Infectious Disease Flashcards
What test should all patients with newly diagnosed HIV recieve?
Latent TB testing!
Either with the Tuberculin skin test (PPD) or with Interferon Gamma Release assay
What PPD induration is considred positive in HIV patients?
greater than 5mm
Active Tb must be ruled out with a CXR.
Patients with no manifestations of active Tb are treated for latent TB with 9 Months of INH!
Pyridoxine is added to prevent INH induced peripheral neuro
If an HIV patient with CD4 below 200 has a negative PPD test what should you do?
this is considered a false negative.. they dont even have enough of an immune response for the test to become positive.
On tese patients you must start HIV treatment.. and then RETEST for Tb once CD4 is above 200.
High urinary pH (above 8) raises concern for which organism.. and puts you at increased risk of which complication?
P. Mirabilis –> produces urease.. which then results in ammonium production and thus ALKALINE urine!
High urine pH reduces the solubility of phosphate –> Struvite sone formation (magnesium-ammonium-phosphate stones).
Coffin lid shaped
Toxoplasmosis symptoms
dormant in most individuals.. only becomes active in SEVERE immunoccompromise.
HIV wih CD4 below 100 is when you see it reactivate.
Causes encephalitis:
- headaches
- focal neuro defecits (twitching in arms)
- Fever / confusion
Diagnosis:
1. HIV with cd4 below 100
Positive t. gondii IgG!
Multiple RING enhancing Lesions on MRI.
Treatment :
- Sulfadiazine + Pyrimethamine (plus leucovorin)
Prophylaxis with TMP SMX (as soon as CD4 drops below 100)
MAC - mycobacterium avium complex symptoms and treatment
causs PUlmonary and GI symptoms (not CNS)
Treatment - clarithromycin
Prevention - Azithromycin
Bacterial Meningitis presentation
very ACUTE! (less than 1 day) of fever, severe headache, and AMS.
Pertussis
Symptoms:
1. Paroxysmal cough, Posttussive EMESIS, Subconjunctival HEMORRHAGES (due to increased intraorbital pressure)
LYMPHOCYTOSIS.
DIagnosis is clinical when above symptoms are present.. PCR of the nasopharynx is helpful for COnfirming diagnosis.
MACROLIDES - GOLD STANDARD for treatment.
Prevention - Acellular pertussis vaccine.
5 doses of DTaP are given during infancy and early childhood (final dose at 4-6 years of age). Tdap booster is given during adolescence (11-18 years) –> those who have not taken it have waning immunity.
What is Heterophile Antibody Testing used to diagnose?
Infectious Mono Due to EBV!
Palpable axillary / cervical lymph nodes vs Supraclavicular lymphn nodes.
Cervical Lymph nodes that are palpable but small 1cm or less and mobile and soft are normal.
Hard / immobile are large (above 2cm) lymph nodes should be looked deeper into.
Palpable Supraclavicular Lymph Nodes are considered Pathologic until proven otherwise!
Osteomyelitis in children
caused by HEMATOGENOUS spread of bacteria.
Staph Aureus!
Definitive diagnosis = biopsy
Treatment = antistaph abx (vanc)
Osteomyelitis after a puncture wound or in IVDU is most likely which organism?
P. Aeruginosa\
However the most common organim causing infective endo in IVDU is STAPH AUREUS!
HACEK organisms leading to endocarditis indicate what?
Dental work.. these organisms are found in the gingival or dental mucosa
S. BOvis or Strep Gallolyticus causing Infective Endocarditis indicates what?
Ulcerative lesins in the colon due to either Colonic neoplasia or Inflammatory Bowel Disease.
Enterococci / Enterococcus faecalis cause up to 30% of all Infective Endo and are a sign of what?
Sign of Noscomial UTIs resulting in infective endo.
How do you diagonse PCP?
Cannot culture it. MUST be examined using Special Microsocpy stains.
Best way to view sputum (least invasive) is inducing sputum (hacking up a loogy)… if that doesnt work then do a BRONCHOALVEOLAR LAVAGE!
PCP is very commonly found in patients after a TRANSPLANT!
Acute UNILATERAL lymphadenopathy in children is caused by what?
MOSt OFTEN
S. AUreus or S. Pyogenes.
Will see ENLARGED, markedly TENDER, warm and erythematous Lymph nodes.
If untreated can become an abscess.
CLINCIAL diagnosis.
EMpiric therapy - CLINDAMYCIN which covers both MRSA and S. Pyogenes.
What is the most common cause of acute BILATERAL lymphadenopathy in children?
Adenovirus!
Will also see pharyngitis, fever and conjunctivitis here.
Which Bacteria is associated with Cat bites and what is the treatment?
Pasturella Multocida!
treatment:
- Copious irrigatin and cleaning
- Prophylactic AMOXICILLIN / CLAVULANATE
- Tetanus booster as indicated
- Avoid Closure
Tetanus vaccine is indicated for those who have incomplete vaccinations as children or those whose last vaccine was OVER 5 years ago.
Ehrlichiosis findings
transmitted by dear tick.
Flu like illness:
- ACUTE febrile illness with malaise and Alterted MENTAL STAUS.
- NOT associated with rash (described as RMSF without the spots).
- CONFUSION, change in mental status, CLONUS. NECK STIFFNESS
Labs = DECREASED WBCs, and DECREASED PLATELETS.
Elevated LIVER ENZYMES and LACTATE DEHYDROGENASE
CLINICAL DIAGNOSIS
DOXYCYCLINE is treatment of choice.
Distinguishing from LYME?
Lyme will have a rash in 80% of patients. The absence of a rash and the presence of a high fever and hematologic and liver enzyme abnormalities = Ehrlichiosis.
Distinguisihgn from RMSF?
RMSF will have a maculopapular rash (involving palms and soles) in 90% of patients.
Unnoticed bite leading to rabies.. what animal caused it?
Bats!
The majority of rabies transmission in the U.S comes form Bat bites!.
Other high risk reservoirs = racoons, foxes and skunks.. but you will def notice these bites.
For rabies bites must do POSTEXPOSURE PROPHYLAXIS:
Rabies IMMUNE GLOBULIN and Rabies VACCINE immediately after exposure to high risk wild animal.
Rubella (german Measles) presentation
Prodrome of Mild fever, lymphadenopathy and mailaise.
RASH = MACULOPAPULAR erupts on the face and SPREADS CAUDALLY within 24 hours, SPARES palms and soles!!!
Patients can have POLYARTHRALGIA or ARTHRITIS.
Most symptoms resolve in a few days.. but arthritis can las up to a month.
Vaccination is done with the LIVE ATTENUATED VACCINE!
Congenital manifestations:
- Sensorineural Hearing loss
- Cataracts
- PDA
Patient with fever and cervical lymphadenopathy gets antibiotics and then develops a Maculopapular rash.. what happened?
this patient has mono.
giving mono patients and Antibiotic –> maculopapular rash!
Rash of Secondary syphilis vs Rubella
Secondary Syphilis:
Maculopapular rash that involves the ENTIRE TRUNK and Extremities –> INCLUDES the PALMS and SOLES
Rubella –> Palms and soles are spared!
Chicken pox rash
Fever and malaise followed by rash.
VESICULAR (rubella is maculopapular).
Appears in crops and crusts after several days.
Scarlet Fever cause and Presentation
Caused by GROUP A Strep (S. Pyogenes)
Strep Pharyngitis - Tonsilar erythema and exudates.
STRAWBERRY Tongue, Tonsillar EXUDATES, PALATAL PETECHIAE.
The ERYTHROGENIC EXOTONXINS, released by S. Pyognes cause the rash!
Rash: Sprreads across the TRUNK, GROIN!!, and Axillae.
SANDPAPER texture.
DESQUAMATIVE Rash –> Peeling of Hands and Feet.
CIRCUMORAL PALLOR (pale mouth with super red cheeks)
Treatment = PENICILLIN (eg. amoxicillin)
DIagnoiss is confirmed by Rapid Strep antigent TEST or Throat culture.
Kawasaki Disease Diagnosis
Requires teh following to make diagnosis.
- More than 4 days of fever and 4 or more of the following clinical criteria:
- 1.5cm or larger CERVICAL lymph nodes
- Polymorphous Rash
- Edema of the HANDS / FEET
- CONJUNCTIVITIS
- MUcosal changes (STRAWBERRY tongue, Dry/ Cracked lips)
Roseola presentation
High fever followed by a MORBILLLIFORM RASH which comes AFTER the patient has gotten better!!!
FOr patients exposed to B. Pertussis who should get prophylaxis?
Pertussis is HIGHLY contagious - spread by respiratory droplets.
the 1st line treatment is a MACROLIDE antibiotic.
ALL CLOSE CONTACTS should recieve PROPHYLAXIS. MAcrolides are also the PREFERRED PROPHYLAXIS antibiotis.
Contacts who are less than 1 month old should get AZITHROMYCIN for 5 days.
Contacts older than 1 month should get one of the following macrolide treatments:
1. Azithromycin for 5 days or 2. Clarithromycin for 7 days or 3. Erythromycin for 14 days.
Patients who are infected with pertussis and are less than 3 months old should be hospitalized because of the risk of APNEA.
Patients should be isolated from others.. but dont need to necessiarily hospitalize for isolatin.. just keep them out of daycare / school.
Mycoplasma pneumo vs Miliary TB presentation on CXR.. how to differentiate.
Both will have a reticulonodular pattern on CXR.. which looks much worse than the patient feels.
The way to tell the difference is by clinical symptoms in the stem:
Tb will cause symptoms for a long time until treated.
Mycoplama is limited to 2-3 weeks of symptoms then it resolves.
Histoplasma Capsulatum cause, findings and treatment
Endemic in Central and Midwestern U.S.
FOund in Soil, BIRD or BAT DROPPINGs.
In immunocopentent = asymptomatic
HIV / Cancer / Immunosuppressed –> DISSEMINATED HISTOplasmosis.
Disseminated histo –> spreads from LUNGS –> Lymph Nodes –> SYSTEMIC circulation –> multiorgan infection.
Reticuloendotheilial manifestations (Lymphadenopathy, hepatosplenomegally)
PANCYTOPENIA (due to bone marrow infiltration)
ELEVATED AST and LDH.
Diffuse interstitial or RETICULONODULAR INFILTRATES on CXR.
Diagnosis is confirmed with SERUM or URINE HISTOPLASMA ANTIGEN IMMUNOASSAY (95% sensitive)
Treatment: Amphotericin B for 1-2 weeks and then switched to Itraconazole for 1 year of maintenance therapy.
Measels (RUbeola)
Cough, Coryza, Conjunctiviits, Fever, Koplik Spots
Koplik Spots = Small white lesions, found on the BUCCAL mucosa opposite the molars.. do not appear in all patients.. but if found are PATHOGNOMONIC of measels and last severl days.
After 2-4 days of illness an ERYTHEMATOUS, BLANCHING, MACULOPAPULAR EXANTHEM characteristically develops on the FACE and SPreads ina CEPHALOCAUDAL and CENTRIFUGAL way to the rest of the body. Rash COALESCES (blends together) and may become NONBLANCHING with Dark, REDDISH brown color.
SPARES the PALMS AND SOLES!!
How to differentiate from Rubella?
Rubella has same Pattern.. but it does NOT DARKEN. Measels does. Also, Measels has KOPLIK spots and a more SEVERE Fever and LONGER duration.
In Rubella the child apperas relatively well.
Distinguishing VIral vs Candidal Esophagitis
Viral - Predominant symptoms = ODYNOPHAGIA (painful swallowing) and NO DYSPHAGIA!
NO ORAL THRUSH
Candidal - Predominant symptom is DYSPHAGIA (difficulty swallowing)
very MODERATE odynophagia (painful swallowing)
MOST have ORAL THURSH
Treatment - FLUCONAZOLE
HSV vs CMV Esophagitis
HSV - ROUND / OVOID Ulcers
CMV - DEEP, LINEAR ulcers
HIB treatment?
IV CEFtriaxone + VANCOMYCIN
Recommended vaccines for Chronic LIver disease patients
- Tdap / Td - Tdap once as substitute for Td Booster, then Td every 10 years.
- Influenza - Annually
- Pneumococcal Vaccine - PPSV23 once, Then Revaccination with sequential PCV13 and PPSV23 at age 65
- HEP A - 2 doses 6 months apart with initial negative serologies
- HEP B - 3 doses at 0 months, 1 month and atleast 4 months with initial negative serologies.
CMV vs Cryptosporidium Diarrhea in AIDS
CMV - Small volume and BLOODY (most of the time) Diarrhea in aids pts.
CRYPTO = LARGE VOLUME WATERY diarrhea
Hydatid Cyst Presentation on imaging
Caused by Echinococcus Granulosus - spread by dogs to humans.
UNILOCULAR cystic lesion that can occur in ANY organ (liver, lung, brain, muscle etc).
THICK WALLED, well defined cyst with EGGSHELL CALCIFICATIONS. May have “DAughter cysts inside).
Treatment = Surgical Resection while also giving ALBENDAZOLE.
Aspiration can be perfomred but may result in ANAPHYLAXIS if cyst content spills.
Cystericosis
pig.
Presents in Either Brain or Muscle.. not in liver or other organs
Treatment of Confirmed CHlamydia
vs
Treatment of confimred Gonorrhea
Confirmed CHlamydia = Azithromycin
Confirmed Gonorrhea = Azithro + Ceftriaxone
E. Histolytica presentation and diagnosis
Abdominal pain, fever, leukocytois and a LIVER ABSCEss on imaging.
Common in areas of POOR SANITATION.
Most infected patients are ASYMPTOMATIC,, but those with symtpoms often develop DYSENTRY.
Extraintestinal manifestations are LIMITED TO THE LIVER.. where the organism develops an ABSCESS.
Imaging shows a SOLITARY LESION.. generally found in the right lobe of the liver.
SEROLOGIC TESTING for E. Histolytica antiboides CONFIRMS DIAGNOSIS.
TREATMENT = METRO
DO NOT DRAIN –> can rupture
TOXIC shock syndrome
TSS-1 –> S. AUreus
fever, RASH and HYPOTENSION!!
Rash - Diffuse erythematous rash throughout the body, including PALMS and SOLES.
Newborns of mothers with HBV should recieve what treatment?
Passive Immunization with HEP B immune globulin
and
ACTIVE immunication with HBV Vaccine
BOTh MUST be given WITHIN 12 hours of birth.
in which patients is Rhino-orbital-cerebral Mucormycosis
seen in diabetics most often
Acute and aggressive - causes PURULENT nasal discharge, headache, sinus pain. NECROTIC INVASION of Palate, orbit and brain.
DIagnose with SINUS ENDOSCOPY with BIOPSY and CULTURE
Treatment = SURGICAL DEBRiDement and LIPOSOMAL AMPHOTERICIN B.
What does the Lymphocyte count of a patient with HIV look like?
They will have a NORMAL ABSOLUTE LYMPHOCYTE COUNT!!!!!
For example on CBC you can/ will see 18,000 Leukocytes… 50% neutrophils, 45% lymphocytes!
They will have a CD4 T Lymphocyte Deficiency!
If you suspect an infant has HIV.. how do you confirm diagnosis?
DNA PCR testing of blood is the COnfirmarotyr test.
Must check periodically.. if after age 18 months, the HIV antibody is showing up.. then that CONFIRMS HIV diagnosis.
A pregnant mother with Hep C should recieve what durring her pregnancy?
Hep A and Hep B vaccination. (they are inactivated (killed) vaccines.
Encourgae breast feeding.
no need for c-section (wont make a difference)
vertical transmission strongly associated with maternal viral load
NEVER give RIBAVIRIN durring pregnancy - teratogenic
What is the outcome of patients infected with HAV?
Complete recovery in 3-6 weeks.
Congenital Toxoplasmosis vs Congential CMV manifestations
Congenital Toxoplasmosis:
- CHORIORETINITIS
- Hydrocephalus
- Diffuse INTRACRAINAL CALCIFICATIONS.
Congenital CMV:
- CHORIORETINITIS
- PERIVENTRICULAR calcification
COngenital Rubella Syndrome
- PDA (machine like murmur)
- Hearing loss
- Cataracts - leukocoria (white papillary reflex)
when is dexamethasone added to the normal treatment of meningitis (ceftriaxone + vancomycin)
Dexamethasone is added when…
HIB is the cause of meningitis in kids
or
S.Pneumo meningitis in adults.
What is the treatment for Enterobius Vermicularis (pinworm) that causes anal puritis.
Pyrantel Pamoate or ALBENDAZOLE
must give to patient and ALL HOUSEHOLD CONTACTS.
Diagnosis - celophane tape – eggs on tape.
Ivermectin is the first line treatment for which 2 diseases?
Strongyloidies - Tape worm.. presents with:
- Utricaria
- abdominal pain
- Resp problmes
Onchocerciasis (river blindness) – causes occular lesions and dermatitis
Aspiration Pneumonia presentation
Presents very quickly - hours to days after aspiratoin.
Foul Smelling sputum production, Dyspnea and Fever.
LOWER LOBES!.. especially right lower lobe.
What is the best way to reduce the risk of CAUTI
Catheter Associated UTI is best reduced by
Clean Intermittent Catheterization.
Periodic insertion and removal (every 4-6 hrs) of a clean urinary cath and can be often peformed by the patient
How do you work up a paitent for Ventilartor assoicated pneumonia?
First step is CXR. If the CXR is normal then it is NOT VAP. because someone with VAP will not have a normal CXR.
If abnormal CXR –> then must do LOWER RESP TRACT SAMPILING (tracheobroncial aspiratoin) for Microscopic analysis (gram stain and culture)
Give patient eperic antibiotics until culture results return
Once they return narrow the abx based on the organisms.
Cavitary lesions on the periphery of the lung (on CT scan) of an IVDU is indicative of what?
Septic Emboli from Infective endocarditis.
Cavitary lesions most commonly occur on the periphery of th elungs.
Most common organism = Staph Aureus.
In which patients is Stap Epidermidis the cause of Infective Endo?
Prosthetic valves, IV shunts and PROSTHETIC joints.
DOes not cause Infective Endo in patients with normal / native heart valves.
Which vitamin is given to patients with Measels?
Vitamin A!
Vitamin A deficency is associated with incrfeased moribditiy with measels infeciotn.
Vitamin A supplementatoin is thus given to HOSPITALIZed measels patients.
This does not help in preventing transmission.
Treatment for Measels = supportive
what precaustions should betaken by health care professionals for Patients with known or suspected measels
Airborne Precautions:
- Negative pressure room for patient
- N95 Face Mask for providers
Porphyria Cutanea Tarda is strongly linked to which Disease?
Hep C virus.
ALl patients with PCV should be screened for HCV.
Wht needs to be done to health care workers who have been exposed to HIV from a patient?
High risk contact:
Blood, semen, vag secretions, or any bodily fluid with visible blood.
These patients MUST get Post Exposure Prophylaxis which is 3 HIV drugs for 28 days started immediately. They should also have their blood taken immediately then again at 6 weeks, 3 months and 6 months to check serological status.
Low risk:
Exposure to urine, feces, nasal secretions, saliva, sweat, tears (with no blood in any secretions) DO NOT NEED poste exposure prophylaxis… but they should still have blood drawn at the intervals above.
Cryptosporidium Parvum is an Intracellular Protozon transmitted via the ingestion of Contaminated water. What kind of diarrhea does it cause?
PROLONGED and very heavy WATERY diarrhea.
Diagnosis - Microscopy with specialized stain.
Healthy adults usually have SPONTANEOUS RESOLUTION within 10-14 days.
Immunocomp patients are at risk for severe disease.
Entamoeba Histolytica causes what kind of diarrhea?
It also causes TRAVELERS diarrhea and causes a BLOODY, MUCOID Diarrhea.
What is the diagnosis?
Fever, weight loss, malaise, dyspnea, cough, pleurisy.
Imaging: Nodular or Cavitary Lesions in the UPPER LOBES!!
Gram Stain - FILAMENTOUS GRAM POSITIVE rods that are WEAKLY ACID FAST
Nocardia.
Cavitary lesions in UPPER LOBES is key.
Makes you think of Tb or Malignancy… but Nocardia is Filamentous.. and thus looks diff in microscopy than Tb.
Also – Tb is STRONGLY acid fast… while NOcardia is weakly acid fast.
What is the most common cause of atypical pneumonia and how does it present?
Mycoplasma Pneumo.
People in close quarters – military, school, dorms.
Indolent symptoms - headache, malaise, fever and PROLONGED DRY COUGH, PHARYNGITIS, and MACULAR / VESICULAR RASH.
Sub-clinical HEMOLYTIC ANEMIA and INTERSTITIAL INFILTRATES on CXR.
Empiric treatment with Macrolide or Fluroquinolone.
HIV patient with CD4 less than 50 has Non specific symptoms (FEVER, COUGH, abdominal pain, DIARRHEA, night sweats, weight loss) + SPLENOMEGALLY and elevated ALK PHOS (reflecting Hepatosplenic involvement)
What is the most likely diagnosis?
MAC.
Disseminated Mycobacterium Avium Complex.
DIagnose through blood cultures or lymph node.
Treatment - 1st line = CLARITHROMYCIN
1st line prophylaxis = AZITHROMYCIN
Cutaneous larva Migrans
BAREFOOT contact with contaminated SAND or SOIL.
DOG or CATs
Caused by HOOKWORM LARVAE.
INTENSELY PURITIC and REDDISH BROWN TRACKS
Treatment = Antihelmintics - IVERMECTIN.
What is the most common complication of Influenza?
Secondary bacterial infection.
This happens most often in elderly after an influenza infection.
Staph Aureus however is the only one that caues secondary bacterial infection in younger patients (below 60)
Patients receiving solid organ transplantation should receive which immunizations?
TMP SMX - for PCP Pneumococcal vaccination HEP B vaccination and Ganciclovir / valganciclovir for CMV
CMV symptoms
CMV can cause PULMONARY symptoms (dyspnea on exertion, dry cough) and GI symptoms (abdominal pain, diarrhea, hematochezia) as well as PANCYTOPENIA.
CMV is diagnosed by doing PCR and finding CMV DNA!
IV GANCICLOVIR is used for severe disease
ORAL VALGANciclovir is used for mild disease.
Causes of Meningitis in Children?
Less than 1 Month:
- GBS
- E.Coli
- Listeria
- Herpes simplex virus
Over 1 Month:
- Strep Pneumo
- N. Meningitids
Sporothrix Schenckii
Gardners and Landscapers… The fungus is found on decaying plant matter / soil.
Skin Papule –> Ulceration with nonpurulent, ODROLESS and NONPURULENT fluid.
Proximal Lesions along lymphatic chain
Diagosis –> Cultures (aspirate fluid or biopsy)
Treatment - 3-6 months of ORAL ITRACONAZOLE
Most common causes for Erysipelas vs Cellulitis
Erysipelas = Step. Pyogenes
Cellulitis = S. Pyogenes OR Staph Aureus.
CMV mononucleosis
CMV produces a mononucelosis-like illness with Fever, Malaise, Fatigue and Absolute Lymphocytosis with ATYPICAL lymphocytes!
Unlike EBV patients.. CMV has mild or absent pharyngitis, lymphadenopathy and splenomegaly.
They will obviously have a NEGATIVE HETEROPHILE ANTIBODY test and a POSTIVE CMV IgM Serology.
Imaging in pyelonephritis is done when?
Patients with uncomplicated pyelo.. NO imaging needed… now if these patients are receiving ABX and after 72 hrs dont improve.. then you do a CT abdomen / pelvis..
COmplicated pyelo.. its pyelonephritis.. but with either a renal abscess, perinephric abscess, or papillary necrosis. These patients need to get CT done right away to evaluate the abscess.
