dsDNA Viruses: Herpesviridae Flashcards
What is the family and genome of the Herpesvirus?
Family Herpesviridae
Genome: Linear dsDNA
What type of capsid does a herpesvirus have?
Icosahedral
(T/F) Herpesviruses have an icosahedral capsid, an integument surrounding the capsid, and it has no envelope.
F (Has an envelope)
How does a herpesvirus replicate?
Budding
(T/F) Not all herpesviruses can achieve latency and lifelong persistence in their hosts.
F (All)
Enumerate some stimuli that can activate a herpesvirus.
Stress
Caffeine
Sunlight
What effects could the activation of a herpesvirus have?
Can cause lesions to reappear
What are the eight known species of human herpesviruses (HHV)?
(HHV-1) Herpes simplex virus type 1 (HSV-1, Human herpes virus type 1)
(HHV-2) Herpes simplex virus type 2 (HSV-2, Human herpes virus type 2)
(HHV-3) Varicella-zoster virus (VZV)
(HHV-4) Ebstein-Barr virus (EBV)
(HHV-5) Cytomegalovirus (CMV)
(HHV6) Human herpes virus 6
(HHV7) Human herpes virus 7
(HHV8) Human herpes virus 8 (Kaposi sarcoma herpes virus)
HSV-1 and HSV-2 belong to what genus?
Simplexvirus
(T/F) Most infections with HSV are symptomatic.
F( (Asymptomatic)
(T/F) HSV-1 - oropharyngeal sores (adults);
HSV-2 - genitalia (young adults)
T
The disease caused by the human simplex virus (HSV) infection is classically divided into two categories: _____ and _____.
Primary(first or initial infection)
Recurrent (Reactivation of the latent virus)
What is the category of an HSV ifection if it is the first or initial infection?
Primary
What is the category of an HSV ifection if it is the reactivation of the latent virus?
Recurrent
How is the HSV infection generally spread? (Mode of transmission)
By contact with contaminated secretions, lesions/ulceration of mucous membranes and genitalia
In a human simplex virus (HSV) infection, lesions usually occur on mucous membranes after how many days of incubation?
2 - 11 days
(T/F) Individuals infected with the human simplex virus (HSV) are lest infectious during the early days of a primary infection.
F (Most infectious)
In an individual infected with the HSV, the virus-infected cells are usually found at what part of the lesions?
Edge and in the base
What are the different clinical manifestations of the Human simplex virus (HSV)?
Oral Herpes Genital Herpes Neonatal Herpes HSV encephalitis Ocular Herpes Herpetic whitlow
Oral herpes infections are usually but not exclusively caused by what type of human simplex virus (HSV)?
HSV-1
How long is the incubatoin period of oral herpes?
varies from 2 days to 2 weeks
(T/F) Oral herpes are usually symptomatic during primary infections.
F (Asymptomatic)
When oral herpes is symptomatic during primary infection, what is/are its common manifestation/s?
Intraoral mucosal vesicles (rarely seen)
Ulcerations that may be quite widespread and involves the buccal mucosa, posterior pharynx, and gingival and palatal mucosae
When oral herpes is symptomatic during primary infection, the ulcerations that may be widespread would involve what parts of the human body?
Buccal mucosa
Posterios pharynx
Gingival and palatal mucosae
The (primary/recurrent or reactivation) HSV infection usually occurs on the border of the lips at the junction of the oral mucosa and skin.
Recurrent or reactivation
(T/F) In oral herpes, the prodrome [an early symptom indicating the onset of a disease or illness] of burning or pain followed by vesicles, ulcers, and crusted lesions is the typical pattern.
T
Genital herpes infections are usually caused by what type of human simplex virus (HSV)?
HSV-2
When genital herpes infection manifests, how will it appear in females?
As vesicles on the mucosa of the labia, vagina, or both.
Cervical and vulvar involvement is not uncommon.
When genital herpes infection manifests, what are the sites that are usually affected in males?
Shaft, glans, and prepuce of the penis
When infected with genital herpes, this part of the reproductive system is usually infected in both sexes.
Urethra
What are the complication that can occur when infected with oral herpes?
Transmission to newborn infant
Aseptic meningitis
Transmission of HIV is doubled
This infection is caused by the transmission of HSV from infected mothers to neonates.
Neonatal herpes
What is the mode of transmission of neonatal herpes?
acquired in utero, intrapartum (during birth), or postnatally (after birth)
Neonatal herpes is most commonly transmitted during _____.
Vaginal delivery
When is there reduced transmission/risk of acquiring neonatal herpes?
Mother has recurrent herpes
Cesarean section or suppressive antiviral therapy at delivery
This clinical manifestation of the human simplex virus infection is rare bu devastating, with a mortality of about 70%.
HSV encephalitis
HSV encephalitis in older children and adults is usually caused by what type of HSV virus?
HSV-1
HSV encephalitis in neonates is usually caused by what type of HSV virus ?
HSV-2
What is the treatment for a patient with HSV encephalitis?
Intravenous (IV) antiviral treatment
Patients who survive from this infection, would usually have permanent neurological disorder.
HSV encephalitis
What are the clinical manifestations of ocular herpes?
Keratoconjuncitvitis (Sore eyes)
Corneal ulceration
This is the most common cause of corneal infection in the US.
HSV
Inadvertent self transmission (autoinoculation) can occur in this clinical manifestation of herpes.
Ocular Herpes
(T/F) Ocular Herpes will heal completely with treaatment.
T
This clinical manifestation of herpes causes an intensely painful infection of the hand involving one or more fingers that typically affect the terminal phalanx
Herpetic Whitlow
Herpetic Whitlow is most commonly caused by what type of HSV virus?
HSV-1
This clinical manifestation of herpes has occupational risks among healthcare workers; persons with skin diseases can have serious infections.
Herpetic Whitlow
HSV infections are diagnosed using _____ and _____.
Antigen detection
Viral isolation
The best specimens for culture of HSV infections are:
Asprates from vesicles
Open lesions
Host cells collected from infected sites
This specimen must be used for the diagnosis of encephalitis.
Brain biopsy
What are the lab diagnosis used for HSV infection?
Cytopathology (CPE) - multinucleated grant cells from skin scrapings PCR - used for systemic/encephalitis Serology - IgG appear 4-7 days - Can't discriminate HSV-1 from HSV-2
Varicella-Zoster virus belongs to what genus?
Varicellovirus
What is the MoT of the Varicella-Zoster virus?
Droplet inhalation
Direct contact with infected lesions
What are the two clinical manifestations of the Varicella-Zoster virus?
Varicella
Zoster
This is the clinical manifestation of the Varicella-Zoster virus that is also known as chickenpox.
Varicella
This is the clinical manifestation of the Varicella-Zoster virus that is also known as shingles.
Zoster (Herpes zoster)
This is the primary infection of the Varicella-Zoster virus. It is highly contagious and more common children.
Varicella
What are the symptoms of Varicella?
Mild febrile illness
Rash
Vesicular lesion (1st - head & trunk, then limbs; heal in 1-2 weeks)
These may develop in adults infected with Varicella.
Painful oral mucosal lesions.
This is the clinical manifestation due to reactivation of the Varicella-Zoster virus (VZV) and usually occurs in adults.
Herpes zoster
After primary infection, the VZV is thought to remain latent in the _____ or _____.
Dorsal root
Cranial nerve ganglia
What is the most common presentation of zoster?
Rash followed by vesicular lesions in a unilateral dermatome pattern.
This clinical manifestation of Varicella-Zoster virus causes an inflammation of ganglia and sensory neurons.
Zoster
What are the lab diagnoses used for Varicella-Zoster virus infection?
Virus isolation
Flourescent-labeled monoclonal antibodies
In atypical cases of Varicella-Zoster virus infection, what diagnoses are used?
Culture of fresh lesions (Vesicles)
Use of Flourescent-labeled monoclonall antibodies against VZV (confirms the diagnosis)
Varicella-Zoster virus can be cultured on _____ or _____.
Human embryonicc lung
Vero cells
(T/F) The vaccination of Varicella-Zoster virus was approved in the US in 1995 and causes lifelong immunity.
T
For what diseases is the MMRV tetravalent vaccine?
Measles
Mumps
Rubella
Varicella
What is the genus of the Epstein-Barr Virus?
Lymphocryptovirus
Infectious mononucleosis (IM) is caused by this virus.
Epstein-Barr Virus
What are the signs and symptoms of the Epstein-Barr Virus that resolve within a few weeks?
Sore throat Fever Lymphadenopathy Hepatomegaly Splenomegaly
This is a symptom of the EBV that lasts longer than the other symptoms (prolonged).
General malaise
What are some complications of the Epstein-Barr Virus?
Splenic hemorrhage and rupture Hepatitis Thrombocytopenia purpura with hemolytic anemia Reye syndrome Encephalitis Other neurologic syndromes
What is the MoT of the Epstein-Barr Virus?
Direct oral contact with saliva
What is the incubation period of the Epstein-Barr Virus?
2 weeks - 2 months
Enumerate some cancers that have been associated with Epstein-Barr Virus?
Burkitt lymphoma
Hodgkin disease
Nasopharyngeal carcinoma (NPC)
This is a mallignant disease of the lymphoid tissue and is seen most commonly in African childen.
Burkitt lymphoma
This is also called the “Non-hodgkins lymphoma,” and is characteristic as cuasing the tumor of jaw area of lymphoid tissue.
Burkitt lymphoma
Fastest growing human tumor
Burkitt lymphoma
This targets/destroys B-cells causing B-cell lymphoproliferative disorders
Epstein-Barr Virus
Epstein-Barr Virus causes B-cell lymphoproliferative disorders such as:
Infectious mononucleosis (IM)
Burkitt’s lymphoma
Hodgkin’s disease
Naspoharyngeal carcinoma (NPC)
A.k.a as Kissing disease or Glandular fever
Infectious mononucleosis (IM)
What is the MoT of Infectious mononucleosis (IM)?
Close contact w/ infectious oral pharyngeal secretions
Blood transfusions
Transplacental route
Organ transplant
A viral culture for EBV requires _____.
Human B lymphocyte
EBV infects circulating B lymphocytes and stimulates them to produce multiple (Heterophile) antibodies, including antibodies to _____ and _____ blood cells and to _____.
Sheep and horse blood cells
Proteus OX19
This is antibody test is excellent for screening antibodies to sheep and horse blood cells and to Proteus OX19
Paul-Bunnel heterophile antibody test
The Paul-Bunnel heterophile antibody test is an excellent screen for antibodies to what type of cells/antigens?
Antibodies to:
Sheep and horse blood cells
Proteus OX19
The EBV-specific serologic tests measure the presence or absence of the following:
Anti-VCA (antibodies against the Viral Capsid Antigen)
Anti-EA (IgG antibody to Early Antigen) IgG
Anti-EA/D (antibody to Early Antigen/Diffuse)
Anti-EA/R (antibody to Early Antigen/Restricted)
Anti-EBNA (antibody to the EBV Nuclear Antigen)
What is the genome of the Cytomegalovirus (CMV)?
Cytomegalovirus
It is the largest genome of the human herpes viruses
Cytomegalovirus (CMV)
(T/F) It replicates only in human cells and much faster than HSV or VZV.
F (Slower than HSV or VZV)
This viruses produces the most common congenital infection in the US.
Cytomegalovirus (CMV)
What is the MoT of the Cytomegalovirus (CMV)?
Spread by close contact with an infected person
Contact with secretions (saliva) & excretions
Transmitted sexually via semen and cervical and vaginal secretions and through blood and blood products
It is also known as the “Salivary gland virus”
Cytomegalovirus (CMV)
In blood & organ transplants, this viruses causes the “40-day fever”
Cytomegalovirus (CMV)
(T/F) The Cytomegalovirus (CMV) is also shed in saliva, tears, urine, stool, and breast milk.
T
Occasionally, in immunocompetent patients this virus may manifest as a self-limiting, infectious mononucleosis-like illness with fever and hepatitis
Cytomegalovirus (CMV)
(T/F) The vast majority of Cytomegalovirus (CMV) infections are asymptomatic.
T
Symptomatic congenital infections caused by this virus is characterized by petechiae, hepatosplenomegaly, microcephaly, and chorioretinitis (Can cause blindness).
Cytomegalovirus (CMV)
Aside from petechiae, hepatosplenomegaly, microcephaly, and chorioretinitis, what are the other manifestations of the Cytomegalovirus (CMV) on symptomatic congenital infections?
Low birth weight CNS involvement Mental retardation Deafness Death
This virus is one of the leading causes of mental retardation, deafness, and intellectual impairment.
Cytomegalovirus (CMV)
What are the groups at risk for Cytomegalovirus (CMV) infections?
Neonates
Transplant patients
Immunocompromised hosts
What are the lab diagnoses used for Cytomegalovirus (CMV) infections?
Viral culture isolation (Best confirmatory)
Viral antigenemia test (Helpful in assessing the efficacy of antivaral therapy)
Molecular-based testing (PCR, branched DNA, hybridization assays - used for blood donor screening/diagnostic applications)
What is the genus of the human herpes virus type 6 (HHV-6)?
Roseolovirus
What are the two indistinguishable variants of the human herpes virus type 6 (HHV-6)?
A and B (Cause of disease)
What is the most likely route of transmission of the human herpes virus type 6 (HHV-6)?
Saliva
What is the MoT of the human herpes virus type 6 (HHV-6)?
Inhalation of respiratory droplets from infected individuals
Close contact with infected individuals
This species of human herpes virus is associated with the childhood disease roseola
human herpes virus type 6 (HHV-6)
Roseola is also called _____, _____, and _____.
Roseola infantum
Exanthem subitum
Sixth disease (role as sixth childhood rash)
Children are protected by maternal antibodies until approximately what age?
6 months
What are the lab diagnoses used for human herpes virus type 6 (HHV-6) infection?
Virus isolation
PCR
This is the most sensitive lab diagnosis used for human herpes virus type 6 (HHV-6) infection and is uses lymphocyte cell culture
Virus isolation
This offers a sensitive and specific means of diagnosing primary human herpes virus type 6 (HHV-6) infection.
PCR
What is the genus of the human herpes virus type 7 (HHV-7)?
Roseolovirus
This species of the human herpes virus was 1st isolated from peripheral blood monocytes of infected patients in 1989
human herpes virus type 7 (HHV-7)
This species of the human herpes virus causes latent infections in T lymphocytes; also cause roseola
human herpes virus type 7 (HHV-7)
Human herpes virus type 7 (HHV-7) can be isolated in culture in what types of lymphocytes?
Peripheral blood lymphocytes
Cord blood lymphocytes
What lab diagnosis can be used for human herpes virus type 7 (HHV-7) infections?
PCR
This is a.k.a “Kaposi sarcoma-associated herpesvirus”
human herpes virus type 8 (HHV-8)
What is the genus of human herpes virus type 8 (HHV-8)?
Rhadinovirus
Human herpes virus type 8 (HHV-8) can be detected in all forms of Kaposi sarcoma, including:
AIDS related
Mediterranean
HIV-1-negative endemic to Africa
Posttransplantation Kaposi sarcoma
This species of the human herpes virus has also been shown to play a role in the development of:
Primary effusion lymphomas
Multicentric Castleman’s disease
It is also isolated from HIV patients
human herpes virus type 8 (HHV-8)
What are the lab diagnosis used for human herpes virus type 8 (HHV-8) infections?
PCR
Serologi tests