H.
BTEC L3 EXTENDED DIPLOMA IN APPLIED SCIENCE
Unit 12: Diseases and Infection
Assignment 12B: Transmission of infectious diseases
Examine the transmission of infectious Infectious diseases like chicken pox and HIV, can be
transmitted directly from human to human through bodily
diseases and how this can be prevented fluids and touch as well as from animal to human through
animal waste such as droppings.
The transmission of these infectious diseases can also
occur indirectly through vectors, contamination, fomite,
and droplets of water.
This assignment will discuss and assess these types of
transmission in terms of prevention and management.
Research will be carried out on specific organisations that
work to limit the spread of diseases.
Methods of transmission for infectious diseases
Direct contact transmission
Transmission of infectious diseases can occur directly
through direct person-to-person contact and direct contact
of bodily fluids, leading to the spread of disease (1). This
can happen when an individual touches/is touched by an
infected individual, resulting in direct person-to-person
contact. For example, conjunctivitis also known as pinkeye
can be transmitted through direct person-to-person contact
(2). This transmission occurs when an infected individual
touches the pus/discharge from their infected eye which
contains conjunctivitis and then touches another individual
who then touches their own eye, transferring conjunctivitis
into it where it reproduces and causes the infections. (2).
1
, H.
BTEC L3 EXTENDED DIPLOMA IN APPLIED SCIENCE
Unit 12: Diseases and Infection
Indirect contact transmission
Transmission can also happen when an individual has Transmission of diseases can also occur indirectly through
direct contact with infected bodily fluids. For example, vectors, contamination, fomite, and infected droplets of
Hepatitis B can be transmitted through direct contact with water.
bodily fluids like blood or open wounds (3). This
Vectors are carriers specifically organisms that transmit
transmission can occur when an infected individual leaves
disease by carrying an infective agent from one host to
infected blood on objects such as razors, toothbrushes, and
another, e.g., mosquitoes, fleas, and lice (8). An example of
syringes, if these objects come into contact with other
a vector that transmits disease by indirect contact is
individuals, this spreads Hepatitis B as the Hepatitis B is
typhus. This disease is transmitted by the vector,
transferred from the object into the uninfected individual
lice/mites/fleas, and occurs when an individual is bitten by
(4).
infected lice, mites, or fleas (9). When these vectors bite an
Direct contact transmission can also occur from animal to infected individual, they pick up the typhus and then carry
human and a term used to describe this transmission is the typhus to another individual when transferring. They
zoonotic- the ability to spread from animals to humans (5). transfer typhus into another individual by biting them. This
An example of a disease that is spread zoonotically is is a form of indirect contact transmission as the individual
anthrax. This disease can be spread from animals, e.g., doesn’t directly come into contact with the disease but a
cattle, deer, and sheep, to humans when the anthrax carrier of the disease.
spores from infected animals are breathed in, ingested
Contamination of food/water can also transmit diseases
from contaminated food/drink, or even absorbed on
indirectly since the virus/bacteria causing the disease can
cuts/scrapes (6). The direct contact of animal waste with
be found in contaminated food/water (1). An example of a
humans can also transmit infectious diseases such as
disease that can be transmitted by contamination of
psittacosis. This disease can spread to humans from direct
food/water is cholera- a disease caused by the
contact with animal waste as infected birds shed the
contamination of water. Water can become contaminated
bacterium causing psittacosis in their droppings and
when physical contaminants such as sediment are released
secretions (7). The drying of the droppings and secretions
into it. Also, chemical contaminants like nitrogen, bleach
forms small dust particles that can be present in the air, so
and pesticides can be found in water which causes it to be
when a human breathes in these dust particles, they are
contaminated. Biological contaminants like microbes can
breathing in the psittacosis and can therefore develop
also be found in contaminated water, consisting of
psittacosis (7).
bacteria, parasites, viruses and protozoan (15). The
2
BTEC L3 EXTENDED DIPLOMA IN APPLIED SCIENCE
Unit 12: Diseases and Infection
Assignment 12B: Transmission of infectious diseases
Examine the transmission of infectious Infectious diseases like chicken pox and HIV, can be
transmitted directly from human to human through bodily
diseases and how this can be prevented fluids and touch as well as from animal to human through
animal waste such as droppings.
The transmission of these infectious diseases can also
occur indirectly through vectors, contamination, fomite,
and droplets of water.
This assignment will discuss and assess these types of
transmission in terms of prevention and management.
Research will be carried out on specific organisations that
work to limit the spread of diseases.
Methods of transmission for infectious diseases
Direct contact transmission
Transmission of infectious diseases can occur directly
through direct person-to-person contact and direct contact
of bodily fluids, leading to the spread of disease (1). This
can happen when an individual touches/is touched by an
infected individual, resulting in direct person-to-person
contact. For example, conjunctivitis also known as pinkeye
can be transmitted through direct person-to-person contact
(2). This transmission occurs when an infected individual
touches the pus/discharge from their infected eye which
contains conjunctivitis and then touches another individual
who then touches their own eye, transferring conjunctivitis
into it where it reproduces and causes the infections. (2).
1
, H.
BTEC L3 EXTENDED DIPLOMA IN APPLIED SCIENCE
Unit 12: Diseases and Infection
Indirect contact transmission
Transmission can also happen when an individual has Transmission of diseases can also occur indirectly through
direct contact with infected bodily fluids. For example, vectors, contamination, fomite, and infected droplets of
Hepatitis B can be transmitted through direct contact with water.
bodily fluids like blood or open wounds (3). This
Vectors are carriers specifically organisms that transmit
transmission can occur when an infected individual leaves
disease by carrying an infective agent from one host to
infected blood on objects such as razors, toothbrushes, and
another, e.g., mosquitoes, fleas, and lice (8). An example of
syringes, if these objects come into contact with other
a vector that transmits disease by indirect contact is
individuals, this spreads Hepatitis B as the Hepatitis B is
typhus. This disease is transmitted by the vector,
transferred from the object into the uninfected individual
lice/mites/fleas, and occurs when an individual is bitten by
(4).
infected lice, mites, or fleas (9). When these vectors bite an
Direct contact transmission can also occur from animal to infected individual, they pick up the typhus and then carry
human and a term used to describe this transmission is the typhus to another individual when transferring. They
zoonotic- the ability to spread from animals to humans (5). transfer typhus into another individual by biting them. This
An example of a disease that is spread zoonotically is is a form of indirect contact transmission as the individual
anthrax. This disease can be spread from animals, e.g., doesn’t directly come into contact with the disease but a
cattle, deer, and sheep, to humans when the anthrax carrier of the disease.
spores from infected animals are breathed in, ingested
Contamination of food/water can also transmit diseases
from contaminated food/drink, or even absorbed on
indirectly since the virus/bacteria causing the disease can
cuts/scrapes (6). The direct contact of animal waste with
be found in contaminated food/water (1). An example of a
humans can also transmit infectious diseases such as
disease that can be transmitted by contamination of
psittacosis. This disease can spread to humans from direct
food/water is cholera- a disease caused by the
contact with animal waste as infected birds shed the
contamination of water. Water can become contaminated
bacterium causing psittacosis in their droppings and
when physical contaminants such as sediment are released
secretions (7). The drying of the droppings and secretions
into it. Also, chemical contaminants like nitrogen, bleach
forms small dust particles that can be present in the air, so
and pesticides can be found in water which causes it to be
when a human breathes in these dust particles, they are
contaminated. Biological contaminants like microbes can
breathing in the psittacosis and can therefore develop
also be found in contaminated water, consisting of
psittacosis (7).
bacteria, parasites, viruses and protozoan (15). The
2
