Everyone carries loads of different germs in their body. Right now there are thousands of nasty little creatures crawling all over your eyelashes and many more running up and down inside your ear holes. There are even millions of them wandering across your skin and climbing up and down your hairs. Oh, and don't forget the millions of germs that are inside your body in just about every place you can imagine. Really and truly, we are all covered ingerms, inside and out.
These germs come in many different forms - they could be bacteria, protozoa, fungi or viruses. On the whole, when we are fit and healthy these germs are pretty harmless, but when our immune system is weakened and unable to control them, then they can wreak all sorts of havoc.
Infections that take advantage of the fact you have a weakened immune system are known as opportunistic. Basically, they take the opportunity to run riot and cause harm.
It is possible to be infected with an opportunistic infection, test positive for it and yet not actually have the disease. This may sound confusing but, for example, almost everybody who is HIV-positive will test positive for Cytomegalovirus (CMV), but it is not common for the disease to actually develop unless your T-Cells fall below 50 (indicative of a very weakened immune system).
Opportunistic infections affect people with impaired immune systems. This includes many people with HIV, but can also mean other people too. Anyone on chemotherapy is highly likely to have a weakened immune system and therefore is highly susceptible to an opportunistic infection. So too is anybody receiving potent medication or with a serious illness.
Back in the 1980s when HIV was fairly new, many people were experiencing all manner of opportunistic infections that were proving fatal. With the advent of antiretroviral therapy things have changed.
While many people still experience opportunistic infections, they are not so common and are often more controllable.
In the early days of HIV, Kaposi's Sarcoma - a type of cancer, Cytomegalovirus - a virus that can lead to blindness and pain behind the eyes, and Pneumocystis carinii pneumonia - a serious and often fatal pneumonia, were frequently seen among HIV-positive people and were often the cause of death.
Nowadays, the main opportunistic infections appear to be candidiasis (thrush), mycobacterium avium complex and toxoplasmosis, although Cytomegalovirus and pneumocystis carinii pneumonia are also still commonly seen.
And one of the biggest opportunistic infections is tuberculosis, a bacterial infection that damages the lungs and can often be fatal: although it can be prevented or treated. In fact, a few of the opportunistic infections can be prevented.
Although you may already carry many of the germs that lead to them, you can reduce your risk by avoiding further exposure to these germs, keeping yourself clean and maintaining high standards of hygiene and avoiding any known sources.
For those infected with an opportunistic infection, there is treatment available that will prevent the disease becoming active - this is known as prophylaxis. Anti-HIV part to play in the prevention of the healthier your immune chance an opportunistic infection has of developing.
By the same token, if you have an active opportunistic infection, antiretrovirals may help restore your immune system and improve your chances of fighting the infection. (For more information on prophylaxis and treatment of opportunistic infections, see the feature 'when opportunity knocks').
What follows is a brief synopsis of some of the many opportunistic infections currently seen in clinics around the United Kingdom.
If you are concerned about any opportunistic infection or would like more information, you should consult with a medical professional.
Ano-genital warts
These are literally genital warts around the anal area area. They are highly contagious and therefore spread very easily. They can be painful, although often people complain of discomfort rather than actual pain.
Candidiasis (thrush)
These are literally genital warts around the anal area. They are highly contagious and therefore spread very easily. They can be painful, although often people complain of discomfort rather than actual pain.
This is an infection affecting the skin or mucous membrane. It is a type of yeast (usually Candida albicans) and is treatable with antibiotics.
Candidiasis can affect the bloodstream, but is usually found in wet areas e.g. the nose, mouth and vagina. It manifests itself as white patches on the skin and in the vagina.
Cryptococcal meningitis
This fungal infection can affect anywhere on the body: most commonly the brain. It causes an inflammation of the covering of the spinal cord and the brain. On the skin it looks like small spots. If it affects the brain, symptoms are headaches, dizziness and a stiff neck. You can acguire cryptococcal meningitis by inhaling dust contaminated with the fungus - this can be from some types of bird droppings.
Cryptosporidiosis
This is an infectious parasite often found in the water supply, although it can also be acquired through eating contaminated food. It can cause chronic diarrhoea and often lasts from five days to a month. No specific treatment is available and you usually have to let it run its course.
However, people with HIV should ensure they drink plenty of water and nutrients to replace what is being lost; dehydration can lead to death.
Cytomegalivirus (CMV)
CMV is related to the herpes simplex virus ans is incredibly common. In people with a healthy immume system the virus lies dormant, but in HIV-positive people the virus can multiply rapidly and infect the whole body. The most common form of CMV is CMV retinitis - it infects the eyes, causing severe pain behind them and can lead to blindness. CMV can also infect the brain (CMV encephalitis), lead to pneumonia, cause diarrhoea and hepatitis (inflammation of the liver).
Epstein-Barr Virus (EBV)
This is another virus that is similar to herpes. EBV can cause mononucleosis, a lack of monocytes in the blood. This can manifest itself through symptoms such as fatigue, mood swings and memory loss.
Hepatitis
This literally means inflammation of the liver and there are several types of hepatitis - the most common ones being A, B and C. Hepatitis A is predominantly spread through contaminated water or seafood, or poor sanitation. Hepatitis B and C can both be transmitted sexually or through contaminated needles (drug use, piercing, tattooing etc).
Herpes Simplex virus (HSV)
There are two main forms of herpes: type 1 causes cold sores and blisters around the mouth, nose and other areas of the face, and type 2 also causes blisters and sores, this time on the anus, vagina and penis.
Both types - HSV-1 and HSV-2 can be incredibly painful and highly contagious. They can easily be spread through kissing and sexual contact.
Histoplasmosis
A lung infection caused by a fungus. Its symptoms are often similar to that of tuberculosis and it can prove fatal.
Histoplasmosis is quite rare and usually only found in certain regions; commonly associated with Ohio and not particularly common in the United Kingdom.
Molluscum contagiosum
These warts are not painful and usually form in big clusters. Often they affect the face and took like clusters of white coral.
The major problem is that they affect people's physical appearance and therefore can cause distress, embarrassment and low self-esteem.
Mycobacterium avium complex (MAC, MAI)
MAC can be spread through the water supply, which makes it very difficult to avoid becoming infected. The organism can exist in your body without causing any harm at all, but if your immune system is impaired e.g. through an HIV infection, it is highly likely that you will become infected.
The initial signs may include diarrhoea and stomach cramps: MAC impacts on your intestinal tract. Symptoms can escalate rapidly. MAC is becoming increasingly more common.
Pneumocystis carinii pneumonia (PCP)
This is a very common organism that causes relatively little harm in people with a healthy immune system. However, in people with HIV it can prove fatal, causing PCP and is one of the most common fatal opportunistic infections. However, if caught early it is treatable with antibiotics.
Salmonellosis (Food poisioning)
Salmonella can be acquired through contaminated drinking water or food (often eggs or undercooked chicken). HIV-positive people should avoid all food made with raw eggs e.g. mayonnaise, homemade ice cream and certain salad dressings. Salmonella can also be found in faeces, so hygiene is important: you should wash your hands thoroughly and avoid sexual practices such as rimming (licking the anus).
Toxoplasmosis
Millions of people are infected with toxoplasma gondii (often acquired before birth or from cats), but it has no impact on someone with a healthy immune system.
However, in someone with HIV it can cause toxoplasmosis - a nasty infection that can lead to retina damage and can affect any part of the body, often the brain, liver and/or lungs.
The main way to acquire toxoplasmosis is through eating undercooked meat.
TUBERCULOSIS
TB is becoming increasingly common in areas of HIV prevalence. There is an emergence of drug-resistant TB occurring in people co-infected with HIV. Many people are infected during childhood, but the symptoms do not become apparent until their immune system is weakened, often as a result of the HIV. TB is highly contagious and can be spread by coughing and sneezing, although prolonged exposure is usually necessary. TB affecting the lungs is called pulmonary TB; if it affects other parts of the body it is known as extrapulmonary TB.
Varicella-Zoster virus (shingles)
Shingles is the same virus that causes the common childhood complaint known as chicken pox.
Anyone who has had chicken pox will have the Varicella-Zoster virus. It lies dormant and can become active when a person's immune system is weakened.
Shingles often starts as a rash round the middle of your stomach and this then affects your whole body. It can be excruciatingly painful and last for weeks.
