What is an opportunistic infection?

This is an automatically translated article.

The article is professionally consulted by Master. Doctor Nguyen Thi Nhat - Doctor of Infectious Diseases - Department of Medical Examination & Internal Medicine - Vinmec Hai Phong International General Hospital. The doctor has more than 10 years of experience in the field of artificial kidneys, and in the field of infectious diseases, examining and managing patients with kidney disease and infectious diseases.
Opportunistic infections are usually caused by opportunistic pathogens, such as bacteria, viruses, fungi, and protozoa. They are usually present but do not cause disease in healthy, immunocompetent hosts. Some situations of immunosuppression are good "opportunities" for these agents to take advantage of to cause disease.

1. Opportunistic infections

An opportunistic infection is an infection caused by pathogenic bacteria, viruses, fungi or parasites when the host's immune system is weakened or due to increased virulence of the microorganisms. object.
The causative agents of opportunistic infections are conditionally pathogenic microorganisms. They can be parasitic, normally capable of causing disease, or symbiotic or mutualistic, and normally do not cause disease.

2. Cause

OIm Advanced HIV infection

Cancer chemotherapy Genetics Skin lesions Long-term antibiotic treatment Medical procedures Pregnancy The HIV virus weakens the body's immune system, thereby creating an opening for muscle infections. attack danger.
People with HIV/AIDS are at high risk for certain viruses, bacteria, and parasites. This condition is also known as an “opportunistic” infection. Infections are called “opportunistic” because they take advantage of a weakened immune system to enter the body and cause a lot of damage.

3. Some opportunistic infections

Some common opportunistic infections include: Candida infections of the bronchi, trachea, esophagus, and lungs.
3.1 Candida infection Candida infection, also known as thrush, is caused by a harmless fungus called Candida. This is a fairly common opportunistic infection and usually occurs in HIV patients with a CD4 count of 200 to 500 cells/mm3.
Candida can appear on the skin, nails and mucous membranes throughout the body, especially in your mouth and vagina. However, Candida is considered an opportunistic infection only when it infects the esophagus or lower respiratory tract, such as the trachea and bronchi or deeper lung tissue.
The most obvious symptoms are white spots or white patches that appear on the tongue or throat. The disease can be treated with prescription antifungal medications. Good oral hygiene and using a chlorhexidine mouthwash can help you prevent this infection.
3.2 Pneumonia Pneumonia is one of the most serious opportunistic infections for people with HIV, caused by a number of fungi such as Coccidioidomycosis, Cryptococcus, Histoplasma, Pneumocystis jirovecii, certain bacteria such as Pneumococcus, and a few bacteria. some viruses such as Cytomegalovirus or Herpes simplex.
Among them, Pneumocystis pneumonia (PCP) is the leading cause of death among HIV patients. The good news for patients is that the infection can be treated with antibiotics.
Symptoms include cough, fever and difficulty breathing. Occasionally, the disease can also spread to the brain, causing cerebral edema. Treatment should be started early so that the patient can achieve the best recovery. There is now an effective vaccine that can prevent Streptococcus pneumonia infection, so all HIV-infected patients should be vaccinated against these fungi.
3.3 Cryptococcus neoformans Cryptococcus neoformans is a fungus commonly found in soil. The disease is sometimes confined to the lungs, but it can spread to other parts of the body, such as the skin, bones, or even the urinary tract.
The fungus usually enters the patient's body through the lungs and can cause pneumonia. Sometimes it can also spread to the brain, causing cerebral edema. If the brain becomes infected with the fungus, the condition is called meningitis.
3.4 Tuberculosis (TB)

Tuberculosis is caused by the bacteria Mycobacterium tuberculosis. TB bacteria can be spread through the air when someone with TB coughs, sneezes, or talks. Inhaling TB bacteria into the lungs can lead to infection in the lungs.
Symptoms of tuberculosis in the lungs include cough, fatigue, weight loss, fever, and night sweats. Although the disease usually affects the lungs, it can also damage other parts of the body, most commonly the larynx, lymph nodes, brain, kidneys, or bones.
3.5 Certain types of cancer Some cancers are considered opportunistic infections, for example:
Invasive cervical cancer is cancer that starts in the cervix and then spreads to other parts of the cervix. body. This cancer can be prevented with regular cervical cancer screenings and exams. Kaposi's sarcoma (KS) is caused by the herpes virus. KS causes small blood vessels, called capillaries, to grow abnormally. KS can be life-threatening when it affects internal organs, like the lungs, lymph nodes, or intestines. Currently, many people with HIV are infected with opportunistic infections, the main cause of which is their weakened immune system. The best way to prevent opportunistic infections is to see your doctor regularly and take your HIV medications as directed by your doctor.

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