Infection Control Principles of Health Science

Journal Question Why should we be worried about controlling infection in health care? Who do you think is responsible for preventing the spread of infection in health care settings?

Why worry about infection control? Because in health care, we deal with people and/or animals which are excellent sources of infection! We could catch infections from our clients Also, health care providers are people with germs, too! We can spread infection to our patients… So we need infection control!!!!

So, who’s responsibility is infection control???? EVERYBODY’S

Basic Microbiology Microorganism – small, living organism not visible to the naked eye. Must be viewed under a microscope. Can be pathogens (germs) which are disease producing or non-pathogens which are part of body’s normal flora and are beneficial in maintaining certain body processes.

Beneficial or Pathogenic? An example of beneficial microbes is the bacteria that live in your large intestine. They aid in the digestion of food and production of Vitamin K. The 700 species of intestinal bacteria include Escherichia Coli also know as E Coli.

Beneficial or Pathogenic? When E Coli enter other body systems besides the large intestine, they becomes pathogens. It is a leading cause of urinary tract infections (UTI’s). E Coli colonies on culture plate.

Beneficial or Pathogenic? Antibiotics given to kill harmful pathogens can also kill beneficial microbes. This can lead to an overgrowth of harmful microbes that are usually controlled by the beneficial ones. An example of this is oral thrush or vaginal candidiasis – both overgrowths of fungus. Oral Thrush

Additional Negative Effects Overgrowth of the bacteria Clostridium difficile can cause colitis and severe diarrhea when antibiotics wipe out competing bacteria in the colon. C. difficile

Bacteria Simple, one-celled organisms that multiply rapidly. They are classified by shape & arrangement. There are approximately 10 times the bacterial cells as body cells in the human creature.

Cocci: Round or spherical shaped bacteria If they occur in pairs, they are called diplococci. They cause such diseases as gonorrhea, meningitis, pneumonia.

Cocci: Round or spherical shaped bacteria When they occur in chains, they are streptococci. Diseases include strep throat and rheumatic fever.

Cocci: Round or spherical shaped bacteria When they occur in clusters or groups, they are called staphylococci. These are most common pyogenic (pus-producing) bacteria. Responsible for wound infections, boils, toxic shock, impetigo.

Bacilla: Rod shaped Bacteria Occur singly, in pairs or in chains. Many have flagella – threadlike projections similar to tails that allows them to move more freely. Form spores – thick-walled capsules that allow them to survive in poor growth conditions. Very difficult to kill when in spore form. Diseases include tuberculosis, botulism, tetanus, diptheria, pertussis (whooping cough), and typhoid.

Bacilla: Rod shaped Bacteria Pertussis - Whooping Cough Spastic Paralysis of Tetanus Mycobaterium Tuberculosis upper left

Flagellum on E Coli

Spirilla: Spiral or Corkscrew shaped bacteria Include the comma- shaped vibrio and corkscrew shaped spirochete. Diseases include syphilis and cholera.

Antibiotics and Bacterial Resistance Antibiotics kill bacterial infections. Some bacteria have developed resistance to certain antibiotics that previously killed them. Now the bacteria are unaffected and new more powerful antibiotics are needed to kill them. Linked to inappropriate use – over prescribing, not completing scripts These include MRSA – methicillin resistant staph aureus and MDR-TB – multi-drug resistant tuberculosis.

MRSA

Understanding Bacteria Video Clips Understanding Bacteria Part 1 (فهم البكتريا / مترجم) - YouTube Understanding Bacteria Part 1 (فهم البكتريا / مترجم) - YouTube

Journal Question Besides bacteria, what are four other classifications of microbes that might infect humans and cause disease?

Protozoa One-celled, animal like organisms Found in decayed material and contaminated water Many have flagella to allow them to move freely Some are pathogenic

Protozoa One example of disease caused by protozoa is malaria. Carried by female anopheles mosquito. It destroys red blood cells as it reproduces.

Protozoa Another example of a protozoal infection is the amoeba - Naegleria fowleri. It has caused six deaths this year in the US by entering the nose and invading and eating the brain tissue. Found in warm standing water.

Fungi Simple plant like organisms that live on dead organic matter. Yeasts and molds are two most common pathogens in humans. Antibiotics do not kill fungi – antifungals must be taken. They are expensive, require long term treatment and can be damaging to the liver. Disease they cause include ringworm, athlete’s foot, oral thrush, yeast vaginitis, and histoplasmosis.

Fungi Yeast – Candida Albicans. Oral, skin, & vaginal infections.

Fungi – Ringworm Tinea Corpis

Fungi - Histoplasmosis

Anti-Fungals Require very long term of therapy - months! Oral form may be hepatotoxic. Are often very expensive therapy

Rickettsiae Parasitic microorganisms that cannot live outside other living organisms. Carried by ticks, fleas, lice and mites. Cause diseases such as Rocky Mountain Spotted Fever and Typhus Fever. Can be killed by antibiotics.

Viruses Smallest microorganisms but the largest group of pathogens… Must be viewed with an electron microscope which magnifies up to 500,000 times Top- Eboli Bottom – Hepatitis A

Viruses They are spread from one human to another by blood or other body fluids – entering through out nose, eyes, mouth, reproductive tract, gastrointestinal tract and breaks in our skin. More difficult to kill because they do not respond to antibiotics and are resistant to many disinfectants.

How a Virus Infects… A virus is not technically alive – it is only a protein coat enclosing genetic material. It does not process nutrients or eliminate waste – cannot reproduce without taking over another cell… And it’s only purpose is just that…to reproduce through “hijacking”.

Viruses Awaits contact w/ correct host cell then inserts its genetic material into cell “hijacking” it to reproduce viruses Kills host cell in the process.

Viruses Cause diseases such as: The common cold Influenza “The Flu” Mumps Measles Herpes Chicken Pox Rabies Warts Certain types of cancer.. such as cervical cancer in women.

Viruses Hepatitis B (HBV) and Hepatitis C (HCV) are both viruses that can affect the liver leading to chronic infection, scarring and destruction of liver cells. There is a vaccine for HBV – it is required by federal law that it is offered to health care workers with exposure to blood or body fluids. You can choose to refuse but a written record must be kept to prove the vaccine was offered. These viruses can survive for several days in dried blood and there is not yet a vaccine for Hepatitis C – So protect yourself!

How to fight viruses… Promote your body defenses by keeping immune system healthy and be defensive! Diet Adequate sleep Stress control Avoid high risk, protect Use immune system to prevent through vaccines

How to fight viruses…. If you become infected.. Anti-viral drugs will slow replication of virus but are often toxic to our cells. Tamiflu is very popular antiviral for influenza – will shorten course of flu by several days if started within first 48 hours of infection symptoms.

How to fight viruses… Immune system derived treatments such as Interferon – version of natural virus fighting substance produced by immune system Immuno-globulin – antibodies harvested from others and infused to fight actual or potential infection.

Using Viruses to….fight cancer by reprogramming them to attack cancer cells

Using Viruses to ….fight bacteria Viruses called bacteriophages have been engineered to weaken bacteria making them more susceptible to being killed by antibiotics. Seen as a possible way to overcome antibiotic resistance.

Understanding Viruses Videos Viruses part 1/17 - YouTube Viruses part 1/17 - YouTube