Syphilis Flashcards
what types of bacteria creates the syphilis infection? what three are responsible for human disease?
- The Spirochetes are G(-) bacteria with a thin, helico structure (0.1-0.5 x 5-20 mm)
- Three species are responsible for human diseases:
i) Treponema - syphilis, endemic syphilis (Bejel),Yaws, Pinta
ii) Borrelia - epidemic relapsing fever, endemic relapsing fever, lyme barreliosis
iii) Leptospira - leptospirosis
what are the diseases of the treponema infections?
- Bacterial Factors
Diseases
Venereal syphilis (T. pallidum subspecies pallidum)
Endemic syphilis or bejel (T.pallidum subsp. endemicum)
Yaws (T. pallidum subspecies pertenue)
Pinta (T. carateum)
what are the virulence factors for treponema infections? what happens with the host’s immune response to infection?
- Bacterial Factors
Virulence Factors
Outer membrane proteins promote adherence to host cells
Hyaluronase may facilitate perivascular infiltration
Coating of fibronectin protects against phagocytosis
Tissue destruction primarily results from the host’s immune response to infection
what is the transmission of treponema infections?
Transmission
Humans are the only host
Venereal syphilis is transmitted by sexual contact or congenitally
Other Treponema infections are transmitted by contact of mucous membranes with infectious lesions
Congenital infections are rare
who is at risk for venereal syphilis or other treponema infections?
Venereal syphilis
- Sexually active adolescents and adults
- Children born to mothers with active disease
Other Treponema infections
- Children or adults in contact with infectious lesions
what is the geography/season for venereal syphilis, endemic syphilis, yaws, or pinta?
Geography/Season
Venereal syphilis is worldwide
Endemic syphilis (bejel) occurs in desert and temperate regions of North Africa, the Middle East, and Northern Australia
Yaws occurs in tropical or desert regions of Africa, South America, and Indonesia
Pinta occurs in tropical areas of Central & South America
No seasonal incidence
what are the modes of control for syphilis?
Modes of Control
Penicillin is the drug of choice
- Tetracycline, erythromycin, or chloramphenicol are administered if the patient is allergic to penicillin
Safe sex practices should be emphasized, as well as treatment of the sexual partners of infected patients
Endemic syphilis, yaws, and pinta can be eliminated through organized public health measures (treatment, education)
- However, these efforts have been inconsistently applied
Is syphilis rare? what is the etiologic agent of syphilis? can it be spread through contact with inanimate objects?
- Syphilis is now a relatively rare disease, but it is still important because of its severity & long-term effects if inadequately treated.
- The etiologic agent of syphilis is T. pallidum, which is a motile helico bacterium with a unique structure.
- Syphilis cannot be spread through contact with inanimate objects because T. pallidum is extremely labile, unable to survive exposure to drying or disinfectants.
what are two major routes of transmission for syphilis?
- Two major routes of transmission are “sexual” and “transplacental”:
- Treponema enters a susceptible host through the mucous membrane or the minute abrasions in the skin surface which occur during sex.
- Treponema can cross the placental barrier from the bloodstream of an infected mother and cause disease in the fetus, and thus cause congenital syphilis.
why is there tissue destruction and lesions in syphilis? and what are the stages of syphilis?
- The tissue destruction and lesions observed in syphilis are primarily the consequence of the patient’s immune response to the infection.
- Typically, the course of infection is divided into 3 stages:
Primary syphilis
Secondary syphilis
Teriary syphilis
What may occur after the first two stages?
- Spontaneous remission may occur after the primary or secondary stages, or the patient may develop late manifestations of disease in which all tissues may be involved (tertiary stage).
what development does the disease usually follow?
Infection with T. pallidum Usually by coitus --->Incubation period (~3 weeks) --> Primary syphilis (2-6 weeks) --> Asymptomatic period (2-24 weeks) --> Secondary syphilis (2-6 weeks) --> latent syphilis --> asymptomatic period (3-130 years) --> tertiary syphilis
what is primary (or initial) syphilis characterized by?
- It is characterized by “1” or more painless skin ulcers (chancres), which are highly contagious, at the site where spirochetes penetrated.
- Spirochetes are disseminated in the bloodstream soon after infection.
- However, the chancre represents the primary site of initial replication - Abundant spirochetes are present and can be disseminated throughout the body by way of the lymphatic system & bloodstream.
- Chancre(s) heals spontaneously within 2 months.
what is tertiary syphilis like?
- A small proportion of patients can progress to the tertiary stage.
- The diffuse, chronic inflammation characteristic of late syphilis can cause a devastating destruction of virtually any organ or tissue
- Ex. Arthritis, dementia, blindness, etc. - Granulomatous lesions (gummas) may be found in bone, skin, and other tissues.
- The nomenclature of late syphilis reflects the organs of primary involvement
(ex. Neurosyphilis, cardiovascular syphilis)
from latent to tertiary syphilis what is the route that occurs?
residual organisms in (?) spleen and lymph nodes –> renewed multiplication –> invasion or cell mediated hypersensitivity –> then to gmmas in skin, bones, liver testis OR cardiovascular syphilis; aortic lesions, etc; heart failure OR cell-mediated hypersensitivity
