If your CD4 count drops below 200, you will be at risk of catching many different types of infection. Infections that 'take advantage' of an HIV-weakened immune system are known as opportunistic infections. However, if you stick to your HIV therapy, the likelihood of developing an opportunistic infection remains low.
The four main types of opportunistic infections are:
People with advanced HIV also have a higher risk of developing some forms of cancer, such as lymphoma (cancer of the lymph system).
Pneumonia
Pneumonia is a bacterial infection of the lungs. It can often develop as a complication of other infections, such as a cold or flu. Left untreated, pneumonia can be fatal because the infection can spread through your blood.
Pneumonia can be treated using antibiotics. There is also a vaccine that can protect you against many of the bacteria that can cause pneumonia. People living with HIV are recommended to receive annual vaccinations.
Tuberculosis (TB)
TB is another bacterial infection of the lung. Globally, it is the leading cause of death for people who are HIV positive. TB can be treated using antibiotics, but some strains of bacteria have developed resistance to this medicine, and these can be more difficult to treat.
Hepatitis
Hepatitis is a viral infection that can cause damage to your liver. This can increase your risk of developing liver cancer. There are three main types of hepatitis: hepatitis A, hepatitis B and hepatitis C.
Vaccines are available for hepatitis A and hepatitis B, but not for hepatitis C. Avoiding sharing needles and using a condom are the best ways to prevent hepatitis.
Candidiasis
Candidiasis is a fungal infection that is common in people living with HIV. It causes a thick, white coating to appear on the inside of the mouth, tongue, throat or vagina.
Though rarely serious, candidiasis can be both embarrassing and painful. It can be treated with antifungal creams.
Tell the staff at your HIV clinic if you have repeated bouts of candidiasis because it could be a sign of a low CD4 count.
Pneumocystis pneumonia (PCP)
PCP is a fungal infection of the lungs, which can be life-threatening if it is not treated promptly. Before the advances in anti-HIV medicines, PCP was the leading cause of death among those with HIV in the developed world.
Symptoms of PCP include:
- a persistent dry cough
- shortness of breath
- difficulty breathing
- in some cases, fever
Report any symptoms of PCP straight away because the condition can suddenly worsen without warning. PCP can be treated with antibiotics and, if your CD4 count drops below 200, you may be given antibiotics to prevent a PCP infection.
Cancer
People with advanced HIV have an increased risk of developing cancer. It is estimated that somebody with untreated late-stage HIV infection (AIDS) is 100 times more likely to develop cancer than somebody without the condition. However, with treatment, the risk of getting cancer is much the same as that of the general population.
The two most common cancers to affect people with HIV are lymphoma and Kaposi's sarcoma. Lymphoma is a cancer of the lymphatic system (a network of glands that makes up part of our immune system). Kaposi's sarcoma can cause lesions to grow on your skin, and can also affect your internal organs.