Chapter 13- Test 3 Flashcards
What’s responsible for reducing the death rate from infectious diseases of children?
- vaccinations
- antibiotics
- public health measures
Before 1900, what was the leading cause of death in the US?
Infectious diseases
What made the most impactive changes in managing infectious diseases?
- improved sanitation
- proper hygiene
- clean water supplies
By the end of the 20th century, the death rate from infectious diseases went down by how much? However infectious diseases are beginning to rise again.
2%
Why are death rates on the rise again?
-AIDS
- diseases reemerging from past
- New diseases (COVID-19)
- drug resistance
Do what all living organisms do which is eat, reproduce, and die. Tiniest living organism on earth.
microorganisms
When part of a microorganisms life cycle involves you. Considered an illness or disease if it interferes with your lifestyle or shortens your life. Cause sudden illness and high risk of death. Can stimulate your body immune response, causing the microorganisms to die. Can persist without signs of illness for years and yet still be passed to other people like HIV. Sometimes this can fought off by the immune system as with tuberculosis that hides as long as the immune system is healthy.
Infections
An infectious agent capable of causing disease. Require a living host and must have a portal of exit from host to cause infection like in respiratory secretions (coughing, sneezing) or through feces, genital secretions, blood on blood contact with skin or products, and through an insect or animal bite. When made contact with someone else, it causes a portable of entry into this new host.
pathogen
Process by which an infectious agent, or pathogen, passes from one organism to another.
Chain of infection
If the transfer from host to host or reservoir to host is carried out by an insect or animal, that organism is called this. In similar terms, if an insect or animal is involved it is called this.
vector
Extent or spread of an infection depends on the following:
- virulence of the pathogen
- mode of transmission
- duration of infectivity
- ease of transmission
- number of people in contact with infectious person
Speed and intensity with which a pathogen is likely to cause an infection.
virulence
How an infection spreads from person to person
mode of transmission
how easy it is for infection to spread throughout host
ease of transmission
length of time during which a person with an infection can spread it to other people
duration of infectivity
how many people the infected person makes contact with
number of people an infected person has contact with while infectious
If the infection is transmitted to many people this occurs. A widespread outbreak of a disease that affects many people.
epidemic
When an illness spreads globally
pandemic
Some of the smallest pathogens and are among the most numerous. It is estimated that there are more different types of this than of all other creatures combined. Unable to reproduce on their own. Once inside, the virus can make copies of itself, burst the cell, and release copies to infect more cells. Can only replicate inside other organism’s cells.
Viruses
Viruses can integrate themselves into a cell’s DNA and alter the growth pattern of the cells. This process can lead to the development of what?
Tumor or cancer
Single-celled organisms of which can be found in almost all environments. They are classified based on shape (spherical, rodlike, spiral), the presence or absence of a cell wall, and growth requirements. Speed of replication varies from 20 minutes to 2 weeks. Many inhabit a person harmlessly or helpfully and are considered part of the person’s normal flora. Normal in one body location and pathogens in another. For example, E coli aids digestion in the large intestine, but in the bladder, it causes bladder infections or urinary tract infections.
Bacteria
What is an important part of the human microbiome and plays a vital role in food processing, vitamin production, and colonizing of areas to reduce risk of harmful pathogens causing disease. Also, however, can cause disease in another location?
Bacteria
The least understood pathogens. Responsible for mad cow disease. Found in brain tissue and initiate the degeneration of brain function. Spread by the ingestion of infected brain or nerve tissue.
Prions
A single-celled or multi-celled plant. Include yeast and molds and can be found in and on human hosts as pat of a healthy microbiome. Yeast and mold can cause infections to humans. Tend to cause serious infections when the host immune system is not working well. Many infections result from exposure to spores in the environment as in the sole or on tile floors except for ringworm in children.
Fungi
Group of fungi that infect the skin, hair, or nails causing athlete’s foot and nail fungus. Sometimes called ringworm or tinea infections.
Dermatophytes
Organisms that live on or in a host and get food at the expense of the host.
Parasites
Also known as parasitic worms. Include roundworms, flukes, and tapeworms. Range from one centimeter to ten meters. People get infected by accidentally ingesting worm eggs in food or water or by having skin invaded worm larvae. These are huge disease burdens. For example, a hookworm attaches to human intestine and causes blood loss and is the leading cause of anemia and malnutrition in developing countries.
Helminths
Can live independently of host organisms. Leading cause of death in Africa, Asia, and Central and South America. Transmitted by contaminated water, feces, or food.
Protozoa
Complex organisms that usually live on or in the skin, where they feed on the host’s tissue or blood. They cause local irritation and are frequently vectors for serious infectious diseases. For example, flees, ticks, lice, mosquitoes, and scabies.
Ectoparasites
True or False?
A single square inch of skin on your arm is home to thousands of bacteria. A sneeze projects hundreds of thousands of viral particles into the air. Bacteria can double in number every 20 mins and a virus can replicate thousands of times within a single human cell.
True
How the body protects itself against pathogens by keeping them out physically and by destroying them chemically.
External barriers
What is the first line of defense of the body in protecting itself against pathogens?
the skin ( most organisms can’t get through the skin unless it’s damaged)
Physical External barriers to Pathogens include:
- skin
- mouth
- lungs
- nasal passages
- vagina
- hair in ear canals and nasal passages
- cough reflex
Damage to any external barriers increase risk of infection. What things can put you at risk for infections?
- alcohol
- tobacco
- current illness
- burns and cuts
- medications (like meds for acid reflux makes the stomach less acidic)
Complex set of cells, chemicals, and processes that protect the body against pathogens when they succeed in entering the body.
immune system
Chemical external barriers that help protect against pathogens:
- saliva
-small intestines bile and enzymes - vaginas acidic environment
- fatty acids and lysozyme in skin
Immune system has 3 functions:
-recognize foreign particles on infectious organisms
- attack and destroy the infected organisms
- communicate to other parts of the immune system about when to begin and end attack
part of the immune system designed to catch and dispose of foreign particles or pathogens in a nonspecific manner.
innate immune system
part of the immune system that recognize specific targets of pathogens.
acquired immune system
Of the innate immune system. The body’s initial reaction to tissue damage, whether it’s due to trauma or infection. A series of changes that increases the flow of blood to the site. Signs of this are redness, warmth, pain, and swelling.
acute inflammatory response
Exposure to a pathogen allows cells to mature and produce antibodies developing this. Reduced susceptibility to a disease based on the ability of the immune system to remember, recognize, and mount a rapid defense against a pathogen it has previously encountered. Discovered by Edward Jenner in 1796, when he realized that people who had been infected with cowpox rarely become ill or died when exposed to smallpox.
Immunity
From the Discovery Edward Jenner made, he found that the body can adapt and produce antibodies from an illness to develop immunity to prevent other deadly illnesses. What did this lead to the development of?
Vaccinations
They are preparations of weakened or killed microorganisms or parts of microorganisms given to develop immunity to various diseases. Developed for many infectious diseases, and have seen reductions in death rates from these diseases since 1900.
Vaccinations
2 functions of vaccinations:
-protect the individual by stimulating an immune response
- protect society
In 1998, who published a story saying there was a link between vaccinations for measles, mumps, rubella, and autism. Then was declared as fraudulent in 2010 resulting in him being guilty of ethical, medical, and scientific misconduct and banned from practicing medicine. Unfortunately, the damage was done and many believe there was this link and the rates of vaccinations dropped. In actuality, the risk of vaccination is far less than the risk of requiring a disease.
Andrew Wakefield
Controllable Risk factors for infectious diseases:
- balanced diet
- exercise
- maintaining stress
- enough sleep
- vaccination
- good hygiene
- avoiding tobacco
Uncontrollable Risk Factors:
- Age ( youngest and oldest are most at risk)
- chronic disease like diabetes
- surgery
- Genetic predisposition
- lack of access to health care
-poverty
Disruptions to Immunity:
- body recognizes immune system as “nonself”
- immune system fails to turn of immune response once an infections is over
- self destruction ( cause damage to body cells and tissues when immune response isn’t turned off)
- allergic reactions
- short term stress
Temporary immunity provided by antibodies from an external source. For example, while breastfeeding a mother’s antibodies can be passed to the fetus to provide temporary immune protection.
passive immunity