Prophylaxis and treatment of opportunistic infection

HIV infection significantly suppresses and weakens the immune system thus increasing the risk for acquiring opportunistic infections due to bacteria, viruses, fungi, and protozoa. These opportunistic infections as they are called are a major source of morbidity and mortality in HIV-infected patients

Different opportunistic infections tend to typically occur at different stages of the infection. In early HIV infection people can develop tuberculosis, bacterial pneumonia, herpes zoster, staphylococcal skin infections and septicaemia. These are diseases that people with normal immune systems can also get, but with HIV they occur at a much higher rate, and it takes longer for the infected person to recover. When the immune system is very weak due to advanced HIV disease or AIDS, opportunistic infections such as PCP, toxoplasmosis and cryptococcosis develop.  Other opportunistic infections may include candidiasis and penicilliosis; and viral diseases such as cytomegalovirus, herpes simplex and herpes zoster virus.  There can also be HIV-associated malignancies such as Kaposi's sarcoma, lymphoma and squamous cell carcinoma.

Some infections can spread to a number of different organs, which is known as 'disseminated' or 'systemic' disease. Combination anti-retroviral therapy or highly active antiretroviral therapy (HAART) has resulted in a dramatic decline in the incidence of opportunistic and other infections in HIV infected persons.  The use of HAART can reduce the amount of HIV in someone's body and restore their immune system.  
 
The prevention and treatment of opportunistic infections remains essential since in many parts of the world millions of people living with HIV in resource-poor communities have no access to antiretroviral drugs. And even where the drugs are available, they do not entirely remove the need for preventing and treating opportunistic infections. Usually it is advisable for people with acute opportunistic infections to begin HIV treatment right away, especially if the infection is difficult to treat. However in certain cases it may be better to delay beginning HIV treatment and instead only administer treatment for the opportunistic infection, especially if there are concerns about drug interactions or overlapping drug toxicities.

Providing prevention and treatment of opportunistic infections not only helps HIV-positive people to live longer, healthier lives, but can also help prevent TB and other transmissible HIV-positive people with a history of treated PCP.  The WHO recommends that treatment of HIV-positive children should continue until at least age five. In general treatment of adults and children should continue indefinitely, though it may sometimes be stopped following successful antiretroviral treatment.  For people who were successfully treated for an opportunistic infection, it may be advisable that they receive a secondary prophylaxis to prevent recurrence. This applies to diseases such as tuberculosis, salmonella, cryptococcosis and PCP.

It is important to note that some opportunistic infections are easier to treat than others. Effective treatment depends on health services being able to procure, store, select and administer the necessary drugs and to provide related treatment, care and diagnostic services to monitor health status and treatment response.

For more information on Prophylaxis and treatment of OIs visit:
www.cdc.gov
www.aidsinfo.nih.gov
www.paho.org