Unit 12 assignment B
How can infectious diseases be transmitted?
Direct contact
The easiest way to catch infectious diseases is if an infected person or someone susceptible
comes in physical direct contact with an infected animal or person infected with that disease.
Infectious diseases can be transmitted through direct contact as:
Human to human
● Infectious diseases are commonly transmitted through direct person to person
contact transferring bacteria, virus, fungi or parasites as it does so. Transmission
happens when a person with the infectious disease touches, kisses, coughs,
sneezes, exchanges body fluids, or has sexual intercourse with another person who
isn't infected. The person who passes on the pathogen may show no symptoms of
the disease but they may be a carrier.
Example of person to person contact disease: Hepatitis A
● Hepatitis A is a viral infection caused by the hepatitis A virus. Hepatitis A is a very
contagious disease which affects the liver cells and causes inflammation to the liver.
The inflammation can affect the function of your liver. The virus can spread by eating
food made by someone with the virus and they didn't wash their hands properly, they
drink contaminated water or eat from that has been washed by the contaminated
water, eat raw shellfish from water which has been polluted with sewage, become
close in contact with a person who has hepatitis A–even if that person doesn't show
any symptoms of hepatitis A, have oral or anal sex with someone who has the virus
or if infected stool enters the mouth of another person, this is the faecal-oral
transmission.
Animal to human
● If you come in contact with an infected animal and they scratch or bite you it can
make you feel sick and in other extreme cases it can be fatal. Animal waste can also
be dangerous for example, when scooping out your pets litter you can get a
toxoplasmosis infection
Example of animal to person contact disease: Anthrax
● Anthrax is a bacterial infection caused by the bacteria Bacillus anthracis. Anthrax is
not a contagious disease. Anthrax is spread if a person has cuts/scrapes which the
anthrax spores get into, this is called cutaneous anthrax and it can happen when a
person deals with infected animals or animal products that have been contaminated
like wool or hair. Cutaneous anthrax is most common on the neck, head and hands of
an individual. It affects the skin and tissue around the site of infection. When anthrax
spores are inhaled, this is called inhalation anthrax. People may inhale the spores
when working with animals that have been infected or contaminated animal products
from infected animals, it affects the lungs and lymph nodes found in the chest and
then spreads to the rest of the body causing breathing problems. Undercooked or
raw meat from an animal infected with anthrax can cause gastrointestinal anthrax if a
person eats it. Once the bacteria has been ingested, the anthrax spores affect the
throat, oesophagus, stomach and intestines.
, Mother to unborn child
● A woman who's pregnant may transfer the germs that cause infectious diseases to
the unborn child. A few germs may pass through the breast milk and placenta. Any
germs present in the vagina of the gestational parent may also be transferred to the
child during child birth. Pregnant women can also spread the infectious disease to
their unborn child via the placenta.
Example of mother to unborn child contact disease: Gonorrhoea
● Gonorrhoea is a bacterial infection which is caused by the Neisseria gonorrhoeae
bacteria. The bacteria is mainly found in the discharge from the penis and vagina.
Gonorrhoea is a very contagious disease.It is not spread by hugging, kissing, or
sharing things such as baths or towels. The Neisseria gonorrhoeae bacteria can’t
survive out of the human body for long periods of time. The mucous membranes of
the reproductive system which include the uterus, cervix, fallopian tubes and vagina
in women and the urethra in men. It can also affect the mucous membranes of the
eyes, throat, mouth and rectum but that's less common. Gonorrhoea is transmitted
through sexual contact with the penis, vagina, mouth, or anus of an infected partner.
Gonorrhoea is not spread by kissing, hugging, swimming pools, toilet seats or
sharing baths, towels, cups, plates or cutlery. The bacteria cannot survive outside the
human body for long. Gonorrhoea is spread through unprotected vaginal or anal sex,
it can also infect the entrance to the womb hence why an unborn child can have
gonorrhoea from its mother. Gonorrhoea can cause permanent blindness to a
newborn baby if treatment is not given
Droplet spread
● The spreading of droplets during sneezing and coughing can spread infectious
diseases. Droplets also come out of your mouth when you speak. This is another
way infectious diseases can be spread. Droplets fall to the ground after a few feet
once they excrete the nose or mouth so this type spreading of diseases require close
contact
Example of droplet spread contact disease: Whooping cough
● Whooping cough is a bacterial infection caused by the Bordetella Pertussis. It is a
very contagious disease. The pathogen can be spread from human to human
through the air by either sneezing or coughing which releases droplets with the
bacteria in them. Other people then inhale the bacteria and get the infectious
disease. Whooping cough can also be spread if a person doesn’t show many
symptoms but they are still a carrier of the bacteria which can then spread to others.
Whooping cough affects the lungs and airways of an individual causing them to
cough continuously with a whooping sound in between coughs.
Indirect contact
Germs can also spread by indirect contact. This is when there is no direct human to human
contact. Many germs remain on objects such as tabletops, door handles/knobs,
contaminated water, mosquitos, flies, fleas or rodents. Infectious diseases can be
transmitted through indirect contact such as:
