Preventing the Spread of Disease by: Ryan and Gavin

Spreading of Disease

Food Insects Water Human-Contact (Direct and Indirect)

AirborneSexually TransmittedBlood or Bodily FluidsSneezing/Coughing

Food

~48million/yr 250 known diseases Caused by: bacteria, viruses or

parasites Bodies reaction to manufactured

chemicals Uncooked meat products Usually transmitted through

ingestion Foods exposed to warmer

temperature = increased growth rate of micro-organisms

Insects

Not caused by the INSECT ( but the organisms passing through their

system when they feed or bite)

Caused by many different micro-organisms

BacteriaVirusesProtozoan

Micro-organism = PathogenInsect = VectorMosquito bites a bird, bird feeds

young....

Water

Waterborne Diseases-water containing infectious viruses or bacteria (human/animal waste)

Water Washed Diseases – skin/eye infections caused by lack of clean water for washing

Water Based Diseases – spread by organisms that develop in water and become human parasites. Insufficiently cooked fish

Introduced to these micro-organisms through dirty drinking water, polluted rain water etc..

Urbanization/dam construction – create new environments for disease to spread.

Climate Change – spreading range of vectors such as mosquitoes

Direct Human Contact

Spread through direct bodily contact with an infected person.

Sexually Transmitted Diseases (S.T.Ds) ▪ Parasites – nourished from the people they

infect (medications can treat these)▪ Bacteria – 1 cell, feed from their host (anti-

biotics)▪ Viruses – complex molecules multiple once

they invade a host (some cannot be cured, but can be controlled with vaccines)

Indirect Human Contact

Open wounds or body discharges infect environment and personal belongings

AIRBORNE- pathogenic microbes small enough to be discharges from an infected person (coughing, laughing)▪ Suspended in air on dust particles

Can be inhaled or contacts the mucus membrane to infect someone

Infectious Agents

3 MAIN TYPES Harmful Bacteria Viruses Parasitic Organisms

Harmful Bacteria

Can survive in the body, but outside individual cells.

Treated with antibiotics Commonly caused by: pneumococci,

staphylococci and streptococci▪ Commensals (live harmlessly on their host but

can become virulent) Give off toxins that damage tissues

▪ Aerobes – require oxygen▪ Anaerobes – grow only in absence of oxygen

(small intestine)

Bacterial Disease Streptococcal bacteria, Neisseria meningitidis,

E.coli Pathogenic bacteria reproduce and crowd out

healthy bacteria, or grow in normally sterile tissue.

Salmonella bacteria- leading cause of food poisoning▪ 2000 types of bacteria that make up salmonella that cause

illness by reproducing in the digestive tract▪ Direct contact or ingestion of something with bacteria on it

( not fully cooked chicken)▪ Reptiles and Amphibians (snakes) carry salmonella on their

skin▪ SYMPTOMS – headache, diarrhea, fever, nausea

Viruses

Not living things, but require “machinery” of living organisms to replicate (human body)

Vaccination is most common treatment for viral infections

Mostly airborne Typically a nucleic acid in a protein

coat

Viral Disease

Chickenpox, herpes and shingles Influenza (flu)– inhalation of virus

(airborne) Attacks cells in the upper respiratory

tract Spread through droplets (caugh, laugh

or talking) Symptoms – cough, fatigue, sore throat

Parasitic Organims

3 main types: Protozoa, Helminths and Ectoparasites

PROTOZOA – One-Celled Transmission through arthropod vector

(blood or tissue)▪ Mosquito bite

Transmission through fecal-oral route (living in intestine)▪ Contaminated food

Organism that lives on or in a host organism▪ Gets its food from the host

Protozoan Disease

Giardia Lamblia – flagellated parasite – colonizes and reproduces in small intestine▪ Remains confined to lumen of S.I and absorbs nutrients

from lumen▪ Transmission – ingestion of contaminated water▪ Symptoms – anorexia, nausea and bloating

Characterized by mode of transportation Flagellates Amebas Spore-Forming Ciliates

Vaccines

It is a biological preparation that improves immunity to a particular disease.

It stimulates the body’s IMMUNE SYSTEM to recognize the foreign agent, destroy it and keep record of it.

Immune System

Made up of: cells, glands, organs, and fluids located throughout the body.

Recognizes germs (antigens) and produces a protein substance called antibodies to fight antigens.

Memory Cells

Remember the original antigen and then automatically defend against the specific antigen if re-infected.

Are responsible for immunity to diseases.

Uses for Vaccines to Prevent Disease

Stimulate the production of Antibodies

Stimulate the production of Memory Cells

Resulting in Immunity to specific diseases

Passive Immunity

Is the transfer of active immunity in the form of readymade antibodies.

Provides immediate protection against an antigen.

Natural Passive Immunity

Refers to antibody-mediated conveyed to a fetus from its mother during pregnancy.

Also provided through the transfer of IgA antibodies found in breast milk.

Artificial Passive Immunity

Short-term immunization induced by the transfer of antibodies.

Used to treat acute infection and poisoning.

Active Immunity

The body’s ability to prepare itself for future infections by creating antibodies and memory cells.

Innate immune system protects an individual from pathogens regardless of experience.

Natural Active Immunity

Occurs when a person is exposed to a live pathogen and the body produces a primary immune response.

It is “natural” as it is not induced by a deliberate exposure.

Artificial Active Immunity

Is induced by a vaccine that contains an antigen.

There are 4 types of vaccinations:1. Inactivated Vaccines 2. Live attenuated Vaccines3. Toxoids 4. Subunit Vaccines

Ways to Prevent getting sick

Wash your hands Cough or Sneeze into the sleeve of

your shirt Avoid sharing toiletries Good nights rest Drink lots of water Eat colourful fruits and veggies Exercise Eat Garlic