Communicable Disease

Definition: (definition changes and is hard to pinpoint)

A condition that impairs normal functioning of a human, plant or animal body and has distinguishing signs and symptoms.

Do you know the name of some diseases????

What is a disease?

Chronic Disease —A disease or health condition that lasts longer than three months, sometimes for the remainder of one's life.

Acute Disease —A disease or health condition that occurs and subsides within three months, usually within days or weeks.

Infection or Disease?

What is the difference between an infection and a disease?

Infection, often the first step, occurs when bacteria, viruses or other microbes that cause disease enter your body and begin to multiply.

Disease occurs when the cells in your body are damaged – as a result of the infection- and signs and symptoms of an illness appear.

For instance, a person gets the disease malaria if he/she carries an infection caused in his/her body by the bite of the female Anopheles mosquito.

(not in notes)

What is the difference?

Communicable vs non-communicable

COMMUNICABLE

A disease that can be passed from one person to another person, animal, or

object.

NON-COMMUNICABLE

Diseases that are not transmitted from one

person to another.Sometimes called infectious or contagious diseases.

Communicable diseases are caused by several kinds of tiny life forms.

These microorganisms that cause diseases are called pathogens.

Sometimes you will hear pathogens called “germs”.

They are specialized to infect body tissues where they reproduce and cause damage that gives rise to the symptoms of the infection.

Communicable Disease

What are Germs ? - Major Types , Diseases, Infections ,Animation Video 5:24 min

Types of PathogensThe two most common kinds of pathogens are: • bacteria • viruses  

Some others include:• fungi• parasites • prions

Let’s look at each type in more detail.

BACTERIA

BacteriaBacteria are one-celled microorganisms too small to see with the naked eye. They exist in virtually all environments in the world.

They are possibly the most numerous types of organisms on the planet.

They can live EVERYWHERE! They can live in sub freezing cold temperatures and boiling hot temperatures. They can live high in the sky and deep below the ocean.

Most bacteria are harmless or helpful, but some are harmful.

In general, a bacterial infection can be treated with antibiotics.

Escheria coli (e. coli) bacterium

Streptococcus bacteria

Antibiotics are used to slow or kill the growth of bacteria. You must take all of the

prescribed medicine or it can come back!

What are antibiotics?

 There are an estimated 75 to 100 trillion cells in the human body.  It is believed by scientists that there are more bacteria in your body than the number of cells in your body.

Strep ThroatCauses inflammation and swelling of the mucous membranes lining the back of the throat and the tonsils.

Easy to relapse!

Lung inflammation caused by bacterial or viral infection, in which the air sacs fill with pus and may become solid.

Pneumonia

 Also known as lockjaw is a serious infection caused by Clostridium tetani bacteria which produce a toxin that affects the brain and nervous system. The toxin leads to stiffness in the jaw muscles as well as other muscles.

Tetanus

Need a booster shot every 10 years.

Could be FATAL!

Bacterial MeningitisBacterial meningitis is a rare, but extremely serious, potentially fatal disease. It can cause the tissues around the brain to swell.

Toxins damage the blood vessels and reduce the flow of oxygen to major organs. This can lead to skin and tissue damage, bone growth problems, organ failure or limb loss.

10-15% Of people who get meningococcal disease will die in spite of treatment with antibiotics.

11-19% Of survivors will lose fingers, toes, arms, or legs; become deaf; have neurological problems; develop mental impairments; or suffer seizures or strokes.

SalmonellaIt is a bacterial disease of the intestinal tract. People become infected mostly through contaminated water or foods, especially meat, poultry and eggs.

Whooping CoughIs a contagious bacterial disease chiefly affecting children, characterized by convulsive coughs followed by a whoop.

More Diseases from BacteriaSome of the most deadly diseases and devastating epidemics in

human history have been caused by bacteria. 

In the year 1900 pneumonia, tuberculosis and diarrhea were the three biggest killers in the USA.

As water purification improved, vaccines and immunization programs evolved, and antibiotic treatment became more advanced - the human death toll in the USA from bacterial diseases has dropped significantly (as well as in the rest of the developed world).

In developing countries, success rates have depended on several factors, such as the strategies implemented by local health authorities, and whether countries enjoyed periods of peacetime (no wars).

Plague – aka “Black Death”

The plague is a serious bacterial infection that can be deadly. Sometimes referred to as the "black plague," the disease is caused by bacteria called Yersinia pestis. This bacteria is found on animals throughout the world and is usually transmitted to humans through fleas.

Plague – AKA Black Death

VirusesViruses are the smallest disease-causing organism. They are even smaller than a bacteria.

They depend upon a host to survive, grow and reproduce. They can’t live outside of other living cells.

The host is who/what they live in or on.

Once they are inside the body, viruses can spread and make people sick. They reproduce by injecting their genes into a cell to produce thousands of new viruses.

Different viruses attack specific cells – so the flu virus attacks the cells of the respiratory system while the virus which causes meningitis attacks the cells of the membranes which cover your brain.

Any medication taken is to treat the symptoms; viruses cannot be cured, they

have to run their course.

Antibiotics can not cure

you if you get a virus like the flu.

Cold

The common cold is a viral infectious disease that infects the upper respiratory system.

InfluenzaInfluenza (the flu) is an acute viral infection of the respiratory tract which is considered to be one of the life-threatening infectious diseases.

ChickenpoxAn infectious disease causing a mild fever and a rash of itchy inflamed blisters. It is caused by the herpes zoster virus and mainly affects children, who areafterward usually immune.

MononucleosisIt is often called the kissing disease. The virus that causes mono is transmitted through saliva, so you can get it through kissing, but you can also be exposed through a cough or sneeze, or by sharing a glass or food utensils with someone who has mono.

However, mononucleosis isn't as contagious as some infections, such as the common cold.

Hand Food & Mouth DiseaseHand, foot, and mouth disease, or HFMD, is a contagious illness that is caused by different viruses. Infants and children younger than 5 years old are more likely to get this disease. However, older children and adults can also get it. In the United States it is more common for people to get HFMD from spring to fall.

MumpsMumps is caused by a virus that is passed from one person to another through saliva, nasal secretions, and close personal contact.

ShinglesAfter you have chickenpox, the virus that caused it, called varicella-zoster virus, remains in your body. It's always inside you, lying dormant (or asleep) in your nerve cells. At some point later in life, Your immune system may weaken, allowing the virus to resurface as shingles. 

Fungi

Fungi are common in the environment.

Most fungi are not dangerous, but some types can be harmful to health.

There are approximately 1.5 million different species of fungi on Earth, but only about 300 of those are known to make people sick.

Diseases such as athlete's foot, ringworm (not a worm), oral and vaginal thrush are examples of fungal infections.

Helpful Fungi Antibiotic penicillin is made from the fungus Penicillium

notatum.

Brewers' and bakers' yeast are types of fungi that grow as individual cells. They have been used for many centuries in the production of beer, wine and bread.

Soy sauce Some types of the stinky cheeses Some fungi attack insects and, therefore, can be used as

natural pesticides

Athletes foot

Thrush caused by candida yeast

ringworm

ParasitesA parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host (who/what it is in or on) . 

Parasites can cause anything from mild disease to death to the host. Parasites can also spread diseases from one organism to another.

Protozoa are one-celled organisms that can be free-living or parasitic in nature.

Malaria is a disease caused by a protozoa that live in certain kinds of mosquitoes. If an affected mosquito bites a human, the person will be infected. Out of all the parasitic diseases, malaria causes the most deaths globally. It kills approximately 627,000 people each year.

People living in the poorest countries are the most vulnerable to malaria. In 2012, 90% of all malaria deaths occurred in the WHO African Region, mostly among children under 5 years of age.

Parasitic organisms which affect the health of people include fleas and head lice which live on the outside of the body and tapeworms which live inside the body.

Elephantiasis is the result of a parasitic infection caused by three specific kinds of round worms.

Lyme Disease is caused by a bacteria carried primarily by deer ticks

Rocky Mountain Spotted Fever

Guinea worm disease Malaria

PrionsDuring the past two decades, evidence has linked some degenerative disorders of the central nervous system to infectious particles that consist only of protein. All known prion diseases frequently result in brain tissue that is riddled with holes.

The known prion diseases include Creutzfeldt-Jakob disease (in humans), scrapie (in sheep), and bovine spongiform encephalopathy ("mad cow disease" in cattle).

While some prion diseases are inherited, others are apparently due to infection by eating infected tissue or inadvertently through medical procedures such as tissue transplants.

When pathogens enter in to your body you get sick.

Pathogens enter the body in the following ways: 

Airborne or droplet infection (colds, flu). Animal borne or insect borne infection (rabies, malaria, Lyme Disease). Blood borne infection (HIV, hepatitis). Food borne or water borne infection (salmonella, giardia). Indirect contact (colds and flu carried from person to person on dirty

tissues, money, door knobs, phones, computer keyboards). Sexually transmitted (chlamydia, gonorrhea, syphilis). Other direct contact (some kinds of warts, scabies).

How are pathogens spread?

Preventing Disease1. Good hygiene – wash hands often

2. Clean utensils before using

3. Cough & sneeze into your sleeve

4. Avoid touching your eyes, nose, and mouth. Especially when sick.

5. Do NOT share personal items – water bottles, toothbrushes etc.

6. Use insect repellent

7. Stay home when sick

8. Clean and disinfect commonly used surfaces

9. Get vaccinated

10.Avoid touching wild animals Why????

ANY QUESTIONS?