Antibiotics
antibiotic; virus; bacteria; bacterium; infection; immunisation; immunise; vaccine; vaccination; resistant; resistance; toxin; medicine; germ; cold; colds; ear; sinus; tonsil; tonsillitis; sinusitis ;
Contents
Antibiotics are powerful and important medicines. When used properly they can save lives, but often they are used unnecessarily for illnesses that do not respond to antibiotics and for infections that our body can handle without medication. Our immune systems have evolved (developed) to enable us to recover from most infections.
There are two main types of germs that cause illness, bacteria and viruses. Antibiotics are not effective against viruses.
Bacteria
- Bacteria are very small single-celled organisms which can live in many places such as within water, soil, food, on the surface of the skin of animals including humans, and inside bodies.
- Bacteria are so small that they can only be seen using a very high powered microscope.
- Bacteria can grow where ever there are nutrients that suit them (foods such as sugars).
- Some of the illnesses of humans that may be caused by bacteria are some ear infections (otitis media), pneumonia, meningitis, tetanus and food poisoning.
- Some of the health problems caused by bacteria occur where the bacteria are growing (such as in a cut on the body, or in the blood) and some health problems occur when the bacteria make a toxin (poison) which is carried to other parts of the body. Tetanus for example is caused by bacteria that grow in a wound on the body. The toxin that they make travels to the nervous system where it causes muscle spasms.
- Some bacteria are useful to the host body. For example some bacteria in our gut help digest food, produce useful chemicals (such as Vitamin K) and help control the growth of other bacteria that can cause illnesses.
Viruses
- Viruses are much smaller than bacteria.
- They are able to live outside of a body for a short time, but to be able to grow they need to enter a living body cell and use the contents of that cell to divide and make more viruses.
- Some of the illnesses caused by viruses are measles, chickenpox, colds, hepatitis, HIV/AIDS and influenza.
Actions of antibiotics
- Antibiotics are chemicals which can kill bacterial cells or stop them from growing.
- They are useful against some bacterial infections because bacteria cells are quite different to the cells of the host (such as the cells of a human). Chemicals which harm bacteria do not harm human body cells.
- After the antibiotics have damaged the bacteria, the body's immune system is able to remove them, leading to recovery. Without an effective immune system, infections are much more difficult to treat (people infected with the Human Immunodeficiency Virus [HIV] have more severe, and difficult to treat, bacterial infections).
- Antibiotics do not work against viruses because the viruses use body cells (of humans or other animals, plants etc) to grow and any chemical which would damage a virus will also damage the body cells. Some medications have been developed to assist the body's immune system to act against some viruses. HIV infections are being treated with some of these medications.
Some illnesses that can be treated by antibiotics
- Many middle ear infections are caused by bacteria and may be usefully treated by antibiotics, although often an ear infection can be controlled by the body's immune system without the child needing antibiotics.
- A cold or the 'flu' is never caused by bacteria.
- Some tonsillitis is caused by bacteria, but a lot is also caused by viruses. Some doctors will prescribe antibiotics for tonsillitis, but many will not because the body is usually able to get rid of a bacterial infection using its immune system without the help of antibiotics.
- Meningitis, urinary tract infections (of the kidneys and bladder), pneumonia, skin infections (such as impetigo [school sores]), syphilis and gonorrhoea are usually treated by using antibiotics.
- Some people have asthma which is triggered by an infection. This infection is almost always a viral infection, so that using an antibiotic for asthma is not helpful.
- The bacteria causing tetanus usually grow in wounds in the skin (deep cuts, or penetrating wounds, such as getting pricked by a splinter). The bacteria can be killed by antibiotics, however the toxin made by these cells needs to be destroyed another way. The immunisation against tetanus that we get, is aimed at helping the body to destroy the tetanus toxin.
Resistant bacteria
- Many bacteria are able to change a little so that the chemical (antibiotic) is no longer able to kill them or interfere with their growth.
- When the antibiotic no longer works, the bacteria are said to be 'resistant'.
- Each time that we use an antibiotic the sensitive bacteria are killed, but some might survive. Because most of the bacteria have been killed, there is 'space' for these resistant bacteria to grow. Sometimes the changes that have caused resistance can be passed on to bacteria of different types.
- Many of the early antibiotics are no longer effective against some common bacteria.
- Special antibiotics may be needed to be used to kill the bacteria, and these antibiotics may need to be given by injection (into a vein).
- Examples of resistant bacteria are Methicillin Resistant Staphylococcus Aureus (MRSA) and Vancomycin Resistant Enterococci (VRE). These bacteria can become major problems in hospitals as they can cause infections which are very difficult to treat and they can be moved from one person to another (transmission).
- Quite a lot of people develop an allergy to some common antibiotics, especially to penicillin and some of the antibiotics containing sulphur based medications.
- An allergy can cause a blotchy, itching rash. Severe allergy can cause difficulty breathing and a fall in blood pressure (anaphyllaxis). This is a rare reaction. Diarrhoea is not usually due to an allergic reaction.
- Often a viral infection will cause a rash, and it can be difficult to work out if the rash has been caused by the infection or by the antibiotic.
- However, if the rash is blotchy and itchy, it could well be caused by an allergic reaction. The antibiotic needs to be stopped and you will need to talk with your doctor about whether another antibiotic is needed.
- There are several different groups of antibiotics and usually a child will be able to use a different type of antibiotic if needed.
- Immunisation is a very effective way of protecting children and adults against many infections caused by viruses, such as measles, mumps, rubella, hepatitis A and B, against the bacterial infection caused by Haemophilis Influenza type B (Hib) and against the toxin made by tetanus bacteria.
- Careful hygiene, including washing hands and careful food preparation will stop the spread of many infections. See the topic 'Food safety'for more information.
What parents can do
- Discuss with your doctor whether an antibiotic is likely to be of use in this illness, and don't ask for antibiotics for illnesses such as a cold, the 'flu' or other viral infections.
- If antibiotics have been prescribed, make sure that they are used as the doctor recommends. Take all of the antibiotics. Do not keep some for the future or use them for someone else.
- Other ways of caring for someone who is unwell are given in the topic 'Feeling sick' and in topics such as 'Colds' and 'Influenza'.
Resources
General
- Topics on antibiotics and antibiotic resistance - Centers for Disease Control and Prevention (USA).
http://www.cdc.gov
The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).
This topic may use 'he' and 'she' in turn - please change to suit your
child's sex.