Test 3

What does an Epidemiologist do

They investigate health-related matters by gathering information, examining data, and looking for patterns. They then define issues of concern, determine causes, establish a timeline, and develop a solution.

What skills does an Epidemiologist need

Clinical medicine, pathology, biostatistics, and social science

Endemic

A disease present in a community or population within a specific geographical area

Example of an endemic

Malaria in Africa, South America, and Asia

Outbreak

A sudden increase of a disease in a localized area

Sporadic

A disease that occurs infrequently

Epidemic

When there is a sudden increase in a disease

Pandemic

An epidemic that has spread across several countries/continents

Nosocomial infection

A hospital-acquired infection

Agents of disease

The types of organisms that cause disease

Inherited disease

Genetic, from your family

Infectious disease

A disease that is contracted/caught

Infection

The establishment of a disease-causing microorganism within a host

Host

An organism that another organism lives in

Disease

The invasion and growth of a pathogen

Pathogens

Disease-causing organisms

Microbes

Microscopic agents of disease

Prion

Non-living, submicroscopic, proteins

How are prions contracted

Through consumption of tainted meat, or medical equipment, or by receiving corneas or organs from those infected

What damage do prions cause

They can cause brain proteins to fold abnormally

What is an example of a prion

Creutzfel-Jakob Disease(CJD)

What are the symptoms of Creutzfel-Jakob Disease (CJD)

It can result in dementia, walking difficulties, hallucinations, confusion, and death

Treatment of Prions

There is no cure, but medication can slow progression.

Prevention of Prions

You can prevent this disease by properly cleaning medical equipment, and telling people who have it to not donate corneas or organs.

Virus

Non-living microscopic agents made of an outer protein shell (capsid) and RNA or DNA

How are viruses contracted

It depends. Some can occur through touch, saliva, blood, or sexual contact.

Why do viruses infect hosts

They can’t replicate on their own so they need to infect a host to steal their protein synthesis process

What damage can be caused by a virus

The host’s cells and tissues are destroyed

How do you treat viruses

TAntivirals may be used sometimes and over-the-counter meds can relieve symptoms (pain relievers, decongestants, and cough syrup)

How do you prevent viruses

Vaccines and personal hygiene

What is an example of a virus

The influenza virus (the flu)

What are the symptoms of the flu

runny/stuffy nose, itchy/sore throat, cough, congestion, body/headaches, sneezing, watery eyes, low-grade fever, and fatigue

Bacteria

Living, microscopic, unicellular, prokaryotic organisms

How are bacteria contracted

It depends, it can occur through an orifice(nose, eyes, mouth), a wound, ingesting contaminated food/water, inhalation, sexual contact, or an imbalance of flora

What damage can bacteria cause

It can invade cells, cause tissue damage, and produce harmful toxins

How do you treat bacteria

Antibiotics

How do you prevent bacteria

Vaccines, keeping everything sanitary, and proper hygeine

What is an example of bacteria

Mycobacterium tuberculosis causes tuberculosis (TB)

What are symptoms of tuberculosis (TB)

It depends on where it is. It typically starts in the lungs and hosts typically experience a bad cough for 3+ weeks, chest pain, coughing up blood/phlegm, weakness, fatigue, weight loss, a lack of appetite, chills, and fever

Protists

Living, microscopic, single-celled, eukaryotic, animal-like organisms

How are protists contracted

Typically from ingestion of food.water contaminated with feces from an infected organism

What damage do protists cause

They infect the digestive tract, blood, or organs to deprive the host of nutrients. They can also cause tissue and organ damage.

How do you treat protists

Some can be treated with antiprotozoal medication

How do you prevent protists

Maintain sanitary conditions and personal hygiene

What is an example of a protist

Giardia lamblia causes giardiasis

How do protists survive

Before the parasites pass through stool, they become encased in cysts that can survive months. When they find a new host these cysts dissolve

What are symptoms of giardiasis

Diarrhea, gas, stomach cramps/pain, abnormal stool, upset stomach, nausea, and dehydration

Helminths

Living, multicellular, microscopic or macroscopic, eukaryotic worms

How are helminths contracted

Depends. It may occur through consumption of contaminated food or water or by being bitten by an insect

What damage do helminths cause

They deprive the host of nutrients and can cause tissue and organ damage

What is the treatment of helminths

Deworming medication

How do you prevent helminths

By avoiding the consumption of feces, ingestion of meat from those infected, and insect bites

What is an example of a helminth

Taenia (tapeworm infection)

What are the symptoms of taenia

Nausea, weight loss, abdomin pain, loss of apetite, diarrhea, and malnutrition. In invasive infections, hosts will have a fever, cystic masses/lumps, an allergic reaction to larvae, a bacterial infection, and neurological responses such as seizures.

Fungi

Living, multicellular, eukaryotic organisms. Includes yeast, mildew, mold, and mushrooms. Both microscopic and macroscopic varieties exist.

How are fungi contracted

Some forms infect when spores are inhaled or when they land on a host

What damage can fungi cause

It can result in tissue damage

How are fungi treated

Antifungals

How do you prevent fungi

By avoiding contact with an infected host

What is an example of fungi

Tinea pedis causes athlete’s foot

What causes athlete’s foot

Thick, tight shoes that squeeze the toes together and create a warm, moist area between them. Damp socks and shoes and warm, humid conditions help fungi grow

What are symptoms of athlete’s foot

Dryness, itching, stinging, burning, crackling and peeling skin, and blisters between toes or on soles of the feet. Toenails may be thick, crumbly, ragged, discolored, or peeling away at the nail bed.

Susceptible host

someone vulnerable to infection

Reservoir

the infected individual

Chain of infection

how a disease infects people/how it behaves

Direct contact

direct contact to susceptible host from an infected host through fluid

Indirect contact

when a susceptible host inhales infected particles, touches an infected object, or is bitten by an infected insect

Infectious dose

the number of organisms it takes to cause an illness

Immune system

a network of cells, tissues, and organs that work together to protect the body from agents of disease

Innate immunity

nonspecific immune defense that we’re born with, it keeps the outside from coming in

Adaptive(acquired) immunity

specific immune defense, acquired over time and uses specific antibodies against antigens

Active immunity

acquired following infection and recovery or from a vaccine, the body makes its own antibodies

Passive immunity

from your mother

How is passive immunity acquired?

Through the placenta or breast milk

Antigen

anything that stimulates immune response, the protein coating on all cells

Antibody

a protein that impairs pathogens

Immunity

the ability to defend against a pathogen

Naturally acquired immunity

after someone is already infected and has T

Vaccine(artificially acquired immunity)

when someone is injected with a mild form of an infection in order to build up immunity

Herd immunity

artificial immunity in which most of the population is vaccinated

Simulation

a representation of a phenomenon, typically virtual, used to more safely study an event

Who’s a susceptible host?

Anyone, but especially children, the elderly, people with weakened immune systems, and unimmunized people (unvaccinated people)

What are the portals of entry?

The skin, respiratory tract, gastrointestinal tract, urogenital, and conjunctive

What are the modes of transmission?

direct and indirect

What are the agents of disease?

Prions, bacteria, fungi, protists, helminths, and viruses

What are three reservoirs?

People, animals, and the environment

What are the portals of exit?

The skin, respiratory tract, gastrointestinal tract, urogenital, and conjunctive

What is the first line of defense?

The physical and chemical barriers

What are the physical barriers of the immune system?

The skin and mucus lining, organisms are stopped by the skin and the mucus lines organs and stops pathogens

What are the chemical barriers?

The lysosomes of the eyes, tears, and acid in the stomach, they kill the pathogens trying to gain entry

What is the second line of defense?

Inflammation (mast cells) and Leukocytes

What does the second line of defense do?

It searches for suspicious objects, and causes blood and white blood cells to attack it, it can do this with harmful and nonharmful invaders

What is an example of a nonharmful invader?

Dust

What is the chemical that signals inflammation?

Histamine

Phagocytes

Cell eaters, they destroy invaders

Macrophages

Eat unwanted pathogens, kill cancer cells

Where can you find Macrophages?

In specific organs, blood, or sites of infection

Natural killer

detects rogue/infected cwells, checks cells, and destroys broken ones

Dendritic cells

links systems and unsed for communication via antigens

Where are dendritic cells found?

In the nose and lungs