Lecture 23: HPV and Viral gastro

Question 1

What is the structure of a human papillion viruses

Answer 1

small non-enveloped icosahedral virus circular double stranded viral DNA

Question 2

How many different types of human papilloma viruses are there

Answer 2

100 types some can cause cancer

Question 3

How are human pavilion viruses transmitted

Answer 3

virus is shed in cells from warty lesions on skin/mucous membranes, comes into contact with cells of new host via small abrasions, infected cells multiple and form new warty lesions

Question 4

What does no viraemia mean

Answer 4

infections are limited to superficial tissue in human papillion viruses

Question 5

____ are protective if lesions are covered in human papillion viruses

Answer 5

barrier methods (e.g., condom)

Question 6

How long do infections persist in human papillion viruses

Answer 6

6-12 months and resolve

It is unclear is resolution includes integration into host cell genome

Question 7

What are the skin-to-skin HPV infections

Answer 7

Plantar warts and common warts

Question 8

What are the low risk mucosal HPV infections

Answer 8

HPV 6, 11 that are associated with genital warts, they are found in the mucosal membrane and are low risk

Question 9

What are the high risk mucosal HPV infections

Answer 9

HPV 16, 18 which can be associated with invasive cancer like cervical cancer

Question 10

Why do most people not know that they are infected with HPV

Answer 10

1% have warts
4% have a subclinical infection by cytology
10% have a subclinical infection (DNA/RNA probe)
50% have a positive by PCR or Antibody

Question 11

Can cervical cancer be prevented

Answer 11

yes, there is first a high-grade precursory that takes on average 10 years to become invasive cancer

It is treatable with a vaccine before the individual becomes sexually active

Question 12

Can HPV be grown a laboratory

Answer 12

it is not practical to grow the virus in a lab, testing for the DNA is available but not yet generally in Nova Scotia

Question 13

In NS how do we rely on detection of HPV

Answer 13

we rely on the PAP smear to detect changes produced by the virus but we cant test this routinely

This might change in the future and a new technique may be implemented to actually look for the virus itself

Question 14

What types of HPV viruses does the vaccine cover

Answer 14

There is now a 9 valent vaccine that covers 9 different types of HPV

It covers HPV types 16, 18 (high-risk) and 6, 11 (low-risk) + 5 others

Question 15

How is the efficacy mediated in the HPV vaccine

Answer 15

It is mediated by humeral immune response, if they produce antibodies with the vaccine

Question 16

How many doses is the HPV vaccine given in

Answer 16

2 or 3

Question 17

Who was the HPV vaccine designed to

Answer 17

females between 9-26 and males between 9-26

Question 18

How is the HPV vaccine not designed for

Answer 18

not recommended for children younger than 9 years old and has not be tested on pregnant women

Question 19

What is the most common type of viral gastroenteritis

Answer 19

Noroviruses

Question 20

What is the most common type of viral gastroenteritis

Answer 20

Noroviruses

Question 21

What season is Norovirus most common in and where was it discovered

Answer 21

“winter vomiting disease” fall/winter

1968, Norwalk Ohio

Question 22

What is the structure of Noroviruses

Answer 22

small RNA viruses with multiple serotypes.

New types arise every few years, like flu

Question 23

Are children or adults more likely to be affected with gastroenteritis

Answer 23

adults

Question 24

How is gastroenteritis transmitted

Answer 24

fecal-oral, but there is also thought of aerosol spread too but probably not

Question 25

How many viruses can cause gastroenteritis

Answer 25

10 viruses can cause disease. Very infectious

Question 26

What is true about the antibodies in noroviruses

Answer 26

antibodies are acquired later in life, in North America half of adults have antibodies by the age of 50

And antibodies are not protective as new types are made

Question 27

What is the structure of Rotaviruses

Answer 27

Naked double stranded RNA viruses

Look like a wheel on electron microscopy

Question 28

Is Rotaviruses usually in endemics or outbreaks

Answer 28

usually endemics but responsible for occasional outbreaks. now reduced with vaccine

Question 29

who is rotavirus most common in

Answer 29

causes disease in all age groups but most severe symptoms in neonates and young children

Asymptomatic symptoms are common

30% mortality rate in malnourished children

Question 30

What is the pathogenesis of gastroenteritis viruses

Answer 30

they replicate in the mucosal cells of the small intestine

Damaging the transport mechanisms (fluid coming out faster than its getting absorbed)
Loss of fluids and electrolytes

There is little inflammation, diarrhea is non-bloody

Question 31

How are enteric viruses spread

Answer 31

Poor hygiene and poor sanitation sysmsthems

Fecal-oral

Contaminated water supplies

Food

Stool contaminated

Filtering shellfish

Fomites

Question 32

How long do enteric viruses last

Answer 32

High numbers in stool for 48 hours then drops. May be shed for weeks in a few

usually symptoms are short lasting (24-48 hrs) the very long and old can take longer like a week or so maybe

Question 33

What is the incubation period for enteric viruses

Answer 33

usually very short, 12hrs to few days

Question 34

What are the symptoms of enteric viruses

Answer 34

vomiting may be prominent (espically in vomiting)

Occasional fever

Diarrhea
- also may be lactose intolerant temporary following the infection while the cells are regenerating

Dehydradtion imbalance

Electrolyte imbalance

Question 35

Who is most at risk to get an enteric virus

Answer 35

baies or immunosuppressed

Question 36

How are enteric viruses diagnosed

Answer 36

clinical syndrome (watery diarrhea of short duration)

PCR nucleic acid detection: outbreaks especially on cruise ships

Antigen in stool with electron microscopy, this is less sensitive so is mostly done in the past

Question 37

What is therapy used for viral gastroenteritis

Answer 37

No specific antivirals are available

Dehydration, intravenous if severe for rehydration

Oral

Anti motility agents

Pepto Bismol

Question 38

How is HPV L1 Virus-Like-Particle (VLP) Vaccine Synthesized

Answer 38

The L1 gene of HPV DNA is taken from inside the virus and is inserted into another organisms plasmid

The organism starts working and producing those proteins from the outside of the virus fused without the DNA on the inside so it can’t replicate but it becomes at little particle with all antigens (antival capsid)

Question 39

What is the significance of HPV Integration

Answer 39

The DNA gets integrated into the a gene inside our own cells, leads to the disruption of a transcriptional repressor which gives rise to genomic instability and gives rise to those types of cells, interfering with the growth regulation of those cells and because of that you can get unrestricted cell growth which can lead to cancer