* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download DNA viruses: Adeno-, Pox-Papilloma
Dirofilaria immitis wikipedia , lookup
2015–16 Zika virus epidemic wikipedia , lookup
Onchocerciasis wikipedia , lookup
Trichinosis wikipedia , lookup
Eradication of infectious diseases wikipedia , lookup
African trypanosomiasis wikipedia , lookup
Herpes simplex wikipedia , lookup
Hospital-acquired infection wikipedia , lookup
Influenza A virus wikipedia , lookup
Oesophagostomum wikipedia , lookup
Leptospirosis wikipedia , lookup
Schistosomiasis wikipedia , lookup
Sexually transmitted infection wikipedia , lookup
Neonatal infection wikipedia , lookup
Hepatitis C wikipedia , lookup
Ebola virus disease wikipedia , lookup
Human cytomegalovirus wikipedia , lookup
Orthohantavirus wikipedia , lookup
Coccidioidomycosis wikipedia , lookup
West Nile fever wikipedia , lookup
Middle East respiratory syndrome wikipedia , lookup
Marburg virus disease wikipedia , lookup
Henipavirus wikipedia , lookup
Hepatitis B wikipedia , lookup
DNA viruses: Adeno-, PoxPapilloma- and Polyoma Viruses Foundation Block, ID#2799 Objectives • Describe general properties of adeno-, pox-, papilloma-, and polyomaviruses • Learn clinical manifestations caused by these viruses • Understand the different routes of transmission of these viruses • Describe diagnostic approaches • Understand the principles of prevention and treatment Adenoviruses Adenoviruses • Description: • Icosahedral, non-enveloped viruses, double strand DNA, virion: 70-90 nm, 252 capsomers • Unique morphological feature (slender fibers) • Replication in cell nucleus • First detected from adenoids • 51 human serotypes • Seven human subgroup: A-G • Different serotypes are associated with different conditions: • • • • Respiratory (mainly subgroup B and C) Enteric (subgroup F serotypes 40&41, subgroup G type) Conjunctivitis (subgroup B and D) Cystitis (subgroup B) Adenovirus • Pathogenesis: – Infection is usually acquired during childhood – Transmitted by direct contact, fecal-oral route, and occasionally waterborne transmission – Virus multiplies in conjunctiva, nasopharynx, lymph nodes, intestinal mucosa – Some types are capable of establishing persistent asymptomatic infections in tonsils, adenoids, and intestines and shedding can occur for months or years in urine or stool – Some adenoviruses (e.g., serotypes 1, 2, 5, and 6) have been shown to be endemic in some parts of the world Adenovirus A.Respiratory syndromes - Account for 5% of RTI 1. Acute febrile pharyngitis -- Infants, young children 2. Pharyngoconjunctival fever – Conjunctivitis, fever, pharyngitis and adenoidal enlargement – Swimming pools 3. Acute respiratory disease – Military recruits, high morbidity – Ad4, 7 and 21 – Crowding, repeated exposure to highly infectious doses and stressful physical exercises – Fever, malaise, sore throat, hoarseness and cough 4. Pneumonia Adenovirus B. Hemorrhagic cystitis: • Hemorrhagic cystitis is lower urinary tract symptoms • Caused by Ad11 and 21 of subgroup B • Infectious – The most common cause of acute (primary) viral hemorrhagic cystitis in children (6-15 yrs. old boys) – Acute dysuria, hematuria and hemorrhage • Noninfectious in immunosuppressed patients • • • • Serious complication due to reactivation of latent virus Asymptomatic hematuria Urinary retention Disseminated to other organs may lead to death Adenovirus C. Enteric infections (serotype 40,41) • Adenoviruses account for 4-15% of all hospitalized children with gastroenteritis • Fecal oral route D. Conjunctivitis (subgroup B and D) • Epidemic keratoconjunctivitis – Swimming pools – Aggressive conjunctivitis, pain, photophobia, lymphadenopathy, keratitis (inflammation of the cornea) result in impaired eye vision Adenovirus • Treatment – No antiviral drug – Supportive and relieving the symptoms • For respiratory infection include increase fluid intake, bronchodilator medication and oxygen supplement • For enteric include rehydration with water, mother milk and administration of electrolytes (orally or by IV fluids) Adenovirus • Prevention – Hand washing – Wearing gloves – Avoid public swimming pools – Vaccine available for acute respiratory disease which consist of Non-attenuated live vaccine • • • • Only for military personnel's not civilians Packed in enteric capsules Replicate only in the intestine Asymptomatic infection Adenovirus • Laboratory diagnosis – Virus isolation – Immunofluorescent test (IFT) – ELISA Poxviruses • Properties: – – – – – Largest (230-280 nm) Enveloped dsDNA viruses 15 enzymes Cytoplasmic replication Poxviruses • Laboratory Diagnosis – Clinical symptoms – Antibody detection – Virus isolation • Transmission – Inhalation of infected air droplets or aerosols Poxviruses Classification: 1. Orthopox viruses 1.Variola 2.Vaccinia 3.Cowpox 4.Monkeypox 2. Parapox viruses 1.Orf 2.Pseudocowpox 3. Molluscipoxvirus Variola • Is the causative agent of smallpox • Fever, chills, headaches, nausea, vomiting and severe muscle pain • The most characteristic symptom is the rash • Macule, papule, vesicles, pustules which form scares Smallpox • During the 18th century killed an estimated 400,000 in Europe each year • During the 20th century killed 300-500 million deaths • In 1950 killed an estimated 50 million cases Smallpox • Eradication of smallpox Why it was possible? No animal reservoir No carrier state Potent vaccine Characteristic symptoms Rare subclinical cases • In December 1979 WHO certified the eradication of smallpox Vaccinia • Closely related to smallpox • Mild self limiting disease • Result in a rash only at the site of vaccination • Live vaccinia virus is administered under the skin • Protect against smallpox Cowpox • • • • • • • Rare Rates are the natural reservoir Cows and human are accidental hosts Resembles smallpox and vaccinia Localized ulcerating lesion Self limiting disease Transmitted by direct contact with the infected animals during milking • Protect against smallpox Poxviruses • Monkeypox virus – – – – First identified in monkeys Prevalent in central and west Africa Disease resembles smallpox Transmitted by contact with infected animal blood, lesion or body fluids – Transmitted from person to person by infected respiratory droplets or touching infected body fluids – Last for 2-4 wks Monkeypox virus • Congo 1970-80: 60 cases 1981-86: 400 “ 1996-03: >500 “ • Outbreak in US – June, 2003, 71 cases • Usually infect prairie dogs, squirrels, imported pets and rodents Orf (pustular dermatitis) • The virus can survive for 6 months in the soil • Transmitted to human by direct or indirect contact with infected sheep or goats • The infection result in a single painless solitary or multiple cutaneous lesions on the hand, forearm or face • Lesions heal relatively slow without complications • Can lead to a serious eye infection • Can be treated by cidofovir Pseudocowpox virus (milker’s nodules) • Pseudocowpox is a worldwide disease of cattle. • Symptoms include ring or horseshoe shaped scabs on the teats, which usually heal within six weeks. • Lesions may also develop on the mouths of nursing calves. • Spread is by vomits, including hands, calves' mouths, and milking machines. • Lesions appear on the hands of milkers. Poxviruses • Molluscipoxvirus Molluscum contagiosum • In children transmitted by saliva – Rash is confined to the face, neck, Palms and arms, painless • In adults transmitted sexually – Rash confined to the genitals, lower Abdomen and inner thighs • Self limiting disease (few months to one year) Papilloma- and Polyoma Viruses • Papillomaviruses – – – – – – – – Icosahedral, non-enveloped virus double strand DNA, 70-90 nm More than100 human types Not growing in cell cultures Direct contact Virion in keratinocytes (horny tissue, brown to grey) Develop into a typical hyperkeratotic nodules-painless Latent infection in basal cells Life cycle of papillomavirus Papillomaviruses Clinical manifestations: 1. Cutaneous warts, hyperkeratosis – Benign lesions on the skin, cauliflower-like surface and are typically slightly raised above the surrounding skin – Peak incident in children between 10-14 yrs (swimming pools and changing rooms) – Start as flesh colored papules which develop into hyperkeratotic nodules (painless) Verruca plana V. plantaris V. vulgaris Papillomavirus 2. Epidermodysplasia verruciformis – Rare life threatening disease – Autosomal recessive genetic hereditary skin disorder associated with a high risk of carcinoma of the skin – It is characterized by abnormal susceptibility to HPVs of the skin – Large proportion of people with the disease are descendant of related marriages – They develop wide spread of scaly macules and papules, particularly on the face, hands and feet – It is typically associated with HPV types 5 and 8 Papillomavirus 3. Condyloma acuminata (Genital warts) – Most common benign genital warts in both sex – Transmitted by sexual contact – Estimated 450,000 new cases per year – The highest incident is seen in late teens and early adulthood – Infection most often regress spontaneously – Majority of infections become latent – Recurrences are common Papillomavirus 4. Laryngeal papilloma • Benign tumor • Rare condition • Found in both adults and children • Result in bad voice and breathing difficulties • Should be removed in a regular basis to prevent blockage of the respiratory tract Papillomaviruses 5. HPV and cervical cancer (intraepithelial cervical neoplasia; ICN) – HPV type 16, 18, 31 and 45 – Account for 11% of all cancers in women and 2% in men – 200,000 death worldwide per year – Malignant and premalignant lesions can be detected by routine cervical screening (PAP smear) – DNA detection technique (PCR) – If detected early the treatment is very successful Laboratory Diagnosis of HPV • PAP smear (routine cervical screening) • Samples are taken from the endocervical and/or vagina • Cells are fixed and stained with a special stain which allow us to see nuclear and cytoplasmic details • Abnormal PAP smear show changes in cells like irregular perinuclear cytoplasmic clearing • PCR (HPV DNA) Treatment options for HPV 1. Cryotherapy – The most commonly used – Liquid nitrogen to freeze the warts and the surrounding tissues – Significant pain – Multiple visits 2. Surgical excision – Remains one of the options – Reccurency rate is high – Secondary infection 3. Laser therapy – Promising results – Recurrency rate high – Costly and require specific skills – Impractical for wide spread Treatment options for HPV 4. Cidofovir – Antiviral drug activated by intracellular enzymes to form an inhibitor for DNA polymerase – Showed promising results for cutaneous and genital warts especially in immunocompromised hosts 5. Cytodestructive therapy – Salicylic acid trichloroacetic acid – Side effect include burning erosions, pain, inflammation and recurrency rate is high 6. Immunomodulators – Imiquimode and Interferon – Enhance the immune response by increasing cytokine production and stimulating CMI to HPV – Significant reduction of total warts area and recurrency rate is high – Side effect is mild Polyomaviruses • JC virus • BK virus • New polyomaviruses: – KI – WU – Merkel cell JC virus • Progressive multifocal leukoencephalopathy (PML), also known as progressive multifocal leukoencephalitis • Rare and usually fatal viral disease that is characterized by progressive damage or inflammation of the white matter of the brain at multiple locations • It occurs almost exclusively in people with severe immune deficiency • It is caused by JC virus, which is normally present and kept under control by the immune system after a primary infection. • Most primary infections are asymptomatic or mild infection after which the virus remains latent in brain cells JC virus • Symptoms include weakness or paralysis, vision loss, impaired speech, coma and death. • Laboratory diagnosis – PML is diagnosed by testing for JC virus DNA in cerebrospinal fluid or in a brain biopsy specimen. – Characteristic evidence of the damage caused by PML in the brain can also be detected on MRI images. JC virus • Treatment – Alter immunosuppressive drugs according to the viral load – Antimalarial drugs • Mefloquine is an antimalarial drug that can also act against the JC virus. • Administration of mefloquine seemed to eliminate the virus from the patient's body and prevented further neurological deterioration. BK virus • • • • • • Primary infection usually asymptomatic Mild respiratory infection or fever Some cases develop haemorrhagic cystitis Remains latent in the kidney and urinary tract Immunosuppressive drugs activate the virus In transplant patients: – Haemorrhagic cystitis (inflammation of the bladder leading to dysuria, hemorrhage and hematuria) – Ureteric stenosis (abnormal narrowing in blood vessels – BKV-associated nephropathy (BKVAN) leading to graft rejection due to damage in the kidney BK virus • Diagnosis is done by the detection of viral DNA: • Blood • Urine • Biopsy from the kidney • Treatment – Stop immunosuppressive drugs – Immunomodulators to restore CMI – Cidofovir Merckel cell Polyomavirus (MCV) • Merkel cell carcinoma (MCC) which is a rare skin cancer and highly aggressive. • Occur more frequently in immunosuppressed patients • MCC occurs most often on the face, head, and neck. • It usually appears as a firm, painless, nodule, or tumor. • These flesh-colored, red, or blue tumors vary in size from 5 mm to more than 5 cm. • MCC metastasizes quickly and spreads to other parts of the body, tending towards the regional lymph nodes. • The tumor tends to invade underlying subcutaneous fat and muscle. • It can also metastasize to the liver, lungs, brain or bones. Polyomaviruses • Diagnosis of MCV – PCR • Treatment – Surgical – Radiotherapy • Polyomaviruses WU and KI – Respiratory infections