IB5 - Biological Agents Flashcards

1
Q

What is a “Biological Agent”?

A

a micro-organism, cell culture, or human endoparasite, whether

or not genetically modified, which may cause infection, allergy, toxicity or otherwise

create a hazard to human health.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the main types of biological agents?

A
  • Fungi, multi celled organisms and microorganisms like mushrooms, moulds, and yeasts
  • Protozoa, single cell organisms, bigger than bacteria, they love moisture and often spread diseases through contaminated water e.g. Cryptosporidium or Plasmodium that live in the blood causing Malaria. A Protozoa is a microscopic parasite.
  • Bacteria, single celled microbes. Eg. the Leptospira, E-Coli, Clostridium botulinum and Legionella bacteria
  • Viruses, the smallest of all microbes, cannot reproduce without host cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the sources of biological agents?

A
  1. Humans - e.g. viral hepatitis.
  2. Animals - e.g. Leptospira.
  3. The environment - e.g. Legionella.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In biology, what is a pathogen?

A

Anything that can produce disease. Diseases caused by pathogens are called infectious diseases. A pathogen may also be referred to as an infectious agent, or simply a germ.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

A disease vector is..

A

Any agent which carries and transmits an infectious pathogen into another living organism.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a zoonotic disease?

A

Is an infectious disease caused by a pathogen (an infectious agent, such as a bacterium, virus, parasite or prion) that has jumped from a non-human animal (usually a vertebrate) to a human.

Zoonoses are diseases that can be transmitted from animals to humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the special properties of biological agents?

A
  1. Rapid Mutation, changing the genetic material of an organism, usually DNA.
  2. Incubation Period
  3. Infectious
  4. Rapid multiplication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are zoonotic diseases?

A

Diseases caused by germs (pathogens) that spread between animals and people, like viruses, bacterial, parasites, and fungi.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How do pathogens spread between animals and people?

A
  1. Direct contact
  2. Indirect Contact
  3. Vector-borne
  4. Foodborne
  5. Waterborne
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Give examples of zoonotic diseases

A
  1. Avian Influenza A, caused by Influenza A virus
  2. Cryptosporidiosis, caused by the cryptosporidium parasite, affects the small intestine and may afect the respiratory tract, this parasite is immune to chlorine and alcohol. Is the most common waterborne diseases.
  3. Psittacosis, caused by a bacterium called Chlamydia Psittaci and contracted from infected birds. Psittacosis is also known as “parrot fever” . Causes fever, diarrhea, conjuctivitis, nose bleeds, low level of white blood cells, pneumonia
  4. Malaria, caused by Plasmodium parasites.The malaria parasites enter that person’s bloodstream and travel to the liver. Causes fever, tiredness, vomiting, and headaches. In severe cases it can cause yellow skin, seizures, coma, or death.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is a parasite?

A
  • Parasite” is a general term that refers to any organism that survives at the expense of its host.
  • There are three main classes of parasites that can cause disease in humans: protozoa, helminths, and ectoparasites
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is cryptosporidiosis?

A

A gastrointestinal disease caused by ingesting water contaminated with cryptosporidium parasite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Are all bacteria harmful for humans ?

A

No, the majority of bacteria ~90% are harmless, or beneficial, or even essential to life.
Only less than 10% are harmful (parasites and pathogens) and disease causing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Give examples of blood borne diseases

A
  1. Human immunodeficiency virus (HIV)destroys white blood cells, it may develop into Acquired immunodeficiency syndrome (AIDS) where the immune system has been severely damaged.
  2. Hepatitis B virus (HBV), causing liver infection
  3. Hepatitis C virus (HCV)

These viruses are passed from person to person through blood, semen or other body fluids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Causation agent and effect from Leptospirosis

A
  1. Leptospirosis is a blood infection caused by the bacteria Leptospira.
  2. The bacteria are spread to humans through animal urine, or water and soil contaminated with animal urine, coming into contact with the eyes, mouth, nose or breaks in the skin
  3. Without treatment, Leptospirosis can lead to kidney damage, meningitis, liver failure, respiratory distress, and even death.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Causation agent and effect from Norovirus illness

A
  • Cause by the highly contagious Norovirus
  • Causes diarrhea, vomiting, nausea, stomach pain, sometimes fever, headache and body aches
  • Norovirus causes inflammation of the stomach or intestines. This is called acute gastroenteritis
  • Also known as the “Winter vomiting bug”
17
Q

Causation agent and effect from Tetanus disease

A
  • Tetanus is caused by a toxin made by spores of bacteria, Clostridium Tetani, found in soil, dust and animal feces.
  • Another name for tetanus is “lockjaw”.
  • It does not spread from person to person
  • Enter the body through breaks in the skin, usually cuts or puncture wounds caused by contaminated objects.
18
Q

What are the optimum growth conditions for legionella bacteria

A
  • Water temp 20-40 degrees ( hot & cold water storage taps and showers)
  • Killed at 60
  • Sstagnant water (pipe work where dead legs exist)
  • Presence of algae, sludge and scale
  • Aerosol production
19
Q

What are the 4 different bio safety levels

A
  1. work with agents with are not human pathogens and present minimum risk to humans
  2. work with agents which cause mild human disease (hospital pathology lab)
  3. work with agents that will cause serious illness or potentially fatal after inhalation - treatment available
  4. agents that can cause serious or fatal illness and there is no treatment available
20
Q

What are the requirements for bio safety level 1 & 2?

A
  • control access
  • PPE
  • changing facilities
  • good hygiene
  • working areas clutter free & decontaminated at the end of the day
  • spillage procedure
  • procedures to minimise the formation of aerosols and pippetting
  • person responsible for bio safety management
  • training
  • waste disposal
  • immunisation / vaccination
  • control of sharps
  • health surveillance
  • biological safety cabinet
  • spacious with impervious wipeable surfaces
  • self closing doors
  • autoclave
  • mechanical ventilation
  • vision panels / CCTV to see what is going on
21
Q

What controls are needed for bio hazards level 3?

A

the same as 1 & 2 plus..

  • signs show bio safety level and supervisor
  • solid front wrap around coveralls and shoe covers
  • biological safety cabinets for open manipulations
  • respiratory equipment needed
  • separate from other areas to restrict traffic flow
  • anteroom to maintain pressure in lab
  • sealable room for decontamination
  • hand washing stations - with hands free controls
  • HEPA (high efficiency Particle air filter)
  • mandatory medical examination
  • medical contact card
22
Q

What controls are needed for bio safety level 4?

A

same as level 3 plus…

  • no lone working
  • complete change of clothing required before entering the lab
  • personnel training on emergency extraction of casualties
  • communication between inside and outside
  • in a separate building with controlled access
  • negative air pressure maintained outgoing air HEPA filtered
  • containment drains
23
Q

What are the signs and symptoms associated with legionnaires disease?

A

Flu like symptoms / dry cough and breathing difficulties / diarrhoea / confusion & delirium / respiratory failure / death

24
Q

What are the preventative control measures for occupational exposure to Hepatitis B and HIV?

A
  • prohibition of eating, drinking smoking and applying cosmetics
  • control and safe disposal of sharps
  • covering all breaks in the skin
  • visors and waterproof coveralls
  • good basic hygiene
  • pre employment medical - protection of high risk workers
  • spillage procedure
  • provide microbiological cabinets for handling samples
  • cleaning & disinfection of surfaces
  • training and supervision
  • procedures for dealing with cuts and wounds
  • procedures for home visits