Rabies & other Zoonosis

Question 1

Describe the structure of Rabies

Answer 1

Rhabdovirus family, -ssRNA virus, helical, enveloped

Question 2

How is Rabies transmitted

Answer 2

By the saliva in the bite or scratch of an infected mammal

Question 3

Does rabies cross species?

Answer 3

Yes, rabies virus easily crosses species

-Different mammals have different strains of the rabies virus

Question 4

Is rabies fatal?

Answer 4

Rabies is nearly 100% fatal; only a few cases have survived

Question 5

Who are the primary carriers of rabies in the US?

Answer 5

Racoons, bats, and skunks. Feral house cats cam also have rabies.

Question 6

What is the incubation time for rabies?

Answer 6

The further the virus needs to travel in the peripheral nervous system, the longer the incubation time. Once it reaches the dorsal root ganglion, it can move faster

-So, the closer the bite is to your brain, the shorter the incubation time
-On average, 20-90 days but can be years

Question 7

What is the first thing you should do when exposed to rabies?

Answer 7

-First, wash the wound for 15 min with soap and water and, if possible, a dilute iodine solution
(Goal is to get as much of the virus as possible out of the wound)
-Next, go to the dr right away

Question 8

If post-exposure prophylaxis is needed, what is that proccess?

Answer 8

-Human Rabies Immunoglobulin (HRIG) is injected into the bite site. If there’s solution remaining, it’s given intramuscularly
-The same day you get HRIG, a shot of rabies vaccine is given at a different site. This vaccine is given on days 3, 7, and 14
-Rabies PEP is close to 100% effective

Question 9

Where does the rabies virus replicate?

Answer 9

In the muscle near the bite site and then enter the nerves.

-PEP is designed to prevent the virus from transferring to the nerves. Once the virus is in the nerve, it is hidden from the immune system, will travel to the brain, and cause rabies

Question 10

What kind of vaccine is the rabies vaccine?

Answer 10

Killed virus vaccine

Question 11

If someone who was previously vaccinated gets exposed to rabies, what should be done?

Answer 11

-Wound needs to be washed and re-vaccination must occur immediately
-HRIG does NOT need to be given. Re-vaccination will cause a substantial boost in antibodies, quickly replacing the HRIG

Question 12

Describe the structure of Bunyavirus Family-Hantavirus

Answer 12

-ssRNA virus, segmented, helical, enveloped

Question 13

What animal caries Hantavirus

Answer 13

Different wild rodents

Question 14

Where is Hantavirus excreted?

Answer 14

-In the rodent’s urine, feces, and perhaps saliva.

Question 15

How is Hantavirus transmitted?

Answer 15

-Being in areas where there are rodent droppings.
-Breathing in these droppings, contaminated hands touching the face, or by a bite from an infected rodent
-Virus is NOT transmitted from person to person
-This is why you should never sweep up or vacuum rodent droppings but instead wet them down with a disinfectant and use gloves to clean them up

Question 16

Does Hantavirus infect their rodent hosts?

Answer 16

No, the rodent sheds virus sporadically throughout their life

Question 17

What syndrome can Hantavirus cause in the US?

Answer 17

-Hantavirus Pulmonary Syndrome (HPS)

Question 18

Who does HPS affect?

Answer 18

Any age group

-Has a high fatality rate
-Virus can cause rapid fatal edema of the lungs

Question 19

What syndrome does Hantavirus cause in Asia and Europe

Answer 19

Hemorrhagic Fever with Renal Syndrome (HFRS)

Question 20

List the different Arenaviruses and their structure

Answer 20

-Lymphocytic choriomeningitis virus (LCMV)
-Lassa virus
-Filovirus

-ssRNA, segmented, helical, enveloped viruses

Question 21

What animal is LCMV found in?

Answer 21

Some house mice. IT can also be found in pet mice and hamsters if colonies had LCMV infection or they were in contact with wild mice

Question 22

What can LCMV cause?

Answer 22

-Meningitis
-Miscarriages
-Severe congenital disabilities is infected while pregnant

Question 23

How is LCMV transmitted?

Answer 23

From mouse urine and droppings, or bites and saliva

Question 24

What should you do if you see mouse droppings to avoid LCMV exposure?

Answer 24

Treat it the same way as for Hantavirus, do not sweep or vacuum. Instead, wet down with disinfectant for 5 minutes and use gloves to clean up

Question 25

What animal carries Lassa virus?

Answer 25

Rat found in Africa

Question 26

What are symptoms of Lassa virus?

Answer 26

-Most people have a mild illness or are asymptomatically infected
-In severe illness, there can be high mortality
-A common sequela is hearing loss

Question 27

Describe the structure of Filovirus

Answer 27

-ssRNA virus, helical, enveloped

Question 28

List the two different viruses of Filovirus

Answer 28

Ebola
Marburg

Question 29

What can both viruses of Filovirus cause?

Answer 29

-Hemorrhagic fevers
-Outbreaks with high mortality

Question 30

Where do all outbreaks of Ebola and Marburg occur?

Answer 30

Africa

Question 31

T/F: Ebola is infectious before symptoms begin

Answer 31

False - Ebola is NOT infectious before symptoms

The level of infectiousness increases with illness. The body is very infectious after death

Question 32

How many Ebola virus particles are needed for infection?

Answer 32

Only 1 to 10

Question 33

How is Ebola transmitted?

Answer 33

-Ebola needs to enter the mouth, eye, nose, or break in the skin
-Ebola is not aerosolized; you need to have direct contact with the body or fluids from the body

Question 34

Can you survive Ebola?

Answer 34

-The death rate is very high
-There are now a large number of Ebola survivors, and they can have lingering problems from the infection

Question 35

The ebola virus is found in the ______ for at least three months and in some much longer

Answer 35

semen

-Infection through sex has occurred

Question 36

Is there a vaccine for Ebola?

Answer 36

-There is now an FDA-approved vaccine
-It appears to be highly effective