Bloodborne Pathogens

Question 1

What are the viral features of HIV?

Answer 1

+ spherical
+ enveloped
+ RNA
+ retrovirus

Question 2

What are the steps involved in HIV progression to AIDS?

Answer 2

1. exposure to HIV
2. seroconversion
3. asymptomatic
4. persistent generalised lymphadenopathy
5. AIDS related clinical features
6. AIDS

Question 3

What is the treatment for AIDS?

Answer 3

+ NRTIs (nucleoside reverse transcriptase inhibitors)

+ NNRTIs (non-nucleoside reverse transcriptase inhibitors)

+ PIs (protease inhibitors)

Question 4

What are the normal treatment combinations for HIV?

Answer 4

+ 1 NRTI and 1 PI

+ 2 NRTIs and 1 NNRTI

Question 5

How is viral load measured?

Answer 5

Quantitative NAAT

Question 6

How is HIV transmitted?

Answer 6

+ via blood/blood products/contaminated needles
+ sexually
+ perinatally

Question 7

Which type of HIV is the most common?

Answer 7

HIV-1

Question 8

What are the viral features of HBV?

Answer 8

+ hepadnavirus
+ double-stranded DNA
+ enveloped

Question 9

What is HBsAg?

Answer 9

surface antigen

Question 10

What does HBsAg indicate?

Answer 10

infectivity

Question 11

What is HBcAg?

Answer 11

core antigen

Question 12

When does HBcAg appear?

Answer 12

Early in infection

Question 13

What is HBeAg?

Answer 13

pre-core antigen

Question 14

What does HBeAg indicate?

Answer 14

high transmissibility

Question 15

What does anti-HBsAg provide?

Answer 15

immunity (appears late)

Question 16

How is HBV transmitted?

Answer 16

+ blood/blood products
+ contaminated needles and equipment
+ association with tattooing, body piercing and acupuncture
+ sexual intercourse

Question 17

What are the stages of HBV infection?

Answer 17

+ long incubation period - up to 6 months
+ development of acute hepatitis
+ fulminant disease carries 1-2% mortality rate
+ 50% patients develop chronic active hepatitis

Question 18

What is icterus?

Answer 18

jaundice

Question 19

What are the clinical features of the pre-icteric stage of HBV?

Answer 19

+ malaise
+ anorexia
+ nausea
+ pain in upper right quadrant (tender liver)

Question 20

What are the clinical features of the icteric stage of HBV?

Answer 20

+ jaundice

+ dark urine (bilirubin)

Question 21

What is jaundice and where does it affect?

Answer 21

Yellow pigmentation affecting the skin, sclerae and other mucous membranes

Question 22

What causes jaundice?

Answer 22

Hyperbilirubemia

Question 23

What is the treatment for HBV?

Answer 23

+ pegylated interferon (peginterferon): sustaining suppression of viral replication

+ nucleoside analogues

Question 24

What are methods of HBV prevention?

Answer 24

+ HBsAg vaccine
+ HBV immunoglobin
+ Blood screening
+ Needle exchange programmes

Question 25

What are the viral features of HCV?

Answer 25

``` + flavivirus + single-stranded RNA + enveloped + replicated in hepatocytes + destroys liver cells + virus cannot be cultured ```

Question 26

How is HCV transmitted?

Answer 26

+ blood and blood products + tattooing, body piercing and acupuncture + haemodialysis + sexual/vertical transmission

Question 27

What are clinical features of HCV?

Answer 27

+ usually asymptomatic + fatigue + nausea + weight loss

Question 28

What can occasionally develop in patients with HCV?

Answer 28

+ cirrhosis | + hepatocellular carcinoma

Question 29

What is the treatment for HCV?

Answer 29

NO VACCINE YET + ribavirin and pegylated interferon alpha + sofosbivur (nucleotide analogue)

Question 30

What are the 5 species of plasmodium that cause malaria?

Answer 30

``` + P. falciparum + P. ovale + P. knowlesi + P. vivax + P. malariae ```

Question 31

What are the main clinical features of malaria?

Answer 31

``` + fever + flu-like symptoms + P. falciparum affects every organ - wide range of complications: - cerebral malaria - circulatory shock - hepatitis ```

Question 32

Infection of which plasmodium can rapidly progress to death?

Answer 32

P. falciparum

Question 33

What is the treatment for malaria?

Answer 33

+ chemotherapy: kills blood stages of parasite | + combo therapy is normal