viruses Flashcards
DNA virus - diagram
DNA virus –> 1. complex nucleocapsid 2. icosahedral nucleocapsid
1. DNA virus –> complex nucleocapsid –> envelop –> DS linear –> poxvirade –> a. smallpox b. molloscum contagiosum c. cowpox
2. DNA virus –> icosahedral nucleocapsid –> a. enveloped
b. non envelop
A. DNA virus –> icosahedral nucleocapsid –> enveloped:
- DS circular –> HEPADNAVIRIDAE (HBV)
- DS linear –> HERPESVIRIDAE (HSV1, HSV2, CMV, EBV, HHV6-8, VZV)
B. DNA virus –> icosahedral nucleocapsid –> nonenveloped:
- DS linear –> Adenoviridae
- DS circular –> Papovaviridae (Papillomavirus, Polyomavirus)
- SS linear –> Parvoviridae (B19)
Adenovirus - causes
- febrile pharyngitis (sore throat)
- Acute hemorrhagic cystitis
- Pneumonia
- Conjunctivitis (“pink eye”)
Papillomavirus (HPV) causes
- warts (serotypes 1,2, 6, 11) (condylomata acuminata on genitalis -6, 11)
- Cervical intraepithelial neoplasia (most commonly 16, 18)
- Cervical cancer (most commonly 16, 18)
- penile/anal cacrinoma (most commonly 16, 18)
- head and neck cancer (mc 16)
B19 virus causes
- aplastic crisis in sickle cell disease, thalassemia β, hereditary spherocytosis,
- slapped cheeks (erythema inectiosum or fifth disease)
- during pregnancy RBCs destruction –> fetal death (1st trimester), hydrops fetalis (2nd trimester), not significant in 3rs trimester
- RBCs destruction also leads to Rheumatoid arthritis - like symptoms and pure RBC aplasia
poxvirus - viruses?
a. smallpox b. molloscum contagiosum c. cowpox
cowpox causes
milkmaid blisters
Moloscum contagiosum - presentation
flesh colored papule with central umblication
HHV-6 causes
Roseola infantum (exanthem subitum) (6th disease)
HHV-7 causes
Roseola infantum (exanthem subitum) (6th disease) (LESS COMMONLY)
Roseola infantum (exanthem subitum) (6th disease) - presentation
high fevers for several days that can seizures, followed by a diffuse macular rash
CMV is also called / transmission
HHV-5
- congenitally
- transfusion
- sexual contact
- saliva
- urine
- transplant
CMV (HHV-5) causes
- mononucleosis with (-) Monospot in immunocompoment)
- congenital infection
- in immunocompromised patients (pneumonia, retinitis, hepatitis, encephalitis, neuropathy) –> esp pneumonia in transplant
CMV (HHV-5) retinitis?
AIDS retinitis –> hemorrhage, cotton-wool exudates, vision loss
CMV (HHV-5) latent in / histology
mononuclear cels
characteristic “owl eye” inclusions
EBV is AKA / transmission
HHV-4
resp secretions, saliva
EBV (HHV-4) causes
- Mononucleosis
- endemic Burkit lymphoma
- Hodgkin lymphoma
- nasopharyngeal carcinoma
- primary CNS lymphoma in immunocompromised patients)
- Hairy leukoplakia (HIV+, organ transplant recipients)
Hairy leukoplakia is occurs in
HIV+, organ transplant recipients
VZV - transmission / aka
respiratory secretions
HHV-3
VZV causes
- chickenbox
- shingles
- encephalitis
- pneumonia
- Acute disseminated (postinfectious) encephalomyelitis (after)
HSV-1 causes
- oral lesions (gingivostomatitis, herpes labialis)
- keratinoconjuctivitis
- temporal lobe encephalitis
- genital lesions (rare) (herpes genitalis)
- herpes whitlow
- Kluver-Bucy
HSV-1 - temporal lobe encephalitis - presentation
- altered mental status
- seizures
- aphasia
HSV-2 causes
- Herpes genitalis
- neonatal herpes
- oral lesion (rare)
- herpes whitlow
HSV identification - process
- viral culture for skin/genitalia
- CSF pcr for herpes encephalitis
- Tzanck test - a smear of an opened skin vesicle to detect multinucleated giant cells commonly seen in HSV1, 2 and VZV infection
- Intranuclear inclisions also seen with HSV-1, HSV-2, VZV
Viral vaccines - categories and viruses
A. Live attenuated vaccines (1. smallpox 2. yellow fever 3. rotavirus 4. VZV 5. Sabin polio 6. Influenza (intransal) 7. Measles 8. Mumps 9. Rubella)
B. Killed (1. Rabies 2. Influenza (injected) 3. Salk Polio 4. HAV)
C. Subunit (1. HBV (antigen=HBsAg) 2. HPV (types 6, 11, 16, 18))
6th disease?
5th disease?
6- Roseola infantum (exanthem subitum)
5- slapped cheeks (erythema inectiosum)
RNA virus - helical nucleocapsid - diagram
helical nucleocapsid –> enveloped:
- SS- segmented:
a. Bunyaviridae)
b. Arenoviridae (Arenovirus)
c. Orthomycoviridae (Influenza A,B,C) - SS+ nonsegmented
a. Coronoviridae –> Coronovirus - SS- nonsegmented
a. Filoviridae (filovirus)
b. Rhbdoviridae (lyssavirus)
c. Paramyxoviridae (Parainfluenza, RSV, Measles, Mumps)
RNA virus - icosahedral nucleocapsid - diagram
- Nonenveloped
A. SS+ non-segmented
- Picornaviridae –> a. Rhinovirus B. enterovirus (Poliovirus, Hepatitis A virus, coxsackievirus, echovirus)
- Caliciviridae –> Clicivirus (Norovirus, Hepatitis E)
B. DS segmented –> Reoviridae (Rotavirus, Coltivirus) - Enveloped
A. SS+ diploid –> Retrovirus (HIV, HTLV-1, HTLV-2)
B. SS+ non-segmented
- Flaviviridae (Flavivirus)
- Togaviridae (rubella, Eastern equine encephalitis, Western equine encephalitis)
C. SS- circular –> Deltavirus (NOT EXACTLY icosahedral nucleocapsid)
coronovirus causes
- common cold
- Severe acute respiratory syndrome (SARS)
- Middle East Respiratory Syndrome (MERS)
Lassa virus causes
Lassa fever ecephalitis (a form of hemorrhagic fever)
Lassa virus transmission
- spread by rodents (contaminated food or water by rodent urine
- person to person via bodily fluids
Hantavirus - characteristics clinical manifestation
hemorrhagic fever, pneumonia
Embola virus - course
abrupt onset of flu-like symptoms, diarrhea/vomiting, high fever myalgia –> DIC, diffuse hemrrhage, shock –> high mortality rate
Rabies virus - Post-exposure prophylaxis
- wound cleaning
- imunization with killed vaccine
- rabies immunoglobulin
(PASSIVE ACTIVE IMMUNITY)
RSV causes
respiratory tract infection (bronchiolitis, pneumonia) in infants
Mumps virus infection - symptoms
- parotitis
- orchitis
- Aseptic meningitis
- Pancreatisis
Mumps virus infection - complication
can cause sterility, especially after puberty
measles (rubeola) usual presentation
prodromal fever with cough, fever and conductivities, then eventually Koplik spots, followed (1-2days) by maculopapular rash that starts on at the head/neck and spreads downward
- Lymphadenitis with Warthin-Finkeldey giant cells (fused lymphocytes) in a background of paracortical hyperplasia
Koplik spots?? They are associated with?
bright red spots with blue-white center on buccal mucosa that precede the measles rash by 1-2 days
measles (rubeola)
measles (rubeola) - possible sequelae
- Subacute sclerosing panencephalitis (SSPE) - years later
- enecephalitis (1:2000)
- giant cell pneumonia (rarely, in imminosuppressed)
Coxsackievirus causes
aseptic meningitis, herpangina (mounth blisters, fever), hand - foot and mount disease, myocarditis, pericarditis
Norovirus causes
viral gastroenteritides
Rotavirus causes
- MCC of fatal diarrhea in children
- the most important global cause of infantile gastroenteritis
- Major cause of diarrhea in USA during winter especially in day care centers, kindergartens
Coltivirus causes
Corolando tick fever
Poliovirus - vaccine (type and rout)
- Salk –> killed (inactivated poliovirus vaccine (IPV)) –> injection
- Sabin –> live attenuated vaccines (oral poliovirus vaccine (OPV)) –> oral
Yellow fever - transmission / reservoir
Aedes mosquitoes (monkey or human reservoir)
Yellow fever symptoms
high fever
black vomitus
jaundice
Rubella virus causes (and aka)
rubella (German (3-day) measles)
rubella - symptoms
MILD disease in children but SERIOUS congenital disease
- Fever
- postauricular and other lymphadenopathy
- arthralgias
- fine rash (confluent macules that starts on the face and spread centrifugically to involve the trank and extremities
congenital rubella causes
- Blueberry muffin appearance (rash)
2. classic triad a. PDA (or pulmonary artery hypoplasia b. cataracts c. deafness
interferons - clinical use
Interferons - α: 1. chronic hepatitis B, C 2. Kaposi sarcoma 3. hairy cell leukemia 4. condyloma acuminatum 5. renal cell carcinoma 6. malignant melanoma
Interferons - β: multiple sclerosis
Interferons - γ: chronic granulomatous disease
interferons - side effects
- neutropenia
- myopathy
- Flu-like symptoms
- depression 1
HSV causes (on CNS)
HSV-1 –> encephalitis
HSV-2 –> meningitis
Hand-foot-month disease is caused by? clinical presentation
Coxsackievirus type A
OVAL-haped vesicles on palms and soles
vesicles and ulcers in oral mucosa
Rubeola (Measles) is caused by? clinical presentation
Beginning at head and moving down (maculopapular). Rash is preceded by cough, coryza, conjuctivitis, and blue white (Koplik) sptos on buccal mucosa
Chickenpox is caused by? clinical presentation
VZV
vesicular rash begins on trunk –> spreads to face and extremities with lesions of DIFFERENT STAGES
hepres zoster (shingles) - clinical features
- prodromal: itching, tingling, burning in dermotomal distribution
- rash: papules + vesicles on erythematuous base, ulceration + crusting, acute neirtic pain
- postherpetic neuralgia: neeuritic pain pain more than 4 months after rash onset
herpes zoster (shingles) - treatment
- antiviral therapy: acyclovir, valacyclovir, famciclovir
- neuralgia: TCA, pregabaln, gabapentin
CMV mononucleosis - manifestation
persistent fever, malaise, fatique with absolute atypical lyymphocytosis on complete blood count and atypical lymphocytes on peripheral blood smear
- unlike EBV: no pharyngitis, lymphadenopathy or splenomegaly
Parvovirus B19 infection - manifestation
- Most are asymptomatic or flulike symptoms
- erythema infectiosum (5th disease): fever, nausea, SLAPPED CHEEK (in children)
- acute summertic arthritis (like RA)
- transient pire red cell aplasia
Parvovirus B19 infection - diagnosis
acute infection : IgM in immunocompetent, NAAT for DNA in immunocompromised
previous: IgG
Reactivation: NAAT for B19 DNA
adults at high risk for influenza complications
- older than 65
- women who are pregnant + up to 2 wks postpartum
- chronic medical illness
- immunosuppression
- morbid obesity
- native americans
- nursing home or chronic care facility residents
indications of oseltamivir in flu
- RF (65 or older, chronic medical problems, pregnancy
2. without RRD who come within 48 hours
IM - complications
airway compromise
- autoimmune hemolytic anemia
- thrombocytopenia
exposure to HBV of a nonimmunized - next step
both HB vaccine (within 12 hours) and immune globulin (within 24 hours)
Infect mono - heterophile antibody test
negative at the beginning (look for atypical lymphocytes)
clinical featrues of chronic HCV - clinical presentation
asymptomatic or nonspecific symptoms
- high transminases
- progression to cirrhosis in 220% and HCC
chronic HCV - extrahepatic
- hematologic, mixed cryoglobulinemia syndrome
- membranoproliferative glumeruloneph
- dermatologic: porphyria cutanea tarda, liches planus
HCV antibodies positive - next step?
HCV RNA PCR testing
- the diagnosis of chronic infection is a 2 step process that requires both positive serologic antibodies + a confirmatory molecular test for the presensnce of circulating HCV RNA
dermatological manifestation of HCV
- porphyria cutanea tarda
2. lichen planus
HCV treatment
ledipasvir-sofosbuvir
check for HSV when STD diagnosis
no: reserved for active symptoms
infectious mono - for how long avoid sports
3 weeks for sports and 4 weeks for contact sports
HBV infection - chances of recovery?
depends of age:
- healthy adults: more than 95% of recovery
- 1-5 years old 50-80% recovery
- perinatal: always chronic infection