PBL 13: Trudy Wakefield -Viruses

Question 1

Define and Describe Viruses

Answer 1

1. Intracellular Obligate Parasite
2. Non-cellular: do not contain the material required to sustain life
3. Can Infect all cells
4. Enveloped and non-enveloped viruses

Question 2

Give an overview of the baltimore classification of viruses

Answer 2

1.

Question 3

What other ways can we classify viruses?

Answer 3

1. Appearance under microscopy
2. Transmissions mechanism
3. Sites of Infection
4. Mode of Transmission
5. Type of Disease they cause
6. Way virus was assembled

Question 4

List common causes of genital inflammation and dysuria

Answer 4

Candida Albicans -Thrust

UTI -e.coli and other gram-negative bacteria

STI -Gonorrhea, Chlamydia, HPV 16/18

Caner

Swollen Prostate

Too much and/or rough sexx

Pre-Post-Menopausal

Toxic Shock Syndrome

Question 5

List the classification, dysuria, pain location, microbiology, urine contents and predisposing factors to STI

Answer 5

Classification: Transmission-based, pain at start of urination (not all cases e.g. HIV)

Dysuria: Pain at start of urination but normal completion

Pain Location: Genitals (urethral orifice)

Microbiology: Foreign infection, Bacteria or Virus

Urine Contents: WBC, RBC, Pathogens

Predisposing factors: questionable sex, sharing needles, blood contamination

Question 6

List the classification, dysuria, pain location, microbiology, urine contents and predisposing factors to UTI

Answer 6

Classification: Location-based, Urethra, bladder, ureter, kidney

Dysuria: Polyuria, incomplete voiding, pain throughout micturition, nocturia, problems starting

Pain Location: Urinary tract, urethra up to kidneys

Microbiology: natural body flora, no virus

Urine contents: Nitrites, Leukocyte esterase, WBC, RBC, Pathogens

Predisposing factors: alteration of vaginal flora due to antibiotics, other genital infections, contraceptives, pregnancy

Question 7

Primary transmission methods of HSV

Answer 7

1. Direct contact: sneezing (droplets), coughing, mucous membrane contact
2. More enveloped virus: more susceptible to external environment

Question 8

Secondary transmission methods of HSV

Answer 8

1. Indirect: oral, surface
   Other viruses: faeco-oral route
2. More enveloped virus -can sustain structure in external environment

Other methods: questionable sex, fluid exchange, sharing razors/towels, kissing, sharing needles

Question 9

Draw a flowchart of the mechanism of action of Acyclovir

Question 10

Following fever symptoms, what are the physical examinations we can perform and what might they indicate?

Answer 10

Chest Sounds: Respiratory Virus -sputum sample, x-ray, auscultation, palpation, percussion

Discharge or painful genitals/oro-genital lesions: STI/UTI - High vaginal swab, cervical-canal swab, urine sample, sexual history

Diarrhea, abdominal tenderness, vomiting: GI virus -stool sample, abdominal palpation, percussion

Question 11

What are common laboratory tests used to identify viruses?

Answer 11

PCR -detects genetic vode

Serology - detects Ab in blood by western blot, ELISA

MCS

Sputum sample: leukocytes, erythrocytes, organisms

Urine dipstick: leukocyte esterase, nitrite, glucose

Question 12

List the 5 types of basic vaccinations

Answer 12

1. Live attenuated (virulence factor minimised organisms)
2. Inactive (dead organism/antigenic protein)
3. Conjugate vaccine (antigenic saccharide conjugated to carrier proteins)
4. Toxoid (Toxin)
5. DNA (pathogenic gene)

Question 13

What is the body’s response to a vaccine?

Answer 13

1. Differentiation of antigen-specific lymphocyte clones into memory cells
2. Memory Cells -larger pool of antigen-specific lymphocyte clones that respond quicker to re-infection with more specificity

Question 14

Draw a graph showing the bodies response to vaccination on first and second anteigen exposures.

Answer 14