1. YOU GAVE ME WHAT? Infection Types and Transmission

2. What is an Infection:
An invasion of body tissue by a microorganism
An infection is the invasion of the body by microorganisms. Invading microorganisms use the host’s resources to multiply and interfere with normal function. Infections are the 3rd leading cause of death in the U. S. The video link is about microorganisms living on your cell phone. Watch the video to see what kind of infections you could be spreading when you share your cell phone with others.

3. Classes of Microorganisms
Non-pathogenic
Pathogenic
Aerobic
Anaerobic
Non-pathogenic normal microorganisms that do not produce disease . They are beneficial.
Pathogenic microorganisms cause infection and disease.
Some microorganisms may be non-pathogenic in one body system, pathogenic in another (E. coli)
Aerobic microorganism requires oxygen to live
Anaerobic does not require oxygen to live

4. Types of Microorganisms
Bacteria
Viruses
Fungi
Parasites
--Rickettsia
--Helminths
--Protozoa
Bordetella pertussis (causes whopping cough)
There are four major categories of microorganisms that cause infections in humans they are bacteria, viruses, fungi and parasites. Bacteria are the most common infection causing microorganisms. It can cause disease in humans and can live and be transported through the air, water, food, soil, body tissues & fluids, and inanimate objects.
Viruses consist of nucleic acid and therefore must enter living cells in order to reproduce.
Fungi include yeasts and molds. Candida albicans is a yeast considered to be normal flora in the human vagina
Parasites live on other living organisms and include protozoa that causes malaria, helminths (worms) and rickettsia (fleas/ticks/mites).

5. Bacteria Unicellular Microorganism Prokaryotes
Come in Three Main Shapes:
--Cocci (shephical)
--Bacilli (rod)
--Spirilla (spirals)
Bacteria is a member of a large group of unicellular microorganisms lacking organelles and an organized nucleus, including some that can cause disease. Bacteria are tiny living beings (microorganisms) - they are neither plants nor animals - they belong to a group all by themselves. Bacteria are tiny single-cell microorganisms, usually a few micrometers in length that normally exist together in millions. An organism without a nucleus is called a prokaryote. They come in three mains shapes cocci, bacilli and spirilla.

6. Humans Need Bacteria to Survive
The human body contains huge amounts of friendly bacteria that are either neutral or help us somehow. Bacteria in the digestive system are crucial for the breakdown of certain types of nutrients, such as complex sugars, into forms the body can use. Friendly bacteria also protect us from dangerous ones by occupying places in the body the pathogenic (disease causing) bacteria want attach to. Some friendly bacteria actually come to the rescue and attack the pathogens.

7. Viruses Viruses small infectious agent require a host for survival
over 5,000 types
can combine in multiple ways to produce a wide range of diseases
produce immune response in humans
treated with antiviral drugs
A virus is a microscopic organism consisting of genetic material (RNA or DNA) surrounded by a protein, lipid (fat), or glycoprotein coat. Viruses are unique organisms because they cannot reproduce without a host cell. After contacting a host cell, a virus will insert genetic material into the host and take over the host's functions. The cell, now infected, continues to reproduce, but it reproduces more viral protein and genetic material instead of its usual products. It is this process that earns viruses the classification of "parasite".

8. How Are Viruses Spread?
Viruses may spread vertically (from mother to child) or horizontally (from person to person). A virus's ability to spread depends on the makeup of the virus. Some viruses can spread by simple contact, exchanges of saliva, coughing, or sneezing. Some require sexual contact, while others go through the fecal-oral route via contaminated food or water. Still other viruses require an insect like a mosquito to carry the virus from person to person. Watch the short video from YouTube to understand more.

9. Fungi A fungus is actually a primitive vegetable
Fungi live in air, in soil, on plants and in water. Some live in the human body. Only about half of all types of fungi are harmful
Some fungi reproduce through tiny spores in the air. You can inhale the spores or they can land on you. As a result, fungal infections often start in the lungs or on the skin. You are more likely to get a fungal infection if you have a weakened immune system or take antibiotics.
Fungi can be difficult to kill
Fungal infections are infections caused by a fungus, a type of microorganism. Two common causes of fungal infections are a fungus called tinea and yeast infections caused by the fungus Candida albicans. Some very common types of fungal infections caused by tinea include: Athlete’s foot, Jock itch, Ringworm and common yeast infections, also called candida and candidiasis, can infect other areas of the body including: Digestive tract, (gastroenteritis), Lungs, Mouth (oral thrush) ,Vagina (vaginal yeast infection, vaginal thrush)
In most cases, fungal infections are treatable in generally healthy people. However, these infections are more likely to occur and can be more difficult to treat in people with weakened immune systems due to such conditions as HIV/AIDS, diabetes, or taking steroid medications or chemotherapy. In these cases, complications of fungal infections may become life threatening.

10. What causes a fungal infection?
What causes fungal infections?
Different types of fungus cause a variety of fungal infections:
Athlete’s foot, jock itch, and ringworm are caused by a fungus called tinea.
Most yeast infections, such as vaginal thrush, oral thrush, and fungal gastroenteritis, are caused by a fungus called Candida albicans. Fungus can also cause fungal infections of the lungs due to inhaled fungal spores.
Certain factors or conditions can result in an overgrowth of fungus in the body. These include:
Taking antibiotics. Antibiotics can kill off “healthy” bacteria in the body, as well as bacteria that cause disease. When antibiotics kill the healthy bacteria, the normal balance of microorganisms in the mouth, vagina, intestines, and other places in the body is altered, resulting in an overgrowth of Candida albicans or other fungi.
Having a weakened immune system due to certain conditions, such as HIV/AIDS or taking steroid medications or chemotherapy
Having high blood sugar due to diabetes, which provides food for Candida albicans and encourages its overgrowth
Fungal infections can also be passed from a pregnant woman to her infant during vaginal delivery or breastfeeding.

11. Parasites Protozoa One celled, animal-like organism
Contain a nucleus and other defined organelles
Rickettsia
Rod-shaped, parasitic bacteria
Live in the tissues of ticks, fleas, and lice
Transmitted to humans through bites
Invade the new host from within
Helminths
Parasitic worm-like organisms
Live inside the host
Feed off their host
Disrupt nutrient absorption
Lead to weakness
Excrete toxins making host susceptible to other diseases
Approximately 30 billion people globally are infected
Parasites are organisms that live inside humans or other organisms who act as hosts. They are dependent on their hosts because they are unable to produce food or energy for themselves. Parasites are harmful to humans because they consume needed food, eat away body tissues and cells, and eliminate toxic waste, which makes people sick.
Because of sanitary living conditions in America, parasites do not cause widespread life-threatening infections. In other parts of the world, however, parasitic infections are epidemic. They kill and disable millions of people every year. Parasitic infection cases in the United States are on the rise due to increased travel to and from underdeveloped countries. In addition, parasitic infections can cause severe infections in AIDS patients and other patients with weakened immune systems.
Because parasites can live inside the human body for years without making their presence known, they are more common than one might think. According to a recent study, approximately half of all Americans have at least one form of parasite. Their presence causes a variety of chronic diseases and conditions such as chronic fatigue, weakness, low energy levels, skin rashes, pain, constipation and frequent colds and influenza.

12. What type of Infections do these microorganisms cause?
Local infection
Systemic Infection
Acute Infection
Chronic Infection
Nosocomial Infection
Endogenous Infection
Exogenous Infection
Opportunistic Infection
A local infection is limited to the specific parts of the body where the microorganisms remain. Symptoms include redness, pain, heat at the site, swelling, drainage, pus (as seen in the picture)
Systemic infections occur when microorganisms spread and damage other parts of the body.
Acute infection appear suddenly or last a short time.
Chronic infections occur slowly over a long period of time and may last months or years.
Nosocomial infections are associated with the delivery of health care services in a health care facility. (Ex. MRSA, UTI that occurred while hospitalized) Also knows as “acquired hospital infections”. This infections are often caused by healthcare workers.
Endogenous Infection type or kind of infection or disease that originates from within the body.
Exogenous infection type or kind of infection or disease that originates outside the body.
Opportunistic infection occur when the body’s defenses are weakened. If example when a patient has AIDS they may develop yeast infection or TB

13. Systemic Infection
Remember systemic infections affects the entire body. Symptoms often include: fever, aches, chills, nausea, vomiting, and weakness

14. Acute Infection
Mastoiditis occurring with an ear infection

15. Chronic Infection

16. Nosocomial Infection

17. Opportunistic Infection
Skin infection obtained by a weaken immune system from HIV

18. Exogenous Infection
Infection from outside the body

19. Endogenous Infection
Endogenous Infection resulting from being on antibiotics.

20. How Did I Get That?

21. Chain of Infection
Six links make-up the chain of infection: the infectious agent, the place where the organism naturally resides (reservoir), a portal of exit from the reservoir; a method (mode) of transmission; a portal of entry into a host; and the susceptibility of the host.

22. The Infectious Agent Causative Factor/pathogen
The extent to which any microorganism is capable of producing an infectious process depends on the number of microorganisms present, the virulence and potency of the microorganisms, the ability of the microorganisms to enter the body, the susceptibility of the host, and the ability of the microorganisms to live in the host’s body.

23. Reservoir Area where pathogens can live
Common reservoirs or sources of microorganisms include: other humans, plants, animals or the general environment

24. Portal of Exit Way for the pathogen to escape from the reservoir
Infectious agents can be shed or secreted via portals of exit (feces, respiratory droplets, skin cells, genital secretions, urine).

25. Method of Transmission
Direct Transmission
Indirect Transmission
--Vehicle-Borne
--Vector-Borne
Airborne Transmission
Direct transmission involves immediate and direct transfer of microorganisms from person to person through touching, biting, kissing, or sexual intercourse.
Indirect transmission may be either vehicle-borne or vector-borne.
A vehicle is any substance that serves as an intermediate means to transport and introduce an infectious agent into a susceptible host through a suitable portal of entry. Fomites such as handkerchiefs, toys, soiled clothes, cooking or eating utensils and surgical instruments or dressings can act as vehicles.
A vector is an animal or flying or crawling insect that serves as an intermediate means of transporting the infectious agent.
Airborne transmission may involve droplets or dust. Droplet nuclei, the residue of evaporated droplets emitted by an infected host such as someone with TB, can remains in the air for long period of times. Dust particles containing the infectious agent can also become airborne. The material is transmitted by air current to a suitable portal of entry, usually the respiratory tract of another person.

26. The way a microorganism enters into a new reservoir
Portal of Entry
The way a microorganism enters into a new reservoir
Before a person can become infected, microorganisms must enter the body. The skin is a barrier to infectious agents; however any break into the skin can readily serve as a portal of entry. Often, microorganisms enter the body of the host by the same route they used to leave the source.

27. Susceptible Host Any person who is at risk for infection
A compromised host is a person “at increased risk”
A susceptible host is any person who is at risk for infection. A compromised host is a person “at increased risk”, an individual who for one or more reasons is more likely than others to acquire an infection. Impairment of the body’s natural defenses and a number of other factors can affect susceptibility to infection. Examples include age (the very young or the very old); client receiving immune suppression treatment for cancer, chronic illness or following a successful organ transplant and those with immune deficiency conditions.

28. Video: Names of Bacterial Infections

29. Case Study:
A premature infant is currently in the newborn critical care unit, during RSV season (RSV is a bad cold that is deadly to a premature baby with an undeveloped immune system). The infant’s mother comes to visit and while there coughs several times without covering her mouth while holding her baby close to her face. Less than 48 hours later the baby begins to have breathing difficulty and winds up intubated on the ventilator (breathing machine). Its is determined the infant has developed RSV.

30. Questions:
1. Is RSV a virus or bacteria? (Remember RSV is a type of cold)
2. Can RSV be treated with an antibiotic?
3. Trace the chain of infection for this baby. Identify the following:
--The Infectious Agent
--Reservoir
--Portal of Exit
--Method of Transmission
--Portal of Entry
--Susceptible Host