Cytomegalovirus (CMV) - Opportunistic Infections
Cytomegalovirus is a very common infection caused by a virus carried by most people. A person with a very healthy immune system can keep what is generally speaking a minor virus like this under control with no symptoms.
But when you have AIDS, cytomegalovirus (a member of the herpes family) can hit you like a ton of bricks. The immune system is already severely compromised as it desperately continues to battle the HIV virus, so the last thing you need is another virus joining the onslaught.
The problem arises when a person’s CD4+ count goes below 100. The immune system is so low that there’s every chance that they will get Cytomegalovirus - so the key to beating it is trying to prevent it in the first place.
Currently very strong anti HIV drugs are the best way of keeping it at bay. They are not a vaccine against the virus but they will keep a person’s CD4+ count high enough to prevent the infection from gaining a grip.
The most common illness caused by CMV is retinitis – an infection of the eye which can quickly lead to permanent blindness if not treated.
It can also spread very quickly through the body infecting other areas such as the spine, lungs, throat and intestine. This can cause a variety of symptoms from diarrhoea to stomach pains and aching joints.
Cytomegalovirus needs to be treated very quickly. The first signs of CMV retinitis are vision problems such as floaters (moving black spots) in front of the eye. Some people may notice blind spots or flashing lights.
It’s important that people with AIDS have regular eye checks to help nip the problem in the bud and certainly if a person has a very low CD4+ count this is vital.
There are currently three drugs used to treat CMV retinitis – glaciclovir, foscarnet and cidofovir. They have been found to slow down the CMV but not cure it.
Until recently all anti CMV drugs had to be given via a vein so a permanent catheter had to be placed in the chest to allow daily intravenous treatment. Glanciclovir is now available in pill form and also it can be used via a device which releases the drug directly into the eye.
Cytomegalovirus colitis causes diarrhoea while the virus in the oesophagus can make swallowing painful. In the spine it affects the myelin tissue surrounding the spinal cord and this can cause numbness which may spread to the legs.
In very rare cases cytomegalovirus can cause pneumonia. However it is more likely that another type of infection like pneumocystis will cause pneumonia in people with AIDS.
CMV found in other parts of the body other than the eye is also treated with ganciclovir and foscarnet.