Lecture 20. Virus Entry, Spread & Exit

Question 1

What are susceptible cells?

Answer 1

Expresses the specific receptors that are recognised by a specific virus through specific VAPs

Question 2

What are resistant cells?

Answer 2

Has no receptor - it may or may not be able to support viral replication

Question 3

What are permissive cells?

Answer 3

Contains the proteins and molecules within the cell that are necessary for replication to occur

Question 4

What are non-permissive cells?

Answer 4

Does not support viral replication, it may or may not be susceptible

Question 5

What are common portals of virus entry?

Answer 5

Conjunctiva
Respiratory tract
Gastrointestinal tract
Skin
Genital tract
Congenital infection

Question 6

What sized droplets are the ones that transmit infection most easily?

Answer 6

Middle sized

Question 7

Where are viruses contained in larger droplets deposited?

Answer 7

Upper respiratory tract

Question 8

Where are viruses contained in smaller droplets deposited?

Answer 8

Lower respiratory tract

Question 9

What are the conditions of the gastrointestinal tract?

Answer 9

Harsh
Stomach acidity
Low pH
Digestive enzymes
Bile in the intestines

Question 10

What are viruses that can infect the GI tract?

Answer 10

Norovirus
Rotavirus
Adenovirus
HAV
Poliovirus

Question 11

How is spread favoured in the GI tract?

Answer 11

Poor sanitation and poor personal hygiene

Question 12

What causes most of the viral eye infections?

Answer 12

Herpes simplex virus type 1 and several of the human adenoviruses

Question 13

How are eye infections transmitted?

Answer 13

Transmission is believed to occur on the accidental introduction of virus

Question 14

What must viruses that infect via genital tract overcome?

Answer 14

Local barriers to infection, such as mucus and the low pH of the vagina

Question 15

How can the skin get infected?

Answer 15

Trauma or inoculation
Medical procedures (sharing needles, HBC, HBV)
Insects or animal bites (rabies, yellow fever)

Question 16

What can in utero vertical transmission (during pregnancy) cause?

Answer 16

Rubella & CMV

Question 17

What can perinatal transmission (during birth) vertical transmission cause?

Answer 17

Neonatal HSV

Question 18

What can postnasal transmission (after birth) vertical transmission cause?

Answer 18

HIV

Question 19

What is vertical transmission?

Answer 19

Vertical transmission refers to the transfer of virus from the mother

Question 20

What viruses cause localised infections?

Answer 20

Rhinovirus and HPV

Question 21

What viruses cause systemic infections (cause infections in different areas)?

Answer 21

Measles and poliovirus

Question 22

What is the portal of exit for HPV?

Answer 22

Skin-to-skin contact

Question 23

What is the portal of exit for rhinovirus?

Answer 23

Respiratory secretions

Question 24

What is the portal of exit for poliovirus and rotavirus?

Answer 24

Faeces

Question 25

What is the portal of exit for HIV and HSV?

Answer 25

Genital secretions

Question 26

What is the portal of exit for adenovirus?

Answer 26

Tears

Question 27

What does viremia mean?

Answer 27

The presence of virus in the blood
Is a common occurrence of infection with several viruses e.g HIV and hepatitis
Such viruses are transmitted through blood

Question 28

What does uraemia mean?

Answer 28

The presence of virus within the urine
Occurs with several systemic viral infections
Hantavirus is shed in the urine and droppings of infected rodents
It is transmitted to people through aerosolise of virions, Human-to-human transmission of hantaviruses has not been documented yet