DNA viruses Flashcards
Smallest DNA - Naked Icosahedral SS; causes 5th disease, Aplastic anemia, Hydrops fetalis, Erythema infectiosum
Parvovirus B19 (Parvoviridae)
Parvoviridae Human bocavirus causes respiratory infections
Human bocavirus
Naked Icosahedral DS, circular, causes Warts, Cervical cancer
Human papillomavirus (HPV) (Papillomaviridae)
Naked Icosahedral DS, circular, causes PML
JC virus (Polyomaviridae)
Naked Icosahedral DS, circular, causes Hemorrhagic cystitis
BK virus (Polyomaviridae)
Naked Icosahedral DS, circular, causes Merkel cell carcinoma
Merkel cell polyomavirus (Polyomaviridae)
Naked Icosahedral DS, circular, causes Trichodysplasia spinulosa
Trichodysplasia spinulosa polyomavirus (Polyomaviridae)
Enveloped Pleomorphic DS, incomplete circular; Serum or Long-incubation Hepatitis
Hepatitis B virus (Hepadnaviridae)
Naked Icosahedral DS; causes Conjunctivitis, Gastroenteritis, Respiratory infection
Adenovirus (Adenoviridae)
Enveloped Icosahedral DS, common congenital infection, cold sores
Herpes simplex virus 1 (Herpesviridae)
Enveloped Icosahedral DS, causes Genital warts
Herpes simplex virus 2 (Herpesviridae)
Enveloped Icosahedral DS, causes chicken pox, shingles
Varicella-Zoster virus (Herpesviridae)
Enveloped Icosahedral DS, causes Fever, Pneumonia, Gastritis
Cytomegalovirus (Herpesviridae)
Enveloped Icosahedral DS, causes Fever, lymphadenopathy, splenomegaly
Epstein-Barr virus (Herpesviridae)
Enveloped Icosahedral DS, causes 6th disease, Exanthema subitum, Roseola infantum, Kaposi sarcoma
HHV-6, HHV-7, HHV-8 (KSHV) (Herpesviridae)
Enveloped, Brick shaped (Complex) DS, causes Smallpox
Variola virus (Poxviridae)
Enveloped, Brick shaped (Complex) DS, causes Pox-like, Keratitis
Vaccinia virus (Poxviridae)
Enveloped, Brick shaped (Complex) DS, causes Sore mouth disease in sheep or goats
Orf virus (Poxviridae)
Enveloped, Brick shaped (Complex) DS, causes Molluscum contagiosum
Molluscum contagiosum virus (Poxviridae)
Enveloped, Brick shaped (Complex) DS, causes Monkeypox
Monkeypox virus (Poxviridae)
All DNA viruses are double-stranded except
Parvoviridae
All DNA viruses are icosahedral except
Poxviridae (complex)
All DNA viruses replicate in the nucleus except
Poxviridae (too large)
Congenital infections (STORCH) include
Syphilis, toxoplasma, others (s. agalactiae), rubella (german measles), CMV (cytomegalovirus), Herpes simplex virus (HSV)
Endemic countries for Hepatitis virus includes
Bangladesh, Nepal, Pakistan, and India
Hepatitis viruses: Infectious/non-chronic hepatitis; Primary transmission: Contaminated food/water/household contact; Other routes: Travel to endemic countries, sharing of needles in drug addicts, sexual (Men-to-men); Tests: HAV RNA through NAAT in stool/blood, IgM/IgG ELISA (common)
Hepatitis A
Pleomorphic, incomplete/partial dsDNA that replicates through RNA intermediate
Hepadnaviridae
Only DNA hepatitis virus
Hepatitis B
Transmission of Hepatitis B: Percutaneous inoculation, perinatal (mother to fetus), sexual; Incubation period: 1-3 months
Hepatitis B Transmission
Coinfection with Hepatitis D virus
Hepatitis B Coinfection
Infection with Hepatitis B: Mild, acute, or chronic; Complications lead to liver cirrhosis and hepatocellular carcinoma
Hepatitis B Infection
Best indication of viral replication and high state infectivity through NAAT (PCR)
HBV DNA
Identification of Hepatitis B virus
HBsAg
Included in Hepatitis B panel: HbeAg, Anti-HBc IgM, Anti-HBsAg
Hepatitis B Panel
High infectivity, Chronic carrier state marker of Hepatitis B
HbeAg
Acute infection marker of Hepatitis B
Anti-HBc IgM
Convalescence, Vaccination, Developed Immunity for Hepatitis B
Anti-HBsAg
Liver parenchymal damage for Hepatitis B; Additional liver function tests
ALT, AST
Hepatitis deficient RNA virus that needs HBV to replicate in cells
Hepatitis D
Hepatitis C virus: Hepatitis, hepatocellular carcinoma; Screening
Anti-HCV EIA or NAAT
Waterborne Diseases
Giardia, Cryptosporidium, HEV
NAAT PCR hepatitis; Transmission: Consumption of drinking water contaminated with animal feces or potentially zoonotic; Disease: Acute and generally self-limiting with liver enlargement but no further disease progression
Hepatitis E
High fatality of Hepatitis E
3rd trimester; Avoid travels to HEV endemic areas like India, Pakistan
Tests for Hepatitis E
IgM/IgG, ALT/AST
Herpesviridae components
dsDNA, icosahedral capsid, tegument, envelope
Unique hallmark characteristic of Herpesviridae
Latency; Reactivation causes: fever, emotional stress, UV light, axonal injury, immunocompromised hosts
Other names for skin lesion caused by HSV-1 and HSV-2
Herpes labialis, facialis, febrilis
Other names for skin lesion caused by HSV-1
Cold sores, Fever blister, Orolabial lesion, Oropharyngeal lesion
Alpha herpesvirinae; Simplexvirus Oropharyngeal and genital lesions Neurons; Encephalitis, mucous membrane disease Rapid antigen, ELISA, PCR, Cell culture
HHV-1 Herpes simplex virus type 1
Alpha herpesvirinae; Simplexvirus; Genital lesions (mucosa, labia, vagina; shaft, prepuce, glans) Neurons Aseptic meningitis, Mucous membrane vesicles; Rapid antigen, ELISA, PCR, Cell culture
HHV-2 Herpes simplex virus type 2
Alpha herpesvirinae; Simplexvirus Vesicular lesion Neurons Meningoencephalitis NAAT
Herpes B virus
Alpha herpesvirinae - Varicella-Zoster virus; Chicken pox Neurons
Varicellovirus HHV-3
Accompanied by Postherpetic neuralgia (with chronic debilitating pain) = Microscopy: Scrape base of lesion and stain with Tzanck, Giemsa, or H&E NAAT, Cell culture
Shingles/Varicella-Zoster virus”
Beta-herpesvirinae; Most common cause of congenital birth defects; Infectious mononucleosis - like illness. Glands, Kidneys, Multi-organ involvement, Sheds in saliva, urine, tears, stool, breast milk, semen Direct antigen, Serology, NAAT, Cell culture (HDF)- human diploid fibrolast owl’s eye appearance (reed-sternberg cells in hodgkin lymphoma)
HHV-5 Cytomegalovirus
Roseolovirus; 6th disease, Exanthem subitum
HHV-6 Human herpesvirus 6
Roseolovirus - Exanthem subitum
HHV-7 Human herpesvirus 7
Pityriasis rosea, Graft-vs Host disease; PCR = HHV-6, HHV-7
HHV-6, HHV-7
Gamma-herpesvirinae - Lympho-cryptovirus Infectious mononucleosis, Kissing disease, glandular fever; lymphadenopathy, splenomegaly, Burkitt lymphoma
HHV-4 Epstein-Barr virus
Kaposi sarcoma-associated herpesvirus; Kaposi-sarcoma = Rhadinovirus HHV-8
HHV-8 Kaposi sarcoma-associated herpesvirus
HPV koilocytes seen in which virus
HPV
HPV type for plantar warts
HPV 1
HPV type for common warts on hands
HPV 2, 4
HPV type for genital warts
HPV 6, 11
HPV types causing cervical cancer
HPV 16, 18
Condylomata acuminata appearance
Cauliflower-shaped genital warts
How to visualize cervical warts
Colposcopy (acetic acid application)
Vaccine for HPV prevention
Gardasil
Virus first isolated from adenoids and tonsils
Adenoviridae
Adenovirus types causing gastroenteritis
Adenovirus 40, 41
Adenovirus types causing keratitis/conjunctivitis
Adenoviridae
Incubation period for adenovirus respiratory infection
2-14 days
Incubation period for adenovirus gastroenteritis
3-10 days
Transmission routes for adenovirus
Droplets, airborne, fecal-oral
Adenovirus cytopathic effect
Grapelike cytopathic effect (hexon)
Which type of animals does Parvovirus B19 infect
Warm-blooded animals
Transmission routes for Parvovirus B19
Respiratory droplets, transplacental (vertical transmission)
Replication site for Parvovirus B19
Erythroid progenitor cells, adult bone marrow, fetal liver cells
Diseases caused by Parvovirus B19
Fifth disease, Slapped cheek syndrome, Erythema infectiosum, Aplastic crisis, Hydrops fetalis
Phases of Parvovirus B19 illness
Biphasic illness: First phase (fever, malaise, myalgia, chills), Second phase (Rash, arthralgia)
Tests for Parvovirus B19
NAAT, IgM/IgG ELISA
Specimens for Parvovirus B19 testing
Blood, amniotic fluid, bone marrow
JC virus full name
John Cunningham
BK virus at-risk population
Renal transplant patients
First human polyomavirus
JC virus / JCPyV
Disease caused by JC virus
Progressive Multifocal Leukoencephalopathy (PML)
Diagnostic test for JC virus
PCR - CSF, Brain biopsy
Polyomavirus associated with hemorrhagic cystitis
BK virus / BKPyV
Diagnostic test for BK virus
PCR - Urine
Polyomavirus associated with skin cancer
Merkel cell virus / MCPyV
Polyomavirus associated with skin disease
Trichodysplasia spinulosa virus / TSPyV
Difference between MPOX Dade I and Dade II
Dade I - Ia and Ib (outbreaks in Africa, more infectious, severe, deadly); Dade II - IIa, IIb (milder, less severe, global outbreak)
Characteristics of Poxviridae
Largest and most complex virus to humans
Poxviridae shape and inclusion bodies
Oval or Brick-shaped; Guarineri inclusion bodies
Virus causing severe smallpox
Variola major
Virus causing less severe smallpox
Variola minor
Virus transmitted through oropharynx, nasopharynx, or skin abrasion
Monkeypox
Symptoms of Monkeypox
Fever, headache, lymphadenopathy, rash on face appears first
Monkeypox disease progression
Incubation period (5-21 days) → Febrile stage → Rash stage → Recovery
Best test for diagnosing Monkeypox
Real-time PCR of OPS/NPS (best sample - vesicle fluid, Lesion swab/crusts)
Monkeypox vaccine type
Mpox live attenuated vaccinia virus
Virus causing water warts
Molluscum contagiosum virus
Transmission of Molluscum contagiosum virus
Direct contact, fomites, or sexual contact
Virus causing painful nodules on hands from sheep to humans
Orf virus
Orf virus transmission
From sheep to humans
Symptoms of Orf virus infection
Single or multiple painful nodules in hands