Infectious disease/STDs Flashcards
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5 P’s of sexual health
1.) Partners
2.) Practices
3.) Prevention of pregnancy
4.) Protection from STIs
5.)Past history of STIs
Gonorrhea
A bacterial STI caused Neisseria gonorroeae (gram-negative diplococci)
Common in young adults (15-24)
* If left untreated in women can lead to PID–>fallopian tube damage–>infertiity or increased risk of ectopic pregnancy.
* If left untreated in men can lead to epididymitis–>infertility (rare).
* Male ejaculation is not a requirement for transmission
* S/S:
-Males and females are often asymptomatic.
-Dysuria, urinary frequency, mucopurulent vaginal discharge (green/yellow), labial pain and swelling, lower abd pain, fever, dysmenorrhea, N/V, white/yellowish-green penile discharge, testicular pain. “GG: Green gooky”
* Lab/diagnostics: Nucleic-acid amplification test (NAAT) using urine sample and/or culture using modified Thayer-Martin media
* Treatment: Persons infected by gonohrrea are also frequently infected with chlyamydia, preempitevly treat for chlamydia.
-<150kg: ceftriazone 500mg IMx1
>150kg: ceftriazone 1g IMx1
If chamydial infection not ruled out then add doxycycline 100mg BID POx7 days.
If ceftriazone not available:
Gentamycin 240mg IMx1 dose plus azithromycin 2g PO x1dose OR
Cefixime 800mg POx1 plus doxycycline 100mg PO BIDx7days if chlamydia not ruled out.
If pregnant:
Ceftriaxone 500mg IMx1 and azithromycin 1g POx1
Syphilis
STI involving multiple organ systems and caused by Treponema Pallidum (a spirochete bacteria).
Called The Great Pretender due to the s/s looking like other diagnoses.
Typically follows a progression of stages for weeks, months to even years.
Infection occurs at the site of inocculation and a small abrasion or sore results.
Can affect the unborn and transported via blood stream.
Four clinical stages:
Primary, Secondary, Latent, Tertiary
- Serologic tests:
-Positive dark field microscopic examination and direct fleuroescent antibody test of lesion exudate are definitve tests for diagnsing early syphilis.
-Non-treponemal antibody test: venereal disease research lab (VDRL) and/or rapid plasma reagin (RPR)
-Confirmed with a treponema test: Treponema pallidum partile agglutination assay (TP-PA), fluorescent treponemal antibody absorption (FTA-ABS). - Treatment:
-For primary, seondary or early syphilis: Benzathine penicillin G, 2.4million units IMx1 dose
-For late latent, indeterminate length or tertiary: Benzathin penicillin G, 2.4million units IM weekly x 3 weeks.
-For neurosyphilis/ocular syphilis/otosyphilis: Aqueous crystalline penicillin G 18-24 million units/day (3-4 million units IV q4hrs or continuous infusion) for 10-14 days
If pt able to be compliant than an alternative tx would be procaine penicillin G, 2.4 million units IM once daily PLUS probenecid 500mg PO QID both for 10-14 days.
-Penicillin allergy: Doxycycline or tetracycline
Primary Syphilis
-Chancre present at site of infection common 3 weeks after exposure.
-Chancre indurated and PAINLESS, heals spontaneously within 1-5 weeks.
-Regional lymphadenopathy.
Secondary syphilis
Occurs 2-8 weeks later.
Flu like symptoms.
Generalized lymphadenopathy.
Generalized reddish brown rash on palsm/soles/trunk (heals within 5-10 weeks)
Latent syphilis
Seropositive, but asymptomatic.
Can last 2-20 years
Early latent: infection lasting less than a year, infectious
Late latent: infection lasting more than a year, non infectious.
Tertiary syphilis
10-30 year after initial infection
Multisystem involvement
Leukoplakia (thick, white patches inside mouth), cardiac insufficiency, infiltrative tumors of skin/bones/liver, CNS involvement.
Chlamydia
A parasitic STI that produces serious reproductive tract complications
-Chlamydia trachomatis.
Remains the most common cause of cervicitis and urethritis.
Most common bacterial STI in U.S.
* S/S: Dysuria, intramenstrual spotting, post coital bleeding, dyspareunia (painful intercourse), vaginal discharge, thick/cloudy penile discharge, testicular pain, rectal tenesmus (persistant feeling of needing to poop).
* Lab/diagnostics: McCoy cell culture is gold standard, NAAT ro detect bacteria DNA or RNA.
* Treatment: Doxycycline 100mg PO BID x7days OR azithromycin 1g POx1 dose (prefered), OR levofloxacin 500mg PO daily x7days.
Vulvovaginitis
Inflammation or infection of the vulva and vagina most commonly cased by bacteria, protozoa and/or fungi.
Characterized by vaginal discharge, vulvar itching/irritation and vaginal odor.
* Three most common diseases: bacterial vaginosis, trichomoniasis, candidiasis.
Only trichomonas is considered an STD.
* Diagnostic tests: Microscopic wet-prep, may use NAAT (urine test) or vaginal culture.
Trichomoniasis
Malodorous, frothy yellowish/green discharge, pruritis, vaginal erythema, petechia (strawberry patches) on cervix and vagina, dysareunia (painful intercourse) and dysuria.
* Diagnostic tests: Normal saline mixture shows motile trichomonads
* Treatment: Metronidazole (GI upset, no alcohol) or tinidazole.
Bacterial vaginosis
Watery, grey, fishy smelling discharge, vaginal spotting.
* Diagnostic tests: Normal saline mixture shows irregularly-shaped vaginal epithetial cells (clue cells which are squamous epithethial cells with poorly defined borders).
* Treatment: Metronidazole PO or clindamycin cream. Other regimens Tinidazole PO, clindamycin PO
Candidiasis
Thick, white, curd like discharge. Vulvovaginal erythema with pruritis.
* Diagnostic test: KOH mixture show pseudohyphae (looks like spaghetti and meatballs).
Treat empirically if wet prep is negative but pt is symptomatic
* Treatment: OTC intravaginal agents clotrimazole, miconazole, tioconazole. Prescription intravaginal agents Butoconozole, terconazole. Oral agent Fluconazole (contraindicated in pregnancy).
Chancroid
Highly contagious STD caused by hemophilus ducreyi.
Must be a part of a differential diagnosis for genital ulcers.
Well established as a cofactor for HIV transmission. Many pts may also be infected with syphilis and HSV.
* S/S: Women are usually asymptomatic and men have a sinle or multiple superficial *PAINFUL *ulcer surrounded by an erythematous halo. Ulcer may be necrotic or severely erosive.
* Diagnosis: Diagnosed by a matter of exclusion. Involved genitalia and unilateral bubo or both (swollen inguinal lymph node).
* Treatment: Azithromycin, ceftriaxone, ciprofloxacin
Herpes (HSV)
A recurrent viral STI with no cure and associated with painful vesicles or ulcers.
Two types, 1 and 2.
Type 1 usually contracted non sexually in childhood. Type 2 is usually transmitted sexually
Most HSV infections are asymptomatic and can be latent.
* Diagnosis: Culture from lesion, NAAT from lesion
* Management: No cure.
-Symptomatic treatment with Docosanol (abreva) for HSV-1 to shorten healing time (should be given at first sign).
-Acyclovir usually 1st drug of choice
-Famciclovir
-Valayclovir (especially useful for reducing asymptomatic viral shedding of HSV-2).
HSV-1
Found on lips, face, mucosa.
Basal ganglia behind cheek.
Triggered by stess, lack of sleep, too much exposure to sun, cold weather and hormonal changes.
HSV-2
Found on the genitals
S/S: HA, fever, body aches, malaise, joint pain (flu like symptoms)
The first outbreak is usually the worst (2-3 weeks). Recur with additional outbreaks but less severe and shorter duration.
Triggered by other viral or bacterial infections, mestrual periods and stress.
The genital lesions are usually groups/clusters of painful/itching/burning blisters or ulcers that appear on the buttocks/anus/thighs/vulva/vagnia/penis/scrotum.
Prodromal sytmpoms (appear before lesions appear) are tingling/burning in the area where the lesions will develop.
Dog, cats and human bites
- All bites lead to infection, particularly human bites.
- Timely, copious, high pressure irrigation with normal saline may be useful to reduce infection rates.
- For animal bites, ask about rabies status.
- Wounds of the hands or lower extremity should be left open.
- Any wound older than 6 hours is generally left oen to heal by secondary intention.
- 3-7 days of oral prophylactic antibiotic coverage for both staphylococci and anaerobes (augmentin).
General approach to managing infections (PSSP)
P: Establish PRESENCE of infection
-Increased or decreased WBC, fever, infiltrated on chest x-ray, erythema, pus, secretions.
S: Estabish SEVERITY of infection.
-Age of pt, immune status, comorbidities.
S: Establish SITE of infection.
-Respiratory, skin, blood, IV-line, urine.
P: Establish likely PATHOGEN.
-Based on anatomical site and/or pt factors.
Gram positive organisms
- Staphylococcus
- Streptococcus
- Enterococcus
- C-diff
Any others assume gram negative
Streptococcus Pneumoniae
Most likely pathogen to cause (itis):
-Acute otitis media
-Sinusitis
-Bronchitis
-Meningitis
-CAP
Other likely pathogens:
2. Haemophilus influenzae
3. Moraxella catarrhalis
Empiric therapy for acute otitis media and sinusitis
-Amoxicillin
-Amoxicillin-clavulanate (augmentin) or
Cefuroxime or trimethoprim-sulfamethoxazole (TMP-SMZ, bactrim)
Endocarditis
Acute:
Causative organism: Staphylococcus aureus
Treat with vancomycin+ceftriazone
Subacute:
Causative organism: Viridans streptococci, enterococci
Treat with penicillin and gentamicin
Peritonitis due to ruptured viscus
Likely pathogen:
Coliforms or bacteroides fragilis
Treat with:
Metronidazole plus cephalosporin or
piperacillin/tazobactam
Intra-abdominal
Likely pathogen:
E-coli, klebsiella, bacteroides fragilis, enterococcus
Treat with:
Cefuroxime or ceftriaxone or ciprofloxacin or levofloxacin each in combo with metronidazole
Cellulitis
Likely pathogen:
Staphylococcus aureus, group A streptococcus
Treat with:
1st gen cephalosporin (cefazolin), vancomycin, clindamycin, linezolid, daptomycin
Sepsis
Can be any pathogen
Treat with:
Vancomycin plus 3rd or 4th generation cephalosporin or piperacillin/tazobactam or imipenem or meropenem
Antibiotic prophylaxis for surgery such as appendectomy
Likely pathogen: Staphylococci, streptococci, enteric gram negative rods
-Use cefazolin
If MRSA positive
-Use vancomycin
Likely pathogen is enteric gram negative rods, anaerobes
-Use cefoxitin or cefotetan or cefazolin PLUS metronidazole
Transplant rejection, what does it look like? What to do?
-Immediate failure of that organ and flu like symptoms.
-Get an immediate biopsy of transplanted organ.
All pts are immunosuppressed pre-transplant, so consider risk of infection.
Anti-rejection regimens
Involves triple therapy (three immunosuppressants from different classes):
-A corticosteroid (methylprednisone or prednisone) PLUS
-Antimetabolite (mycophenolate mofetil (cellcept)) and either a
-Calcineurin inhibitor (tacrolimus) OR a
-Mammalian target or rapamycin (mTOR) inhibitor (sirolimus)
Herpes Zoster (Shingles)
An acute vesicular eruption due to infection with varicella-zoster virus. May be life threatening in immunocompromised adults.
S/S:
-Pain along a dermatomal distribution, usually on the trunk or chest first.
-Grouped vesicle eruption or erythema and exudate along the dermatomal pathway.
-Regional lymphadenopathy may be present.
Management:
Antivirals
-Acyclovir, famciclovir, valacyclovir
-If suspected ocular involvement, immediate referal to ophthalmologist as it’s a medical emergency
-If pt has post herpetic neuralgia give gabapentin or pregabalin (lyrica)
-Shingrix (vaccine) is indicated for all dults >50. It’s a two dose regimen with 2nd dose given within 2-6 months. May cause arm soreness.
Keratoses and skin cancers
- Actinic keratoses
- Squamous cell carcinoma
- Seborrheic keratoses
- Basal cell carcinoma
- Melignant melanoma
Actinic Keratoses
- Small patches occurring on sun-exposed parts of the body
- Premalignant to SCC
- Aysmptomatic, small patches may be tender.
- Rough, flesh colored pink or hyperpigmented.
- Treat with liquid nitrogen
Squamous cell carcinoma
- Arise out of actinic keratoses
- Firm, irregular papule or nodule
- Develop over a few months
- Prolonged sun exposure areas in fair skin people
- Keratotic, scaly bleeding
Treat with biopsy and Mohs surgical excision
Seborrheic keratoses
- Benign, not painful lesions although they look the worst.
- Beige, brown or black plaques
- “Stuck on” appearance.
- 3-20mm in diameter
Treat: none or liquid nitrogen
Basal cell carcinoma
- The most common skin cancer
- Slow growing lesion
- Waxy, pearly, appearance
- Central depression or rolled edge
- May have telangiectatic vessels (spider veins running from the lesion)
Treat: shave/punch biopsy and surgical excision
Malignant melanoma
- Mortality rate highest of all skin cancer
- Median age is 40
- May metastasize to any organ
-Asymmetry
-Border irregularity
-Color variation
-Diameter >6mm
-Elevation
-Enlargement
Treat with biopsy and surgical excision
