Infectious Disease Flashcards
Gram stain results for strep?
G+, catalase -, cocci in chains
Clinical findings of strep throat
sudden onset fever/chills difficulty swallowing tender anterior cervical adenopathy red, swollen throat purulent exudate in pharynx
strep throat + rash =
Scarlet Fever
Clinical findings of Scarlet Fever
- strep throat sx’s
- Rash:
Blanches
Fine papules that feel like “sandpaper”
Starts on neck, face, chest
Circumoral pallor
Key Word: bright red swollen strawberry tongue
Erysipelas is skin infection caused by ________.
Group A strep
Clinical findings of Erysipelas
- Painful/itchy rash with raised borders, well demarcated, historically on face (currently common on legs)
- Fever
- H/o sore throat
Antibiotic of choice for streptococci infections
penicillin
honey crusted lesions
impetigo
epidemiology of impetigo
young children or demented person who has runny nose and can’t wipe; poor hygiene
Most common cause of cellulitis in U.S.
Strep A
Tx impetigo
topical Mupirocin (Bactroban) gentle washing of area several time per day
Clinical findings of cellulitis
Local pain/tenderness, erythema, and sharp distinct borders
Cellulits tx
abx (penicillin)
severe cases may need debridement
Deep subcutaneous infection that results in destruction of fascia and fat
necrotizing fasciitis
_______ can occur 2-3 weeks after strep pyogenes infection, commonly in children 6-15 yo.
Rheumatic Fever
How is Rheumatic Fever diagnosed?
Jones’ Criteria for acute RF; pt must have either 2 major or 1 major + 2 minor
Major criteria: carditis, erythema marginatum, subcutaneous nodules, Sydenham chorea, arthritis
Minor criteria: fever, polyarthralgias, reversible prolongation of PR interval, elevated CRP, h/o rheumatic fever
Rheumatic Fever TX
- aspirin for pain and fever
- penicillin if strep infection present
- corticosteroids for joint sx’s if aspirin not enough
Complications of rheumatic fever
Valvular defects (mostly mitral) CHF Rheumatic pneumonitis Arrhythmias (a-fib) Pericarditis with effusion
Most common presentation of Salmonella. One of the most common type of food poisoning (under-cooked chicken, eggs)
gastroenteritis
3 presentations of Salmonella
Gastroenteritis/enterocolitis
Bacteremia
Typhoid Fever
How does gastroenteritis caused by Shigella present?
8-48 hrs after ingestion
abd pain, F/C, N/V
bloody diarrhea
Tx of diarrhea from Shigella
fluid and electrolyte replacement
sx last 2-5 days
_______ bacteria attack the mucous of intestines and begins to replicate in Typhoid Fever.
Salmonella typhi
“Typhoid Mary”
some people can be asx carriers and pass bacteria in their stool for years
Clinical presentation of Typhoid Fever
progressive fever reaching over 103 abd pain/distention/tenderness delirium rose spots = small pink spots on belly and chest that blanch bradycardia splenomegaly
Tx of Typhoid Fever
Fluid and lyte replacement
Ampicillin, Chloramphenicol, and Bactrim
Tx of carriers typically ineffective
Complications of Typhoid Fever
30% of untreated cases will have some complication
intestinal hemorrhage, intestinal perforation, nephritis, myocarditis, pneumonia, peritonitis
Viral signs of pharyngitis
rhinorrhea, cough, hoarseness
Bacterial signs of pharyngitis
fever, tonsillopharyngeal erythema, exudates, beefy red swollen uvula, tender anterior cervical lymphadenopathy, petechiae on palate
How is strep throat dx’d?
rapid antigen test
throat culture
Strep throat tx
abx only for confirmed cases
Penicillin x 10 days is 1st line
Amoxicillin x 10 days - tastes better and easier to give kids
8 yo comes to clinic with fever, weird involuntary movements, and joint pain
Rheumatic fever
Why no honey during first year of life?
infant botulism
Why does botulism cause neurological symptoms?
Clostridium botulinum makes toxins that inhibit release of ACh at NMJ
3 types of botulism
Infant botulism - honey
Food borne botulism - canned food
Wound botulism - soil
Neuro symptoms in botulism
symmetric muscle weakness or paralysis, diplopia, dilated pupils, ptosis, trouble breathing
Botulism tx
- Antitoxin available from CDC
- Breathing assistance (mechanical ventilator)
- Rehab for paralysis
Most common sexually transmitted disease
Chlamydia
Labs and dx studies for Chlamydia
G stain negative
Swab for culture and PCR (cervix for female, urethra for male)
Chlamydia tx
1 g Azithromycin (or doxy)
Prevention: abstinence, barrier protection, few partners
Screening: women under 25, pregnant women
Toxin produced by vibrio cholerae results in hyper secretion of what?
water and chloride
Cholera on gram stain
G-, comma shaped with single flagellum
Hallmark of cholera
“rice water” diarrhea
3-5 gallons per day!!!!
Epidemiology of cholera
people in crowded places with poor sanitation
Treatment of cholera
FLUIDS!!! (IV if severe)
Electrolyte replacement
Self-limiting but abx speed up recovery (doxycycline, azithromycin)
Characteristics of diphtheria on microscope
G+, facultative anaerobic
Hallmark sign of diptheria infection
grey pseudomembrane covering pharynx/tonsils
Treatment of diptheria
antitoxin abx: penicillin, erythromycin Laryngoscopy to remove pseudomembrane Intubation prn Isolation and tx of contacts, report to CDC
Where in the body does Neisseria gonorrhoeae attack?
mucous membrane of reproductive tract (cervix, uterus, fallopian tubes, urethra)
may also affect mouth, throat, eyes, anus
Signs/Sx of gonorrhea
- yellow, creamy purulent discharge from penis or vagina (maybe blood-tinged)
- painful/freq urination
- painful intercoarse
eye infection, septic arthritis
Dx of gonorrhea
PCR culture Gram stain (G-, diplococci) UA pelvic U/S
Tx of gonorrhea
1 g IM Cefriaxone
How to get infected with Salmonellosis?
ingest contaminated food or water
Stain characteristics of Salmonellosis
G- rod
Why does patient with Salmonellosis come to clinic?
Enteric fever (typhoid) - high fever abd pain/distention - constipation/diarrhea - elevated HR - pink papular rash on trunk
Gastroenteritis
- crampy abd pain
- fever
- N/V
- bloody diarrhea
how to treat Salmonella
Enteric fever
- Fluoroquinolones (Cipro)
- 3rd generation cephalosporin (ceftriaxone)
Gastritis
- Self limiting
- Bactrim or Cipro may be used
Stain characteristics of Shigellosis
G-, facultative anaerobe, rod
Shigella mode of transmission
fecal-oral route
Epidemiology of Shigella
day care centers, nursing homes, refugee camps; places where conditions are crowded and sanitation is poor
Signs/sx of Shigella
abd discomfort/cramps
diarrhea with blood, pus, or mucus
fever
rectal tenesmus
Shigella treatment
Fluids and electrolytes!
Meds: Bactrim, Cipro, Ampicillin
Organism characteristics of Tetanus
G+, obligate anaerobe, rod
Effects of Tetanus neurotoxins
uncontrollable muscle spasm
signs/sx of tetanus infection
pain and spasticity at site trismus (lockjaw) risus sardonicus (facial spasms) difficulty swallowing stiffness of neck and abd spasm of respiratory muscles
Tetanus treatment
Vaccination with a booster every 10 years
Mild cases: tetanus immunoglobulin, Metronidazole, diazepam
Tracheostomy and mechanical ventilation prn
Mg2+ to prevent muscle spasm
Where can Candidiasis infect in body?
skin and/or mucous membranes of mouth, intestines, or vagina
Sx’s of thrush
- sore/painful/burning mouth
- dysphagia
- white patches on oral mucosa (cheek, throat, tongue, gums)
Sx’s of vulvovaginal candidiasis
- erythematous vagina and labia
- thick, curd-like discharge (cottage cheese)
- burning urination
How is Candidiasis dx’d?
- KOH prep: pseudohyphae and budding yeasts
- Gram stain
Candidiasis tx?
Topical, oral azoles (IV Amphotericin B if severe)
Good hygiene
Cryptococcosis usually affects who?
immunocompromised
How is Cryptococcus spread?
inhalation of airborne fungi
Cryptococcus on microscope
encapsulated yeast
Different types of Cryptococcus
Wound or cutaneous
Pulmonary
Meningitis
signs/sx’s of Cryptococcus
Pulm: productive cough, pleuritic chest pain
Meningitis: HA, confusion, lethargic, N/V, fever, stiff neck, vision changes, seizures, etc.
How is Cryptococcus dx’d?
- Cutaneous lesions: biopsy and cultures
- Blood: culture, antigen testing
- CSF fluid: India ink smear, culture, antigen testing
Cryptococcus treatment
Antifungals: IV amphotericin B
How is Histoplasmosis spread?
Inhaled spores often found in bird and bat droppings
signs/sx’s of Histoplasmosis infection
Chest pain Chills Cough Fever Joint pain and stiffness Muscle aches and stiffness Extreme weakness
How is Histoplasmosis diagnosed?
- Medical and travel history
- Labs: blood and urine antigen detection (systemic disease), CBC (mild anemia, pancytopenia), Alk phos (elevated), Sputum culture, Complement-fixing antibodies, Immunoprecipitating antibodies
- Chest x ray shows MILIARY INFILTRATES
- CT Scan of lungs
Tx of Histoplasmosis
Symptoms may go away w/o treatment
Meds:
Antifungals - Itraconazole for several months is 1st line
Amphotericin B
Corticosteroids - for acute respiratory distress sx’s
Most common opportunistic infection in HIV/AIDS
Pneumocystis jirovecii pneumonia (PJP)
Diagnostic studies for Pneumocystis jirovecii pneumonia?
CXR: diffuse interstitial infiltrates Hypoxia Sputum induction or bronchoscopy for sputum sample Bronchoalveolar lavage Biopsy to confirm dx
Treatment of Pneumocystis jirovecii pneumonia?
Bactrim (TMP-SMX) is given as empiric treatment to all immunocompromised patients who present with a cough
Steroids also used
What component of Bactrim are patients often allergic to?
sulfa
How would you treat a vaginal candida infection?
Fluconazole one time dose of 150 mg
