what causes infections

Children are susceptible to infections that often cause illness. Children get into care services and early childhood education while their immune systems are not fully developed. These children may not have any exposure to common germ-causing infections yet, and they could be too young for any vaccines against common diseases. So, children in care services are susceptible to illnesses that may quickly spread.

This is why the hltinf001 course is fundamental to those working in health facilities and those working in care services. The course offers knowledge and skills required to follow organizational infection prevention and control procedures, which include applying transmission-based and standard precautions and responding to risks of infection.

So, what causes infection?

Germs or microscopic living things are everywhere, and some of them can cause diseases to humans. Germs have four major types:


The virus should be in a living cell called a host to grow and reproduce. Most viruses cannot thrive outside the host. When they get into the human body, they can quickly multiply and cause diseases. The common diseases humans can get from the virus are gastroenteritis, common colds, measles, chickenpox, and flu.


Bacteria can survive almost everywhere, including the human body. Most of them are living near us but are not harmful. However, some of them are harmful enough to infect a human body, causing various diseases. Common bacterial infections are meningococcal disease, streptococcal sore throat, and pertussis or whooping cough.


Protozoa are microorganisms that thrive on moisture and usually spread diseases in the water. Some protozoa can cause infections in the intestine, leading to nausea, diarrhea, and stomach upsets. For instance, Giardia and Cryptosporidium can be acquired through drinking contaminated water.


Fungi are various groups of organisms, which include mushrooms, moulds, and yeasts. They can thrive in a warm, damp environment. Some fungi are not harmful, such as baker’s yeast and edible mushrooms. However, most of them can cause diseases, like ringworm, athlete’s foot, and thrush, to name a few.

Germs are not the only culprits for diseases caused by infection. Some infections are caused by parasites, such as hookworms and roundworms. Moreover, mites like scabies and insects like head lice may also cause scratching and infestations, leading to secondary infections.

Spread of infection

The chain of infection happens when the germs spread. This chain has important steps for the germs to be transferred from one person to another. Breaking the chain can control and prevent the spread of infections. Breaking the chain can be done at any of the steps.

The chain of infection

  1. The germs get their host: This happens when a person picks up germs from the surroundings or directly from a person with the infection.
  2. The host spreads the germs.

    The germs spread in three main ways:

    • Droplet: When an infected person coughs or sneezes, he or she is spreading the germs. When not covered, the mouth and nose can shoot tiny droplets in the air, landing on nearby surfaces. Droplets from a sneeze can travel around two meters away. It can be inhaled directly by another person.
    • Contact: Any surface, such as chairs, tables, doorknobs, beddings, toys, and toilets, can become contaminated once touched, sneezes, or coughs on by an infected person. When an uninfected person touches any of these surfaces and then touches their eyes, nose, mouth, broken skin, germs get in, the infection begins.
    • Airborne: Germs are smaller than droplets. They can spread when an infected person speaks, breathe, sneeze, or cough—the germs that can travel in the air through air-conditioning systems or ventilation.
  3. The germs get another host to infect.

    Once the germs get another person to infect, they will become ill and may continue spreading the germs, and then the infection.

The only way to keep the infectious diseases from spreading is by breaking the chain. The infection should be prevented and controlled, a necessary procedure that you can learn by applying for an hltinf001 course.

This course is essential, especially when the whole world is experiencing a pandemic situation caused by the Covid-19 virus.