PLACE INVADERS

Invasive Diseases

Infectious Disease Also known as

Contagious DiseaseCommunicable DiseaseTransmissible Disease

Caused by a pathogen that causes disease

Not all infections cause disease that can be transmitted

Infectious Diseases Pathogens can be:

VirusesBacteriaParasitesFungiProtozoaPrions

Viruses Can Infect Plants People Animals Bacteria Other Single Celled-organisms

Viruses in Plants Transmitted by

-Chewing Animals such as Insects -Sucking Insects such as Aphids

-Fungi-Single-celled Organisms-People Through Tools or Hands-Generation to Generation Through Seeds and Pollen

-Nematodes

Viruses in Plants Don’t infect humans or animals

Reduce Yield Deform fruits and vegetables

Plum Pox Virus in peaches

Tomato Mosaic Virus in cucumbers

Examples of Plant Viruses

Pepper mild mottled virus

Tobacco Mosaic virus

Tobacco Mosaic Virus in Orchids

Examples of Plant Viruses

Potatoes infected with Y virus

Tobacco Mosaic virus in tomatoes

Healthy Eggplant (left) compared to damaged eggplant infected with Tomato Bushy Stunt virus

Would you eat these?

Virus Control In Plants Once plants are infected with viruses little can be done.

There is not effective treatment.

The best control is prevention.

Scientists are working on creating vaccines but they are in the early stages of research.

Virus Prevention Includes

insect control removing weeds that may harbor viruses or their insect vectors

grow from seeds for plants that transmit viruses through seed, use indexed seed

discard all virus infected plants disinfect tools used for vegetative propagation

Viruses In Animals Transmitted

Biting and/or Blood-sucking Insects

CoughingSneezingFecal-oral RouteDirect Blood to Blood Direct Body FluidsSexual transmission

Viruses In Animals Some Viruses can infect a number of species

Other Viruses are Species Specific

Viruses can mutate new “strain” of a virusexpand host populationsalter transmission method

Viruses need live tissue

Viruses In Animals Vaccines are used to create immunity to viruses

Antivirals can now be used to treat some virusesTamifluRelenza

Antibiotics DO NOT work on viruses!

Examples of Animal Viruses

Foot and Mouth Disease Hemorrhagic Fever Influenza (flu) Avian Influenza Herpes Viruses West Nile Virus Encephalitis Yellow Fever

Influenza Virus

Examples of Animal Viruses

Distemper Rabies Measles Polio Chickenpox Smallpox

Girl with Smallpox in Bangladesh in 1973

Bacteria Single-celled microorganisms Rods, spheres, spirals Reproduce by Binary fission

http://en.wikipedia.org/wiki/File:Binary_fission_anim.gif

Bacteria Live in every environment on earthSoilFresh water Salt waterAcidic hot springsOn all surfacesIn very inhospitable places

Live in and on the human body

Live in and on plants and animals

Bacteria Very important in nutrient cyclesNitrogen fixationDecomposition

Some bacteria beneficialProbioticsFermented foods

CheeseYogurtPicklesSourdough bread

Bacteria Some bacteria live symbiotically

Some bacteria harmfulpathogens

Most bacteria do not affect humans, plants or other animals

Most bacteria have not been classified or studied

Bacterial Diseases Cholera Tuberculosis Anthrax Leprosy Syphilis Bubonic plague Bacterial pneumonia Tetanus

Bacillus anthracis (Anthrax)

Eschericia Coli (E. Coli)http://en.wikipedia.org/wiki/File:E.-coli-growth.gif

Bacteria Exist virtually everywhere including in the air

So transmission is possible by every means

Bacterial can live for years in very inhospitable environmentsSpores in soil

Post-harvest Bacteria Bacteria do not only cause disease in plants and animals

Bacteria cause food spoilage

Bacteria cause food-borne illnesses

Food preservation and pasteurization techniques are used to prevent both

Parasites Live in or on a host and cause harmNourishmentProtection

May be as small as a single cell Protozoa1 to 2 micometers

May be a large wormHelminthsJust visible to naked eye to 2 meters long

Parasites May have a single permanent host

Or many intermediary hosts In animals, often excreted in feces

Infest animals and plantsHumansMammalsBirdsInsects

Parasites May Be Transmitted from human to human

Transmitted from animal to animal

Transmitted from human to animal

Transmitted from animal to human

Transmitted from human to bird to mammal and back to human

May be transmitted by insect vectors

Parasites Transmitted from fecal contamination

Transmitted from direct blood contamination

Transmitted by vectors

Diseases Caused by Parasites

Found in food or water Cause foodborne illness Cause waterborne illness Can range from mild discomfort to debilitating illness or even death

Transmitted primarily through fecal contamination

Diseases Caused by Parasites

Trichomoniasis Malaria Giardia Cryptosporidium Cyclospora Toxoplasmosis Trichinosis Tapeworms

Prevention of Parasitic Diseases

Proper hand washing with soap Drink either municipal treated water or boil water

Cook foods thoroughly Do not swallow or breath in water when swimming

Consume only pasteurized beverages

Use gloves when handling uncooked meat, cat litter, gardening.

Human Fungal Diseases Athlete’s Foot/Jock Itch Yeast Infections (Candida)

Thrush Ringworm Diaper Rash Fungal Sinusitis Nail Fungus Histoplasmosis

Plant Fungal Diseases

Powdery Mildew Fusarium Wilt Root rots Phytopthora infestans –

late blightCause of the Irish Potato Famine

Still the most pathogen of potato crops

Powdery Mildew

Diseases Caused by Fungi

Transmitted by contact with fungal spores

Transmitted by air Treated with antifungal agents in humans and animals

Treated with fungicides in plants

Protozoan Diseases Malaria, Giardia, Cryptosporidium, and Toxoplasmosis

African Sleeping Sickness Amebic Dysentery

Protozoan Diseases Transmitted by insect vectors

Tse Tse FlyMalarial mosquito

Transmitted in contaminated water

Transmitted in contaminated food

Contamination with cysts from infested fecal material

Prevention of Protozoan Diseases

Proper hand washing with soap

Boil water before drinking Cook foods thoroughly Prevent fly contamination of food

Drink only pasteurized beverages

Strict sanitation when working with lab animals

Treatment of Protozoan Diseases Drug treatments are available

Depending upon infestation, a sequential use of several drugs may be used.

Chlorine does not kill protozoans so heating water to 122°F is necessary

Diseases Caused by Prions Prions are a caused by a yet to be determined transmission agent

cause abnormal folding of proteins in the brain which leads to brain damage

Diseases Caused by Prions Mad Cow Disease – BSE Scrapie Chronic Wasting Disease Creutzfeld-Jakob Disease Kuru

Treatment of Prion Diseases

The disease is always fatal. No known treatment is available.

Brain and spinal tissue is removed from slaughtered animals prior to butchering to prevent any possible contamination by prions.