Micro Flashcards
Chronic granulomatous disease affecting peripheral nerves and superficial tissue (nasal mucosa)?
Leprosy
Reservoir for Leprosy?
Armadillos + humans
Acid fast bacilli causing “glove and stocking” loss of sensation?
M. leprae
Causes diffuse skin lesions esp. Ear + perforation of nasal mucosa+ loss of fingers + atrophy of testicles?
Lepromatous Leprosy
Fist sings of Lepromatous leprosy?
Edema + rhinitis
Single peripheral skin lesions w/ low numbers of acid fast bacilli? Prognosis?
Tuberculoid leprosy
Good prognosis= spontaneous healing
Characterized by low cell-mediated immunity with a Humoral Th2 response (LACK Th1 mediators)?
Lepromatous leprosy
What is the characteristic of Tuberculoid leprosy immunity response?
High cell mediated response with Largely Th1 mediated response
Tx of Tuberculoid leprosy?
Sulfone (Dapsone) + rifampin for 6 months
MOA of Sulfone?
Inhibits para-aminobenxoic acid metabolism
Tx of lepromatous leprosy?
Dapsone + rifampin + Clofazimine (at least 2yrs)
Prophylaxis tx for Leprosy in children?
Dapsone
LEpromatous leprosy is?
LEthal
Herpes Virus Genome?
Enveloped DS linear DNA
Method for HHV detection?
PCR
Tzanck test
Tzanck test?
HHV–> smear to detect multi nucleated giant cells in VZV infected skin fragments
VZV is a?
Alphaherpesvirus
HHV6 + HHV7?
Betaherpesvirus
Latency HHV?
Soon after initial infection
NO virus particles are produced
Entire genome maintained extrachromasomally
Neurotropic latency?
VZV
Lymphotrophic latency?
HHV6 + HHV7
Fever followed by itchy rash starting on scalp and trunk? (primary infection only)
Varicella (chickenpox)
Shingles?
Reactivation of VZV
Adult w/ Sudden onset of pain and rash or Pneumonia? Reactivation
Shingles (VZV)
Tx for Adult w/ Pneumonia and Painful rash?
Acyclovir and Steroids
Vaccine for VZV?
Live attenuated vaccine w/ MMR regiment
adults>50yo: Designed to boost immunity to prevent or lessen Zoster
HIGH fever–> Seizures–> Macular rash?
Roseola (HHV 6+7)
Age range for HHV 6+7?
3mo – 6yo
Time course for VZV to show up as chickenpox?
Infection-> replication in lymph nodes-> primary viremia-> Replication in organs-> 2nd viremia-> SKIN Vesicular Rash (14 days)
Parvovirus structure?
Linear single stranded DNA + nonenveloped
Where do parvovirus replicate?
Rapidly dividing cells-> to use active DNA poly
RBC precursors
Virus that causes decreased reticulocyte count?
Parvovirus B19
Five most common childhood diseases?
Chickenpox measles Rubella Roseola Parvo B19
“fifth disease” or “slapped cheek rash”
Erythema infectiosum (B19)
Causes “Lacy rash on the trunk and limbs?”
B19 erythema infectiosum
Adult experiencing Joint pain or swelling (polyartheritis) + flu like symptoms + small rash?
B19 erythema infectiosum
What virus causes transient aplastic crisis in SCD patients?
B19 because it replicates in RBC precursors and thus reduces the reticulocyte count
B19 infection in pregnant women?
Transplacentally transmitted to fetus and can cause fetal anemia. hydrops fetalis, or miscarriage
Variola virus structure?
Smallpox= Complex (“brick shaped”), intracellular core, lateral bodies, enveloped
Large DS DNA
Where does Smallpox replicate?
Even though its a DS DNA virus it replicates in the CYTOPLASM
Rash that starts in Head or limbs w/ vesicles that hve a dot in the middle + which become hard then crust over and fall off?
Smallpox infection–> all lesion @ same stage
Two basic forms of Smallpox?
Variola major–> 25% death rate
Variola minor–> 1% death rate
Smallpox mode of transmission?
Inhalation causing systemic disease w/ generalized rash
pt w/ HIGH fever, malaise, aches, red spots in the mouth and tongue, firm pitted lesions all same stage?
Smallpox infection
Afebrile pt w/ superficial lesions all in different stages?
Chickenpox
Tropical disease w/ lesions on face, trunk, and limbs?
Childhood Molluscum contagiosum
Young adulthood form of Molluscum contagiousum?
Lower abdominal lesions
Sexually transmitted
Lesions disappear 2-12 months
Large cytoplasmic inclusions in eosinophils?
Molluscum contagiosum (adulthood form)
Who should not receive the Live smallpox vaccine?
Pregnant or breast feeding women
Immunocomprimised
People w/ eczema, atopic dermatitis, severe acne
CHF pts
Life threatening complications of Live smallpox vaccine?
Progressive vaccinia (CMI defects)
Postvaccinial encephalitis
Eczema
Myopericarditis or heart attacks
Measles Prodrome 3Cs?
Coryza
Cough
Conjunctivitis
Pt w/ white spots overlying erythematous base in the buccal mucosa?
Koplik spots (measles)
Complications of Measles?
Giant cell pneumonia
Acute appendicitis (children)
Otitis media
NON teratogenic
3 day Rash beginning at hairline and spreading cephalocaudally + Red spots on Posterior soft/hard palate?
Rubella (Togavirus)
Painful Postauricular LAD + polyarthritis?
Rubella (togavirus)
Viruses causing polyarthritis in adults?
Rubella + parvovirus
Child <2 yo w/ high Fever and maculopapular rash?
Roseola infantum (HHV 6)
Child w/ generalized rash >3 days, Temp> 38.3 + cough, conjunctivitis and rhinorhea?
Measles
Measles genome and mode of transmission?
- RNA
Lacks NA but has H rather than HA protein
trans: Respiratory route
Measles rash coincides w/?
T cell response and clearance of virus
Replication in lymphoid tissue results in reticuloendothelial Giant cells?
Early stage of Measles
Complication of Measles?
0-1 month–> acute Encephalitis
1-9 months–> Measles inclusion body enceph
1-12 years–> Subacute slerosing Panencep
Both measles and mumps are antigenically stable monotypic viruses?
Once infected or vaccinated Immunity is for Life
Virus initially infects nasal mucosa + URT epithelium and spreads via lymph nodes?
Mumps
Pt with infected Parotid gland?
Mumps (first clinical sign)
Complications of mumps?
Aseptic meningitis Deafness Gonadal atrophy Myocardial invasion type I DB Abortion
Pt w/ low grade fever, conjunctivitis, sore throat, LAD and Morbilliform rash?
Rubella
Rubella virus in pregnant women?
Abortions
Birth defects: motor or mental, deafness, CHD, cataracts
Rubella tx and antivirals?
vaccine for Fetal protection
NO antivirals because Disease is mild
What virus has H protein, lacks NA, and forms intracellular inclusion?
Measles virus
Measles virus genome and transmission?
non segmented -RNA
Respiratory route
What does the Rash in measles coincide with?
T cell response and virus clearance
Rash lasting >3 days
Temp >38.3
Cough, rhinorrhea, conjunctivitis ?
Measles
Wathin-Finkeldey cells= Reticuloendothelial giant cells?
measles replication in lymphoid tissue
Maculopapular rash + Koplik spots?
Measles
Complication of Measles includes?
ADEM + PIE-> encephalomyelitis (AI demyelinating)
MIBE–> Measles inclusion body encephalitis
SSPE–> Subacute sclerosing panencephalitis
Measles vaccine?
Live attenuated–> life long protection
Viruses exhibiting monotypic antigenic stability?
Measles + Mumps–> Monotypic meaning no Ag shift or drifts ONE VACCINE needed
First clinical sign of Mumps infections?
Infection of Parotid gland
Complication of Mumps?
CNS: Aseptic meningitis + Deafness
Few: gonadal + myocardial + abortions
Togavirus genome?
Rubella= nonsegmented +RNA
Mild disease w/ low fever,conjunctivitis, Sore throat, LAD and RASH?
Rubella
Spread of Togavirus (rubella)?
Virus sheds from skin after rash diapers (up to 1mo)
Pregnancy and Rubella?
Causes congenital birth defects
Rickettsia characteristics?
G- Rods
Obligate intracellular parasites
Rickettsia replication?
Cytoplasm of Endothelial and muscle cells of small BV
Vehicle for Rocky mountain spotless fever?
TICKs
Flu symptoms–> Rash from ankles+ wrists to palms + soles+ trunk?
Rocky mtn spoted fever (RMSF)
Rash on soles and palms w/ significant calf tenderness?
RM Spotted Fever
Measures cross reactivity of anti-rickettsial antibodies to Proteus OX strains?
Weil-Felix test
Dx of RM Spotted Fever?
Indirect fluorescent Ab assay
Weil-Felix test
Tx of RMSF?
Prevention
Doxcycyline
Typhus mode of transmission?
Body lice
Associated w/ Poverty + war?
body lice thus Typhus
Ehrlichia chaffeensis (HME) transmission + replication?
Lone Star Deer Ticks
replicated in MONOCYTES
Dx of E. chaffeensis?
Wright/ Giemsa stain of Morulae in Monocytes
Tx of E. Chaffeensis?
Doxycycline
Morulae?
inclusion bodies formed by replicating microbes
What organisms form Morulae?
E. chafeensis
A phagocytophilia
A. phagocytophilia transmission and replication?
Ixodes Deer Tick
HMA= replicates inside granulocytes
Cause of “Rocky mtn Spotless fever?”
A. phagocytophilia (RASH is rare)
Cause of “Rocky mtn spotted fever?”
Rickettsia
Replicates in monocytes?
Anaplasma
Replicates in Granulocyte?
Ehrlichia
Cause of relapsing fever in Borrelia?
Undergo Antigenic variation
B. burgdorferi is causative agent of?
Lyme disease
Lyme disease is transmitted by?
Ixodes deer tick NyMPH
Classic Bull’s eye rash @ site of bite?
Early Lyme disease
Arthritis, Facial palsy, and peripheral neuropathy?
2nd Lyme disease (disseminated)
Erosive arthritis @ KNEEs + numbness + Bell Palsy?
Chronic Lyme disease
Dx of Lyme disease?
ELISA + Western blot
PCR based NAATs
Tx of early and chronic lyme disease?
Early-> Doxycycline
Chronic–> IV cephalosporins
B hermsii or B recurrentis cause?
Relapsing fever
Transmission of B. hermsii?
TIck
Transmission of B recurrentis?
Louse
Endemic in Western US?
B hermsii
Dx and Tx of relapsing fever?
Wright/ Giemsa stain
Serology
Tx: DOXY
Leptospira interogans is transmission?
Water contaminated w/ Animal urine
Flu symptoms + Renal Damage + Jaundice + Meningitis?
Leptospira
Tx and Dx for Leptospirosis?
Serology + penicillin
Bartonella hensalae transmission?
Cat scratch fever
Swollen lymph nodes and scratch marks–> TX?
Erythromycin or spontaneous