[MS] ID Flashcards
What are the reasons for Staphylococcus aureus to have pathogenicity?
Enterotoxin, Endotoxin, Coagulase, and PV leukocidin
What is the gene that confers methicillin-resistance?
mecA
What are the common findings of Bullous Impetigo?
Flaccid, coalescent pustules with bullae on previously normal skin
What does a positive D-test indicate when treating a skin infection?
Do NOT use Clindamycin to treat the S. aureus infection
What patients are at risk for Staphylococcus aureus infections of the CNS?
Severe congenital cyanotic heart disease due to septic emboli
Patients post-neurosurgery
When do patients with toxic shock syndrome show desquamation of the hands/feet?
1 to 2 weeks after onset
What are the criteria to diagnose toxic shock syndrome?
Temperature greater than 38.9 Centigrade
Systolic blood pressure less than 90 (or 5th percentile)
Rash with subsequent desquamation
Involvement of more than 3 organ systems
Negative serology for RMSF, measles, and leptospirosis
Which type of toxic shock syndrome typically has positive blood cultures?
Streptococcal
What is the treatment for streptococcus-induced toxic shock syndrome?
Penicillin + Clindamycin with or without IVIG
What is the cause of Staphylococcal Scalded Skin Syndrome?
Exfoliative toxins A and B
What are the common presenting symptoms of Staphylococcal Scalded Skin Syndrome?
Fever with Nikolsky sign (a rash that causes removal of the superficial epidermis with minimal friction)
What is the most common cause of food poisoning?
Staphylococcus aureus
What is the typical course for Staphylococcal food poisoning?
Incubation period of less than 4 to 6 hours
Duration of 1 to 2 days
What antibiotics are most strains of Staphylococcus epidermidis resistant to?
Methicillin
What type of infection dose Staphylococcus saprophyticus cause?
UTIs in adolescent females
What is the most common cause of late-onset sepsis in preterm infants?
Coagulase-negative Staphylococcus
What serotype of pneumococcus currently causes the most amount of invasive disease?
19A
What are the symptoms of post-splenectomy pneumococcal sepsis?
Flu-like symptoms, purpura, and DIC
What are the symptoms associated with Streptococcus pyogenes pharyngitis?
Temperature greater than 100 degrees Fahrenheit
Tender cervical lymphadenopathy
Exudative pharyngitis
How many days should antibiotics be started by in order to reduce the risk of Acute Rheumatic Fever?
Within 9 days
What is the common presentation of Scarlet Fever?
Fine, diffuse, red rash with acute streptococcal pharyngitis
What is the difference between Erysipelas and Impetigo?
Erysipelas is tender and involves deeper layers of the skin
What is the treatment of choice for an Erysipelas infection?
Surgical debridement
Penicillin
Clindamycin
What is the most common reason for Penicillin failure when treating Streptococcus pyogenes infections?
Non-adherence to the regimen
What are the key defining differences in post-Streptococcal glomerulonephritis and IgA nephropathy?
Post-Strep GN occurs roughly 21 days post-illness
IgA Nephropathy occurs within 5 days post-illness
What bugs are treated by Ampicillin in neonatal infections?
Group B Streptococcus
Listeria
Enterococcus
What are the associated factors seen with early-onset GBS infection in neonates?
Within 7 days of birth History of obstetric complications History of prematurity Septecemia is the most common presentation Fatality rates between 5% and 15%
What is the most common presentation of group C Streptococcus infection?
Outbreaks of pharyngitis in college students
What are the classic symptoms of a diphtheria infection?
Upper respiratory tract infection Gray-white pharyngeal membrane Hoarseness and sore thorat Low-grade fever Bull-neck sign
What is the treatment for diphtheria?
Diphtheria equine antitoxin
Erythromycin
What are the symptoms of an Arcanobacterium hemolyticum infection?
Fever, pharyngitis, and a desquamative rash but no petechial palatal hemorrhages or strawberry tongue
What are the three most common presentations of Anthrax?
Cutaneous
Gastrointestinal
Pulmonic (“wool-sorters” disease)
What are the symptoms of cutaneous Anthrax?
Painless papule to painless vesicle to painless ulcer to painless black eschar with painless induration
What is the prophylaxis of choice for Anthrax?
Ciprofloxacin or Doxycycline
What is the typical facial feature of a tetanus infection?
Risus Sardonicus – raised eyebrows, narrowed palpebral fissures, downward angles of the mouth, and pressure of the upper lips into the teeth
What is the treatment of tetanus?
Human Tetanus Immune Globulin
Metronidazole
What is the next step for the following patient:
Marla has a clean injury and a minor wound from a staple. Her tetanus status is unknown, but the mother feels that it is less than three vaccines total.
Give Tdap if 7 years or older
Give DTaP if less than 7 years
Do not do anything if more than 3 vaccines have been given with the most recent within 10 years
What is the next step for the following patient:
Marla steps on a nail covered in cow feces. Her dog attempts to lick the wound clean. Her immunizations are known.
If less than 3 immunizations, then give Tdap/DTaP and Human TIG
If 3 or more immunizations but greater than 5 years ago, give Tdap/DTaP
If more than 3 immunizations and 5 or less years ago, then do nothing
Who should receive prophylaxis when exposed to a person with Neiseria meningitidis?
Household contacts
Daycare contacts
Close intimate contacts
Passengers seated directly next to the index case on a flight lasting greater than 8 hours
What are the various stages of eye discharge in the neonatal period typically associated with?
0 to 48 hours – chemical irritation
2 to 7 days – Gonorrhea
7 to 14 days – Chlamydia
What bacteria should be considered after a nail puncture wound through a tennis shoe?
Pseudomonas aeruginosa
What is the classic presentation of infantile shigella infections?
An infant that presents with a seizure and has a large bloody stool during the lumbar puncture
What is a known complication of Shigella infections?
Seizures
When may kids with Shigella return to daycare?
When the diarrhea has stopped for more than 24 hours and the stool cultures are negative
What is the most common reservoir for Yersinia enterolitica?
Pigs
What are the most common locations for patients to develop Legionairre’s disease symptoms?
GI tract - diarrhea
Brain - CNS disease
Kidney - AKI
What are the major types of Brucella infections?
Culture negative endocarditis
Thyroiditis
Sacroiliitis
What is the typical reasoning for recurrence of Brucella infections?
Premature discontinuation or monotherapy
Resistance is not a factor
What are the morphologic and geographic characteristics of Tularemia?
Small, gram-negative pleomorphic bacillus
Found mostly in Arkansas, Missouri, and Oklahoma
What are the two diseases that are caused by Bartonella henselae?
Cat Scratch Disease (immunocompotent) Bacillary Angiomatosis (immunocompromised)
What is the presentation and cause of the Oculoglandular Syndrome of Parinaud’s?
Presents with conjunctivitis with ipsilateral preauricular lymphadenitis. Caused by Bartonella henselae.
What is the typical treatment for Cat Scratch disease?
Symptomatic with or without Azithromycin
What infection most commonly causes Guillan-Barre syndrome?
Campylobacter
What are the typical vectors for Campylobacter infections?
Puppies and kittens
What is the treatment of choice for Campylobacter infections?
Azithromycin or Erythromycin
What is a common complication of Citrobacter infections?
Brain abscess
What is the cause of Rocky Mountain Spotted Fever?
Rickettsia rickettsii (gram-negative coccobacillus)
What is the mnemonic for Q fever?
Cattle
Cats
Conception
Coxiella (Q fever)
What other organisms can be seen in coinfections with Erlichia?
Babesia microti
Borriela burgdorferi
What is the treatment for the most commonly tested gram-variable organism?
Metronidazole to treat Gardnerella vaginalis
What is the primary treatment for lymphadenitis from MAC in immunocompetent hosts?
Node excision
What is the 4-drug regimen for treatment of tuberculosis?
Rifampin + Isonazid + Pyrazinamide + Ethambutol
What is the most common side effect of Ethambutol?
Decrease in visual acuity with early decreased color perception
What is the most common means of transmission for Leptospirosis?
Dog or rat urine
What is the classic description of a Candidal diaper rash?
Bright red, fiery rash with sharp borders and pinpoint “satellite” papules/pustules
What are the two treatment options for a Candidal urinary tract infection?
Fluconazole
Removal of an indwelling Foley catheter
What is the best test to perform to evaluate for sequelae from Candidal sepsis?
CT scan to look for hypodense abscesses
What is the treatment for Candidal sepsis?
Removal of the catheter
Amphotericin B (neonates) or Fluconazole/Micafungin (immunocompotent)
Resection of all suppurative veins
What are the findings associated with Cryptococcus infections?
Contact with pidgeon droppings
Pulmonary cavitary lesions
Peripheral “cannonball” skin lesions
What is the most severe form of Cryptococcal infection and how is it treated?
Cryptococcal meningitis
Treated with Amphotericin B and 5-Flucytosine
Can treat less ill patients with Fluconazole
What is the most common complaint in immuncompromised patients with esophageal Candidaisis?
Pain with swallowing
What are the most important data regarding Coccidiodes infections?
Located in the US Southwest (“Valley Fever”)
Disease presents weeks after inhalation
Presents as a self-limited flu-like illness
What is the most important data regarding Histoplasma infections?
Located in the Mississippi and Ohio River valleys
Presents as an asymptomatic interstitial pneumonia, palatal ulcers, and splenomegaly
Treat symptomatically or with Itraconazole and Amphotericin B
What is the most important data regarding Blastomyces infections?
Located in Arkansas and Wisconsin hunters/loggers (“Beaver Dam” exposure)
Presents similar to Histoplasma, but with skin crusted lesions and bony lesions
Treat with Itraconazole and Amphotericin B
What is the hallmark sign of an invasive Aspergillus infection?
Angioinvasion with thrombosis and dissemination, likely secondary to the fumigatus or flavus strains
What is the classical morphology of Aspergillus seen underneath the microscope?
Branched and septate hyphae on KOH preparation
What is the treatment of choice for invasive Aspergillosis?
Voriconazole (Amphotericin in neonates)
What is the organism that causes tinea versicolor and what is the more severe disease it causes?
Caused by Malassezia furfur. It can present as a fever and bilateral pulmonary infiltrates in NICU babies receiving TPN
What types of people typically contract Sporotrichosis and what is the treatment?
Rose gardeners contract it. Treat with Itraconazole.
What are the features seen with severe congenital toxoplasmosis?
Microcephaly, hydrocephalus, hepatosplenomegaly, thrombocytopenic purpura, chorioretinitis, and widespread intracranial calcifications
What is the postnatal treatment for congenital toxoplasmosis?
Pyrimethamine, sulfadiazine, and leucovorin for 12 months
What is the treatment for cryptosporidium-induced diarrhea?
Nitazoxanide
Where are cryptosporidium outbreaks most likely to arise from?
Swimming pools
What are the differences between Cryptospora and Isospora?
Isospora is seen in HIV patients, and is large and oval
Cryptospora is small and round
Treat Isospora with TMP-SMX
What is the usual source of Cryptospora infections?
Imported food from developing countries
What is the most diagnostic finding consistent with falciparium Malaria?
“Banana” gametocytes on peripheral blood smear
What type of malaria is most commonly associated with nephrotic syndrome?
P. malariae
What is the treatment for malaria?
Chloraquine with Primaquine for P. vivax and P. ovale to eradicate hypnozoites
What are the main reasons for malaria in the US?
Not taking Chloraquine prophylaxis
Stopping the prophylaxis too soon
What is the prophylaxis regimen for malaria?
1 to 2 weeks before leaving
4 to 6 weeks after returning
What are the defining features of Babesiosis?
Febrile
Hemolytic anemia
“Maltese cross” in the blood cells
What is the most common disease-causing parasite in the US?
Giardia lamblia
What is a common infectious cause of pruritis ani?
Pinworms (Enterobius vermicularis)
What is the most common complication from Varicella infections?
Secondary bacterial infections
How long are children potentially contagious after being exposed to Varicella zoster?
Day 10 to 21 post-exposure
What is the treatment of choice for symptomatic congenital CMV infection?
IV Ganciclovir
What is the most common side effect of Foscarnet?
Reversible renal failure
How long should patients with EBV-induced splenomegaly avoid contact sports?
1 to 3 months
What are the symptoms associated with Roseola (“sixth disease”)?
Fever for 3 to 5 days followed by an abrupt cessation of fever and development of a maculo-to-maculopapular rash
What are the classic findings associated with Rubella (“German Measles”)?
Postauricular and occipital lymphadenopathy
Rash spreading from face to trunk
Low-grade fever
What two congenital infections are associated with a “blueberry muffin” baby?
Rubella
CMV
What are the symptoms associated with Rubeola (“Measles”)?
Cough
Coryza
Conjunctivitis (with photophobia)
Koplik spots on the buccal mucosa (before the rash)
Rash starting at the hairline and spreading downward
What is the preferred intervention for cases of measles outbreaks?
Measles vaccine given within 72 hours of exposure to those as young as 6 to 11 months. If otherwise at risk, give immunoglobulin.
What type of influenza vaccine can children with mild egg allergies be given?
Trivalent Inactivated Vaccine
What is the next step if a non-Hawaiian child wakes up with a bat in their room?
Prophylaxis against raibes
What are the symptoms of rabies?
Restlessness
Excitement
Severe spams of the larynx when looking at water
What is the rash associated with erythema infectiosum?
Slapped cheeks that turns lattice-like when exposed to sun or hot water
What are the symptoms of Dengue fever?
Severe myalgias with high fevers
Retro-orbital pain leading to a rash over the body and ending with a recurrence of the fever
What strains of HPV cause cervical cancer?
16, 18, 31
What are the symptoms of subacute sclerosing panencephalitis?
Dementia, myoclonus, and new-onset seizures from a mealses infection at less than 2 years of age
What therapies have successfully reduced the mother-to-child transmission of HIV?
ART during pregnancy
Zidovudine during delivery
6 weeks of twice daily Zidovudine in newborns
No breastfeeding
What is the means of diagnosis of HIV in children older than 18 months?
EIA Test
Westen blot (confirmation)
HIV DNA PCR (earliest sign)
What are the key side effects of Zidovudine?
Bone marrow suppression
Myopathy
What is the most common side effect of Didanosine?
Pancreatitis
What is the most concerning side effect of Abacavir?
Fatal hypersensitivity reaction
What is the utility of testing HIV viral load?
Good, long-term predictor of outcome
Which combinations of antiretrovirals are INCORRECT when exposed to HIV?
Zidovudine + Didanosine combined
Zalcitabine as an option
Single-drug therapy
Which situations do NOT require postexposure prophylaxis to HIV?
Intact skin exposure
Urine source exposure
Which vaccines should HIV-exposed children be given?
All vaccines, but only give Live vaccines if the CD4+ count is greater than 15%
What causes the neoplasia of blood vessels in HIV patients (Kaposi sarcoma)?
HHV-8
What are the symptoms of acute retroviral syndrome?
Mononucleosis-like syndrome that occurs 2 to 4 weeks after exposure and lasts 1 to 2 weeks
What are the Duke criteria for endocarditis?
Major - Positive Blood Culture or Abnormal Echo
Minor - Predisposing Condition, Fever, Vascular Phenomenon, Immunologic Phenomenon, Blood Culture Positive
Diagnosis - 2 Major, 1 Major + 3 Minor, or 5 Minor
What organism should be considered to cause meningitis in patients who swim in brackish water?
Naegleria fowleri
What nerve palsy classically manifests with Tuberculosis meningitis?
CN XI
What is the most common cause of encephalitis in the United States?
Arbovirus
What are the potential antimicrobial therapies for entertoxigenic E. coli induced diarrhea?
Azithromycin
Quinolone
TMP-SMX
What is the common presentation of Mycobacterium marinum?
Non-healing ulcer in patients who work around fish tanks
When may children with Salmonella diarrhea return to daycare?
When the diarrhea resolves and after 3 negative stool cultures
