Communicable Diseases

What is a Pathogen?

A micro-organism that can cause diseases.

What is Communicable disease and how are they caused?

A communicable disease is an illness caused by a pathogen that can be spread from one organism to another.

Give me examples of micro-organisms that are pathogens?

Bacteria - reproduce rapidly and can produce toxins which damages tissue

Viruses - reproduce rapidly within host cells causing cell damage

Fungi

Protists

How are communicable diseases spread?

Through transmission like direct contact, contaminated water or in droplets carried in the air.

VIRUSES : How do viruses reproduce rapidly?

By inserting their genetic material into host cells and creating new protein capsules to build new viral particles. Once many copies have been made the host may burst open releasing the viral particles which can go and infect other cells

Give me some examples of Viruses

Measles, Influenza, HIV and TMV

What are the symptoms of measles and how is it spread?

Symptoms : High fever, Red Skin rash, cough, inflammation.

It spreads by the inhalation of droplets from coughs and sneezes and infects cells in the respiratory system.

What are the symptoms of HIV and how is it spread?

HIV attacks white blood cells which weakens immune system.

Symptoms: Flu-like illness, rash, sore throat, fatigue

It is spread by direct sexual contact and in the exchange of bodily fluids such as blood for example it can be transmitted when drug users share needles

What can HIV lead to?

AIDS

What is Tobacco Mosaic Virus? (plant virus)

It is a widespread plant pathogen that infects 150 species of plants including tomatoes and cucumbers.

What are the symptoms for TMV and how is it spread? (virus)

• Distinctive mosaic pattern of discolouration of the leaves

• Damages the chloroplasts in leaf cells which reduces the plants ability to photosynthesise

It is spread from plant to plant on gardeners hands, clothing or tools as well as through direct transmission.

BACTERIAL DISEASES: What are bacterial pathogens?

Cells that can infect plants and animals, causing disease. They can produce toxins which can cause damage to cells and tissues. Once they are inside the organism, they reproduce rapidly through binary fission.

What is the differences between Viruses and Bacteria?

Bacteria are living cells, much larger, reproduce by binary fission, can be killed by antibiotics whereas viruses are not living, enter host cell to reproduce and antibiotics do not work (uncurable)

What is salmonella how is it spread and what are the symptoms?

Salmonella is food poisoning and is spread by bacteria ingested in food (it is found in the gut of many difference animals). It spreads through contaminated food that has not been cooked properly and can be found in eggs etc.

Symptoms: Diarrhea, fever, stomach cramps, vomiting, nauseous, headache

How do we prevent from getting Salmonella?

Cooking meat thoroughly, preventing raw meat from contaminating cooked meat, washing hands.

What is Gonorrheoa how is it spread and what are the symptoms?

Gonorrheoa is a sexually transmitted disease (STI), spread through sexual contact.

Symptoms: thick yellow unusual discharge, painful urinating.

How can Gonorrhoea be prevented?

Barrier methods of contraception such as a condom or just not having intercourse.

What is Tuberculosis, how is it spread and what are the symptoms?

Tuberculosis is a contagious, airborne bacterial infection primarily affecting the lungs.

It is spread from person to person through the air when someone with active lung or throat TB coughs, sneezes, speaks, or sings.

Symptoms: fever, chest pain, fatigue, weight loss

FUNGAL DISEASE: What is Rose Black spot?

Is a fungal disease of plants where purple or black spots develop on the leaves which often turn yellow and drop early.

How does rose black spot affect the plant?

It affects the growth of the plant as photosynthesis is reduced (less chloropyll) since the black spots prevent light from being absorbed.

How is rose black spot spread?

It is spread through the spores of the fungus that are produced in the black spots. The spores can be transmitted in air or water as well as being transferred from plant to plant by gardeners tools and hands.

How can you prevent/treat Rose black spot?

Can be treated with fungicide chemicals, leaves can be burned, tools should be disinfected.

PROTISTS: What are Protists?

Are a diverse group of eukaryotic and usually unicellular organisms and they often need a vector to transfer from one host to the next

What is Malaria and how does it work?

Malaria is caused by a protist (mosquitoes). It happens by a female mosquito biting the human, malaria parasite infects the liver and reproduces asexually, then the parasites are in the human blood so when mosquitoes consumes infected blood when feeding, sexual reproduction of malaria parasite occurs.

How can we prevent/treat Malaria from happening?

• Mosquito nets

• Using antimalarial drugs

• Removing standing water buckets since that’s where the mosquitoes breed