L 95-96 Syphilis, Gonorrhea, Chlamydia MisSTDs

Question 1

What is the causative agent of Syphilis?

Answer 1

Treponema pallidum

It is a g(-) spirochete that has axial filaments which give it its spiral shape

Don’t live long outside body

Question 2

What are the hosts of Syphilis and how is it spread?

Answer 2

Humans only hosts

Spread through sexual contact

Intact skin is resistant, needs an abrasion or mucous membrane to invade

Only takes 4-8 spirochetes to get infected

Question 3

How many stages are possible with syphilis?

Answer 3

Primary, Seconday, Tertiary, Latent, Congenital

Question 4

Describe the primary stage of syphilis

Answer 4

After 2-4 weeks of sexual contact PAINLESS chancres will appear on any surface that was involved in the contact–genital, lips, anal region, etc.

No systemic manifestations

Untreated cases will spontaneously resolve in most cases

Question 5

Describe secondary syphilis

Answer 5

2-10 weeks after the primary chancre heals

Sprichetemia is present along with other systemic manifestations–fever, sore throat, headache, LAD, rash, arthralgias, anorexia

Maculopapular rash can appear anywhere on the body, but especially on the palms and soles–rash is very contagious

Ocular manifestations are possible

Condylomas on the genitals

Question 6

Describe Tertiary Syphilis

Answer 6

Shows up years later

Gummas: granulomatous lesions on the skin and anywhere in the body including bone

Tabes: degenerative atrophy of CNS

Treponemas are rare in tertiary lesions

Question 7

Describe congenital Syphilis

Answer 7

Syphilis can cross the placenta and infect the fetus

Classic SSx are: hutchinson’s teeth, interstitial keratitis, 8th CN deafness, saddle nose deformity

Question 8

Syphilis diagnostic tests

Answer 8

Dark Field Microscopy: visualize motile spirochetes

Blood Tests: VDRL and RPR used for screening and look for flocculation

Fluorescent antibody test: tagged antibodies light up when bound to target

Question 9

Syphilis treatment

Answer 9

Penicillin G or Ceftriaxone (latter only requires one dose)

For penicillin allergy use: Doxycycline, Azithromycin

Question 10

Causative agent of gonorrhea and its characteristics

Answer 10

Neisseria gonorrhoeae

G(-) diplococci, has LOS, no capsule, non-motile, may possess pili which are necessary for cell attachment and infection

Facultative intracellular, grows on chocolate agar

Question 11

What are the similarities and differences between Neisseria gonorrhoeae and meningitides?

Answer 11

Both are g(-) diplococci

meningitides has a capsule and gonorrhoeae does not

Question 12

Patient presents with a mucopurulent discharge from the urethra. What is the DDx?

Answer 12

Gonorrhea

Chlamydia

Trichomonas vaginalis

Question 13

Patient is known to have decreased levels of complement and they develop a mucopurulent discharge from the urethra, bacteremia, and pustules on the hands and feet. What is the likely diagnosis?

Answer 13

Disseminated gonorrhea

Opsonization by complement and antibodies is important in the destruction of gonorrhea. Decreased levels of C5-9 are associated with disseminated gonorrhea.

Question 14

Gonorrhea likes to live inside monocytes after being phagocytosed. How do they survive the lysosome and subsist in the cell?

Answer 14

They produce catalase which converts H2O2 into water and oxygen. This allows it to resist oxidative damage and death.

Question 15

How does gonorrhea present in males and females?

Answer 15

Mucopurulent discharge in both sexes

Men can progress to epididymitis and become sterile

Women can progress to any form of PID

The bacteria can infect the eyes of adults from self-inoculation

Neonates can be infected by their mothers in the eyes and go blind without treatment

Question 16

What is the greatest risk factor for gonorrhea?

Answer 16

Sexual promiscuity

Question 17

A male presents with penile discharge and the following is visualized under microscope. How would you treat this disease?

Answer 17

There are g(-) diplococci inside a PMN. This is a sign of gonorrhea.

This is treated with Ceftriaxone

Question 18

Why might a gram stain work for diagnosing gonorrhea in men but not women?

Answer 18

Gram staining in women is less diagnostic because they have a large number of g(-) bacteria that are part of their normal vaginal flora

Question 19

What virulence factor helps Neisseria gonorrhea attach to cells?

Answer 19

Pili

Question 20

Which of the bacterial STD’s discussed is g(-), spherical, has LPS, no peptidoglycan, obligate intracellular, has serotypes D-K?

Answer 20

This describes Chlamydia trachomatis

Question 21

Explain the life cycle of chlamydia

Answer 21

Elementary body: hardy infective form

Reticulate body: fragile intracellular form

Intracellular inclusions: vacuole w/ elementary bodies

The elementary body will penetrate cells by phagocytosis. Inside vacuoles, reticulate bodies produce new elementary bodies that are released and spread.

Question 22

What types of chlamydia cause NGU (non-gonococcal urethritis)?

Answer 22

Strains D-K

Question 23

How will chlamydia present?

Answer 23

Clinically it resembles GC and has a mucopurulent discharge.

It is the most common cause of epididymitis in men and PID in women.

Alos causes inclusion conjunctivitis in neonates

Question 24

Treatment for chlamydia

Answer 24

Doxycycline

Azithromycin

Question 25

What is the diagnosis?

Answer 25

Trichomonas vaginalis

Question 26

Woman presents with vulvitis, itchy vulva, strawberry cervix, and copious white/yellow discharge that is malodorous. What do you tell her about giving birth in this condition, risk for HIV, and menstruation?

Answer 26

She likely has Trichomonas vaginalis

These Sx are generally worse during menstruation

The intense inflammation makes her more at risk for HIV infection

Being pregnant with these Sx puts her at risk for preterm delivery

Question 27

What are the virulence factors that help progress the infection of Trichomonas vaginalis?

Answer 27

Adhesins like lectins

Proteases that thin mucous

Flagella that help spread

Question 28

How would you diagnose a case of Trichomonas vaginalis and what would be the best treatment options?

Answer 28

Saline wet mount looking for trophs associated with epithelial cells

Tinidazole, Metronidazole

Question 29

Woman has discharge and you scrape the epithelium and make a saline wet mount showing the following:

Answer 29

Trichomonas vaginalis