Controlling the Spread of Disease

Cholera

• Cholera is caused by the bacterium vibrio cholerae, which contaminates food and drinking water
• This bacterium infects the small intestines with a toxin called CTX , which in turn causes severe diarrhoea

• Normally present in coastal waters, attaching to crustaceans known as copepods which are found in plankton rich environments

(WordPress, 2014).

• This bacteria does not always make people ill however, this bacteria may come out in stools, which can contaminate the water supply
• When vibrio cholerae enters the human body toxic poisons are released, causing diarrhoea
• The nutrients in the water enables provides ideal condition for the bacteria to multiply

Prevention

• To prevent contracting cholera use bottled or boiled water when drinking and preparing food and drink
• Thoroughly washing hands on a regular basis

Malaria: a potentially life threatening disease

The life cycle of malaria

• Malaria plasmodium parasites have two hosts; female anopheles females and humans
• Female anopheles mosquitos infected by malaria parasites Inject sporozites into humans whilst feeding on their blood
• Sporozites then infect cells within the liver; transforming into thousands of merozoites.
• These merozites travel out of the liver and then invade the red blood cells; where they multiply forming new merozites
• Red blood cells then burst; this releases merozites which go on to infect other cells

• Whilst invading red blood cells merozites can develop into gametocytes; which is the sexual reproductive stage.
• Gametocytes are sucked up by mosquitos when they are feeding; fusing with gametes to make zygotes in the mosquitos gut
• Zygotes become fertilised and form motile ookinete; which turn into oocyst, these then multiply producing thousands of sporozoites
• These then move into the salivary gland of the mosquito after around a week; ready to infect humans

So what can be done to protect against malaria?

• The use of mosquito nets are commonly used to stop mosquitos from biting as well as the use of insect repellent
• Some medicines are given to people to help prevent the risk of contracting malaria: doxycycline, proguanil with atovaquone, mefloquine; some of which need to be taken for weeks after return

(disqus, 2014).

Influenza

• Influenza (flu) is a common viral infection which attacks the nose, throat and lungs (respiratory system)
• Influenza is air borne and can be transmitted between people if someone has the virus and sneezes, others can inhale this
• The virus can also be present on objects an infected person has touched
• Cytokines are produced when the innate immune system starts to respond to the threat these induce responses such as the inflammatory response

Lifecycle

• The flu enters its host and then invades cells within the respiratory system
• The virus uses its host cell to replicate its DNA; forcing the cell to make copies of the virus
• This triggers the body’s immune response which sends white blood cells to the area of infection
• If not stopped the virus can then break free from the host cell allowing it to infect other cells around the body

(fitbuff.com, 2009).

Prevention

• Vaccinations are offered to protect against influenza but are not one hundred percent effective
• Washing hands regularly prevents the spread of infection

Athlete’s foot (trichophyton)

• Trichophyton rubrum causes tinea pedis (athletes foot) which feeds off keratin in the upper layer of the skin, hair and nails
• Trichophyton rubrum form part of the dermatophytes which is a group of fungi
• Within four to ten days symptoms appear as a result of body’s inflammatory response; resulting in a red rash on the skin
• The blistered and itchy skin occurs as a result of the trichophyton reproducing on the skin, particularly they like moist places such as in-between the toes
• If the fungus infection is not treated it can spread to other areas of the feet such as the toe nails
• This fungi can be passed from person to person and is prevalent in public showers and swimming pools, where skin particles are left around

Symptoms

• Skin between the toes can burn and become itchy
• Early treatment is recommended
• If untreated in the first instance it can cause the skin to become cracked and infected further with bacteria
• The fungus infection may cause an unpleasant smell

Prevention

• Thoroughly washing feet daily and making sure all areas are completely dry before putting socks on
• Not wearing socks and shoes where possible to allow air to circulate around the feet
• Changing socks regularly, this is because fungus can multiply on flakes of skin

Bibliography

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References

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Rachel Sylvester

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