DNA Viruses Flashcards
Adenoviruses Replication
Cell nucleus
Adenovirus Three Main Groups
Respiratory Diseases —> B and C
Eye Infections —> B and D
Gastrointestinal Disease —> F40, F41, G52
Adenovirus more common in?
Adenovirus Latency?
May occur in LYMPHOID TISSUE, ADENOID, TONSILS, INTESTINE with occasional and low-level shedding of virus during life
Adenovirus Clinical Manifestations (4)
1- Respiratory diseases
2- Ocular diseases
3- Non-respiratory syndromes
4- Intestinal Infections
Adenovirus- Respiratory Diseases (4)
1- Acute Febrile Pharyngitis (Infants, young children, cough, fever, stuffy nose)
2- Pharyngoconjunctival Fever (Children and young adults- outbreaks at children summer camps e.g. swimming pool conjunctivitis)
3- Acute Respiratory Disease (Outbreaks of URT and LRT infections in military recruits)
4- Pneumonia (among AIDS and Immunocompromised)
Adenovirus- Ocular Diseases (2)
1- Conjunctivitis (Red eye)
(Complete recovery)
2- Epidemic keratoconjunctivitis (Shipyard eye)
(Aggressive conjunctivitis mainly in adults, pain, photophobia, lymphadenopathy, keratitis - (inflammation of cornea) result in impaired eye vision
Adenovirus- Non-respiratory syndromes (Immunosuppressed) (2)
1- Hemorrhagic cystitis
2- Meningoencephalitis
Adenovirus- Intestinal infections (F40, F41)
Adenoviruses account for 15% of gastroenteritis among children (Acute Diarrhea)
Adenovirus Treatment (3)
Supporting and relieving symptoms
NO ANTIVIRAL drug
Most infections self-limited and do not warrant specific therapy
Adenovirus Prevention (2)
1- Live oral vaccine against type 4 and 7 for military only
2- Keep swimming pools adequately chlorinated
Poxviruses General Characteristics (3)
Largest of all viruses
Enveloped
Brick-shaped
Poxviruses Replication
Within Cytoplasm of affected cell
Poxviruses Transmission
Zoonotic disease: humans, vertebrates, arthropods are natural hosts
What do Poxvirus infections result in? (3)
Lesions, Skin Nodules, Disseminated Rash
Smallpox (Variola) Transmission (2)
1- Coughing or sneezing
2- Direct contact with fluid in Papules and Scabs
ERADICATED
Vaccinia Virus (2)
Virus used as LIVE ATTENUATED vaccine to eradicate SMALLPOX
Papules at site of vaccination, rash, vesicles, swelling, and inflammation
Cowpox Virus (6)
Closely related to Variola
Mildly eruptive disease in cows (ulcers on teats)
Wood mice are natural reservoir
Cows, cats, and humans are accidental hosts
Rare infection of humans (Farm workers). Transmitted by direct contact with infected cows during milking
Self-contained, localized ulcer on hands, face, or at other sites where scratched or abrasions allowed entry of virus
Monkeypox Virus (3)
Disease resembles Smallpox with significant mortality rate
Sources: Squirrels (main reservoir), Priarie dogs, Gambian giant rats, Primates
Transmission:
- Contact with infected animal blood, lesion, or body fluids
- Infected respiratory droplets or touching infected body fluids
ORF (3)
Transmitted to human by direct contact with infected sheep
PUSTULAR DERMATITIS (Painless solitary or multiple cutaneous lesions on hand, forearm, or face)
Treatment —> CIDOFOVIR
Pseudocowpox Virus (4)
Disease of cattle (cows, bulls, oxen, or calves)
Causing ring or horseshoe shaped coatings on teats, which usually heal within 6 weeks
Lesions may develop on mouths of nursing calves
In humans, lesions are NODULAR, appear on hands of milkers (MILKER’S NODULES)
Molluscipoxvirus (Molluscum Contagiosum)- Children
Transmitted by saliva
Nodular lesions on trunk and extremities
Round, firm, umbilicated, and painless
Molluscipoxvirus (Molluscum Contagiosum)- Adults
Transmitted sexually
Lesions limited to genitals, lower abdomen, and inner thighs
Self-limiting disease
What is Electron microscopy used to distinguish between?
Pox and Herpes virions
Papillomaviruses General Characteristics (3)
Non-enveloped
Not growing in cell cultures
Develop into nodules- painless
What do Papillomaviruses infect? (3)
Infect basal cells
Vision in keratinocytes
Excessive growth of brown to grey tissue
Papillomaviruses- Latency
In basal cells
Papillomaviruses- Clinical Manifestations (6)
1- Hyperkeratosis (Cutaneous warts)
2- Condyloma acuminata (Genital warts)
3- Epidermodysplasia verruciformis (EV)
4- Laryngeal papilloma
5- Intraepithelial Neoplasia
6- Cervical cancer
Hyperkeratosis (Cutaneous warts) (2)
Flat warts —> Verruca planae
Common warts —> Verruca vulgaris
Condyloma Acuminata (Genital warts) (3)
Benign genital warts in both sex (LOW RISK types)
LATENCY
RECCURENCIES
Epidermodysplasia Verruciformis (EV) (3)
High risk of CARCINOMA of skin exposed to SUNLIGHT
Scaly macules and reddish papules, particularly on face, hands, and feet
HPV 5 and 8
Laryngeal Papilloma (4)
Most common in CHILDREN
HPV 6 and 11
Transmitted during DELIVERY and establish PERSISTENT infection
Bad voice and breathing difficulties
Intraepithelial Neoplasia
HPV 16, 18, 31, 45 causation of carcinoma in both Cervix and Penis
HPV Treatment (4)
1- Cryotherapy
2- Surgical excision
3- Laser therapy
4- Cidofovir
HPV Vaccines (3)
Cervarix—> HPV 16 and 18 (cause cervical cancer)
Gardasil—> HPV 6 and 11 (cause genital warts) and HPV 16 and 18 (cause cervical cancer)
Gardasil 9 —> HPV 16, 18, 31, 33, 45, 52, 58 (cause cervical cancer) and HPV 6 and 11 (cause genital warts)
Polyomaviruses (5)
Non-enveloped
Widespread in nature, mammals, and birds serve as natural hosts
Common CHILDHOOD infection, mostly asymptomatic
In immunocompetent hosts, viruses remain LATENT after primary infection
REACTIVATE during immunosuppression
Polyomavirus JC- Clinical Manifestations (4)
Progressive Multifocal Leukoencephalopathy (PML)
Rare and fatal —> Progressive damage or inflammation of WHITE MATTER of brain
Occurs in people with severe immunodeficiency e.g. AIDS
Symptoms include weakness, paralysis, vision loss, impaired speech, coma, and death
Polyomavirus JC- Treatment (2)
1- Antiviral Drugs —> Cidofovir
2- Antimalarial Drugs —> Mefloquine
Polyomavirus JC- Diagnosis (2)
1- PCR: In CSF or brain biopsy specimen
2- MRI: Characteristic evidence of damage in brain
Polyomavirus BK- Clinical Manifestations (4)
Immunocompetent —> Asymptomatic, after primary infection LATENCY in KIDNEY and URINARY TRACT
Transplant patients —>
1- Hemorrhagic Cystitis (in HSCT recipients)
2- Ureteric Stenosis (in Renal transplant recipients)
3- BKV-associated Nephropathy (leading to graft rejection due to damage of kidney)
Polyomavirus BK- Treatment (2)
1- Lowering immunosuppressive agents
2- Cidofovir
Merckel Cell Polyomavirus (MCV)- Clinical Manifestations (3)
Merkel Cell Carcinoma —> Rare skin cancer and highly aggressive
SUM-EXPOSED face, head, and neck
Metastasizes quickly, tending towards regional lymph nodes
