Transcript Health and pathogens

Lesson 1
Lesson 2
Lesson 3 & 4
Lesson 5
Lesson 6
Lesson 7
Lesson 8
Lesson 9
2.2.2 Health and Disease
• All – Recall keywords
• Most – Describe the different types of
pathogen with examples
• Some – Explain how different factors
can affect the epidemiology of certain
diseases.
2.2.2 Health and Disease
• All – Recall keywords
• Most – Describe the different types of
pathogen with examples
• Some – Explain how different factors
can affect the epidemiology of certain
diseases.
What is HEALTH?
Health is more than simply the absence of disease.
It can be defined as your physical, mental and
social wellbeing. If you are in good health you are…
•Free from disease
•Able to carry out normal physical and mental tasks
•Well fed, with a balanced diet
•Usually happy, with a positive outlook
•Suitably housed with proper sanitation
•Well integrated into society
Draw a table with 4 columns showing what
type of microbe causes these infectious
diseases…
Mumps
Athlete’s
foot
Typhoid
dysentery
Influenza
Tuberculosis
Malaria
Chicken Pox
HIV
Cholera
Ring
worm
Type of
microbe
Bacteria
Virus
Protozoa
Fungus
Dysentery
Ring
worm
Malaria
Athlete’s
foot
HIV
Infectious
disease
Cholera
Mumps
Tuberculosis
Influenza
Typhoid
Chicken
pox
Match the key word to the definition
1. The
rate of occurrence of new cases of a particular
disease in a population being studied
2. A branch of medical science that deals with the
incidence, distribution, and control of disease in a
population
3. A micro-organism which causes disease
4. The total number of cases of a disease in a given
population at a specific time.
5. Anything which impairs the normal functioning of the
body.
6. ‘A state of complete physical, mental and social wellbeing and not merely the absence of disease of infirmity’
(World Health Organisation)
7. An organism that grows, feeds, and is sheltered on or in
a different organism while contributing nothing to the
survival of its host, even causing it damage
Incidence, Pathogen, Epidemiology, Parasite, Health, Disease, Prevalence,
Match the key word to the definition
 Health: ‘A state of complete physical, mental and social well-being and not
merely the absence of disease of infirmity’ (World Health Organisation)
 Disease: Anything which impairs the normal functioning of the body.
 Pathogen: A micro-organism which causes disease
 Parasite: An organism that grows, feeds, and is sheltered on or in a different
organism while contributing nothing to the survival of its host, even causing
it damage
 Epidemiology: a branch of medical science that deals with the incidence,
distribution, and control of disease in a population
 Prevalence: The total number of cases of a disease in a given population at
a specific time.
 Incidence: The rate of occurrence of new cases of a particular disease in a
population being studied
Tuberculosis
Mycobacterium tuberculosis
DOTs: Directly observed therapy
HIV virus
Capsid, made
of protein
RNA molecule
Core
Reverse
transcriptase
(makes DNA
from RNA)
Phospholipid
Envelope
Glycoprotein
5nm
Malaria
Plasmodium lifecycle
• Zygotes of the parasite undergo a stage of asexual reproduction in the
mosquito’s gut wall
• The parasite returns to the blood and invades the red blood cells
• Here the parasite produces gametes (sexual stage)
• More reproduction within RBCs causes these cells to swell and burst (lysis)
• The mosquito feeds on the blood of a non-infected human
• Anopheles mosquito ingests a blood meal from an infected human
•
Plasmodium is transferred from the human to the stomach of the mosquito
• Plasmodium transferred from mosquito to human
• Plasmodium migrate to the human’s liver to undergo asexual reproduction
• Fertilisation occurs
Plasmodium lifecycle
• Anopheles mosquito ingests a blood meal from an infected human
• Plasmodium is transferred from the human to the stomach of the mosquito
• Here the parasite produces gametes (sexual stage)
• Fertilisation occurs
• Zygotes of the parasite undergo a stage of asexual reproduction in the
mosquito’s gut wall
• The mosquito feeds on the blood of a non-infected human
• Plasmodium transferred from mosquito to human
• Plasmodium migrate to the human’s liver to undergo asexual reproduction
• The parasite returns to the blood and invades the red blood cells
• More reproduction within RBCs causes these cells to swell and burst (lysis)
Prophylactics
Prevention is better than a cure!!
Disease
TB
Malaria
Pathogen
Method of
transmission
Effects on
body
Treatment
Human
immunodeficiency virus
(retrovirus)
Unsafe sex,
shared
needles,
needle stick
injuries
Infect lung cells
– night sweats,
cough, bloody
mucus
Combination
therapy to
slow viral
replication eg
AZT
Plasmodium
falciparum or
P.virax
(protozoa)
Affects immune
Airborne
system (T
droplets,
lymphocytes) so
unpasteurized
oppurtunistic
milk
infections take
Antibiotic
courses eg.
Streptomycin
and rifampin
over
Mycobacterium
HIV/AIDS tuberculosis or
M.bovis
Anopheles
mosquito
vector
Infects red
blood cells,
results in fever
Prophylactics
and
antimalarials
eg quinine
Disease
TB
Malaria
HIV/AIDS
Pathogen
Method of
transmission
Effects on
body
Infect lung cells
Mycobacterium
Airborne
– night sweats,
tuberculosis or
droplets,
M.bovis
unpasteurized cough, bloody
mucus
milk
Plasmodium
falciparum or
P.virax
(protozoa)
Human
immunodeficiency virus
(retrovirus)
Anopheles
mosquito
vector
Unsafe sex,
shared
needles,
needle stick
injuries
Infects red
blood cells,
results in fever
Affects immune
system (T
lymphocytes) so
oppurtunistic
infections take
over
Treatment
Antibiotic
courses eg.
Streptomycin
and rifampin
Prophylactics
and
antimalarials
eg quinine
Combination
therapy to
slow viral
replication eg
AZT
Can you explain each of the following trends in
epidemiology of disease? (use pg 167 to help if unsure)
1.
2.
3.
4.
People who live in crowded conditions are at most risk
of contracting TB
From the middle of the 19th century the incidence of TB
has decreased
In the late 1980s there was a dramatic increase of TB
in the UK
There are certain strains of antibiotic resistant TB
emerging