Sandbox/AL

Before the widespread use of potent combination antiretroviral therapy (ART), opportunistic infections (OIs), which have been defined as infections that are more frequent or more severe because of immunosuppression in HIV-infected persons, were the principal cause of morbidity and mortality in this population. In the early 1990s, the use of chemoprophylaxis, immunization, and better strategies for managing acute OIs contributed to improved quality of life and improved survival.[1] However, the widespread use of ART starting in the mid-1990s has had the most profound influence on reducing OI-related mortality in HIV-infected persons in those countries in which these therapies are accessible and affordable.

Disease	Description	Clinical Findings	Diagnosis	Prophylaxis	Treatment
Pneumocystis Pneumonia (Click here for more information)	Caused by the fungus Pneumocystis jirovecii. 90% of cases occurred among patients with CD4+ <200 Incidence among HIV patients: 2-3 cases per 100 person-year	Subacute onset of progressive dyspnea, fever, nonproductive cough, and chest discomfort that worsens within days to weeks. Tachypnea, tachycardia, and diffuse dry rales are found in the physical examination.	Clinical presentation, blood tests, or chest x-rays are not pathognomonic for PCP.	Start TMP-SMX prophylaxis when CD4+ <200 cells/µL or history of oropharyngeal candidiasis. Discontinue prophylaxis when CD4+ is >200 cells/µL for >3 month.	TMP-SMX Administer adjunctive corticosteroids in patients with pO2 <70 mm Hg or arterial-alveolar O2 gradient >35 mm Hg
Toxoplasma gondii Encephalitis (Click here for more information)	Caused by the protozoan Toxoplasma gondii The greatest risk of disease occurs among patients with a CD4+ <50 cells/µL Primary infection occurs after eating undercooked meat containing tissue cysts or ingesting oocysts that have been shed in cat feces and have sporulated in the environment	Focal encephalitis with headache, confusion, or motor weakness and fever	Diagnosis is done with IgG antibodies. CT scan or MRI of the brain will typically show multiple contrast-enhancing lesions, often with associated edema. Definite diagnosis requires a brain biopsy.	Start TMP-SMX prophylaxis when CD4+ <100 cells/µL Discontinue prophylaxis when CD4+ is >200 cells/µL for >3 month.	Administer: Pyrimethamine, PLUS Sulfadiazine, PLUS Leucovorin
Cryptosporidiosis (Click here for more information)	Caused by the protozoan Cryptosporidium (C. hominis, C. parvum, and C. meleagridis) The greatest risk of disease occurs among patients with a CD4+ <100 cells/µL
Microsporidiosis
Mycobacterium tuberculosis
Table adapted from Guidelines for Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents