Host - Parasite Interaction

The invasion and multiplication of microorganisms in or on a host. May or may not cause disease, but can trigger an immune response. Symptoms may be mild or undetectable.

The ability of a microorganism to cause disease. This ability varies depending on the host's individual immune system, the amount of the microbe, and how it entered the body.

An infected individual who doesn't show symptoms but can still spread the disease.

A disease caused by the bacterium Bacillus anthracis. Symptoms include fever, chills, and skin lesions that can become ulcerated.

A disease caused by the bacterium Mycobacterium tuberculosis. Symptoms include coughing, fever, and weight loss.

The ability of a microorganism to evade the host's immune defenses, survive antibiotic treatment, attach to host cells, and produce harmful substances.

The ability of a microorganism to produce toxins or other harmful substances that damage the host's tissues.

A microorganism's preference for a specific type of tissue in the body. For example, the influenza virus targets the respiratory system.

Enzymes produced by microorganisms that can break down tissues and promote infection. For example, hyaluronidase breaks down connective tissue, allowing the pathogen to spread.

Proteins released by bacteria that can cause various harmful effects on the host, including cell lysis, inflammation, and tissue damage.

A set of criteria used to establish a causal relationship between a microorganism and a specific disease.

An organism that lives in or on another organism (the host) and benefits by obtaining nutrients at the host's expense.

Any living organism, such as an animal (including humans) or a plant, that supports a parasite.

A microorganism capable of causing an infectious disease.

A kind of pathogen that can cause disease in a healthy host.

A microorganism that normally doesn't cause disease in healthy people, but can cause disease in a host with weakened defenses.

The collection of microorganisms, including bacteria, fungi, and viruses, that live on and in the human body.

The way a disease is spread from one person or organism to another.

A situation where a type of organism dramatically increases in population size, potentially disrupting the balance of an ecosystem.

A chain of events where the decrease in one population causes a ripple effect through the food web, impacting other species.

An imbalance or disruption in the composition and function of the microbiome. It can be caused by factors like antibiotics.

A change in the microbiome that can lead to various health problems, including infections, weakened immunity, and metabolic issues.

Infectious diseases can start from within the body, like when natural barriers break down or the immune system weakens.

Infectious diseases can be acquired from external sources like air, water, or contact with animals or contaminated objects.

The way a pathogen travels from one person or animal to another. Examples include direct contact, airborne droplets, or contaminated surfaces.

A living organism that carries a pathogen and can spread it to others. Humans, animals, or even the environment itself can be reservoirs.

Anatomic barriers, such as skin, mucus membranes, and stomach acid, act as the first line of defense against pathogens. These barriers prevent pathogens from entering the body.

Tiny particles of liquid expelled from the nose or mouth during coughing or sneezing, containing infectious agents.

Neutrophils and macrophages are white blood cells that engulf and destroy pathogens. This is a crucial part of the innate immune system.

Lysozymes, found in saliva and tears, are enzymes that break down bacterial cell walls. They help to prevent infection in the eyes and mouth.

A disease that can naturally spread from animals to humans.

The order for removing personal protective equipment (PPE) to prevent spreading infection. Gloves, eye protection, gown/apron, mask.

The complement system is a cascade of proteins that enhance inflammation, attract phagocytes, and directly kill bacteria. Opsonins are molecules that coat pathogens, making them easier to be engulfed by phagocytes.

A disease that can be spread through touch.

Adaptive immunity is a targeted response to specific pathogens, involving antibodies (proteins that bind to pathogens) and T cells (which kill infected cells). These responses require exposure to the pathogen and are more effective at fighting off subsequent infections.

The microbiome is the community of microorganisms living in and on our bodies. It plays a key role in protecting us from pathogens, aiding in digestion, and influencing our immune system.

Factors like age, genetics, prior infections, and certain medical treatments can influence the immune system's ability to fight off infections.

A balanced microbiome is essential for resisting infections. When the microbiome is disrupted, the risk of disease increases.