Communicable disease 2

Question 1

what is the BBB?

Answer 1

blood brain barrier that provides a host defence for the brain

Question 2

The BBB includes what 3 structures?

Answer 2

Choroid plexus, arachnoid membrane & cerebral microvascular epithelium

Question 3

The cerebral microvascular epithelium has _________ which minimizes entry on infectious agents into CSF.

Answer 3

tight junctions

Question 4

Why is the BBB bad sometimes?

Answer 4

doesn’t always allow antibiotics to diffuse through the blood vessels and is hard to treat brain infections.

Question 5

what are the properties of CSF?

Answer 5

clear, colourless, sterile fluid

Question 6

Who are at risk for CNS infections?

Answer 6

old and young, immunocompromised and nutritional deficit individuals & comorbid people (have other medical conditions)

Question 7

Who are at the highest risk for meningitis? Who is at the second highest risk for meningitis?

Answer 7

1. New borns

2. Teenagers

Question 8

How does a CNS infection travel?

Answer 8

blood - entering through the subarachnoid space through the choroid plexus or blood vessels of the brain. spread directly from site of injury to the brain or spinal fluid. direct intra neural spread

Question 9

Is it rare for infection to travel along the nerves?

Answer 9

Yes

Question 10

is it rare for a virus to travel to the brain via the nervous system?

Answer 10

Yes

Question 11

List the chain of transmission for Rabies.

Answer 11

Reservoir - animals like raccoons, rats, dogs
Portal of exit - animals mouth
transmission - direct
portal of entry - broken skin
host - anyone that gets bitten or is contaminated

Question 12

What are symptoms of Neisseria meningitis?

Answer 12

very sudden onset, fever, severe head ache, vomiting confusion, seizures, drowsiness, stiff neck, rash on hands and feet.

Question 13

Where did frequently meningitis occur?

Answer 13

africa - called meningitis belt

Question 14

List the chain of transmission for Neisseria meningitis.

Answer 14

Reservoir - humans
Portal of exit - mouth, skin if open wound*
transmission - typically direct, mucous to mucous membrane or indirect, coughing
Portal of entry - mouth, cut*
Host - people who are not vaccinated

Question 15

How do you prevent Neisseria meningitis?

Answer 15

avoid crowded living, institutions and barracks. educate people on public cough etiquette and hand hygiene.

Question 16

People can be a _________ of Neisseria meningitis and have pathogens and spread it to other but not get sick

Answer 16

carriers

Question 17

Discuss the Neisseria meningitis OB. How was it cured?

Answer 17

in oklahoma with students, 2 died, 2 recovered fully, and one had all four limbs removed. Mass vaccinations were administered and antibiotics to at risk people. cure is to remove dead tissue –> usually limbs: the farther away from the heart the more capillaries.

Question 18

What is streptococcus agalactiae?

Answer 18

biggest leading cause of prenatal meningitis. this bacteria normally lives in vagina and bowels - normal vaginal flora for some people. transmitted before birth from mom to fetus. carriers are identified by bacterial screening or vaginal swab. cant be cured but bacteria can be removed before birth for a few days so the baby doesn’t get meningitis.

Question 19

What two bacterias cause meningitis?

Answer 19

streptococcus agalactiae & Neisseria meningitis

Question 20

What is septicemia or sepsis?

Answer 20

bacteria or toxins in the blood stream

Question 21

what is septic shock ?

Answer 21

hypertension due to toxins or bacteria in the blood stream and leads to fever, acute respiratory distress, shock, renal failure, organ system failure

Question 22

what are the risk factors for blood infections?

Answer 22

decreased immune system
increased use of invasive procedures - surgeries
age
antimicrobial resistance - bacteria is resistant to antibiotics
untreated UTI
when other infections are not treated

Question 23

what are the 4 layers of the skin?

Answer 23

epidermal layer: squamous epithelium and keratin
dermal layer: connective tissue layer with nerves
Subcutaneous layer: fat
Fascia: thin membranes covering muscles and connective tissues

Question 24

what is a physical barrier of the skin?

Answer 24

dead keratinocytes

Question 25

what makes the skin a poor reservoir for pathogens

Answer 25

high salt, very dry, low Ph and surface temp is too low for pathogens

Question 26

When do bacterial skin infections occur (3)?

Answer 26

trauma, poor hygiene, pre existing skin conditions

Question 27

what are the 3 key lines of attack for the skin that pathogens might do?

Answer 27

breach intact skin
skin manifestations
toxin mediated skin damage

Question 28

What is folliculitis? what bacteria causes it?

Answer 28

infection of the hair follicle and has pustules that is the red area surrounding the pore. 
staphylococcus aureus (most common) & pseuodomonas aeruginosa (from swimming pools)

Question 29

what is the most common cause of impetigo?

Answer 29

streptococcus pyogenes. blister like lesions with clear yellow fluid that spread by touch and can cause strep throat

Question 30

what is anthrax ?

Answer 30

baciilus anthracis - ulcerative skin lesions can be pulmonary and systemic and used as a bioterrism organism

Question 31

what is necrotizing fasciitis ?

Answer 31

skin eating disease by streptococcus pyogenes & other bacteria
superfical gangrene –> necrotizing fasciitis –> myonecrosis
infection of the fascia and subcutaneous tissue
spread rapidly

Question 32

what is the treatment of necrotizing fasciitis ?

Answer 32

rapid surgical removal of infected areas because the bacteria is producing toxins that are harming the muscles and nerves. toxins that are released into blood stream cause patients to die.

Question 33

Who gets necrotizing fasciitis ?

Answer 33

teenagers - from trauma or freshwater contamination

Aeromonas hydrophilia