Question

Instructions

I.
A. What are the 6 elements of Chain of infection and explain how it will lead to infection?

B. Differentiate the different kinds of reservoirs.

C. What is the single most important way to stop the chain of infection?

D. As a future health worker, give 5 ways on how to cut the chain of infection.

II. Below is an example of infectious diseases. Complete the following:

Dengue Hemorrhagic Fever- is a mosquito-borne tropical disease caused by the dengue virus. Symptoms typically begin three to fourteen days after infection. These may include a high fever, headache, vomiting, muscle and joint pains, and a characteristic skin rash occurs.
Dengue is spread by several species of female mosquitoes of the Aedes genus, principally Aedes aegypti. The virus has five serotypes infection with one type usually gives lifelong immunity to that type, but only short-term immunity to the others. Subsequent infection with a different type increases the risk of severe complications.
Complete the following

Pathogen:

Reservoir:

Portal of Exit:

Mode of transmission:

Portal of Entry:

Possible host:

Answer 1

The Chain of Infection

There are a number of events that help microorganisms to cause diseases in an individual. These events are called as ‘chain of infection’.

The 6 elements of chain of infection and how it will lead to infection are explained below:

1.The reservoir

It is the place where pathogen can grow and multiply. This can be individuals, animals, insects, health care equipment, water ,soil etc.

2.The portal of exit

It is the means through which the germ leaves the reservoir. There are human portals of exit (e.g. hands, open wounds, droplets , and body fluids) and  non-human portals of exit (e.g. unclean medical equipment , including commodes, pillows, mattresses and reusable items).

3.The mode of transmission

This is the way how the microbes can be passed on. It occurs through a variety of methods such as contact, ingestion, or inhalation.

4.The portal of entry

It is the means by which an infectious agent invade a new host. They can enter the body through open wound, mucous membranes, respiratory passage, catheters and tubes etc.

5.The susceptible host

People who are vulnerable to be invaded by an infectious agent is called as a susceptible host.

It can be any individual receiving medical care. Examples of susceptible hosts are very young children, chronically ill and immunocompromised persons.

6.The infectious agent

An infectious agent is the microorganism that causes diseases. It includes bacteria, viruses, fungi and parasites.

Example of chain of infection

Commode used by a patient (reservoir)

Touching commode with our hands(Portal of exit)

Direct patient contact with unhygienic hands (Mode of transmission) on an open wound (portal of entry)

            

Wound infection with Bacteria (Infectious agent)

Differentiate the different kinds of reservoirs.

Reservoirs are

· Human reservoirs.

· Animal reservoirs.

· Environmental reservoirs

Human reservoirs	Animal reservoirs	Environmental reservoirs
Man is the reservoir of many diseases. Example:sexually transmitted diseases Small pox. Asymptomatic reservoir of an infection is called carrier. Example ‘typhoid Mary’	These are animal hosts in which the germs live and multiply. Example:in anthrax,sheep is the reservoir. Diseases that are transmitted from animal to man are called zoonosis.	It includes plants, soil and water. Example: Legionella pneumophila grows in water suppies and causes Legionnaires disease.

The single most important way to stop the chain of infection is given below :

Hang washing using soap and water is the single most important way to stop the chain of infection

As a future health worker, 5 ways to cut the chain of infection.

5 ways are:

1. Vaccination

2. Diagnosis and treatment of infectious diseases

3. Disinfection and sterilization

4. Patient education

5. Strict adherence to infection control policies