VIRUS Flashcards
What are the DNA viruses?
poxvirus
adenovirus
herpes virus
hepadna viruses
papova viruses
What virus is under poxvirus?
variola
vaccinia
What type of virus is viriola?
DNA poxvirus
What type of virus is vaccinia?
DNA poxvirus
What illness does variola cause?
smallpox
What type of infection does variola cause?
systemic infection with vesicular rash affecting:
face
arms
legs
Describe the mortality of variola virus.
high mortality rate
What is vaccinia virus used for?
immunize against smallpox
What is vaccinia derived from?
cowpox
What virus is used to immunize against small pox?
vaccinia
What type of capsid do adenoviruses have?
icosahedral
What illness does adenovirus cause?
- upper respiratory tract infections
- latent infections in tonsils and adenoids
- tumors on injection into hamsters, rats or mice
What are the viruses under herpes virus?
Herpes simplex virus - HSV1 and HSV2
Varicellazoster VSV
Cytomegalovirus CMV
Epstein-Barr Virus EBV
What type of capsid do HSV1 and HSV2 have?
enveloped
icosahedral
What type of herpes is HSV1?
oral
What type of herpes is HSV2?
genital
What illness does HSV1 cause?
infection of oral membranes in children.
individual retains the HSV1 DNA in the trigeminal nerve ganglion for life after primary infection
What nerve is the HSV1 retained after primary infectopm?
trigeminal nerve ganglion
Describe HSV1 reinfection.
50% of developing cold sores triggered by:
UV sunlight
viral infection
What is the percentage of HSV1 infection.
> 80% infection by adolescence
What type of capsid do varicella zoster virus have?
enveloped
icosahedral
What illness does varicella zoster virus cause?
human herpes virus 3
chickenpox- children
shingles- adults
Where is the VZV retained after infection?
dormant in any dorsal root ganglion of the CNS
What type of capsid do cytomegalovirus have?
enveloped
icosahedral
What virus causes human herpes virus 5?
CMV cytomegalovirus
What illness does cytomegalvirus cause?
human herpes virus 5
- subclinical infection generally acquired in childhood
- induce congenital abnormalities in pregnancy
What illnesses does the cytomegalovirus cause in immunocompromised pts?
pneumonia
hepatitis
encephalitis
What complications can CMV cause in pregnancies?
congenital abnormalities in fetus
Where is the CMV retained after infection?
50% of adults in WBC
What virus causes human herpes virus 4?
epstein-barr virus
What type of capsid does the epstein-barr virus have?
enveloped
icosahedral
How does the EBV infection occur?
salivary exchange
What illness does EBV cause?
human herpes virus 4
Mechanism of EBV in children.
- commonly asymptomatic but virus stays in latent form in lymphocytes
- the infection is delayed until adolescence = then causes mononucleosis
What does mononucleosis cause?
fever
pharyngitis
adenopathy
How does EBV present in tropical Africa?
severe EBV infection causes predisposes children to:
malignant factal tumors - Burkitt’s lymphoma
> must be co0infected with malaria
How does EBV present in china?
EBV with consumption of fish may trigger nasopharyngeal carcinoma in adults
What is required for EBV to cause illness?
aquisition of viral gene followed by:
environmental/dietary exposure to chemical carcinogens
What type of capsid does the Hepatitis B virus have?
spherical
enveloped
icosahedral
Describe the genetic material in HBV.
partial double-stranded DNA
How does HBV manifest in South-East Asia and Africa?
most children infected by prenatal transmission
How does HBV manifest in the Western world?
contact with contaminated blood
sexual intercourse
What can chronic infections with HBV progress to?
hepatocellular carcinoma
liver cancer
How can liver cancer due to HBV be triggered?
high alcohol consumption
smoking
exposure to fungal toxin - alflatoxin
What virus is under papovavirus?
human papilloma virus
What type of capsid does the papovavirus virus have?
naked
icosahedral
What cancer is HPV associated with?
cervical carcinoma
Describe mechanism of HPV infection.
multiply in epithelial cells of skin and mucous membrane
causes warts
How did cervical cancer cases decrease?
effective HPV vaccine design
successful vaccination program
What kind of virus is HPB?
hepadna virus
What illness does hepadna virus cause?
hepatitis B
What are the viruses under myxoviruses?
influenza virus
What type of virus is the influenza virus?
myxovirus
What type of capsid does the influenza virus have?
enveloped
helically symmetric capsid
Describe the genetic material in influenza virus.
segmented RNA
What spikes are on the envelop of the myxovirus?
hemagglutinin
neuraminidase
Where does the influenza virus go in the body?
multiplies in the cells lining the upper respiratory tract
What adaptation is influenza capable of?
extensive antigentic variation - alter antigens that human does not have effective immunity against
the new antigenic types can cause influenza pandemics