Week 2- Columbian Exchange (Syphilis)

Question 1

What was the Columbian Exchange?

Answer 1

The exchange of goods, ideas, and disease between the Old and New World

Question 2

List 4 subspecies of treponeme and the disease they cause

Answer 2

T. pallidum ssp. pallidum: syphilis
T. pallium ssp. pertenue: yaws
T. pallidum ssp. endemicum: Bejel/ endemic syphilis
T. pallidum ssp. carateum: pinta

Question 3

What are the characteristics of treponemes?

Answer 3

bacteria, spirochete shape, microaerophilic, cannot be grown in vitro, too small to be seen with regular microscope

Question 4

How is syphilis transmitted?

Answer 4

Direct penetration; sexually or transplacentally

Question 6

What are the characteristics and symptoms of primary syphilis?

Answer 6

chancre (painless ulcer at site of infection), local lymphadenopathy, highly infectious, usually resolves in 1-6 weeks

Question 7

What are the characteristics and symptoms of secondary syphilis?

Answer 7

• 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

Question 8

What are the characteristics and symptoms of latent syphilis?

Answer 8

• latency can occur between any stage
• only clinical sign is serology
• unlikely to be infectious at this time

Question 9

What are the characteristics and symptoms of tertiary syphilis?

Answer 9

• 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

Question 10

What are the characteristics and symptoms of congenital syphilis?

Answer 10

• 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

Question 11

How is yaws (T. pallidum ssp. pertenue) transmitted?

Answer 11

direct penetration (contact with lesions)

Question 12

What are the clinical signs of yaws?

Answer 12

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

Question 13

How is Bejel (T. pallidum ssp. endemicum) transmitted?

Answer 13

direct penetration (using contaminated eating utensils)

Question 14

What are the clinical signs of Bejel (endemic syphilis)?

Answer 14

Primary/Secondary: oral lesions

Late: gummas (skin, bones, nasopharynx affected)

Question 15

How is pinta (T. pallidum carateum) transmitted?

Answer 15

Direct penetration (contact w/ lesions)

Question 16

What are the clinical signs of pinta?

Answer 16

early: initial papilloma @ site of infection, enlarged plaques, lasts months-years
late: areas of hyper-pigmentation/ depigmentation
* no cases since 1979

Question 17

How did syphilis spread throughout Europe?

Answer 17

• 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

Question 18

What is the Columbian theory?

Answer 18

• 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

Question 19

What is the Pre-Columbian Theory?

Answer 19

• 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

Question 20

Explain the history of T. pallidum ssp. pertenue (yaws).

Answer 20

• Probably oldest member of treponeme family
• genetically similar to a baboon strain
• still present in tropical areas of Africa, Indonesia, Pacific Islands, S. America

Question 21

Explain the history of T. pallidum ssp. endemicum (Bejel).

Answer 21

• probably evolved from ssp. pertenue

- present in arid regions of Eastern Mediterranean, Central and S. America

Question 22

Explain the history of T. pallidum ssp. pallidum (syphillis).

Answer 22

• probably evolved from ssp. pertenue
• present worldwide
• genetically most closely related to a S. American strain

Question 23

What has been the effect of climate on treponemes?

Answer 23

• 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

Question 24

What factors led to the emergence of syphilis in Europe?

Answer 24

• international travel
• movement of military personnel
• possibly evolution of infectious agent
• possibly climate