Other Genitourinary Tract Infections Flashcards
Normal Vaginal Microbiota
***Lactobacillus*** (Predominantly composed of this during child-bearing years) Gardnerella Mobiluncus Mycoplasma Prevotella Staphylococcus Ureaplamsa
Fungi: Candida
Lactobacillus (Characteristics)
- Gram-positive, microaerophilic, or anaerobic rods
- Do not cause UTI because they CANNOT grow in urine
- Glycogen is metabolized to LACTIC ACID by lactobacilli resulting in a vaginal pH of 4 to 5
- Optimal for growth and survival of lactobacilli and inhibits growth of many other organisms*
Alterations in Normal Microbiota of Vagina
1) Age (lower prevalence of Lactobacillus as you move away from reproductive age (both younger and older))
2) Menstruation (Transient changes)
3) Hysterectomy with removal of the cervix
- Increases Bacteroides fragilis and, of the aerobes, increases E. coli and Enterococcus species
These 3 species are frequently found in cultures obtained from women who develop pelvic infections following hysterectomy
Bacterial Vaginosis (BV) (Characteristics)
Common, complex, and poorly understood clinical syndrome that reflects ABNORMAL VAGINAL MICROBIOTA (Dysbiosis)
Overgrowth of ANAEROBIC species including Garderella vaginalis, Ureaplasma urealyticum, Mobiluncus species, Mycoplasma hominis, and Prevotella species
Reduction of Lactobacillus
Bacterial Vaginosis (BV) (Symptoms)
Can be asymptomatic Discharge Odor Pain Itching Burning
Bacterial Vaginosis (BV) (Risk Factors)
Oral sex Douching Smoking Sex during menses IUD Early age of sexual intercourse New or multiple sex partners Sexual activity with other women (WSW)
NOT considered an STD, although is associated with sexual activity
Bacterial Vaginosis (BV) (Diagnosis: Amsel Criteria)
Amsel Criteria (3 of 4 of these must be met)
1) Discharge, usually WHITE or GREY and MILKY
2) Microscopic evaluation of a vaginal secretion saline preparation reveals CLUE CELLS
3) Release of volatile amines produced by anaerobic metabolism (foul, fishy odor)- WHIFF TEST
- Several drops of a potassium hydroxide (KOH) solution are added to a sample of vaginal discharge to see whether a STRONG FISHY ODOR is produced
4) Determination of the vaginal pH (pH > 4.5 is associated with BV)
Bacterial Vaginosis (BV) (Diagnosis: Nugent Score)
Numerical score based on semi-quantization of:
1) Large gram-positive rods (Lactobacillus spp.)
2) Small gram-variable rods (G. vaginalis or Bacteroides spp.)
3) Curved gram-variable rods (Mobiluncus spp.)
0-3: normal; lactobacillus dominant
4-6: intermediate; mixed morphotypes
7-10: BV; absences of lactobacilli; predominance of 2 other morphotypes
Bacterial Vaginosis (BV) (Complications)
Having BV…
1) Can increase a woman’s SUSCEPTIBILITY TO HIV INFECTION
2) Increases the chances that an HIV-infected woman can PASS HIV TO HER SEX PARTNER
3) Has been associated with an increase in the DEVELOPMENT OF AN INFECTION FOLLOWING SURGICAL PROCEDURES such as hysterectomy or an abortion
4) While pregnant may put a woman at increased risk for some complications of pregnancy, such as PRETERM DELIVERY, MISCARRIAGE, AND INFECTION AFTER DELIVERY
5) Can increase a woman’s SUSCEPTIBILITY TO OTHER STDs, such as HSV, chlamydia, and gonorrhea
Bacterial Vaginosis (BV) (Treatment)
1) Oral Metronidazole (Anaerobes and parasites; inhibits nucleic acid synthesis)
2) Clindamycin (Gram positive cocci and anaerobes)
***Recurrence is common
Vulvovaginal Candidiasis (Yeast Infection) (Characteristics)
Common FUNGAL infection in women of child-bearing age
Pruritis with THICKE, ODORLESS, WHITE VAGINAL DISCHARGE Cottage-cheese like
Vulvovaginal Candidiasis (Yeast Infection) (Complicated vs Uncomplicated)
Complicated: Recurrent (4 or more episodes per year) or SEVERE VVC, non-albicans candidiasis, or the patient has uncontrolled diabetes, debilitation, or immunosuppression
Uncomplicated: Sporadic or infrequent mild-to-moderate symptoms in otherwise healthy patient
Candida Species (Appearance)
Oval yeast-like forms that produce BUDS, PSEUDOHYPHAE, and HYPHAE
Candida albicans —> Germ Tubes
Candida Albicans (Characteristics)
NORMAL FLORA of the GI tract, vagina, and urethra, skin, and finger/toe nails
Found in air, water, and soil
Most episodes of candidiasis represent endogenous infection by normally commensal host flora (i.e. an OVERGROWTH of NORMAL FLORA)
Candida Albicans (Pathology)
Vaginitis: 20 million cases/year in US
More frequent after taking ANTIBIOTICS
Diaper Rash, Oral thrush
Immunocompromised –> Esophagitis, Disseminated
Candida Albicans (Pathogenesis)
Seen in individuals with local or generalized IMMUNOSUPPRESSION or in settings which FAVOR OVERGROWTH:
- Oral contraceptives
- Pregnancy
- Diabetes
- Systemic corticosteroids
- HIV infection
- Antibiotic use
Candida Albicans (Diagnosis and Treatment)
Diagnosis: Microscopic examination 10% potassium hydroxide (KOH) reveals HYPHAE and BUDDING YEAST
-Cultures with Nickerson medium may be used if Candida is suspected but not demonstrated
Treatment:
- 1-3 day regimen of topical AZOLE for uncomplicated VVC
- 7-14 days of a topical regimen or two doses of oral FLUCONAZOLE 3 days apart for complicated VVC
Trichomoniasis (Characteristics)
Most common, curable sexually transmitted disease
Most women are ASYMPTOMATIC or have scant, watery, vaginal discharge
SYMPTOMS CAN RANGE FROM MILD TO SEVERE VAGINITIS with INFLAMMATION associated with ITCHING, BURNING, and DYSURIA
Yellow-green, froty, foul-smelling discharge
Men serve as ASYMPTOMATIC CARRIERS/RESERVOIRS for infection (occasional urethritis, prostatitis, or other urinary tract problems)
Trichomonas vaginalis (Characteristics)
- Small, pear-shaped PROTOZOA
- 4 anterior flagella and an UNDULATING MEMBRANE are responsible for MOTILITY (key for diagnosis)
- Rigid axostyle involved in attachment
- Anaerobic
- Exist ONLY IN TROPHOZOITE form (strict parasite, cannot survive long outside of host; reservoir is human urogenital tract)
Trophozoite = replicating, metabolically active form of a protozoa
Trichomonas vaginalis (Pathogenesis)
- Destruction of epithelial cells, neutrophil influx, and PETEHCIAL HEMORRHAGE
- Strawberry Cervix*
-No clinically significant immunity (Can be reinfected over and over)
Trichomonas vaginalis (Diagnosis and Treatment)
Diagnosis:
- Detecting swimming T. vaginalis in exudate (Discharge)
- Asymptomatic infection often detected by Pap smear
Treatment:
-Metronidazole, treat BOTH partners
Menstrual Toxic Shock Syndrome (TSS)
TSST-1 producing strains of Staphylococcus aureus could multiply rapidly in HYPERABSORBANT TAMPONS and release toxin
TSS is usually seen from S. aureus infecting a wound nowadays
Staphylococcus aureus
Catalase Positive, Coagulase Positive, Gram Positive cocci arranged in clusters
Normal flora on human skin and mucosal surfaces
Person to person spread through direct contact or exposure to contaminated fomites (e.g. bed linenes, clothing)
Facultative INTRACELLULAR
S. Aureus (Clinical Manifestations)
Toxin-Mediated:
- Scalded skin syndrome
- Food poisoning
- Toxic shock
