Communicable Diseases Flashcards
What are three examples of viral diseases? (3)
Measles, HIV and TMV
How does someone become infected with HIV?
It can be sexually transmitted, from blood, from mother to child and breast milk, needle sharing and blood transfusions.
What are the symptoms for HIV?
Flu-like illness
Immune System damaged
Weakness in immune system leads to increase in infections and Cancers
How is HIV treated?
People have to take regular use of antiretroviral drugs which can give them an almost normal life expectancy
How can HIV be prevented?
Use condoms (not just any contraception!), not sharing needles, screening blood of transfusions. HIV+ mothers should bottle-feed their children.
How is measles transmitted?
through sneezes and coughs through the droplets; airborne particles inhaled by others.
What are symptoms of measles?
High fever, runny nose, cough, rash. In worst cases, can lead to deafness and eye infections.
How is the spread of measles prevented?
Vaccination of babies so they develop an immunity
How is measles treated?
There is no treatment. The body’s immune system overcomes it after a couple of weeks.
What is TMV?
Tobacco Mosaic Virus
How is TMV transmitted?
Via contact between plants, and insect vectors.
What are the symptoms of TMV?
A mosaic pattern of discolouration on leaves which reduces growth due to a lack of photosynthesis
Why does TMV reduce growth?
Discoloration is due to a reduction in chlorophyll.
Reduced chlorophyll means less photosynthesis occurs, so less glucose is produced.
Glucose is needed for growth (respiration), so growth is reduced.
How can TMV be prevented?
Selective breeding of plants with a resistance to this disease can be grown.
Viruses reproduce by
inserting its DNA into a human cell, causing it into a virus making factory producing copies of the virus.
Viruses cause illness by
the human cell being killed by the mass-production and release of virus copies.
What is a carrier?
a person or animal that can give a disease to others but is not affected by it
What is a parasite?
an animal or plant that lives in or, on another animal or plant and gets food or protection from it
What are red blood cells?
Part of the blood that carries oxygen
Symptoms of Malaria
Symptoms resemble flu, Weakness, fever, chills, aches, diarrhoea and vomiting. High risk of birth complications
What is the Malaria parasite life cycle?
The parasite lives in the human, infecting the liver then red blood cells. The parasite can then be transmitted to another person via the blood consumed by mosquito vectors.
Some strategies to prevent transmission of malaria:
Mosquito nets and spray, avoiding mosquito breeding grounds, rapid diagnosis and treatment.
Malaria is caused by a
Protist pathogen, Plasmodium.
Rose Black Spot is caused by a
Fungal pathogen, Diplocarpon Rosae.
Rose Black Spot is
A disease of roses where leaves develop purple or black spots that stunts growth.
Why does Rose Black Spot stunt growth?
The loss of leaves causes a reduction in photosynthesis, and so also a reduction in glucose production. Grown uses glucose, so growth is stunted.
Rose black spot can be treated
with fungicide, which kills fungi.
Rose black spot transmission occurs by
water moving from one leave to another by rain or wind.
Rose black spot transmission can be prevented by
Removing affected leaves
Where can salmonella be found?
In raw meat, poultry, eggs and egg products such as mayonnaise.
How does Salmonella cause disease?
Salmonella divides/reproduces rapidly, causing toxins to be released.
What is a cause of the salmonella infection?
Eating undercooked food when the bacteria have not been killed or preparing food in unhygienic conditions where the food is contaminated from the salmonella bacteria from raw meat
What are the symptoms of salmonella?
The symptoms develop between 8-72 hours of eating infected food. Fever, abdominal cramps, vomiting and diarrhoea caused by the bacteria and toxins they secrete
Who can salmonella be most fatal to?
young children and old people because of the dehydration
How is salmonella prevented in the UK?
Poultry are vaccinated against salmonella to control the spread of disease. Hygienic cooking practices.
How can salmonella be prevented in the kitchen?
Keep raw chicken away from food which is eaten uncooked, avoid washing raw chicken (it sprays bacteria around) and wash hands and surfaces well after handling raw chicken and cook thoroughly
How can Salmonella be treated?
The body’s immune system usually manages the disease itself, but anti-biotics can be necessary sometimes.
What is gonorrhoea?
A sexually transmitted disease
How is gonorrhea spread?
unprotected sexual contact with an infected person
What is a symptom of Gonorrhoea?
An early symptom is a thick yellow or green discharge from the vagina or penis on urination
What can untreated gonorrhoea lead to?
long term pelvic pain, infertility, and ectopic pregnancies. babies born to infected mothers may have severe eye infections and even be blind
Can Gonorrhoea be treated?
Yes, with antibiotics as it is bacterial
What drug is used to treat Gonorrhoea and why is it harder to treat it now than before?
Penicillin is used but now many antibiotic resistant strains have developed.
How can the spread of Gonorrhoea be prevented?
By using a barrier method such as a condom and reducing the amount of sexual partners.
What are antibiotics?
Drugs which inhibit the reproduction of new Bacteria cells.
What is a pathogen
An organism that causes disease
What are viruses?
Viruses can only reproduce inside host cells, and they damage the cell when they do this
What is vaccination
injection of a weakened or mild form of a pathogen to produce immunity
What is communicable disease?
a disease that is spread from one host to another
What is a protist?
A eukaryotic organism that cannot be classified as an animal, plant, or fungus.
What is a microorganism?
A small living plant or animal seen only with a microscope; a microbe
Communicable diseases can be passed by:
Contaminated food By another animal Through dirty water Through air Direct contact
How does salmonella travel?
Travels from person to person and when handling food
How is the measles virus spread?
Spread by coughing and sneezing on another person
Transports through air
What is a pathogen?
A micro-organism that causes disease
What 4 types of pathogen are there?
Bacteria, virus, fungi and protist
How can disease be spread in animals and plants?
By direct contact, water or air
What do bacteria and viruses do once inside the body?
Reproduce rapidly
What do bacteria release to make us feel ill?
Toxins
How do viruses make us feel ill?
The live and reproduce inside our cells, damaging them and bursting them open.
What are two symptoms of measles?
Fever and a red skin rash
How do we protect against measles?
Most children are vaccinated against it in the MMR vaccine
How is measles spread?
The inhalation of droplets from sneezes and coughs
What is HIV?
A virus that attacks white blood cells to stop the body’s natural immune system.
What type of pathogen causes salmonella and gonorrhoea?
Bacteria
How is HIV spread?
Through sexual contact or by exchanging body fluids such as blood.
What are the symptoms of HIV?
Initially, flu-like symptoms.
What is AIDS?
Acquired Immune Deficiency Syndrome - a fatal condition of the immune system caused by HIV, last stage of the HIV infection.
How is HIV treated?
With antiretroviral drugs that stop the virus replicating in the body.
What type of cell is a bacterial cell?
Prokaryotic
What pathogen causes malaria?
Protists carried by a vector (mosquitoes)
What organism transports the protist pathogen between hosts and acts as a vector?
Mosquitoes
An organism that spreads disease without directly causing it
A vector
