Genital Pathogens and STI's Flashcards
Sexually transmitted infections (STI’s)
- spread via person-to-person sexual contact
- some can be transmitted mother to baby during birth or blood products
CDC reccomendations
- yearly chlamydia and gonorrhea screenings for at risk women
- annual chlamydia screening for women age 25
- annual screening of men who have sex with men for syphilis, gonorrhea, chlamydia, and HIV
Normal urethral flora
CoNS, Corynebacteria, Anaerobes, Lactobacillus, non-hemolytic strep, Neisseria
Normal vulva and foreskin flora
Mycobacterium smegmatis, Gram-positive organisms
Prepubescent and postmenopausal female genital flora
- CoNS, Corynebacteria
- varies with pH and estrogen
Normal genital flora of reproductive age females
Enterobacteriaceae, Strep, Staph, Anaerobes (Lactobacillus), Clostridium, transient yeast
Endogenous Genital infections
result from organisms that are normal flora
Exogenous Genital infections
STI’s, result from instrumentation or foreign bodies
Primary Genital Pathogens
- Chlamydia trachomatis
- Neisseria gonorrhoeae
- Treponema pallidum
- Human papilloma virus
- Gardnerella vaginalis: bacterial vaginosis, premature labor
- Trichomonas vaginalis
- Haemophilus ducreyi
- Klebseilla granulomatis
- Mycoplasma hominis
- Ureaplasma urealyticum
Chlamydia trachomatis
Most prevalent STD in UK (90,000 diagnoses in GUM in 2003)
Obligate intracellular bacterium (cell wall deficient)
- cervicitis with mucus
- PID leading to infertility
- Preterm births
Chlamydia trachomatis
in what age range has chlamydia gone up and why?
45+ age group has gone up; more divorce, forgotten safe sex
transmission of chlamydia
Transmission via infected secretions
where does infection start?
Infection of mucosal membranes (cervix/urethra/mouth/rectum)
what are the symptoms in females?
Asymptomatic in 75% of women
Dysuria, vulval irritation, abdominal pain
what are the symptoms in males?
asymptomatic in 25%
urethral discharge, prostatitis
what are the complicates associated with chlamydia?
Pelvic inflammatory disease
Infertility
Conjunctivitis
Neonatal pneumonitis
Prostatitis
Perihepatitis
SARA
Pelvic Inflammatory Disease (PID)
- cervical microorganisms travel to endometrium, fallopian tubes and other pelvic structures
- N. gonorrhoeae and C. trachomatis
- associated with IUD’s (Actinomyces)***
how is it diagnosed?
Endocervical/urethral swab/urine/rectal s/eye
IF/culture/ELISA/PCR
Serology
what is the treatment?
Tetracyclines/quinolones/macrolides
or Doxycycline
Week of antibiotic will cure
- may be #1 STI
- penile malignancy, cervical carcinoma
- genital warts
Human papilloma virus (HPV)
Organisms associated with homosexual practice
- Protozoa: Giardia, Entamoeba
- Bacteria: Salmonella, Shigella, Campylobacter, N. meningitidis
- Viruses: CMV, Hepatitis, HIV
Genital tract pathogens
- Fungi: Candida, yeast
- Viruses: CMV, HPV, Herpes
- Protozoa: Trichomonas vaginalis, scabies, lice
Genital tract infections (clinical manifestations)
- women asymptomatic
- discharge, dysuria, skin lesions
Vaginosis and Vaginitis
- inflammation of vaginal mucosa
- discharge and odor
- Trichomonas vaginalis and Candida albicans
Bacterial vaginosis
- polymicrobial or Gardnerella vaginalis
- most common vaginal infection in women of child-bearing age
Replacement of normal lactobacilli by high concentrations of anaerobes (Prevotella and Mobiluncus) and G. vaginalis.
overgrown bacteria
what are the physical symptoms?
a homogeneous, white, noninflammatory discharge that smoothly coats the vaginal walls;
lab diagnosis?
the presence of clue cells on microscopic examination;
a pH of vaginal fluid >4.5; and
a fishy odor of vaginal discharge before or after addition of 10% KOH (i.e., the whiff test).
Clue cells
- epithelial cells surrounded by gram-positive coccobacilli
Cervicitis
- inflammation of cervix
- increased number of PMN’s
- N. gonorrhoeae, C. trachomatis
anorectal lesions
- HPV, HSV, viruses, parasites, N. gonorrhoeae, C. trachomatis
- itching, discharge, anal pain
- proctitis: N. gonorrhoeae and C. trachomatis
- due to HIV in ICP’s
Batholinitis
- infection of glands on either side of vaginal orifice
- N. gonorrhoeae and C. trachomatis
- polymicrobial infections (commonly)
Post-gyneclogic surgery infections
pelvic cellulitis or abscesses, usually from own flora
Pregnancy-associated infections
- bloodborne or ascending routes from mum to baby
- Chorioamnionitis: infection of uterus and contents during pregnancy; anaerobes, genital mycoplasmas, Group B strep, E. coli
Epididymitis
- inflammation of epididymis
- complication of gonorrhea or chlamydia
Proctitis
inflammation of rectal lining
Specimen collection
- discharge for Neisseria and Chlamydia (males and females)
- discharge for yeast, beta-hemolytic strep, Gardnerella (females)
- discharge for ureaplasma and chlamydia (males)
- urethral swab for ureaplasma, chlamydia, trichomonas (Dacron swab)
Urine specimen (organisms)
Chlamydia (males), Trichomonas (males), Neisseria gonorrhoeae
Cervical swab (organisms)
Neisseria gonorrhoeae, Trichomonas vaginalis, yeast, beta-hemolytic strep, herpes simplex
Transport
- gonococci: Stuart’s or Amie’s charcoal media
- Chlamydia and Mycoplasma: specific transport media
Gram-stain dipplococci (cocci usually in pairs)
N. gonorrhoeae
how is it identified?
Relatively fragile and fastidious organism
Requires Haemin, yeast extract, and 3-10% CO2 to grow
Oxidase test will help
explain the peaks
Peak at war
Then penicillin
Peak coz oral contraception introduced
HIV and AIDS campaigns cause drop
Now there are hiv treatments; so safe sex is practiced less
what are the symptoms of gonorrhea in females?
discharge,
asymptomatic infection is common,
Pelvic Inflammatory Disease
what are the symptoms of gonorrhea in males?
urethritis (“flow of seed”), dysuria, asymptomatic infection important in transmission, prostatitis, orchitis
what complication is common?
Disseminated infection (spread to other areas)
what complication can happen in pregnant women?
Ophthalmia neonatorum
an infectious neonatal conjunctivitis, typically contracted during vaginal delivery from exposure to bacteria from the birth canal
Gonococci media
Modified Thayer Martin, New York City agar, JEMBEC
Yeast media/serology
CNA, BAP
Hybridization assay
Gardnerella media/serology
CNA, V agar
Hybridization assay
Beta-hemolytic media/serology
CNA, BAP
Rapid antigen tests
Mycoplasma/ureaplasma media
A8 agar
Chlamydia media
Cell culture on McCoy media
Chancroid
- Haemophilus ducreyi
- painful genital ulceration, bubo formation
- pleomorphic, gram-negative coccobacilli, school of fish
Lymphogranuloma venereum (LGV)
- C. trachomatis serovars L1, L2, L2a, L2b, L3
- secondary stage spreads to lymph nodes
Donovanosis
Klebsiella granulomatis
Infections of neonates
- transmitted via birth canal
- HSV, CMV
- Group B streptococcal sepsis
- Gonorrhea
- Chlamydia conjunctivitis and pneumonia
- E. coli
Common, affecting 75% of women
Commensal of GI and genital tract
Imbalance of ecology
Genital candidosis
what are the predisposing factors?
Diabetes mellitus - raise in urine sugar levels makes better environment for colonization
Antibiotics- destroys normal flora, no competition
Pregnancy
treatment?
Easy to treat; antifungal for a week
Rx topical/oral imidazoles
how is it diagnosed?
Microscopy
Culture
Syphilis (lab diagnosis)
- Darkfield microscopy and DFA
- nontreponemal antibody tests
- treponemal specific antibody tests
what causes syphilis?
Treponema pallidum
Slender, tightly coiled helical cells
Cannot be grown in vitro
why is syphilis peaking again?
Resistant strains of syphilis on the rise
what are the clinical features of syphilis? initially
There was a young man from Back Bay,
Who thought syphilis just went away.
He believed that a chancre was only a canker,
That healed in a week and a day.
further ones (next few years)
But now he has acne vulgaris,
(or whatever they call it in Paris);
On his skin it has spread from his feet to his head
And his friends want to know where his hair is.
next decade
There’s more to his terrible plight
His pupils won’t close in the light
His heart is cavorting, his wife is aborting,
And he squints through his gun barrel sight
more serious
Arthralgia cuts into his slumber,
His aorta is in need of a plumber;
But now he has tabes,
And sabre-shinned babies
While of gummas he has quite a number
final symptoms
He’s been treated in every known way,
But his spirochaetes grow day by day;
He’s developed paresis,
Has long talks with Jesus
And thinks he’s the Queen of the May!
what is Trichomoniasis caused by?
Protozoan flagellate 10-30um
what are the symptoms?
Itching, offensive discharge in F, M often asymptomatic, occasional urethritis/prostatitis and epidydimitis
how is it diagnosed?
easily from a swab
then using microscopy/culture
what is the treatment?
metronidazole
