The Mood of Transmission and Chain of Infection of COVID-19
COVID known as Corona Virus Disease belongs to a large family of viruses which causes mild illness ranges from the common cold to severe diseases such as pneumonia or bronchitis. The virus that causes covid-19 is known as Severe Acute Respiratory Syndrome (SARS-CoV-2).
Such virus are tiny infectious agent that are too small to be seen with the common human eye or even under a normal microscope. They can only replicate and multiply if inside a living organism such as a human, animal which acts as the host.
Respiratory viruses infect the lungs and airways. Respiratory infections tend to affect the normal function of the lungs causing breathing problems.
Modes of Transmission
Droplet Transmission: Droplet transmission happens when an infected person coughs, sneezes, or even talks and tiny drops from the infected person enter into another person’s eyes, nose and mouth. It may also happen when a person is in close contact within 1 meter distance with someone who has respiratory symptoms like(coughing or sneezing) and is therefore at risk of having his/her mouth and nose or eyes exposed to infective respiratory droplets.
Contact Transmission: Contact transmission takes place when there is a physical contact between an infected person/contaminated object and another person.
This can happen in one the two ways:
- Through direct contact where the infection travels to another person through touch.
- Through indirect contact when a person touches an object contaminated by covid-19.
The covid-19 virus can be transmitted through contact. When an infected person coughs, droplets can land on objects and surfaces around them. When another person touches these surfaces around them. When another person touches these surfaces, their hands can get contaminated with the virus. If they touch their nose or mouth with contaminated hands, they can get infected.
Airborne Transmission: Air borne transmission of virus occurs when small particles in the air less than 5 micrometer in size containing the virus are inhaled into a person’s respiratory. These infected particles can live in the air for a long period of time leading to a spread of infection.
Chain of Infection
A chain of infection refers to the path that viruses take to enter a person and to be transmitted from one person to another. There are six steps in the chain of infection and we know that transmission will only take place if all six elements in the chain are present.
- The first element in the chain is an infectious agent, which can cause a disease. It could be a virus, bacteria, or fungi.
- The second element is the reservoir, or the place where the infectious agent live. It can be a person, an animal, soil or water.
- Then we have a port of exit, which is the way the agent leaves the body. This can happen through the mouth, if a person coughs or sneezes, through a cut, if a person is bleeding, during diaper changes or toileting.
- The next element is the mode of transmission, which is how the infectious agent is transmitted from one person to another. It can be in form of droplets, direct or indirect contact, or through airborne transmission.
- The fifth element in the chain of infection is the port of entry, or the place where the infectious agent enters another person’s body. This is similar to the port of exit, it can be a mouth, nose, eyes, an open cut etc.
- At last, we have a susceptible host – it is either a baby, an elderly person or someone with a weakened immune system. To prevent the spread of the disease, one of the links in the chain of infection must be broken.
Beebagr Azim is BE student of Balochistan University of Engineering & Technology. He can be reached at [email protected]