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
