Pneumonia, one of the defining diseases of AIDS

When HIV completely destroys the immune system, so-called opportunistic diseases develop, which exploit the lack of defenses (CD4 cells) to develop.

Pneumonia caused by Pneumocystis jiroveci was the most common AIDS-defining disease (32.4%) in Spain during 2013-2022, followed by tuberculosis (16.3%) in any location, according to data provided by the Spanish Ministry of Health and Hospital Carlos III Health Research Institute, through HIV and AIDS Epidemiological Surveillance.

Pneumonia is an acute infection caused by a virus, bacteria, or fungus that causes one or both lungs to fill with fluid or pus.
The first symptoms of the Pneumocystis jiroveci strain, which originated from a fungus identified in 1988 and initially mistakenly thought to be caused by a parasite, are: dry cough, shortness of breath, high fever, chills, chest pain and weakness. In people with HIV, this condition occurs repeatedly.

How does this infection occur?

Millions of viruses and bacteria coexist in our bodies, maintaining a delicate balance, and the immune system is the guarantee of this balance. In this sense, the nose and throat are filled with bacteria and sometimes viruses, which upon entering the body are usually eliminated by the defense mechanisms of our lungs. One of them is coughing, which helps expel mucus and foreign matter.

Additionally, there is a network of cells, proteins, and white blood cells surrounding the lungs that attack pathogens. When these defense mechanisms fail to function effectively, pneumonia occurs, typically originating in the lungs due to the entry of microorganisms through the respiratory tract.

Diagnosis and treatment

It is important to know what type of pneumonia it is so that the most appropriate treatment can be given (antibiotics if it is bacterial pneumonia).
The most basic diagnostic tests are: blood analysis, chest X-ray, and analysis of sputum samples (sputum, secretions).
For people living with HIV, optimal adherence to antiretroviral therapy is critical. This way you are more likely to avoid pneumonia infection.
People with weakened immune systems (such as those with HIV) are 10 times more likely to contract pneumonia than people with normal defenses.
Before the HIV pandemic, Pneumocystis jiroveci was a rare infection, but now, for people with weakened immune systems, it can be fatal if treatment is not started quickly.

source:

Pneumocystis jiroveci pneumonia-Pulmonary Disease-MSD Manual Professional Edition (msdmanuals.com)
GUIDE_PREVENCION_INFECCIONES_OPORTUNISTAS.pdf (gesida-seimc.org)
What are opportunistic infections? | Well Project
Report_HIV_SIDA_2023.pdf (sanidad.gob.es)
Introduction to Pneumonia – Lung and Airway Disorders – Merck Manuals Consumer Version (msdmanuals.com)