STDs Flashcards
STDs
relatively few clinical syndromes MOST COMMON SYMPTOMS 1. urethritis 2. cervicitis 3. vaginitis or vaginosis 4. genital ulcers
Inflammatory/Exudate Causes of STDs
Urethritis -> N. Gonorrhea, C. trachomatis
Cervicitis -> C. trachomatis
Vaginitis -> T. vaginalis, C. albicans
Vaginosis -> Gardnerella
Nonexudative Causes of STDs (Genital Ulcers)
Syphilis -> T. pallidum (not painful) Herpes -> HSV-2 (painful) Chancroid -> H. ducreyi LGV -> C. trachomatis Genital Warts -> HPV (not painful)
Systemic Infections
AIDS -> HIV 1 and 2
PID -> N. gonorrhea, C. trachomatis, anaerobes
Cancer from STDs
Cervical carcinoma - HPV
Kaposi sarcoma - HHV-8
HPV
dsDNA -> circular -> icosahedral -> nonenveloped -> papoviridae
- transmitted by direct contact (wart like growths)
- has oncogenes (16, 18)
- vaccine available, no treatment (incurable)
- dependent on host cell replication -> if cell it infects is not replicating, virus cannot infect
Neisseria Gonorrhea
gram (-) -> diplococci -> glucose oxidizer
Grows on Thayer-Martin media
- specialized pili with antigenic variation, endotoxin, no capsule, IgA protease
- kills ciliated cells
- treat with ceftriaxone, also pair with doxycycline for chlamydia co-infection
- prophylactic erythromycin eye drops for neonates
N. Gonorrhea 3 types of infections
- Local infection -> genital tract or anorectal infection
- Systemic arthritis -> invasive pathogen, most common cause of systemic arthritis in sexually active individuals
- Untreated –> PID, ectopic pregnancy, sterility, Fitz-Hugh-Cutris Syndrome
Herpes Simplex Virus 2
dsDNA -> linear -> icosahedral -> enveloped -> alpha herpes virus
- transmitted via direct contact, latency in neurons
- encodes for several proteins required to promote replication (DNA polymerase and thymidine kinase)
- treatment only effective during lytic infection
- visualized on Tzanck smear –> multinucleated giant cells
Treatment of Herpes
ACYCLOVIR –> a prodrug that is a guanine base with a modified sugar -> requires viral thymidine kinase to activate -> gets incorporated into viral DNA –> chain terminator
- has 100x more affinity for viral than human
Gancyclovir
used for beta-herpes infections
- doesn’t use thymidine kinase -> uses different enzyme
Trichomonas Vaginalis
small, pear-shaped protozoa –> 4 anterior flagella and 1 undulating membrane = 5 flagella
- white or yellow-green frothy discharge, foul-smelling, fishy odor
- transmitted via direct contact, treat both patient and partner with metronidazole
- vaginal pH will be elevated
- not an opportunistic infection
Candida albicans
- opportunistic infection* –> due to disruption of normal bacterial microbiota
- itchiness, white, clumpy discharge (common cause of vaginitis)
- pseudohyphae indicate rapidly growing
- tx with topical/oral azoles –> tx both patient and partner
HIV 1 and 2
RNA virus -> icosahedreal -> enveloped -> ss(+) diploid -> retroviridae
- infects CD4+ Tcells with CXCR4 or CCR5
- gp120 -CXCR4/CCR5, gp41 - entry into cell
- gag = virion core
- pol = RT, integrase, protease
- env = glycoproteins
Trepnema pallidum —> SYPHILIS
spirochete -> microaerophilic
- painless ulcers that go away –> come back as full body rash
- rapid plasma regain test
- 3 stages of disease
1. Primary - appearance of hard chancre at site of entry, loaded with spirochetes
2. Secondary - weeks/months after -> fever, headache, sore throat, lymphadenopathy, red/brown rash on soles and palms
3. Tertiary - enter highly varied latent period (years) -> can cause cardiovascular effects (aortic rupture) -> uncommon today because penicillin G effective against all stages of syphilis
Argyll Robertson Pupil
condition from syphilis that accomodates to near objects but does not react to light
Congenital Syphilis
bacterium can pass through placenta (ToRCHeS)
- most common in 2nd or 3rd trimester
- deafness, mulberry molars, saber shins, saddle nose, Hutchinson’s incisors
FTA-BS
fluorescent treponemal antibody absorbance test -> test serum reacts with treponemal cells and then reacted with antihuman globulin antibody labeled with fluorescent dyes -> if antibodies present -> show up labeled
Gardnerella vaginalis
no itching
white-gray color
moderate discharge that is malodorous
Chlamydia trachomatis
- has both elementary body (EB) and reticulate body (RB)
- multiplies by binary fusion
Serovars D-K = urethritis, PID, neonatal pneumo, conjuctivitis
A-C = trachoma (chronic conjuctivitis)
L = lymphogranuloma venereum
Pathophysiology of C. trachomatis
D-K = infects columnar epithelium and generates epithelium
- can spread to fallopian tubes = ectopic pregs –> can infect liver (Fitz-Hugh-Curtis syndrome)
- males can spread to joints -> Reiter’s syndrome
A-C = hand-eye contact and conjuctivitis -> blindness
L - rare but leads to painless ulcers and leads to proctitis and rectal stricture
- treat with azithromycin and tetracyclines
