This is and electron microscope picture of the malaria pathogen, Plasmodium falciparum.
AIDS and HIV.
AIDS stands for acquired immune deficiency syndrome. HIV stands for human immunodeficiency virus. The virus (HIV) infects the body cells of the immune system and in time destroys them. This causes a decline in immunity to other diseases. The cells in destroys are called T Helper Lymphocytes. When the numbers of these cells fall below a certain level then the body cannot fend off infections. So far no treatment for the disease has been found. AIDS in not a disease, but the name given to the opportunist infections associated with HIV.
HIV can be contracted in a number of ways. The first way is through sexual intercourse. The disease is carried in virginal fluid and semen in infected people. When this comes in contact with the fluid they will also contract the disease. Another way HIV can be spread is by blood donation by a person been given a blood transfusion from someone who has HIV. Also the use of hypodermic needles that have been in contact with another person’s blood that has the disease. You can also contract HIV through you mother’s placenta when you are in womb, or through breast milk.
This picture shows what the AIDS Virus Looks like under an Electron microscope.
This is an Electron Micro-graph of the HIV pathogen invading the body.
Tuberculosis.
Tuberculosis is a disease that affects the lungs and breathing. It is caused by the pathogen called Mycobacterium tuberculosis. The symptoms of the disease are a server cough, coughing blood, chest pain, shortness of breath, fever, sweating and weight loss. The secondary infection affects the lymph nodes and the bones and gut. It is possible for you to be a carrier of the disease with having it your self or passing it onto other people. It is most likely for you to get tuberculosis when your body has been weakened by another disease, such as HIV. It is not until you show symptoms of the disease that you can infect others.
Tuberculosis is contracted through airborne droplets that carry the disease. These enter the air when infected people cough or sneeze. It can also be contracted through un-pasteurised milk and meat. This infection is caused by a different pathogen called M. bovis. When you come in contact with the pathogen it quickly multiplies in the body and causes the symptoms. The treatment for the disease can take as long as a year because the infection takes a long time to kill.
This is an x-ray of person’s lungs who has the T.B infection.
The Worldwide Importance of These Diseases.
The four diseases, cholera, malaria, HIV and tuberculosis, are of current concern across the world as the number of cases of each disease is rising. All of these diseases cause serious public health and because of the nature of the disease they are easily spread from one person to another. In 1992 a new strain of the cholera disease became apparent. This started the eight epidemic of the disease. Malaria holds a serious risk to health of people living in tropical countries and the number of cases has been on the increase since the 1970’s. This increase is also due to the increase of foreign travel meaning the disease is brought back to this country when it has not been prevented before travel. Aids came apparent in 1981 but the infective HIV was recognised years before. Since HIV was discovered the numbers of infected people has risen. Tuberculosis is a threat in both developed and developing countries. It was once thought to have been eradicated, but this was found to be untrue.
The social, economic and biological factors in the prevention and control of the named diseases.
Cholera can be prevented from spreading by not drinking water that could be contaminated by the pathogen vibrio cholerea. In countries where swage is a problem and the people drink untreated water, such as places like Africa, Asia and South America, then the spread of the disease could be decreased if a proper swage and cleaning system was set up. However this may not be possible because of the lack of funds in the country. Also overcrowded living conditions contribute to the disease spreading because if an uncontaminated person comes in contact with the pathogen they to have a high chance of getting cholera. This problem could also be overcome if money was available for new housing in those areas.
If you are travelling to a country where there is a high risk of catching cholera then you should avoid drinking or using water that has not been sterilised. Also avoid ice cubes unless they have been made from “safe water”. Foods that you are advised to avoid are raw fish and shellfish and fruit and vegetables. People that travel to different counties should follow this advice and if they become infected then they should try and stop others becoming infected. A simple way to do this is by washing your hands after you have been to the toilet.
You can prevent being infected by the Malaria pathogen by taking preventive medicines before, during and after, you travel to countries that have a high malaria risk. The tablets build up your immunity to it so if you get bitten you will not develop the disease.
In countries where the malaria infection is high then people who are constantly in contact with the disease develop immunity to it and do not become ill if bitten. However this immunity is quickly lost so people from those countries who go on holiday lose their immunity and need to take the same precautions as others when they return.
The Aids virus is only caused by direct contact with an infected person, such as in vaginal fluid and semen. To protect your self from becoming infected make sure condoms are worn during sexual intercourse and in using hypodermic needle, they are clean and un used. Having multiple partners increases the chances of the disease spreading from one person to the next.
No cure has been found to tackle HIV and AIDS. At the moment there are only drugs to slow the effects of the disease. These drugs are very effective but can cause both permanent and temporary side effects. The drugs are also very expensive and have to be taken in a combination at a certain time each day; people who do not have a routine in taken them can become resistant to the drugs.
Due to the cost involved in treatment developing countries, like Uganda, find it more economical to educate people about the use of condoms; this has made the country see a fall in the number of cases of HIV and AIDS. In developing countries they focus on “contract tracing”. This means that people who are infected who are willing and able to identify those who they may also have infected are given the chance to have a HIV test. This means that infected people can be quickly identified and treatment for the disease can start immediately. This increases the person’s chances of surviving the disease for many years.
Tuberculosis also uses “contact tracing” in trying to prevent the spread of the disease. With tuberculosis being transmitted though the air then catching the infection before it has had time to infect others is very important. People who have been in contact with others with the disease are screened and have results within two weeks. Cattle are also regularly tested for the infection as they can pass the disease onto people through milk and meat products.
Another problem with tuberculosis is making sure that an infected person takes all of there medication. It can take up to nine months to completely kill the disease. If an infected person stops taking there medication they are still infected with the disease and can pass it on to up to fifteen people.
To prevent tuberculosis in children a vaccination called a BCG is given to them. This vaccine protects up to eighty percent of children and has reduced infection numbers in children. However this vaccines effectiveness decreases in time making people susceptible again. You should get vaccinated when you are an adult as well as a child to prevent becoming infected.
In developing countries vaccines against tuberculosis may be too expensive. The cramped living conditions also increase people’s chance of becoming infected. This makes the numbers of people with tuberculosis hard to control. People with the disease should be separated from healthy people as soon as possible, in both developed and developing countries, to prevent others becoming infected.
Anti - biotics.
Anti-biotics are used to treat infections, some even cure them. Different types of anti-biotic are used to treat different kinds of infection. This is because some infections are resistance to certain types of anti-biotic. There are two types of anti-biotic, “broad spectrum” which are used for a wide range of infections and “narrow spectrum” which can only be used to treat a few different types of infection.
Anti-biotics work by inhibiting certain aspects of growth or metabolism. These include protein synthesis, synthesis of bacteria walls, plasma membrane function and enzyme actions. Most anti-biotics are made of living cells. However there are some drugs, such as isoniazid, which is used in the treatment of tuberculosis, which is synthetic.
Finding the most effective type of anti-biotic for a disease is a fairly straight forward process. It involves growing the infection on an agar plate. Then filter paper disks, that contain the anti-biotic, are placed on the grown cells. You can tell which anti-biotic is the best by measuring the radius where no cells are growing around the filter paper.
This photo shows how the selection process is done.
Due to the overuse of anti-biotic some people or infections become immune to them. This makes the infection more difficult to treat and also decreases the patient’s chances of survival in some cases.
The cholera pathogen can be killed by using and anti-biotic, such as doxycycline, but sometimes this is not necessary if you are able to replace the fluids lost with salt water. Tuberculosis is treated with a combination of anti-biotics. A combination is needed to prevent the pathogen becoming resistant to it, which would cause serious consequences to the patient. AIDS / HIV are also treated with a combination of drugs. However anti-biotics do not kill of the infection, mealy slow down its effects. If the anti-biotics are not taken at the correct time of day then resistance to them may be caused. Malaria is not treated with anti-biotics.
