Pathogens

Define a pathogen.

A disease-causing organism.

What are communicable diseases?

Diseases caused by foreign organisms invading the body and multiplying there.

What is meant by contagious diseases?

Communicable diseases that can be passed on by direct contact with an infected person or with objects they touched.

What is a vector in the context of disease?

An intermediate host of a pathogen that can spread communicable diseases, such as mosquitoes or fleas.

What differentiates non-communicable diseases from communicable diseases?

Non-communicable diseases can be caused by environmental, genetic, or other factors without involving a specific pathogen.

What is a prokaryote?

A unicellular organism lacking a nucleus, with DNA that either floats freely or is in circular plasmids.

What defines a virus?

An infectious agent too small to be seen with a light microscope, consisting of a protein sheath surrounding nucleic acid.

Can viruses reproduce on their own?

No, viruses are totally dependent on living cells for reproduction.

What is the main structural difference between viruses and bacteria?

Viruses are not living cells, while bacteria are living prokaryotic cells.

How do viruses interact with host cells?

Viral DNA or RNA induces the host cell to manufacture more virus particles.

What are bacteriophages?

Viruses that multiply in bacterial cells causing the death of the bacterium.

What do protozoa and fungi have in common?

They are both eukaryotic organisms that can cause illness.

What is a common way through which zoonotic infections are transmitted?

Zoonotic infections are infections passed from animals to humans.

Name an example of a zoonotic infection.

Examples include SARS, MERS, avian influenza, swine flu, rabies, Ebola, and Zika.

What is direct contact transmission?

Transmission that involves the actual physical contact with an infected person.

What is indirect contact transmission?

Transmission that occurs by touching an object that an infected individual has touched.

What role do body fluids play in pathogen transmission?

Transfer of body fluids can lead to the transmission of infections when fluids come into contact with mucous membranes or bloodstream.

Give examples of diseases spread by body fluids.

Human Immunodeficiency Virus, Hepatitis B, and Hepatitis C.

How can infections be spread through droplets?

When tiny droplets emitted during breathing, talking, sneezing, or coughing come into contact with others.

What type of infections can be transmitted by airborne transmission?

Infections like measles and chickenpox can spread through airborne particles.

What does ingestion of contaminated food or drink lead to?

It can result in diseases such as dysentery, typhoid fever, and salmonella food poisoning.

What types of diseases can be transmitted by vectors?

Vector-borne diseases like malaria, dengue fever, and Lyme disease.

What are common vectors for spreading diseases?

Insects like mosquitoes, ticks, and fleas can act as vectors.

What is the relationship between the number of pathogens and the risk of illness?

Some pathogens can cause illness or death even in relatively small numbers.

What is the role of beneficial bacteria in humans?

They assist in the digestive process and other vital functions.

What defines communicable diseases?

Diseases that are spread from one person to another through pathogens.

How is genetic modification of bacteria beneficial?

Genetically modified bacteria can produce insulin for diabetes treatment.

Which structures do bacteria have that viruses do not?

Bacteria have a cell wall and are living cells, while viruses do not.

What is one way fungi can cause infections?

By releasing spores and taking advantage of low resistance to fight infection.

Why are viruses used in gene therapy?

They can insert new genes into other organisms.

List one effect of the presence of bacteria in a human environment.

They play a crucial role in decomposition and cycling of elements.

What is the effect of high moisture droplets in transmission of diseases?

They can harbor pathogenic organisms and lead to infections when inhaled.

How are pathogens transmitted?

Pathogens can be transmitted through various routes such as direct contact, indirect contact, airborne transmission, through contaminated food or water, and vector-borne transmission.

What is direct contact transmission?

Direct contact transmission occurs when a pathogen is transferred from one person to another through physical contact.

What is indirect contact transmission?

Indirect contact transmission occurs when a pathogen is transferred via an intermediary object, surface, or organism.

Explain airborne transmission of pathogens.

Airborne transmission involves pathogens being carried through the air in droplet nuclei or dust particles, which can be inhaled by individuals.

What is vector-borne transmission?

Vector-borne transmission involves pathogens being transmitted by vectors such as insects, which can carry the disease from one host to another.

How can contaminated food and water transmit pathogens?

Contaminated food and water can serve as vehicles for pathogens to enter the body, leading to infections or illnesses.

Describe how respiratory droplets transmit pathogens.

Respiratory droplets are expelled when an infected person coughs, sneezes, or talks, and can directly enter the mouth, nose, or eyes of nearby individuals, leading to potential infection.

What factors influence the transmission of pathogens?

Factors include the mode of transmission, pathogen virulence, host susceptibility, and environmental conditions such as humidity and temperature.

What is the transfer of body fluids?

The transfer of body fluids refers to the exchange or movement of fluids such as blood, saliva, semen, and vaginal secretions between individuals, which can facilitate the transmission of pathogens.