Infectious Diseases Flashcards
Evaluation of suspected ventilator-associated pneumonia
- Suspect for Ventilator-associated pneumonia (VAP)
- abnormal chest X-ray - Lower respiratory endotracheal tube sample
- culture
- microscopy - Empiric antibiotics
- gram (+)
- antipseudomonal & gram (-)
- MARSA (methicillin-resistance Staph. aureus)
—-
3.1 negative culture:
- discontinue antibiotics + evaluate for other causes
3.2 positive culture & clinical improvement
- narrow antibiotics (according to the culture result)
3.3. Positive culture without clinical improvement:
- likely VAP
- Consider changing antibiotics
- assess for VAP complication ( abscess, empyema)
- consider evaluating for other causes
Ventilator-associated pneumonia
Feature:
- occurs after 48 hours of endotracheal tube incubation
- associated with:
1. Gram (-) bacilli ( pseudomonas, E.coli, Klebsiella)
2. Gram (+) cocci ( MRSA, Streptococcus)
Signs:
- fever
- leukocytosis ( increase WBC)
- purulent secretion
- difficulty with ventilation ( increase RR, decrease Tidal volume)
Meningococcal meningitis
Epidemiology:
- Neisseria Meningitis
- most common in young children & young adult
Feature:
- initially: non-specific fever, headache, vomiting, myalgia, sore throat
- within 12-24 hours: petechiae/purpura, meningeal signs (stiff neck), altered mental status
Diagnosis:
-blood culture (before starting antibiotics)
- lumbar puncture
Treatment:
- ceftriaxone ( ± vancomycin for coverage of PRSP)
-treatment should not be delayed for lumbar puncture
Complication:
- shock
- DIC
- adrenal hemorrhage
Prevention:
- droplet precautions
- chemoprophylaxis ( Rifampin, ciprofloxacin, or ceftriaxone) —> for close contacts
Tularemia ( rabbit fever, or deer fly fever )
- typically attacks the skin, eyes, lymph nodes and lungs
- infection with: Francisella Tularensis
LEAD TO:
- unilateral conjunctivitis with ipsilateral pre-auricular lymphadenopathy ( parinaud oculoglandular syndrome) —-> this is also seen with Bartonella henselae (catscratch), & herpes simplex virus
Epidemiology:
- transmission from:
1. Wild animals ( hare, rabbit) hunting
2. Tick/mosquito bite
3. Bioterrorism agent
Feature:
1. Nonspecific symptoms ( fever, malaise)
2. Ulcero-glandular disease ( tender lymphadenopathy)
3. Pneumonia
Microbiology:
- poorly staining, gram (-) coccobacillus
- most strains require cysteine for growth
- evade most immune defenses & replicate within macrophages/ neutrophils
Adenovirus
Lead to:
- pneumonia
-regional lymphadenopathy
-Conjunctivitis (minimal or no purulence)
Candida Albican
- seen in:
1. People with compromised immunity ( prolonged neutropenia)
2. Recent eye trauma or surgery
3. Indwelling central catheters
4. Not seen in healthy people
Yersinia Pestis
- transmitted by fleas from rodents & wild/domestic animals
- exposure can occur from hunting/trapping
- lead to very painful suppurative lymphadenitis
Entamoeba histolytica ( Protozoal infestation )
Risk factors:
- resource limited regions (contaminated food/water)
Clinical:
- prolonged blood/mucoid diarrhea
- RUQ pain + fever
- complication: pleural effusion + rupture to peritoneum/pleural space
—> dysentery: abdominal pain + diarrhea + bloody stools
Diagnosis:
- stool PCR antigen
Treatment:
- Metronidazole or tinidazole
PLUS
- intraluminal antibiotics (paramomycin)
Creutzfeldt-Jackob (Mad Cow disease) ( prion)
Hx:
- rapidly progressive dementia
- handling brain (autopsy)
PE:
- ataxia
- cerebellar dysfunction
- myoclonic jerks
Etiology:
- ingestion or contact of infected brain or cattle causes brain shrinkage & deterioration
- transmitted by: surgical instrument, EEG electrodes, corneal transplantation, dura mater graft, human pituitary hormones
Epidemiology:
- most common prion disease
- rare
- medical examiner
- forensic pathologist
- mortician
DX:
- diagnosis of exclusion
TX:
- death within 8 months
- supportive care
Cryptococcal
(Fungal disease)
(More neurological symptoms)
Hx:
- neurologic ( fever, headache)
- respiratory ( non-productive cough, pleuritic chest pain)
PE:
- neurologic ( papilledema, nuchal rigidity)
-respiratory ( rales )
- pustular rash
Etiology:
- inhaled spores of cryptococcus neoforman yeast In birds & bat feces
- causes meningitis (most common presentation )
- or pulmonary disorder
Epidemiology:
- immunocompromised
- farmers
- demotition Crew
- pacific coast (colonize in eucalyptus trees)
Dx:
- lumbar puncture (if neurologic)
- sputum culture (if respiratory)
- cryptococcal antibody titer
- lesion biopsy
Tx:
- oral antifungal ( Amphotericin B)
Histoplasmosis
(Fungal disease)
(More respiratory symptoms)
Hx:
- asymptomatic (90%) (if solve resolve within 4 weeks)
- night sweat
- mainly respiratory symptoms ( dyspnea, dry or productive cough, hemoptysis)
PE:
- maculopapular rash
Etiology:
- Histoplasma Capsulatum Fungus in soil with bird or bat feces
- is inhaled & grows into yeast
Epidemiology:
- ohio, Missouri, Mississippi River Valley
- ( ideal soil composition & moisture)
- immunocompromised
Dx:
- sputum + blood cultures
- antibody titer
- chest X-ray ( hilar masses)
Tx:
- most cases self resolve within 4 weeks
- if longer than 4 weeks, consider Amphotericin B
Pneumocystis Jirovecii Pneumonia (PJP)
(Fungal disease)
Hx:
- weight loss, dyspnea, severe dry cough (sputum is too thick to be expectorated)
PE:
- tachypnea, fever, decrease oxygen saturation (SPO2)
Etiology:
- fungal pneumocystitis jirovecii spores ( formerly called, Pneumocystitis Carinii, but this species was found to only infect rats)
Epidemiology:
- most common infection in AIDS & immunocompromised
Dx:
- sputum culture
- positive Beta -D- Glucan ( assay detects fungal cell wall)
- Chest X-ray: diffused perihilar infiltrates
- CT: ground glass
Tx:
- TMP/SMX (Bactrim)
- steroids
- mortality 20%
Pinworms (helminth)
(Helminthic/worm disease)
Hx:
- nocturnal perianal pruritus
PE:
- Anal excoriations
- less than 1 cm perianal white worms
Etiology:
- Enterobius Vermicularis
- fecal-oral route
- female lay eggs outside of anus at night & cause itching
Epidemiology:
- most common Helminth infection
- 30% of children ages (5-14)
- daycare
- crowded living situation
Dx:
- scotch tape test (over anus shows eggs or worms)
Tx:
- mebendazole (vermox)
- albendazole ( albenza)
- treat household contacts ( clean linens in hot water, frequent hand wash) —> highly contagious
Helminth intestinal infestation
Hookworm:
- Ancylostoma duodenale, Necator Americanus
- eggs in animal feces/soil absorbed through skin, walking barefoot
- reside in intestine
- lead to iron deficiency anemia
Tapeworm:
- raw or uncooked pork (Taenia Solium), Beef (Taenia Saginata), rarely fish (Taenia latem)
- reside in intestine
- cause weight loss & malnutrition
- treat with: praziquantel
Ascarids:
- Ascaris Lumbricoides
- Contaminated soil on food/hands, ingested
- roundworms grow & multiply in intestine
-cause malnutrition & intestinal obstruction
Flukes:
- Clonorchis sinensis, opisthorchis viverrini
- contaminated water —> burrow in skin
- undercooked seafood
- reside in intestine, blood, liver, lung
Trichinosis:
- Trichinella worms ( Trichinella spiralis)
- raw or undercooked pork
- encapsulates in muscle & brain tissue ( difficult to treat)
Helminth Infestation
Filariasis (Elephantiasis)
- Wuchereria Bancrofti (most common)
- Filariid worms transmitted by mosquitos
- reside in lymphatic system, skin
- causes lymphatic pooling, skin breakdown
Guina worm ( Dracunculiasis)
- Dracunculus medinensis
- contaminated water
- reside in skin, head will emerge
- removed small amount at a time, breakage can cause secondary infection
Loa loa worm (loiasis)
- filariid worm transmitted by bite of Chrysops Fly (mango or deer fly)
- migrates to and reside in eye
Tropical viral fevers ( Dengue, Yellow )
(Viral diseases)
Hx:
- 80% of Dengue fever are asymptomatic
- Myalgia + malaise + headache
PE:
- both have fever & petechial rash
1. Dengue: usually mild mucosal bleeding
2. Yellow: 15% develop jaundice (yellow), mucosal & GI bleed —> hypotension —> death
Etiology:
- both are spread by Aedes mosquito, incubation of 1 week
1. Dengue: dengue virus, 5% develop Hemorrhagic GI bleeding
2. Yellow: Flavivirus, 15% develop liver failure
Epidemiology:
- Latin America, Southeast Asia, Africa
Dx:
- CBC ( neutropenia, thrombocytopenia)
- PCR
- ELISA
TX:
- IV fluid
- Acetaminophen
- Fresh frozen plasma ( if bleed)
- prevent with vaccine
- Dengue: resolves in 10 days; Mortality with GI bleeding is 25%, without is 1%
- Yellow: resolves in 5 days. Mortality with Jaundice 20-50%, without is 7%
Ebola Virus ( viral hemorrhagic fever)
( viral disease)
Hx:
- headache, diarrhea, vomiting, abdominal pain, travel to endemic area
PE:
- High fever, rash, ciliary injection, internal & external bleeding.
- in lateral stages, liver & renal failure, bleeding in eyes, ears, nose
Etiology:
- infected primate ( hunting & eating)
- virus transmitted through any body fluid
- incubation 2-21 days
Epidemiology:
- Africa, healthcare worker
DX:
- CBC ( thrombocytopenia)
- coagulation panel ( prolonged PT, PTT, Bleeding time)
- PCR
- ELISA
TX:
- IV Fluid
- oxygen
- supportive
- 50-90% mortality within 6-16 days of symptoms onset
- Remdesivir is experimental
Zika virus
(Viral diseases)
Hx:
- 80% asymptomatic
- arthralgia, headache, travel to endemic area within 2 weeks
PE:
- rash, fever
Etiology:
- flavivirus transmitted by Aede mosquito
- sexually transmitted
Epidemiology:
- Africa, Southeast Asia, South America, Virgin Island, Puerto Rico
Dx:
- urine PCR
TX:
- self resolved (7 days)
- teratogenic if pregnant (microcephaly, eye deformity)
Hantavirus
(Viral disease)
Hx:
- prodrome (3-5 days of GI): vomiting, diarrhea, abdominal pain
- cardiopulmonary phase (1-2 days of respiratory): dyspnea, dry cough
PE:
- Rales, dehydration ( sunken eyes, decreased skin turgor, dry mucous membrane)
Etiology:
- inhaled Sin Nombre Virus in rodent waste
Epidemiology:
- arid, dusty climate (desert)
Dx:
- smear ( atypical lymphocytosis)
- PCR
- ELISA ( elevated IgM & IgG)
TX:
- supportive
- ventilation
Infectious Mononucleosis
(Viral disease)
Hx:
- extreme fatigue, pharyngitis, sharing drinks, kissing
PE:
- cervical lymphadenopathy, tonsillar exudates, splenomegaly, fever, jaundice, faint transient rash, petechiae on soft palate.
Etiology:
- Epstein- Barr Virus infection of B lymphocyte
Epidemiology:
- young adult
Dx:
- CBC (leukocytosis)
- smear (atypical lymphocytes)
- heterophiles (mono-spot)
- screening test
- elevated EBV IgM
Tx:
- NSAIDS & rest
- self resolve 10 days- 3 months
- no contact sport ( lead to splenic rupture)
- may get rash if given Penicillin antibiotics ( amoxicillin)
Cytomegalovirus
(Viral disease)
Hx:
- flu-like symptoms + sore throat
PE:
- fever, cervical lymphadenopathy
Etiology:
- HHV5 transmitted by bodily fluid
- in immunocompromised: can cause hepatitis, retinitis, colitis, pneumonitis, esophagitis, encephalitis
Epidemiology:
- 90% of human can get it during lifetime
Dx:
- smear ( Owl’s eye infected cells)
- PCR
-ELISA
TX:
- IVIG ( if severe)
- antiviral in immunocompromised (reduce mortality; ganciclovir; foscarnet)
- teratogenic if pregnant ( cognitive & motor defects)
HIV & AIDS
(Viral disease)
Hx:
- unprotected sex ( #1 receptive anal), multiple partners, other STDs, IV drug use, transfusion
- prodrome ( 2-4 weeks): flu-like illness, truncal rash, neuropathy, diarrhea
- clinical latency (3-20 years): fever, weight loss, lymphadenopathy
- If untreated, 50% will develop AIDS 10 years after exposure: opportunistic infection ( Kaposi sarcoma, Burkitt lymphoma, thrush, PJP, TB, toxoplasmosis, shingles, dementia).
Etiology:
- HIV-1 (common), HIV-2 (rare)
- blood borne ( mother to child, IV needle, needle stick, genital ulcers, rough sex)
Epidemiology:
- Sub-saharan Africa
- men have sex with men ( anal sex)
- IV drug users
Dx:
- PCR
-ELISA
- antibody test
- CD4 T cell count ( CD4 < 200 = AIDS)
TX:
- highly active antiretroviral therapy (HAART) = normal life expectancy ( without it = 10 years)
- condom use, antiviral vaginal gel
- pre-exposure prophylaxis: tenofovir/ emtricitabine
- post-exposure (48-72 hours): 3 antiviral drug combo
Rabies
( viral disease)
Hx:
- aggressive animal bite patient 1-3 months before symptoms.
- triads ( paresthesia, pain, intense itching at bite site)
- malaise, headache, fever, insomnia
PE:
- furious type (80%): agitation, delirium, hydrophobia & aerophobia ( attempting to drink or having air blown in the face cause pharyngeal spasms), excessive salivation, convulsion, autonomic dysfunction —> arrhythmia, hypotension —> death
- paralytic type (20%): priapism, anisocoria, facial palsy, progressive paralysis —> death
Etiology:
- CNS- acting Lyssavirus
- dog/cat, bat, skunk, coyote, wolf…
Epidemiology:
- 2 human death annually
Dx:
- nuchal skin biopsy of patient ( rabies virus in cutaneous nerve)
- test questionable animal
- salivary PCR
TX:
- debride wound,
- rabies vaccine at bite site
- IVIG
- 100% mortality due to respiratory failure within 1 week of emergence of neurologic symptoms —> prevent with vaccine
Influenza
( viral disease)
Hx:
- myalgia, fever/chills, headache, sinus pressure, fatigue, dry cough
- exposure to sick contact, no flu shot
PE:
- ill appearing, fever, clear fluid behind tympanic membrane, pharyngeal erythema ( post-nasal drip)
Etiology:
- Type A: severe, peak Nov/Dec
- type B: mild, peak Jan/Feb
- H1N1 ( swine flu): severe variant of type A
Epidemiology:
- highly contagious, common, may lead to pneumonia
Dx:
- nasopharyngeal swab rapid flu test
- PCR for H1N1
TX:
- flu vaccine ( prevent)
- inactivated (IM) shot for older than 6 months & pregnant women.
- live-attenuated for ages 2-49
- may cause flu-like symptoms & injection site reaction.
-Within 48 hours of symptoms onset: oseltamivir, zanamivir
Common Cold
( viral disease)
Hx:
- headache, pharyngitis, sneezing, rhinorrhea, malaise, dry cough
- mild fever or myalgia
- exposure to sick contact
PE:
- Clear fluid behind tympanic membrane, pharyngeal erythema (postnasal drip)
Etiology:
- spread through respiratory droplet, fomites, direct contact.
- Rhinovirus, coronavirus, parainfluenza, respiratory syncytial virus, enterovirus, metapneumovirus
Epidemiology:
- highly contagious, common, adult have 2-3 a year, children have 6-8 a year
Dx:
- clinical
Tx:
- self resolve in 7- 10 days
- NSAID, cough suppressant, nasal decongestion, zinc supplement (shorten duration)
- may develop secondary infection of otitis media, sinusitis
Erythema infectiosum (5th disease)
(Viral disease)
Hx:
- 3 days of low fever before pruritic rash
- 2-3 days of malaise
PE:
- slapped cheek rash + truncal lucy rash + lymphadenopathy
Etiology:
- parvovirus B19
Epidemiology:
- under age 15 ( most common)
Dx:
- clinical, serum IgM
TX:
- self-resolve (weeks)
- acetaminophen (for fever) + fluid ( for dehydration) + diphenhydramine, hydroxyzine, topical camphor/menthol ( for rash )
Exanthema subitum ( roseola infantum, 6th disease)
Hx:
- 3 days high fever, febrile seizure ( 15%)
- rash starts as fever resolves
PE:
- non- pruritic morbilliform rash over entire body, erythematous papule on the soft palate & base of the uvula ( Nagayama spots)
Etiology: herpes virus 6
Epidemiology:
- under age 3
Dx:
- clinical, serum IgM
TX:
- self-resolve (weeks)
- acetaminophen (for fever) + fluid ( for dehydration) + diphenhydramine, hydroxyzine, topical camphor/menthol ( for rash )
Measles ( Rueola)
( viral disease)
German Measles ( Rubella)
(Viral disease)
Mumps
( viral disease)
Condylomata Acuminata
(Viral disease)
Herpes simplex virus ( type 1 oral ; type 2 genital)
Antiretroviral therapy (ART)
- indicated for all patients with HIV (regardless of CD4 count)
- to reduce HIV- related mortality & death
Leprosy (Hansen Disease)
- hypo-pigmented + anesthesia (no sensation to pinprick) patch with nerve nodularity/ pain
Epidemiology:
-mycobacterium leprae ( acid fast bacillus)
- primary developing world ( Asia, Africa, south america)
-transmutation via: respiratory droplets/ nine banded armadillo
- low infectivity
Manifistation:
- macule, anesthetic skin lesions with raised borders
- nodular, painful nearby nerves with loss of sensory/motor function
Diagnosis:
- full thickness biopsy of skin lesion edge (active edge)
- M leprae is not culturable
Treatment:
- Dapsone + Rifampin ( for paucibacillary: minimal lesion)
- Dapsone + Rifampin + clofazimine —> if severe (multibacillary)
Lyme disease
- manifest as: erythema migrans ( slowly spreading erythematous lesion with central clearing = bull’s eye lesion)
- sensory & motor neuropathy may sometimes occur early disseminated disease
Primary syphilis
-characterized by painless chancre ( shallow, non-purulent ulcer with raised, well demarcated borders.
Tertiary syphilis
- cause skin gummas ( soft, ulcerative masses with necrotic centers)
Common cause of diarrhea in patient with AIDS
- Cryptosporidium ( CD4 < 180)
- Severe watery diarrhea + low grade fever + weight loss - Micro-sporidium / Isosporidium ( CD4 < 100)
- watery diarrhea + crampy abdominal pain + wight loss + fever is rare - Macro-bacterium Avium complex ( CD4 < 50)
- watery diarrhea + high fever > 39.0 + weight loss + cough - Cytomegalovirus (CD4 < 50)
- frequent, small volume diarrhea + hematochezia + abdominal pain + low grade fever + weight loss
Legionella pneumonia
exposure to possibly contaminated water
- recent travel (cruise + hotel stay) within previous 2 weeks
-contaminated potable water in hospital/nursing homes
Clinical:
-fever >39
- bradycardia related to high fever
-confusion
- diarrhea
- unresponsive to beta-lactam & amino-glycoside antibiotics
Laboratory:
1. hyponatremia
2. hepatic dysfunction
3. hematuria & proteinuria
4. sputum gram stain shows many neutrophils ( & no microorganisms)
5. Chest x-ray: lobar infiltrates
Treatment:
- respiratory fluoroquinolone ( levofloxacin)
or
- newer macrolide ( azithromycin)
Infectious genital ulcers
Painful ulcers:
- HSV:
- pustules, vesicles, or small ulcers on erythematous base
- tender lymphadenopathy
- systemic symptoms common - Haemophilus Ducreyi (chancroid):
- larger, deep ulcers with gray/yellow exudate
- well-demarcated borders & soft, friable base
- papule —> pustule —> ulcer ( conversion) + inguinal lymphadenitis
- sexually transmitted + gram (-) rod
- in Africa, Southeast Asia + Latin America
- trade sex for drugs
- treat with: Azithromycin ( new macrolide)
Painless ulcers:
1. Treponema pillidum ( Syphilis)
-usually single ulcer (chancre)
- indurated borders & hard, non-purulent base
- Chlamydia Trachomatis serovars L1-L3 ( Lymphogranuloma venereum)
- initial small, shallow ulcers (often missed)
- then painful & fluctuant adenitis (buboes)
Note:
- gonorrhea: most common STD. Causes cervicitis or urethritis
Diagnostic serology for Syphilis
Non- treponemal ( RPR, VDRL):
- Antibody to Cardiolipin- Cholestrol-Lecithin (CCL) Antigen
- Quantitative ( titer; ####)
- Possible negative result in early infection
- decrease in titer confirm treatment
Treponema ( FTA- ABS, TP-EIA)
- antibody to trepanema antigen
- Qualitative ( present, or not)
- Greater sensitivity in early infection
- positive even after treatment
Note:
- RPR: rapid plasma reagin
- VDRL:
- FTA-ABS: fluorescent trepanomal antibody absorption —> best for primary syphilis, particularly early in the disease course
- TP-EIA: trepanema pallidum enzyme immunoassay
Community-acquired Pneumonia (CAP)
Treat with:
- Amoxicillin - clavulanate
- these medication works against —> beta-lactamase hemophilus & maroxella
Note:
- Drugs treat: otitis media, sinusitis
Pneumococcus + Haemophilus + Moraxella
Treat with
- Ceftriaxone
Aspiration pneumonia + lung abscess
Treat with:
- clindamycin ( type of macrolide)
Nosocomial Pneumonia ( when risk MRSA is high) —> ventilator acquired pneumonia ( VAP)
Treat with:
- vancomycin
Post-Exposure to HIV
- Determine if high risk ( urgent Tx) or low risk ( no need for tx)
- Urgent treatment (WITHIN FIRST FEW HOURS) & continue for 4 weeks
- Regimen of combination of 3 drugs:
- two nucleotide/nucleoside reverse transcriptase inhibitor ( tenofovir, emtricitabine)
PLUS
- Integrase strand transfer inhibitor (raltegravir), protease inhibitor, or non-nucleoside reverse transcriptase inhibitor
Malaria prevention
- initiate chemoprophylaxis ( before, during, & after) traveling
- drugs:
1. Atovaquone-proguanil
- Mefloquine ( 2 weeks before traveling, & continued 4 weeks after travel)
- Doxycycline
- Tafenoquine
Neisseria Gonorrhea
Symptoms:
- cervecitis or urethrasitis
- conjunctivitis + pharyngitis + arthritis
Major pathologic mechanisms of food-brone illness
Enterotoxin Ingestion:
- Staph. Aureus + Bacillus Cereus ( reheated rice)
- symptoms:
1. Quick onset: 1-6 hours
2. Vomiting predominant
Enterotoxin made in intestine:
- Clostridium perfringens ( ETEC/STEC) + Vibrio cholerae
- symptoms:
1. Delayed onset: > 1 day
2. Watery/bloody diarrhea
Bacterial epithelial Invasion:
- Campylobacter jejuni + Nontyphoidal salmonella + Listeria Monocytogenes
- symptoms:
1. Variable onset
2. Watery/bloody diarrhea
3. Fever
4. Systemic illness ( Listeria)
Note:
- ETEC: Enterotoxigenic E.coli
- STEC: shiga toxin- producing E.coli
Entamoeba Histolytica
- liver abscess ( after episode of dysentery)+ lived or travelled to developing country
- syx: fever/ RUQ pain/ anorexia/ increase liver enzymes / increase WBC
-Treat with:
1. Metronizadole or tinidazole
Or
2. Paromomycin
Sexually transmitted infection screening
All patients:
1. Neisseria Gonorrhea ( via NAAT)
2. Chlamydia Trachomatis ( via NAAT)
3. Syphilis ( via RPR, VDRL, AFB-ABS, TP-EIA)
4. HIV ( via 4th generation antigen/antibody)
Additional testing for certain populations:
- women only: Trichomonas vaginalis ( wet mount)
- HSV screening ( serology) only when history of characteristic lesions
Febrile neutropenia (FN)
- Febrile with normal chest x-ray & urinalysis
Defined as:
- neutrophil count < 1500/ mm3
- severe neutropenia < 500/ mm3
- are at higher risk for overwhelming bacterial infection due to blunted/absence of neutrophil mediated inflammatory response
Approach
- start on empiric broad-spectrum antibiotic ( as soon as possible) after blood culture is obtained
- empiric mono-therapy with anti-pseudomonal agent:
1. Cefepime
2. meropenem
3. piperacillin-tazobactam
- Cefepime
- meropenem
- piperacillin-tazobactam
To treat:
- pseudomonal aureginosa that can lead to febrile neutropenia
Acyclovir
Treat:
-herpes simplex virus
Ceftriaxone
Ciprofloxacin
Linezolid
Vancomycin
- has no gram (-) activity
To treat:
- MRSA
- catheter-related infection
- skin/soft tissue infection
- pneumonia
- hemodynamic instability
Variconazole
- anti fungal
- recommended in patients with:
Neutropenic patient + Persistence fever after 4-7 days of initial therapy
HIV is associated with TB reactivation
Syx:
- weeks of fever, weight loss, cough, night sweat, fatigue
- productive/bloody cough in the early morning
- lung upper lobe cavity lesion (chest x-ray)
Treatment for TB
RIPE:
1. Rifampin
2. Isoniazid (INH) ( develop mild elevated aminotransferase; minor hepatic injury; self-resolve)
- adverse effect: hepatotoxicity (± hepatitis)
3. Pyrazinamide
4. Ethmabutol
Note:
- viral hepatitis (similar to INH hepatitis): fatigue, nausea, flu-like symptoms, jaundice, aminotransferase > 10 times upper limit
- severe hepatitis (due to daily alcohol, liver disease, or age > 50):
Syphilis treatment
Primary (chancre)+ secondary (diffuse rash: start at trunk and spread: lymphadenopathy: oral lesion)
- 1st: penicillin G (IM) * 1
-2nd: Doxycycline * 14 days
Tertiary ( cardiovascular; gummata)
- 1st: penicillin G (IM) * 3
-2nd: Doxycycline * 28 days
Neurosyphilis ( meningitis, ocular)
- 1st: penicillin G (IV) * 10-14 Days
-2nd: Ceftriaxone (IV) * 14 Days
Note:
- ( RPR= rapid plasma reagin): a 4-fold decrease in antibody titer at 6-12 months indicates treatment success
( Example: 100 titer ——> 25 titer)
Toxoplasma encephalitis
Syx:
- headache, confusion, fever, focal neurologic deficits/seizure
Dx:
- AIDS with CD4 count < 100
- positive toxoplasma gondii (IgG)
- Multiple ring-enhancing brain lesions (MRI)
Trx:
- sulfadiazine & pyrimethamine ( plus leucovorin)
- anti-retroviral initiated within 2 weeks
- prophylaxis: TMP-SMX ( CD4 count < 100)
Post-exposure prophylaxis of Hepatitis B infection
- unvaccinated individuals should receive both HB vaccine & HB immune globulin as soon as possible
Infectious mononucleosis
Feature:
- fever
- tonsillitis/pharyngitis ± Exudates
- cervical lymphadenopathy
- significant fatigue
- hepatospelnomegaly
- rash after amoxicillin
Complication:
- acute airway obstruction
- autoimmune hemolytic anemia & thrompocytopenia
- splenic rupture
Antibiotic ladder
( fight gram negative)
-Penicillin —> syphilis
- amino-penicillin ( beta-lactamase sensitive) —> fight gram (-)
1. Amoxicillin
2. Ampicillin
—> when adding beta-lactamase inhibitor to Amox or Amp: they extend to cover gram (+):
1. Amoxicillin- clavulanate ( strap. & gram -)
2. Ampicillin - sulbactam
—-> anti-pseudomonal penicillin (+ beta-lactamase Inhibitor) to extend to cover gram (+) :
1. Piperacillin-tazobactam ( cover everything, but Staph)
2. Ticarcillin-sulbactam
—->
1. Carbapenem: ( 1. meropenem)
2. Monobactam: (1. Aztreonam) —> only with severe penicillin allergy or beta-lactam allergey that are anaphylactic
- Beta-lactamase penicillin —>
-
Antibiotic ladder
Penicillin —>
- Methicillin- sensitive staph. Aureus ( MSSA):
1. Nafcillin
2. Dicloxacillin ( oral form) - Methicillin- resistance Staph Aureus ( MRSA):
1. Vancomycin
2. Daptomycin (Treat Bloodstream infection)
3. Linezolid ( treat lung infection; PO/IV forms)
Cephalosporin
1st Gen: ( treat gram positive) ( cover Strep. & MSSA)
1. Cephalaxin (Keflex): PO; prophylaxis & surgery for skin infection
2. Cephazolin (Ancef): IV; cellulitis, UTI, pneumonia, endocarditis, joint infection, biliary tract infection
2nd Gen:
- don’t matter
3rd Gen: ( treat gram negative & Strep. ) ( does not cover Staph) ( can’t treat pseudomonas)
- Ceftriaxone:
4th Gen: ( anti-pseudomonal) ( no gram positive activity) ( good gram negative coverage)
1. Cefepime:
Note:
1st: Gram (+)/ Strep. —> 3rd: Strep./ gram (-) —> 4th: gram (-)/ pseudomonas
Gram positive coverage of 1st generation cephalosporin
( cephalexin & cefazolin)
Fluoroquinolone
- Gram (-) coverage:
- urinary fluoroquinolone ( treat UTI bugs) ( double coverage of pseudomonas) - Ciprofloxacin:
- Gram (+) coverage:
- respiratory Fluoroquinolone ( treat Strep. That cause pneumonia) - Moxifloxacin
- Levofloxacin
Anaerobic coverage
- Metronidazole: in gut & vagina
- Clindamycin: used everywhere else
Addition of: beta-lactames & fluoroquinolone
Rules:
- If sick go broad ( ex: moxifloxacin IV form NPO, once a day)
- Escalate quickly ( patient is deteriorating on antibiotic —> add bunch)
- Deescalate slowly-> remove one coverage a day
—-add bunch at once & remove once per day——
- Target cultures. Sensitization ( when you have a known bug & drug —> pick the antibiotic the bug is sensitive to that is lowest in the ladder)
- Use empiric therapy ( should be lowest on the ladder)
Community acquired pneumonia (CAP)
-inpatient: Ceftriaxone + azithromycin
Or
- outpatient: Azithromycin
—————
Patient with CAP & life threatening Beta-lactamase allergy:
- Moxifloxacin ( PO & IV form) is the respiratory fluoroquinolone
MRSA & Pseudomonas (HCAP)
- ( vancomycin) or ( Linezolid)
Plus
- (Piperacillin-tazobactam) or ( meropenem)
NOTE:
- treatment can take > 6 weeks
Meningitis
- vancomycin
- ceftriaxone ( 2 gram, twice a day)
- steroids ( methylprednisolone)
- ampicillin ( if they are immunocompromised)
Urinary tract infection (UTI)
- Outpatient: amoxicillin
If beta-lactame allergic —> nitrofurantoin
Or
- TMP-SMX ( alternative)
Or
- ciprofloxacin ( should not be used for urinary tract infection…..not you cant use it !!!!)
Examples:
- pyelonephritis —> ceftriaxone
Cellulitis
From
- strep
1. Outpatient: amoxicillin (PO)
2. Inpatient: ceftriaxone (iv) - staph
1. Outpatient: Clindamycin ( IV or PO)
2. Inpatient: vancomycin
Note:
1. Strep: The infection is often accompanied by an extremely sore throat with white patches, difficulty swallowing, and a fever.
2. Staph: is a skin infection that is most often the result of surgery or an open wound.
Prosthetic joint infection
Less than 3 months:
- staph. aureus + Pseudomonas aeruginosa
3- 12 months:
-Staph. Epidermis
Bacillary Henselae or Bartonella Quitana
- lead to bacillary angiomatosis in advanced HIV
- cat scratch or homeless or shelter living
TREATMENT:
- doxycycline or erythromycin
- antiretroviral therapy
Infectious urethritis in men
Etiology:
- Niesseria Ghonnorhea
-chalamedya trecomatis
-Mycoplasma Genitalium
-Trichomatus Vagenalis
Feature:
-dysuria
-discharge
Diagnosis:
-stain & culture
- NAAT
Treatment:
- gonococcucal urethritis: ceftriaxone
- gonococcal urethritis + chalamydia: ceftriaxone + doxycycline
- chlamydia + mycoplasma: azithromycin
-trichomanus: metronidazole
Penicillin
- penicillin G, penicillin V
- gram positive
- syphilis, strep pharyngitis, dental procedure, rheumatic fever
Penicillase resistance ( anti-staphyloccocal penicillin)
- naficillin, oxacillin, dicloxacillin
- gram positive (staph)
- MSSA ( bacteremia, osteomyelitis, cellulitis, endocarditis)
Amino-penicillin
- amoxicillin, ampicillin
- gram positive, gram negative
- acute otitis media, step pharyngitis, listeria
Beta-lactamase inhibitor penicillin
- amoxicillin-clavulanate (augmenten—> severe diarrhea)
- ampicillin-sulbactam
- gram positive, gram negative, anaerobes
- aspiration pneumonia, animal bites, acute sinusitis
Anti-pseudomonal penicillin
- piperacillin- tazobactam
- ticarcillin-clavulanate
- gram positive, gram negative (pseudomonas), anaerobes
- hospital acquired pneumonia
Adverse drug effect of penicillin
- GI (diarrhea)
- hypersensitivity reaction
- hematologic reaction
Cephalosporin (lose gram positive—> gain gram negative, as generation increases)
First generation:
- cephalaxen (PO)
- Cefazolin (IV)
- gram positive (strep, staph)
- skin infection (MSSA)
- surgical prophylaxis ( cefazolin)
———————————————————
Second generation: ( 2 furry foxes drinking tea on the floor)
- cefoxitin, cefuroxime, cefaclor, cefotetan
- gram positive, gram negative, anaerobes
- intra-abdominal/ pelvic-infection
———————————————————
Third generation: (you can TRI TAXing me, but i wont give you a DIME)
- ceftriaxone, cefotaxime, ceftazidime
- gram negative (including pseudomonas with ceftaxime)
- gonococcal infection
- meningitis
- community acquired pneumonia ( hospitalization)
—————————————————
4th generation:
- cefepime
- covers gram negative ( including pseudomonas)
—————————-
5th generation:
- ceftaroline
- covers MRSA
Manobactam
- aztreonam
- covers gram negative ( including pseudomonas)
-no cross reactivity with other beta lactam antibiotics (except ceftazidime)
— can be used in patient with renal insufficiency
Carbapenem
- Impinem-cilastin
- meropenem
- ertapenem (does not cover pseudomonas)
- covers: extremely broad-spectrum antibiotic ( covers gram positive, gram negative-ESBL, Pseudomonas-, anaerobes
- reserved for severe infection
- adverse drug reaction:
- lower seizure threshold = causes CNS toxicity ( particularly imipenem)
Sotrovimab
- for treatment of Covid infection
Septic shock ( management with antibiotics)
(Infectious origin strep coccus —> soft tissue infection )
- merapenm ( start with this )
- vancomycin ( continue with this)
- for
- MRSA —> tx for 4 weeks
- osteomyelitis tx. for 4 weeks to 6 weeks —> 2 weeks of iV, & 2 weeks of oral
- endocarditis (Tx. For 4 weeks)
Kliebsiella is less resistance to E.coli
Fosfomycin used for treatment of UTI of kliebsiella or E.coli
Cephalexin
Treat: bacterial infections, such as pneumonia and other chest infections, skin infections and urinary tract infections (UTIs).
Infection of Gi ( poly
-
Lobar (typical):
- strep pneumo
Atypical
Kliebsiella
Legionella
Clamydia
Atypical pneumonia ( interstitial infiltrates)
- Chlamydia
- Legionella
- Mycoplasma pneumoniae
Typical pneumonia ( lobar consolidation)
- Strep pneumo
- H. influenza
- Moraxella
Hospital acquired or nosocomial acquired
- E.coli
- Pseudomonas
- Staph aureus
Mechanical ventilation
Predispose to aspiration pneumonia —> usually in the right lower lobe —> see air/fluid level that indicates abscess formation
X-ray:
1. Multiple cavities, fluid level, aspiration lung abscess
Outpatient treatment for pneumonia
Typical pneumonia :
1. Amoxicillin
Atypical pneumonia:
2. Azithromycin
Inpatient treatment for pneumonia
- Fluoroquinolone
Aspiration pneumonia:
1. Clindamycin (to cover for anaerobes)
Hospital-acquired pneumonia: (Cover for pseudomonas)
1. Zosyn = pipercillin-tazobactem
2. Cefepime
Investigation of TB:
PPD skin test (1st step)
Chest X-ray ( 2nd step)
Positive PPD test:
- Healthy person & > 15 mm —> positive
- 10-15 mm —> positive, if Incarcerated or health care worker or foreigner
- > 5 mm —> positive, If with HIV or got in contact to TB.
Chest X-ray:
- positive finding:
- upper lobe cavitation + B symptoms ( fever,
weight loss, night sweat) + hemoptysis
—> treat with: RIPE ( rifampin, isoniazid/vitamin B-6, Pyrazinamide, ethanbutenol
—> Treatment duration: RIPE (for 2 months) + RI ( extra 4 months)
- upper lobe cavitation + B symptoms ( fever,
- Negative finding:
- treat with: isoniazid for 9 months
Note:
—> Purified protein derivative (PPD)
—> if patient got TB (BCG) vaccine & have a positive PPD test & negative chest x-ray —> still be treated with isoniazid for 9 months
TB medication
RIPE:
1. Rifampin —> lead to hepatotoxicity + orange sweat/tears
2. Isoniazid —> lead to hepatotoxicity + neuropathy + hepatitis
3. Pyrazinamide —> lead to hepatotoxicity + gout
4.Ethambetol —> hepatotoxicity + visual defect/vision loss/retrobulbar neuritis
- All TB med —> lead to hepatotoxicity
- only stop taking RIPE —> if LFT are greater than 3 times the normal
Meningitis
- present with headache, fever, neck stiffness, photophobia, Brudzinski neck sign
- Laboratory:
- Viral infection—> high WBC, high protein, normal glucose —> lymphocyte predominant
- bacterial infection—> high WBC, high protein, low glucose —> neutrophil predominant
- fungal infection —> high WBC, high protein, low glucose —> lymphocytes predominant
Note:
1. Brudzinski neck sign—> passive flexion of the neck lead to flexion of both the thigh & leg
- fungal infection —> mainly in immunocompromised patients; AIDS: cryptococcus neoforman —> india ink positive stain; Treated with amphotericin B)
- Viral infection —> most common—> herpes ( affect temporal lobe, seizure, lumbar puncture has blood), echo, enterovirus
- Bacterial infection—> TB—> has the basilar enhancement &
Meningitis treatment
- Less than 3 months & elderly
- Common organism:
- strep pneumo
- H. Influenza
- Neisseria meningitidis —> will cause a rash
If less than 3 months:
1. Group B strep
2. E. Coli
3. Listeria
Treatment empirically above 3 months old :
1. Vancomycin ( cover strep pneumonia)
&
2. ceftriaxone ( cover Neisseria)
Treatment empirically less than 3 months old, elderly or immunocompromised :
1. Vancomycin
&
2. Ceftriaxone
&
3. Ampicillin (Covers for liesteria)
UTI
- usually treated empirically without urinalysis
- first line treatment:
1. Nitrofurantoin
2. TMP-SMX
2. Fluoroquinolone - if pregnant women:
1.Nitrofurantoin
2. Amoxicillin
3. Cephalosporin
** avoid fluoroquinolone ( tendinopathy)
** avoid TMP-SMX ( neural tube defect) - In complicated UTI: ( diabetic, pregnant , male, immunosuppressed pt.)
1. Order Urine culture - if patient have 2 UTI per year—> give them TMP-SMX as prophylaxis
Prostatitis VS. Epididymitis VS. orchitis
Young patient:
1. Chlamydia
2. Gonorrhea
- treat with:
1. Ceftriaxone
2. azithromycin
Old patient:
1. E.coli
- treat with:
1. Fluoroquinolone
HIV in pregnant women
- Do C-section —>
- if viral load is greater than 1000
- Deliver vaginally—>
- if viral load is below 1000
Note:
1. HIV is contraindication to breastfeeding
- HIV prodrome —> sore throat, malaise, fever, LAD, Rash, diarrhea
- (smilier to mono prodrome except for diarrhea, rash)
- Prophylaxis starts at CD4 OF 200 OR LESS:
- TMP-SMX —> prevents pneumocystis pneumonia ( caused by pneumocystis Jirovecii)
- If CD4 drops below 50, prophylaxis with:
- Azithromycin —> covers for mycobacterium avium complex ( causes fever, diarrhea, weight loss)
Complication of AIDS/HIV
- Cryptococcus meningitis
- treated with: Amphotericin
- associated with pigeon exposure - Cytomegalovirus (CMV)
- causes colitis, esophagitis, retinitis, bloody diarrhea
Three types of diarrhea in AIDS
- Cryptosporidium
- a lot of watery diarrhea - CMV
- bloody diarrhea - MAC
- fever + diarrhea
Types of vaccination in HIV
- people with HIV gets three vaccines:
- Pneumovax
- influenza
- HAPPY
Lymphogranuloma venereum
Vs.
Granuloma inguinale
Lymphogranuloma venereum
- Type of chlamydia ( L1 to L3)
- Painless Genital ulcer + inguinal lymph adenopathy
- Has Buboes (big painful hard red inguinal nodes)
Granuloma inguinale
1. Caused by Klebsiella Granulomatis
2. Painless Genital ulcer + inguinal lymph adenopathy
3. Nodes ulcerates & turn into granulomas
Neurosyphilis (case 1)
-Treatment with —> benzadezapen (penicillin)
-Left arterial uveitis ( sign of neurosyphilis)
-ENT —> otitis media & osteomestatitis ( use audiogram investigation with ENT —> for speech assistance)
-
(CASE 2)
-Blast injury
- fever + tachycardia ( several days maybe due to pain) —> look at infectious causes —>
- mixed organisms: enterococcus fecalis, candida, bactrem, klebsiella, pseudomonas, staph aureus —> treated with tegacyclin ( to cover entercocus & staph aureus) , merapenem ( pseudomunas coverage)
- PEG line inserted —> ( 85% burn patient ) —> send culture, if positive change PEG LINE
- Note: if use tazosyn instead of meropenem & sos instead of tegacyclin—-> will by time for patient
- HA
- candida aureus can stay at line —->
Case 3 ( RASH)
- young + pakistan + 10 days history of rash all over his body at extremity + vesicle with different stages + headache + No recent travel + no cough + good appetite
- vesicle are fluid filled some are crusted and some are not /// no ulcers
- lymph node at peripheral
- is it monkey pox ? Is it veresella ? IgG & IgM & PCR for diagnosis of the vesicle
- chicken pox (in adults manifistation as: 1. Pneumonitis , 2. CNS: ENCEPHALITIS, meningitis , or meningeal encephalitis ) ( in children manifistation of CNS within 10 days & treat with steroid)
- DANGI manifistation is 3 weeks —>
Case 4 (
46 year old + somali + 3 months ago abdomenal & back pain —> descitis at x-ray + Now: lower limb swelling & immobilization
- Down syndrome, diabetes , HTN
- admit as cellulitis ( foroproxicellin for treatment )
- plan: do MRI for spine & leg to look for descitis —> check for brucella —> drain if needed
- the mother died and had TB
- DESCITIS can be possibly due to TB IN THE patient
- ## staph aureus can present with descitis
Case 5
- MRSA = use vancomycin
- Plan TEE
- covid infection —>
- septic arthritis —>
Case 5 ( drug use)
- changes in CT scan is rapid —> inflammatory of autoimmune response —> could be miliary TB
- NITROFURANTOIN FOR UTI
CASE 6 (
- 58 year old women, diabetes HTN dyslipedemia
- LIVE IN INDIA
- COME TO uae 10
- fever, body pain ( a week ago)
- cefexeme initially treatment …ECG, ECHO, Blood tests —> are not remarkable, mild elevation in LFT enzyme, negative covid
- stop tazosyn treatment Are replace it with ceftriaxone +…..
——-
Approach:
- Fever not improving after 7 days & tachycardia & desaturating ( very hypoxic; require High flow O2), no cough, no diarrhea, no rash,no history of sick contact —>
- CTPE is done —-> no PE, but suggest congestion—>
- Could be due to cardiac issue —>
- Rexicia & dingi & malaria send in serology —>
chickenpox (varicella)
The classic symptom of chickenpox is a rash that turns into itchy, fluid-filled blisters that eventually turn into scabs. The rash may first show up on the chest, back, and face, and then spread over the entire body, including inside the mouth, eyelids, or genital area.
Case 7 (
- Bangladish + smoking + present with fever & fatigue for 3 months +
- fever, pancytopenia, no lymph node, mild hepatosplenomegaly + weight loss in last + no night sweat
- EBV pcr —> 700,000
- diagnosis : hematologic malignancy ( pancytopenia)
- order bone marrow biopsy
Case 8 (
Hx:
-Bacterecemia + scrotal abscess + MRSA managed
- scrotal enlargement + abscess —> order ultrasound to look for
- patient on vancomycin & tazo
-blood culture shows —> polymicrobial (pseudomonas, epidermatis)
—> stop vancomycin
—>
Case 9 (
- ## bacteremia with MSSA
Genital ulcers ( different diagnosis)
1.Syphilis
- well-circumscribed chancre (ulcer)
- painless genital ulcer & painless LAD
- caused by: treponema pallidum
- treated with:
1. penicillin G
2. Doxycycline, if allergy to penicillin
3. Desensitize than treat with penicillin, if pregnant women or patient with patient with syphilis involving CNS
4. Ceftriaxone: if tertiary syphilis
5. Note: patient treated with penicillin —> treponema pallidum can release endotoxin that lead to fever, myalgia & chills ( Jerish Herxheimer Rxn) —> prevented with prednisolone —> treated with: NSAID & IV fluid
- LGV
- small & shallow ulcer —> forms buboes
- painless genital ulcer & painful LAD
- caused by: Chlamydia trachomatis ( L1 to L3)
- inclusion bodies within the cytoplasm of epithelial cells & leukocytes
- treated with: - Doxycycline
- Granuloma inguinale
- extensive granulation tissue
- Painless genital ulcer & no LAD
- shows Donovan bodies ( gram negative intracytoplasmic cysts)
- caused by: Klebsiella granulomatis
- treated with: doxycycline - Genital herpes
- group of ulcer with shallow & erythromatous (red) base
- painful genital ulcer & mild LAD
- cowdry type A & multinucleated giant cells in biopsy
- caused by: Herpes simplex virus
- treat with: acyclovir - Chancroid
- deep ulcer with grey base
- painful genital ulcer & painful LAD/ with puss
- bacteria is seen in clumps within the chancroid
- caused by: Haemophilus Ducreyi
- treat with: azithromycin
Syphilis types
Primary syphilis
- start as a painless chancre ( on genital mostly)
Secondary syphilis
- rash on the palms/soles + chomdyloma lata over the genital
Late phase:
- present with Gummatous leison that has ulcerated ( seen on forehead)
Tabes dorsalis:
- affects the dorsal column + meningitis
Tertiary syphilis
Neurosyphilis
Cellulitis (common bugs)
- strep pyogene ( group A streptococcus)
- gradual onset
- deep border
Symptoms:
1. Irritated area of skin that tends to expand
2. Red, swelling, painful, warm, tender to touch + fever + chills
2. Like “ peel of orange”
Aures pallus
- caused by strep pyogene
- rapid onset
- clear distinct borders
Abscess
- caused by staph aureus
Necrotizing fasciitis
- caused by:
1. Strep pyogene (most common)
2. Clostridium perfringen (if, gas bubbles or gas gangrene presents)
Found in:
1. Alcoholics, diabetes, insect bites, post surgery
Symptoms:
1. Erythema & swelling at the affected site
2. Irritated area expands fast
3. When barely touched, patient screams in pain
4. Severe pain disproportionate to a local findings
5. Sign of severe sepsis ( tachycardia, hypotension, metabolic acidosis)
Tetanus (Algorithm)
Ask yourself:
- More than 3 vaccines Or Less than 3 vaccines
- Clean wound Or dirty wound ?
If,
- More than 3 vaccines & clean would (superficial, no dirt)
- give vaccine, if last vaccine was more than 10 years ago - Less than 3 vaccines & clean wound:
- give vaccine - More than 3 vaccine & dirty wound:
- give vaccine, if last vaccine was more than 5 years ago - Less than 3 vaccine & dirty wound:
- give vaccine & antibodies - If patient have tetany —> add diazepam to minimize muscle spasm
Note:
- tetany —> involuntary muscle contraction/spasm——> is caused by hypocalcemia ( low Ca level)
Septic arthritis vs. osteomyelitis
- both have common bugs:
- Staph aureus
- Salmonella ( if, sickle cell disease)
- Pseudomonas (if, IV drug user)
Any swollen, red, painful joint —> next step is to aspirate or do arthrocentesis for analysis —> suspect septic arthritis
Staph aureus is involves in:
- Hospital acquired or nosocomial acquired
- Abscess
- Septic arthritis
- Osteomyelitis
- Toxic shock syndrome (TSS)
Septic arthritis
Common bugs:
- staph aureus
- salmonella (if, sickle cell disease)
- pseudomonas (if, Iv drugs users)
Symptoms:
- fever, leukocytosis, inability to bear weight on the joint or move it at all + swelling/red joint
Diagnosis:
- aspiration —> shows > 50,000 WBC
Lyme disease
- caused by: Borrelia burgdorferi
- starts as erythema migrans rash ( target rash) —> red center surrounded with clear area than surrounded with red border—> forming (bull’s eye pattern) —> can spread & warm
Treatment:
1. Doxycycline (if, patient is older than 8 years)
2. Amoxicillin ( if, patient is younger than 8 years)
Note:
1. Doxycycline can cause teeth coloration as side effect which is not good for little kids
Malaria
- Plasmodium falciparum
- constant fever
- treatment: mefloquine - Plasmodium vivax/ovale
- q 48 hours fever (fever every 2 days)
- treatment: mefloquine + primaquine (kills hypnozoites in liver) - Plasmodium malariae
- q 72 hours fever (fever every 3 days)
- treatment: mefloquine
Note:
- if cyclic fever + recent travel history (india or africa) —> think of malaria
Rabies
Treatment:
- irrigate the wound + give antibodies + vaccine
Symptoms:
- hydrophobia + encephalopathy + afraid to drink water (too late stage, can be fetal)
Caused by:
- when infected saliva gets into open wound, exposure to bat or getting bitten by animal
Cat scratch disease
caused by:
1. Bartonelle hanselae
Symptoms:
- present with distal cat scratch + proximal lymphadenitis
Treatment:
1. Macrolide (azithromycin)
2. Doxycycline
Aspirgellucs
- Allergic bronchpulmonary aspergillosis (ABPA)
- asthma & eosinophilia - Aspirgilloma
- hemoptysis with chronic cough
- x-ray shows fungus ball on upper lobe of lung - Invasive aspirgillosis
- affect immunosuppressed patients (recent transplant)
- systemic symptoms ( fever, leukocytosis, hemoptysis with classic halo signs, which is pulmonary nodule with surrounding ground glass opacity
Treatment:
- Amphotericin
Dimorphic fungi
(present as both mold & yeast, due to changes in temperature )
Symptoms:
- similar to TB, but differentiated based on location
- B-symptoms (fever, night sweat, weight loss) + hemoptysis
Mnemonic —> His Coc Blasts Spores
- Histoplasma
- associated with bats & caves
- x-ray shows bilateral hilar lymphadenopathy - Coccidiodes
- west coast ( Arizona or California) (Valley Fever)
- unilateral hilar adenopathy + respiratory symptoms - Blastomyces
- Chicago disease (a person from midwest, Iowa, Illinois)
- purple skin lesion + pneumonia - Sporothrix
- hand is cut by a thorn + lymphadenitis that follows a trail up their arm
Treatment:
- itraconazole ( by moth 3-6 months)
- potassium iodide
Note:
- found in the environment as mold, infect human as yeast
Cryptosporidium
- HIV with severe watery diarrhea
Hook worms
Mnemonic —> SANd
- Ancylostoma deudenale
- Nector americanus
Path:
- walking bare foot —> penetrate—> go to lung —> cough it out —> swallow it —> go to GI
Symptoms:
1. Itchy, localized rash, abdominal pain, diarrhea + eosinophilia
Cystisoma
- snail
- person from middle-east with hematuria & eosinophilia
Note:
- snail releases trematode, which penetrates skin —> invades circulation —> adult deposits eggs in bladder wall —> inflammation —> hematuria
Toxic shock syndrome (TSS)
Caused by:
1. Staph aureus —> Exotoxin hyper-activates T-cells, which release a lot of cytokines & lead to shock
Symptoms:
- Shock + nosebleed ( leave a tissue/tampon inside nose for a while) + desquamation (skin peeling)
Treatment:
1. Iv fluid + vancomycin
Neutropenia —> Neutropenic fever
-Neutrophil count is less than 1500
Neutropenic fever:
- Treat empirically at first (culprit pseudomonas)
- Treat with zosyn (piperacillin-Tazobactem) to cover pseudomonas
Gastroenteritis (causes diarrhea & vomiting)
- bloody or watery diarrhea
- Most common bloody diarrhea (SEECSY) —> fever + bloody diarrhea
- Salmonella
- E.coli (EHEC)
- Entamoeba (protozoa)
- Campylobacter
- shigella
- Yersinia Enterocolitica - Most common watery diarrhea
- Norovirus ( begins 12-48 hours after contact & lasts 1-3 days)
- Rotavirus ( begins 2 days after contact, lasts 3-8 days)
- ETEC (if, recent travel to south American)
Note:
1. Best next step is stool analysis for WBC
2. If positive WBC (from stool analysis)—> do stool culture
Treatment:
1. Most bloody diarrhea treated symptomatically
- Give antibiotics ( if, really young/old, or immunosuppressant)
- Avoid antibiotics for EHEC ( predispose to hemolytic uremic syndrome—> HUS)
Timing of diarrhea
- N/V + diarrhea within 1-6 hours:
- Staph aureus
- Bacillus cereus ( heated rice) - Abdominal cramps + diarrhea within 8-16 hours:
- Clostridium perfrinogens
- bacillus cereus - Diarrhea only ( water or bloody) after 16 hours:
- vibro cholera ( watery)
- E.coli (EHEC; Bloody), ETEC; watery)
- salmonella ( bloody)
- campylobacter ( bloody)
- shigella ( bloody)
C. Difficile
- patient taking antibiotics and developed diarrhea afterwards
Investigation:
- look for C.difficile toxin
Rocky mountain spotted fever
(
- rickettsia infection
- transmitted by tick bite
- peak in summer
Symptoms:
1. Constitutional symptoms (headache, fever, myalgia, arthralgia)
2. Rash
3. Complication: encephalitis, pulmonary edema, bleeding, shock
Laboratory:
1. Low platelets
2. Low sodium
3. High AST & ALT
Diagnosis:
1. Rickettsia serology
2. Skin biopsy
Treatment:
Doxycycline
Rocky mountain spotted fever
(Mainly in the summer)
- is a tick-borne illness caused by Rickettsia
-classic symptoms include a few days of fever & headache
- followed by maculopapular or petechial rash that involves the palm & soles.
- without emperic treatment (doxycycline), noncardiogenic pulmonary edema & shock can occur
Pertussis
- gram negative coccobacilli
- 1/2 weeks of rhinitis & cough
- 2/8 weeks of severe dry cough & vomit
Diagnosis:
1. Pertussis PCR
2. Pertussis culture
Prevention:
1. Acellular pertussis Vaccination (immunity wane off after 5-10 years)
2. Macrolide (azithromycin) for close contact
Culture- positive endocarditis
(holosystolic murmur at apex —> mitral regurgitation with MVP)
( splinter hemorrhage + audible murmur + petechia )
( treat with: vancomycin to cover MRSA, Enteroccoci, Strep.)
- Enterococci (enterococcus facalis)—> common cause of endocarditis associated with nosocomial Urinary Tract Infection
- Staph aureus & epidermidis —> endocarditis due to prosthetic valves & intravascular catheter
- Viridin (strep sanguinis)—> endocarditis due to dental care
- Candida —> endocarditis due to prolonged antibiotic use
- Strep. Gallolyticus ( Bovis) —>bacteremia+ endocarditis associated with colon cancer —> require colonoscopy to evaluate for occult malignancy
Secondary bacteria occurs as complication of common influenza
- worsen fever & pulmonary after initial improvement
- usually age > 65
- but, MRSA occurs in younger patients
Shiga-toxin producing E.coli
food-borne pathogen (contaminated beef) —> inflammatory diarrhea ( stool initially watery, then becomes bloody)
Different types of diarrhea
- Shiga-producing toxin E.coli
- bloody diarrhea only + associated with contaminated beef - Rotavirus:
- nonbloody diarrhea + associated with unvaccinated children - Listeria:
- watery diarrhea + self-limited lasting 3 days + associated with immunocompetent patient - Clostridium perfringen:
- nonbloody diarrhea + abdominal pain + associated with contaminated & undercooked meat + symptoms resolve in 1-2 days
Strep. Pneumonia
- most common cause of bacterial meningitis in elderly patient ( followed by: H.influenza, Neisseria)
- in children ( Group B strep, E.coli, Listeria)
Pyelonephritis ( caused by proteus mirabilis)
- fever+ flank pain + dysuria
- lead to urinary tract infection
