U4 AOS1 Topic 7: Pathogen Breakout Inhibition

A patient suffering from infectious disease is tested to identify the pathogens before treatment. There are several methods to identify the pathogens which are as follows:

1.   Physical method: the pathogens are visualized under the microscope.

2.   Phenotypic method: pathogens are identified based on their expression. For example,

a.           Selective media in which an agar plate is prepared on which only certain pathogens can grow.

b.           Biochemical tests are used to identify the genus or species of the pathogens by performing a series of biochemical tests. For example, Gram staining.

3.   Immunological method: It is used to identify the pathogen by looking for specific antigen or antibodies in the blood sample of patient.

4.   The molecular method: It is used to identify the pathogen on molecular level. For example,

a.           Hybridization based detection where known sequence is allowed to hybridize with the sequence of pathogen’s genome. This hybridization can be detected when a signal is generated.

b.           Whole-genome sequencing of pathogen’s genome can be used to identify the pathogen.

Modes of pathogen transmission

Pathogens can be transmitted via following routes:

1.   Airborne transmission is the spread of pathogens via air.

2.   Droplet transmission is the spread of pathogens via respiratory droplet containing pathogens.

3.   Direct physical contact transmission is the spread of pathogens via touch and exchange of body fluids etc.

4.   Indirect physical contact transmission is the spread of pathogens via food, water or any other vector such as mosquitoes.

5.   Fecal-oral transmission is the spread of disease when food becomes contaminated by infected feces or inhaling the pathogens present in feces.

Controlling disease transmission

There are different strategies to control the transmission of pathogens.

1.           Prevention: Handwashing, sterilizing surfaces, lockdown and vaccination can prevent the spread of disease.

2.           Screening: Routine testing screens for the presence of pathogens in a population and helps to control the spread of disease.

3.           Quarantine: isolating an affected person from healthy people can control the spread of disease.

4.           Treatment of infected person: medications such as antibiotics against bacteria, antiviral against viruses and fungicides against fungi can control the transmission of respective pathogen.

5.           Controlling the mode of transmission: identifying the pathogen and controlling its mode of transmission can control the transmission of disease. for example, reducing the risk of airborne transmission can control the transmission of respiratory pathogens.