Adenoviridae and Respiratory Diseases
39 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary cause of nonbacterial pharyngitis and tonsillitis?

  • Adenovirus types 21–25
  • Adenovirus types 15–20
  • Adenovirus types 1–7 (correct)
  • Adenovirus types 8–12

    • Which serotypes of adenovirus are most associated with pneumonia in adults?

  • Types 3, 7, and 21 (correct)
  • Types 1, 2, and 3
  • Types 5, 6, and 7
  • Types 8, 9, and 10

    • What is a characteristic of the adenovirus structure?

  • Naked icosahedral capsid with linear double-stranded DNA (correct)
  • Membranous envelope with single-stranded DNA
  • Complex branched structure with RNA
  • Enveloped and spherical

    • What is the primary mode of transmission for adenoviruses?

    <p>Respiratory droplets and fecal-oral route</p> Signup and view all the answers

    What is the typical incubation period for respiratory infections caused by adenovirus?

    <p>2-14 days</p> Signup and view all the answers

    What is the most common age range for children affected by erythema infectiosum?

    <p>4-11 years</p> Signup and view all the answers

    Which diagnostic method is preferred for detecting acute parvovirus B19 infection in immunocompromised patients?

    <p>PCR</p> Signup and view all the answers

    Which of the following components make up the herpes virus virion?

    <p>Nucleic acid core, capsid, tegument, and envelope</p> Signup and view all the answers

    Which herpes virus type is primarily associated with lesions above the waist?

    <p>Human herpes virus type 1</p> Signup and view all the answers

    What is the hallmark characteristic of herpesviridae?

    <p>Latency</p> Signup and view all the answers

    Which method is used for diagnosing fetal infection with parvovirus B19?

    <p>PCR and Antibody testing using cord blood</p> Signup and view all the answers

    What type of virus is most commonly associated with causing respiratory and gastrointestinal infections?

    <p>Adenovirus</p> Signup and view all the answers

    What is a common transmission route for HSV type 2?

    <p>Sexual contact</p> Signup and view all the answers

    What stimulates the reactivation of herpes simplex virus (HSV)?

    <p>Fever, stress, and UV exposure</p> Signup and view all the answers

    Which of the following statements about Papillomaviruses is correct?

    <p>They can cause cervical cancer due to transforming proteins E6 and E7.</p> Signup and view all the answers

    What is the main method of transmission for high-risk HPV types associated with cancer?

    <p>Sexual contact</p> Signup and view all the answers

    In which patient group is the non-attenuated live Adenovirus vaccine specifically used?

    <p>Military personnel</p> Signup and view all the answers

    Which of the following is NOT a common clinical manifestation of Papillomavirus infections?

    <p>Viral Pneumonia</p> Signup and view all the answers

    Which serotypes of adenovirus are specifically associated with diarrhea and vomiting?

    <p>Serotypes 40 and 41</p> Signup and view all the answers

    What type of infection is caused by adenovirus in immunocompromised patients?

    <p>Systemic Infection</p> Signup and view all the answers

    Which type of DNA does Papillomavirus contain?

    <p>Circular double-stranded DNA</p> Signup and view all the answers

    What is the primary method that can distinguish between Herpes Simplex Virus and Varicella-Zoster Virus?

    <p>Immunofluorescence of skin scrapings</p> Signup and view all the answers

    Which agent is the drug of choice for treating Herpes Simplex Virus infections?

    <p>Acyclovir</p> Signup and view all the answers

    What is the most common complication of Varicella infection?

    <p>Secondary bacterial infection of vesicles</p> Signup and view all the answers

    How long does it typically take for antibodies to appear after an initial Herpes Simplex Virus infection?

    <p>1-2 weeks</p> Signup and view all the answers

    What is the primary mode of transmission for Varicella-Zoster Virus?

    <p>Respiratory droplets and direct contact with lesions</p> Signup and view all the answers

    What is a characteristic feature of Varicella during the primary infection?

    <p>Widespread vesicular rash</p> Signup and view all the answers

    Which diagnostic method is routinely used for herpes simplex encephalitis?

    <p>PCR</p> Signup and view all the answers

    What is a major concern regarding the use of older antiviral agents like Idoxuridine?

    <p>They are highly toxic</p> Signup and view all the answers

    What is the primary cause of shingles?

    <p>Varicella-Zoster Virus</p> Signup and view all the answers

    What symptom is often associated with herpes zoster?

    <p>Intensive pain</p> Signup and view all the answers

    Which complication is associated with shingles?

    <p>Ramsay Hunt Syndrome</p> Signup and view all the answers

    Which testing method is used to confirm a recent varicella-zoster virus infection?

    <p>VZV IgM test</p> Signup and view all the answers

    Which vaccine is recommended for prevention of shingles in adults over 50 years old?

    <p>Zostavax</p> Signup and view all the answers

    What is a common mode of transmission for Epstein-Barr Virus?

    <p>Saliva and sexual contact</p> Signup and view all the answers

    What is the main site of latency for Epstein-Barr Virus in the body?

    <p>Memory B-cells</p> Signup and view all the answers

    What does a rise in VZV IgG titer indicate?

    <p>Recent shingles infection</p> Signup and view all the answers

    What type of treatment is commonly used for herpes zoster?

    <p>Acyclovir</p> Signup and view all the answers

    Which of the following is a serious complication associated with chickenpox?

    <p>Viral pneumonia</p> Signup and view all the answers

    Study Notes

    Adenoviridae

    • Naked icosahedral capsid, linear double stranded DNA
    • About 70-90nm in size
    • First isolated from human adenoids and tonsils in the 1950s
    • Stable at 37°C for about a week, inactivated at 50°C
    • Resistant to ether and bile salts
    • Targets epithelial cell nuclei
    • Genus: Mastadenovirus (human infections), Aviadenovirus (infects birds)
    • 85 human adenovirus serotypes divided into seven species (A through G)
    • Common causes of respiratory and gastrointestinal disease
    • May cause conjunctivitis, keratitis, and disseminated multi-organ disease in immunocompromised individuals
    • Modes of transmission: respiratory droplets, fecal-oral route, and fomites
    • Incubation period: 2-14 days (respiratory infections), 3-10 days (gastroenteritis)

    Respiratory Diseases

    • Pharyngitis: Major cause of nonbacterial pharyngitis and tonsillitis, presenting as a febrile common cold
    • Types 1–7 are commonly responsible for pharyngitis
    • Pneumonia: Adenovirus types 3 and 7 are associated with pneumonia in adults
    • Types 3, 7, and 21 are responsible for about 10–20% of childhood pneumonias
    • Type 7 can lead to serious and fatal pneumonia in infants and young children
    • Acute respiratory diseases (ARD): Adenovirus is a cause of ARD syndrome among military recruits

    Systemic Infections

    • Meningitis: Serotypes 3 and 7
    • Immunocompromised patients:
      • SCID: Pneumonia and hepatitis
      • AIDS: Latent kidney infections (urine), subgenus D seen in stool
      • Bone marrow transplant recipients

    Treatment and Prevention

    • No specific antiviral chemotherapy, supportive care only
    • Adequate chlorine levels in water are recommended for swimming pool-associated conjunctivitis
    • Vaccine: Non-attenuated live Adenovirus types 4, 7, and 21 packaged in enteric capsules, available for military use only

    AAVs (Adenovirus Associated Viruses)

    • Members of the Parvoviridae family
    • Dependent on Adenoviruses or Herpes Simplex Virus to provide missing functions

    Key Points

    • Adenoviruses are 70-90nm in size, first isolated in the adenoids
    • Adenoviruses cause a variety of infections, including respiratory and gastrointestinal infections
    • Diarrhea and vomiting are caused by adenovirus serotypes 40 and 41
    • No specific treatment, supportive care only
    • Vaccine available for military use only (Adenovirus 4, 7, 21)

    Papillomavirus

    • ~55nm in size
    • Can cause infections in humans, dogs, cattle, monkeys, and other species
    • HPVs (human papillomaviruses) cause warts
    • Targets cutaneous and mucosal tissues
    • Over 200 serotypes

    Papillomaviruses - Oncology

    • Envelope proteins E6 and E7 are transforming proteins associated with cancer initiation
    • High-risk HPV genotypes cause cervical, vulvar, vaginal, squamous cell oropharynx, anal, and penile cancer
    • 95% of all cervical cancers are HPV-related
    • 70% of cervical cancers are caused by HPV 16 and 18

    Papillomaviruses - Epidemiology

    • Modes of Transmission: Sexual, Vertical, Direct contact with infected material
    • Incubation Period:
      • Genital warts: 3 months after exposure
      • Cancer: Several years after infection

    Papillomaviruses - Clinical Manifestations

    Skin

    • Common Warts (Verruca vulgaris): HPV 1, 2, 4
    • Flat Warts (Verrucae plana): HPV 3
    • Epidermodysplasia verruciformis

    Mucus Membrane

    • Genital Warts:HPV 6, 11
    • Laryngeal Warts:HPV 6, 11

    Carcinoma

    • Cervical Cancer: HPV 16, 18, 31, 33, 35

    Parvovirus B19

    • Mode of Transmission: Respiratory droplets
    • Diagnosis:
      • Antibody Testing (Parvovirus IgM): Detects acute infection
      • PCR: Detects acute infection in immunocompromised patients and those with aplastic crisis
      • PCR and Antibody testing using cord blood: Diagnoses fetal infection
    • Treatment: Supportive care

    Summary

    • Parvovirus is the smallest DNA virus, approximately 22nm in size
    • Naked icosahedral DNA capsid
    • 2 subfamilies: Parvovirinae and Densovirinae
      • Densovirinae: Infects insects
      • Parvovirinae: Infects vertebrates
    • Dependoparvovirus: Adeno-associated virus
    • Bocaparvovirus: Human Bocavirus
    • Erythrovirus: Parvovirus B19
      • Associated with the P antigen
      • Causes Erythema Infectiosum (5th disease)

    Herpesviridae

    • Enveloped icosahedral capsid, linear double stranded DNA
    • Approximately 120-300nm in size
    • "Herpes" means "to creep"
    • Virion consists of four components: nucleic acid core, capsid, tegument, and envelope
    • 3 subfamilies:
      • Alphaherpesvirinae: HSV type 1 and 2, VZV
      • Betaherpesvirinae: CMV, HHV-6, HHV-7
      • Gammaherpesvirinae: EBV, HHV-8

    Herpesviridae - Latence and Reactivation

    • Hallmark characteristic: Latency
    • Reactivation can be triggered by:
      • Fever, stress, UV exposure, axonal injury, immunosuppression
    • Form Cowdry type A intranuclear inclusion bodies

    Human Herpesviruses

    • Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2)
    • Varicella-zoster virus (VZV)
    • Epstein-Barr virus (EBV)
    • Cytomegalovirus (CMV)
    • Human herpesviruses 6 and 7 (HHV-6 and HHV-7)
    • HHV-8 (associated with Kaposi sarcoma)

    Herpes Simplex Virus

    • Infects either the skin or genitalia
    • HSV type 1 (HHV type 1) is usually isolated from lesions in and around the mouth. Transmitted by direct contact or droplet spread from cases or carriers. Infections occur above the waist.
    • HSV type 2 (HHV type 2) is transmitted sexually or from a maternal genital infection to a newborn. Infections occur below the waist.

    Herpes Simplex Virus - Pathogenesis

    • Initially infect and replicate in mucoepithelial cells
    • Establish latent infection in innervating neurons
    • Infections in immunocompromised hosts are particularly dangerous

    Herpes Simplex Virus - Laboratory Diagnosis

    • Direct Detection:
      • Electron microscopy of vesicle fluid: Rapid result but cannot distinguish between HSV and VZV
      • Immunofluorescence of skin scrapings: Can distinguish between HSV and VZV
      • PCR: Now used routinely for the diagnosis of herpes simplex encephalitis and other herpes simplex infections
    • Virus Isolation:
      • HSV-1 and HSV-2 are easily cultivated
      • Results usually available within 1-5 days
    • Serology:
      • Not useful in the acute phase because antibodies appear 1-2 weeks after infection
      • Used to document recent infections

    Herpes Simplex Virus - Treatment

    • Acyclovir: Drug of choice for most situations
      • IV: For HSV infection in normal and immunocompromised patients
      • Oral: For treatment and long-term suppression of mucocutaneous herpes and prophylaxis of HSV in immunocompromised patients
      • Cream: For HSV infection of the skin and mucous membranes
      • Ophthalmic ointment: For eye infections
    • Famciclovir and valacyclovir: Oral only, more expensive than acyclovir
    • Other older agents: Idoxuridine, trifluorothymidine, Vidarabine (ara-A)
      • These are highly toxic and are suitable for topical use for ophthalmic infections only

    Varicella-Zoster Virus

    • Varicella: Causes chickenpox (primary infection)
    • Zoster: Causes shingles (secondary infection)
    • Common childhood disease with highest prevalence in 4-10 year olds
    • Highly contagious, attack rate of 90% in close contacts
    • Mode of Transmission: Respiratory droplets, direct contact with lesions
    • Transmission: Gains entry via the respiratory tract, spreads to the lymphoid system
    • Incubation Period: 14 days
    • After primary infection, the virus remains latent in the sensory ganglia

    Varicella-Zoster Virus - Varicella (Chickenpox)

    • Primary infection
    • Incubation period: 14-21 days
    • Presents with fever, lymphadenopathy, and widespread vesicular rash
    • Diagnosis usually made on clinical grounds alone
    • Complications occur more frequently and with greater severity in adults and immunocompromised patients
    • Most common complication: Secondary bacterial infections of vesicles
    • Severe complications include:
      • Viral pneumonia
      • Encephalitis
      • Hemorrhagic chickenpox

    Varicella-Zoster Virus - Herpes Zoster (Shingles)

    • Usually affects a single area of the skin
    • Most common in patients over 50 years old
    • Reactivation of latent virus in a sensory ganglion
    • Reactivated virus travels down the sensory nerve to the appropriate segment
    • Eruption of vesicles in the skin, often accompanied by intense pain (postherpetic neuralgia)
    • Complications include:
      • Ophthalmic zoster
      • Generalized zoster
      • Ramsay Hunt Syndrome

    Varicella-Zoster Virus - Clinical Indications and Testing

    • Clinical Indication:
      • Chickenpox
      • Shingles
      • Encephalitis/meningitis (if patient has had VZV infection before)
    • Specimens:
      • Vesicle fluid
      • CSF
      • Clotted blood
    • Tests:
      • Electron microscopy
      • PCR
      • Virus Culture
      • VZV IgM
      • VZV IgG
    • Interpretation of Positive Results:
      • Indicates a herpes virus infection (all herpes viruses look alike in the EM, so cannot distinguish between VZV and HSV)
      • Indicates VZV infection
      • Indicates recent VZV infection
      • Indicates previous VZV infection

    Varicella-Zoster Virus - Treatment

    • Self-limiting
    • Acyclovir
    • Famciclovir and valacyclovir: For Herpes zoster

    Varicella Zoster Virus - Prevention

    • Chickenpox:
      • Live attenuated vaccine (2 doses): Varivax®, ProQuad®
    • Zoster:
      • Zostavax for adults over 50 years old
      • Shingrix for adults over 50 years old
    • Prophylaxis:
      • Passive immunization with Varicella-zoster immunoglobulin (VZIg)

    Epstein-Barr Virus (EBV)

    • Human herpesvirus 4
    • Mode of Transmission: Saliva and sexual contact (hence the name "kissing disease")
    • Common in younger children and sexually active adolescents
    • Site of latency: Memory B-cells
    • Infected B-cells are transformed to become capable of continuous growth in vitro
    • Associated with various infections

    ### Epstein-Barr Virus - Clinical Manifestations

    • Infectious mononucleosis (mono)
      • Presenting symptoms: Fever, fatigue, sore throat, lymphadenopathy, and splenomegaly
      • Classic mononucleosis: Sore throat. Often have tonsillitis with a white exudate.
      • Other symptoms:
        • Headache
        • Abdominal pain
        • Rash
        • Hepatitis
        • Splenomegaly
    • Other infections:
      • Nasopharyngeal carcinoma: In endemic areas with a high incidence of EBV infection
      • Burkitt lymphoma: Common in Central Africa
      • Hodgkin's lymphoma
      • Systemic lupus erythematosus
      • Multiple sclerosis

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Adenoviridae PDF

    Description

    Explore the fascinating world of Adenoviridae, focusing on its structure, transmission, and effects on human health. This quiz covers various adenovirus serotypes and their association with respiratory and gastrointestinal diseases. Test your knowledge about the impacts of adenoviruses, especially on immunocompromised individuals.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser