Viruses microbiology

• What are medically important viruses classified as?

  Obligate parasites that infect animals, plants, and other microbes
• What is the structure of all DNA viruses except parvoviruses?

  All DNA viruses are double-stranded
• What type of viruses are all RNA viruses except reoviruses?

  All RNA viruses are single-stranded
• What is the limitation of viruses regarding their hosts?

  Viruses are limited to a particular host or cell
• Where do most DNA viruses bud off from?

  Most DNA viruses bud off the nucleus
• Where do most RNA viruses multiply and get released from?

  Most RNA viruses multiply in and are released from the cytoplasm
• What is the range of viral infections?

  Viral infections range from very mild to life-threatening
• What are zoonoses?

  Zoonoses are viruses transmitted by vectors
• Can some viruses become permanent residents of host cells?

  Yes, most DNA and a few RNA viruses can become permanent residents
• What can several viruses cross to cause congenital issues?

  Several viruses can cross the placenta
• What do poxviruses produce?

  Poxviruses produce eruptive skin pustules called pocks or pox
• What is unique about poxviruses compared to other viruses?

  Poxviruses are the largest and most complex animal viruses
• What type of DNA do poxviruses possess?

  Poxviruses possess double-stranded DNA
• Where do poxviruses multiply?

  Poxviruses multiply in the cytoplasm in factory areas
• What virus causes smallpox?

  Variola virus
• What was the first disease to be eliminated by vaccination?

  Smallpox
• How is smallpox transmitted?

  Exposure through inhalation or skin contact
• What are the symptoms associated with smallpox infection?

  Fever, malaise, prostration, and a distinctive progressive rash
• What are the two types of variola virus?

  Variola major and variola minor
• What is the virulence of variola major compared to variola minor?

  Variola major is highly virulent, while variola minor is less virulent
• When were the last cases of smallpox reported?

  1977
• When did routine vaccination for smallpox end in the US?

  1972
• When was the smallpox vaccine reintroduced?

  2002
• What type of viruses are herpesviridae?

  Large enveloped icosahedral double-stranded DNA viruses
• Where does replication of herpesviridae occur?

  Replication occurs within the nucleus
• What are the eight herpesviruses that infect humans?

  • HSV-1
  • HSV-2
  • VZV
  • CMV
  • EBV
  • HHV-6
  • HHV-7
  • HHV-8
• What type of infections do herpesviridae cause?

  Herpesviridae cause latent and recurrent infections
• How do complications of herpesviridae infections change with age?

  Complications become more severe with age and cancer chemotherapy
• What are the common opportunistic infections among AIDS patients caused by herpesviridae?

  CMV retinitis and genital herpes
• What lesions does HSV-1 cause?

  Lesions in the mouth and oropharynx, such as cold sores
• At what age does HSV-1 typically occur?

  Occurs in early childhood
• What lesions does HSV-2 cause?

  Lesions on the genitalia
• At what age does HSV-2 typically occur?

  Occurs in ages 14-29
• Can HSV be spread without visible lesions?

  Yes, HSV can be spread without visible lesions
• What is the treatment for HSV infections?

  Acyclovir, famciclovir, and valacyclovir
• What does VZV cause?

  Chickenpox and shingles
• How is VZV transmitted?

  Transmitted by respiratory droplets and contact
• What characterizes the primary infection of chickenpox?

  Characterized by vesicles
• What happens to VZV after the primary infection?

  The virus enters neurons and remains latent
• What results from the reactivation of VZV?

  Reactivation results in shingles