Task 1- Hand out
Infections and transmissions-
Infections are invasions of microorganisms in the body, causing harm to a person’s health in the body. The invasion of an
infection causes the growth of germs in your body. The infection can start anywhere in the body and can spread to any place as
well. Infectious diseases are caused by organisms such as viruses, fungi, bacteria and parasites. These organisms enter the body
and live off of the host, making a person sick and very ill.
Infection transmission is the spread of the infection from host to host. There are 2 main ways of how infections can transmit-
direct contact and indirect contact. Direct contact is contact that is directly from an infected host. Direct contact can be anything
such as- Touching, kissing, sexual contact, and airborne droplets. Indirect contact transmission occurs when there is no host-to-
host contact. These can be things such as contaminated objects, food and drinking water, animal to person contact and
environmental reservoirs. An example of indirect contact is being infected with salmonella from food. The infectious disease can
be transmitted from eating food with the salmonella bacteria present in the food.
Infections are spread directly from an infected host to a healthy host. Contact transmission is the most common form of
transmission that there is. Contact transmission is a direct transfer that can easily infect a non-infected person. These direct
contacts can be things such as kissing, sexual intercourse and airborne transmission sch as coughing or sneezing. Once the
bacteria, virus or other germs is on the host- this is when the microorganisms enter the body and with due time, the person
starts to show symptoms. Blood contact is also a form of direct contact, coming into contact with an infected host’s blood can
cause you to become infected. For example, if your partner has a cut on their lip and their blood enters your body. Being bitten
by an animal or being scratched by an animal can transmit an infection. This is because an animal can have bacteria on their
teeth or claws. When an animal who is in infected bites or scratches a human, this causes an open wound for bacteria to enter
which can then lead to an infection. This spreads the animal’s infection to the human. This is an example of direct transmission.
This example can be prevented by cleaning an pen wound straight away and not touching an open wound constantly as this can
lead to ongoing infections.
Vectors-
Indirect transmission is another form of how infections can spread.
Indirect contact is transmitting infection through objects, parasites or
food. A lot of germs are found on parasites. An example of a parasite is a
mosquito. These move from person to person, spreading infection These
are called vectors. Vectors are commonly known as an organism that
carries a disease or infection but does not cause it. Vectors are organisms
such as fleas, lice, ticks, and mosquitos. Vectors transmit infectious
diseases. Vector-borne diseases make up more than 17% of all infectious
diseases. These vectors can be blood-sucking vectors. When feeding from
a host through blood contact, they ingest disease-producing
microorganisms.
, Vector Disease Caused Type of pathogen
Mosquito Yellow fever Virus
Zika Virus
Rift Valley Fever Virus
Aquatic snails Schistosomiasis Parasite
Blackflies Onchocerciasis Parasite
Fleas Plague Bacteria
Tungiasis Endoparasite
Lice Typhus Bacteria
Louse-borne relapsing fever Bacteria
Sandflies Leishmaniasis Parasite
Sandfly fever
Ticks Lyme disease Bacteria
Relapsing fever Rickettsial Bacteria
diseases
Triatome bugs Chagas disease Parasite
Tsete flies Sleeping sickness Parasite