STEPTRACKERMICROBIOLOGY + ONCOLOGY + HEMATOLOGY | DNA VIRUSES | HIGH-YIELD REVIEW

Adeno, Papilloma, Polyoma, Parvo & Pox

The non-herpes DNA viruses — four naked families that resist the environment, plus the giant cytoplasmic poxviruses.

FOCUS ON
Adenovirus: pharyngoconjunctival fever (swimming pools), keratoconjunctivitis, pneumonia (military recruits), hemorrhagic cystitis, gastroenteritis. HPV: 6/11 → warts, condylomata acuminata, laryngeal papillomas; 16/18 → cervical, anal, oropharyngeal cancer (E6 inactivates p53, E7 inactivates Rb); koilocytes; 9-valent vaccine. Polyoma: JC → PML (AIDS, natalizumab); BK → transplant nephropathy, hemorrhagic cystitis. Parvo B19: erythroid precursors (P antigen) → slapped-cheek rash, aplastic crisis in sickle cell, hydrops fetalis, arthritis in adults. Pox: molluscum (umbilicated papules), smallpox, mpox.
DISEASE
VIRUS · MECHANISM
CLINICAL PICTURE
CLUE · MANAGEMENT
Pharyngoconjunctival fever
Adenovirus (respiratory, swimming pools)
Fever, pharyngitis, follicular conjunctivitis, preauricular nodes
Summer camp outbreaks
Epidemic keratoconjunctivitis
Adenovirus, highly contagious (fomites, eye clinics)
Red, watery eye, foreign-body sensation
Hand hygiene; naked virus survives
Adenovirus pneumonia · cystitis
Military recruits · children, transplant
Atypical pneumonia · hematuria with dysuria
Oral vaccine for recruits · cidofovir if severe
Warts
HPV 1, 2, 4 (common, plantar)
Hyperkeratotic papules on hands, feet
Cryotherapy
Condylomata acuminata · laryngeal papilloma
HPV 6, 11 (low risk)
Cauliflower anogenital warts · hoarse child (vertical transmission)
Imiquimod, cryotherapy, excision
HPV cancers
HPV 16, 18 (high risk); E6 → p53 degradation, E7 → Rb release of E2F
Cervical squamous carcinoma, anal, penile, oropharyngeal (p16 ⁺) cancers
Koilocytes (perinuclear halo, raisinoid nucleus) · Pap/HPV testing · vaccine ages 9–26 (up to 45)
Progressive multifocal leukoencephalopathy
JC virus infects oligodendrocytes → demyelination
AIDS (CD4 < 200), natalizumab, rituximab: progressive focal deficits, vision loss, cognitive decline
Non-enhancing white-matter lesions · restore immunity
BK nephropathy
BK virus reactivation in kidney transplant
Rising creatinine, graft dysfunction; hemorrhagic cystitis after bone marrow transplant
Lower immunosuppression
Erythema infectiosum (fifth disease)
Parvo B19 via respiratory route
Child: "slapped cheek" rash → lacy reticular rash on limbs
Not contagious once rash appears
Aplastic crisis
B19 infects erythroid precursors (P antigen) → red cell production stops 1–2 weeks
Sudden severe anemia with low reticulocytes in sickle cell, hereditary spherocytosis
Transfusion
Hydrops fetalis · adult disease
B19 crosses placenta → fetal anemia, heart failure · immune complexes in adults
Fetal edema, ascites · symmetric small-joint arthritis (women)
Chronic anemia in immunocompromised · IVIG
Molluscum contagiosum
Poxvirus; skin contact
Flesh-colored, dome-shaped, umbilicated papules; extensive in AIDS
Molluscum bodies (eosinophilic inclusions)
Smallpox · mpox
Variola (eradicated; bioterror) · monkeypox (close contact, sexual)
Synchronous deep pustules, centrifugal · mpox: pustules + prominent lymphadenopathy
Tecovirimat · vaccinia-based vaccines

Mechanism — how HPV causes cancer

High-risk HPV integratesBreaks E2 gene
→
E6, E7 overexpressed
→
E6 → p53 degradedNo apoptosis
E7 → Rb inactivatedE2F free → S phase
→
Dysplasia → carcinoma

Viral childhood rashes

DISEASE
VIRUS
RASH CLUE
Measles
Paramyxovirus
Head → down, after Koplik spots
Rubella
Rubivirus
Head → down, fast; postauricular nodes
Fifth disease
Parvo B19
Slapped cheek → lacy
Roseola
HHV-6
After fever breaks
Chickenpox
VZV
Vesicles in all stages
Hand-foot-mouth
Coxsackie A
Oral ulcers + palm/sole vesicles

How it's tested

COMMON CONFUSIONPML (JC virus, oligodendrocytes, non-enhancing lesions) vs toxoplasmosis (ring-enhancing lesions) vs primary CNS lymphoma (single enhancing lesion, EBV) in AIDS.
THE TRAPParvovirus aplastic crisis has a low reticulocyte count — unlike hemolytic crises, where reticulocytes rise.
YOUR APPROACHNaked DNA virus → tissue it targets (eye/airway, squamous epithelium, oligodendrocyte/kidney, erythroid precursor) → host → expected disease.

If you see… think…

Fever, pharyngitis, conjunctivitis after a swimming pool → adenovirus
Child with hematuria after bone marrow transplant → adenovirus or BK virus
Koilocytes on Pap smear → HPV
E6 and E7 oncoproteins → HPV 16/18 (p53, Rb)
Hoarse toddler with laryngeal papillomas → HPV 6/11
MS patient on natalizumab with new progressive deficits → PML (JC virus)
Rising creatinine in a kidney transplant, decoy cells in urine → BK virus
Sickle cell child with sudden anemia, reticulocytes near zero → parvovirus B19
Fetal hydrops after maternal "slapped cheek" exposure → parvovirus B19
Umbilicated pearly papules in a child → molluscum contagiosum