Question

what are the three steps in the chain of infection. apply what is known about covid 19 to each step

Answer 1

The three steps in the chain of infection are:

1- The germ has a source

2- Spread of germ from the source

3- The germ infects another person

​​​​​​Application and correlation of the steps in chain of infection with the available knowledge of Covid-19:

(1) The germ has a source.

The germ in covid-19 is the corona virus 'SARS-Cov-2'.

The source or host of this virus is said to be humans and bats. Some researches also says that Civets are also carriers of SARS cov 2.

In the current situations, humans are the most available and biggest source or host of SARS Cov2 virus.

(2) Spread of germ from the host.

The spread of Covid-19 occurs from suspected animal to humans and from humans to humans.

The human to human transmission usually occurs through droplets coming from mouth. Some sources also says that this virus spreads through air.

Saliva and droplets are main factors responsible for spread of this virus.

This virus also spread through contaminated materials but the life of virus on these contaminated materials are less.

(3) Infection of another person

The person to contract this virus from infected person through their droplet or saliva gets infected soon.

The incubation period of virus, is said to be 2-14 days. Infected persons starts to show symptoms within this period and starts to transmit this virus to other people.

It is said that one infected person infects an average of 2 people, while super carriers spreads infection to a lot more people.

Transmission power of SARS-COV2 is very high and that is the reason why the virus is spreading all around the world to become a pandemic.