, climate, genetics)
- phylogenetic evidence supports this theory
What is the Pre-Columbian Theory?
- said syphilis existed in Europe prior to 1494, but was not recognized as syphilis (maybe due to misdiagnosis)
- review of literature does not support this as no definitive cases with accurate date are reported before 1493
Explain the history of T. pallidum ssp. pertenue (yaws).
- Probably oldest member of treponeme family
- genetically similar to a baboon strain
- still present in tropical areas of Africa, Indonesia, Pacific Islands, S. America
Explain the history of T. pallidum ssp. endemicum (Bejel).
- probably evolved from ssp. pertenue
- present in arid regions of Eastern Mediterranean, Central and S. America
Explain the history of T. pallidum ssp. pallidum (syphillis).
- probably evolved from ssp. pertenue
- present worldwide
- genetically most closely related to a S. American strain
What has been the effect of climate on treponemes?
- yaws present in hot-humid areas
- endemic syphilis (Bejel) present in hot-arid areas
- syphilis may have evolved after being transported to a temperate region
What factors led to the emergence of syphilis in Europe?
- international travel
- movement of military personnel
- possibly evolution of infectious agent
- possibly climate
