14 Virus 2

Question 1

human-human transmission involves

Answer 1

> Acutely infected individuals

> Chronic carriers

Question 2

human-human direct contact example

Answer 2

sexual

Question 3

human-human environmental

Answer 3

> Faecal oral

> Aerosols

Question 4

animal-human transmission

Answer 4

• Direct bite
• Insect transmission
• Environmental
• Zoonosis – transmission across species barrier, e.g. SIV=HIV

Question 5

Respiratory route

Answer 5

Usually takes place following sneezing or coughing

• Inhalation of aerosol droplets
• Contaminated surfaces
• Survival of virus in droplets varies between viruses and ambient temperature

Question 6

respiratory route - contaminated surfaces

Answer 6

Major transmission of rhinoviruses is hand to eyes / mouth / nose rather than inhalation

Question 7

what protects against airborne virus

Answer 7

Cilia and mucus provide important physical protection against airborne viruses

Question 8

Gastrointestinal tract infections

Answer 8

Faecal - oral route
Food and water contamination
Virus must withstand GI tract conditions

Question 9

Faecal - oral route

Answer 9

Enteroviruses (Coxsackie, Polio etc.), Small Round Structured Viruses

Question 10

Food and water contamination

Answer 10

• Developing countries
• Poor personal hygiene
• Infants and mentally ill

Question 11

Virus must withstand GI tract conditions

Answer 11

• Acid stable

- Non-enveloped (bile salts)

Question 12

what is an effective infection barrier

Answer 12

skin

Question 13

Transcutaneous Route

Answer 13

skin is overcome by direct inoculation

• Insect or animal bite
• IVDA, needlestick injury and transfusion

Question 14

Insect or animal bite diseases

Answer 14

> Rabies = animal with “la rage”

> Dengue fever and all arthropod borne viruses = insect bites

Question 15

IVDA, needlestick injury and transfusion reduced

Answer 15

> Reduced risk by careful handling and screening blood / blood products

Question 16

Sexual Transmission

Answer 16

Genital tract or rectal mucosa

Question 17

what increases the transmission of HIV

Answer 17

concomitant STIs

Question 18

what can viral infections result in

Answer 18

• Acute infection
• Persistent / chronic infection
• Latent infection

Question 19

Hepatitis B virus (RT DNA virus) contagious

Answer 19

Infectious to other individuals

Question 20

how many people have Hepatitis B virus (RT DNA virus)

Answer 20

10% become chronic carriers

Question 21

Hepatitis C virus chronic cases

Answer 21

Chronic infection apparent in 60-80% of cases

Question 22

HIV persistent infection rates

Answer 22

100%

Question 23

what does HIV result in

Answer 23

AIDS

Question 24

what shows latency

Answer 24

herpesvirus

Question 25

what causes Secondary, or reactivation

Answer 25

Caused by host/environmental factors, usually associated with suppression of immune system

Question 26

examples of viruses associated with cancer

Answer 26

- Papillomaviruses (cervical cancer) | - Human herpesviruses

Question 27

In vivo evidence of EBV transformation

Answer 27

B cell lymphoma in immuno suppressed patients, e.g. transplant patients receiving cyclosporin. Reconstitution of immune control = clearance of EBV and frequently tumour

Question 28

Chronic hepatitis virus infections (hepatocellular carcinoma)

Answer 28

Mechanism of transformation unknown but likely to involve inhibition of apoptosis

Question 29

CPE

Answer 29

cytopathic effect

Question 30

cytopathic effect

Answer 30

As virus grows some cells undergo morphological changes > Primary cell cultures > Continuous (cancer) cell lines

Question 31

Diagnostic CPE

Answer 31

> syncytia or multinucleated cells > cell lysis > Inclusion bodies

Question 32

inclusion bodies

Answer 32

A virus might cause different CPE in different cell lines

Question 33

what can viral diseases be like

Answer 33

Acute infection can be symptomatic or asymptomatic | outcome can be age-dependent

Question 34

Early acute symptoms of viral disease symptoms

Answer 34

- fever - aches - shivers

Question 35

what are the virus specific symptoms

Answer 35

- Vesicles in HSV, VZV, Hand Foot and Mouth | - Rash in mumps, measles and rubella

Question 36

Anogenital warts

Answer 36

- Genital warts associated with cancer | > Vulva, vagina, cervix, peri-anal skin, anal canal and penis

Question 37

Clinical features - Rash

Answer 37

Vesicles and rashes are collectively known as viral exanthems

Question 38

Clinical Features – Congenital Infection

Answer 38

TORCH Syndrome

Question 39

TORCH acronym meaning

Answer 39

(T)oxoplasmosis, (O)ther Agents, (R)ubella (also known as German Measles), (C)ytomegalovirus, and (H)erpes Simplex