Microbiology Diseases

Question 1

Smallpox

Answer 1

• Variola Virus (major/minor) - Major causes smallpox
• Linear, double stranded, enveloped DNA with about 186,000 nucleotides
• Transmission: Airborne/contact
• Characteristics: High fever and a rash in the mouth/through because of point of entry. It will spread to face, arms, legs, etc.
• The rash will become raised bumps with opaqe fluid. Scabs will fall off leaving scars.
• Due to inoculation in 1977, smallpox is the first infectious to be eradicated.

Question 2

Shingles

Answer 2

• Herpes Zoster
• It is a reactivation of varicella-zoster virus. Typically happens around 60.
• VZV lies dormant in nerve cells. It’s reactivation typically results in painful blisters. These blister are localized.
• Transmission: Can happen to someone who hasn’t been exposed to VZV/vaccine. They develop chickenpox during the contagious part.
• Mild symptoms: treated with over the counter drugs
• Sever symptoms (painful blisters): treated with anti-viral Acyclovir

Question 3

Chickenpox

Answer 3

• Varicella virus (or Zoster virus)
• Family: Herpesvirus
• Linear, double stranded enveloped DNA that is 125,000 nucleotides long.
• Transmission: Airborne/contact
• Characteristic: Small itchy, fluid-filled blisters that can form anywher.
• Once blisters appear, they are infectious two-days prior and until scabs grow over.

Question 4

Rubella (measles)

Answer 4

• Linear, single stranded, enveloped RNA with about 10,000-15,000 nucleotides
• Family: Togaviridae
• Transmition: Airborne
• Multiplies in the URT but can spread elsewhere. For pregnant women, it can cross the placenta membrane.
• Symptoms: Fever, flu-like symptoms, cough conjunctiva. Koplik (red dots) develop on face first than move down.
• Once 1 year old, MMR can be given and is completely inoculated

Question 5

Mumps

Answer 5

• Epidemic parotitis
• Linear, single-stranded, enveloped RNA about 15,000 nucleotides long
• Family: Paramyxovirus
• Transmission: airborne/contact (very contagious)
• Contagious 7 days before symptoms and 8 days after
• Best characteristics: swollen salivary glands (parotid), tests, ovaries, pancreas.
• Intiail symptoms: cold, fever, headache, muscle ache

Question 6

Polio

Answer 6

• Poliomyelitis
• Single stranded, non-enveloped RNA about 7,700 nucleotides long
• Family: Picornaviridae
• Only 30nm in size (considered the most significant small virus)
• The virus attacks the CNS and can be found in infected neurons in the spinal cord, brain stem, and motor cortex regions.
• Can cause partial/complete paralysis
• 1955 introduced the polio vaccine. 90% immune for initial shot and then 99% immune with boosters.
• oral vaccine allows for 95% immunity. It contains a live but weakend virus.

Question 7

Influenza

Answer 7

Segmented, single-stranded enveloped RNA virus.

• Family: Orthomyxoviridae
• Three subtypes: A, B, or C. A is the most pathogenic subtype.
• Viral enveloped contains two key glycoproteins: 1) hemagglutinins (HA) and neuraminidase (N).
• Hemgglutinins (16 types): Involved in the entry into host cells
• Neuraminidase (9 types): Involved in the budding and release of new viral particles.
• HA/N are common drug targest for therapeutic intervention.
• Because of many different subtypes, a vaccine doesn’t always work.
• H2N2: Asian flu 1957
• H1N1: 2009

Question 8

Human Immunodeficiency Virus (HIV)

Answer 8

• Linear, single-stranded, enveloped RNA virus about 10,000 nucleotides
• Family: Retroviridae
• Treatment is a regiment of anti-retroviral medicine.
• If infection continues, AIDS is high. AIDS is defined as a severe loss of the body’s immunity.
• An individual does not die from HIV but rather from other infections.