A 46-year-old woman comes to the office to be tested for HIV after one of her prior sexual partners found that he was HIV-positive. She feels healthy and has no symptoms. The patient has never had a sexually transmitted infection and has no chronic medical conditions. She has had several sexual partners in her lifetime and uses condoms inconsistently. Physical examination shows no abnormalities. HIV antigen/antibody immunoassay and a confirmatory HIV-1 antibody test are positive. Further studies reveal plasma HIV viral load is 250,000 copies/mL and CD4 lymphocyte count is 150 cells/mm³. After discussing the results and need for treatment, the patient agrees to start antiretroviral therapy. An additional medication to prevent opportunistic infections is also planned. This added treatment is most likely being used to prevent infection from which of the following pathogens?

Question

A 46-year-old woman comes to the office to be tested for HIV after one of her prior sexual partners found that he was HIV-positive. She feels healthy and has no symptoms. The patient has never had a sexually transmitted infection and has no chronic medical conditions. She has had several sexual partners in her lifetime and uses condoms inconsistently. Physical examination shows no abnormalities. HIV antigen/antibody immunoassay and a confirmatory HIV-1 antibody test are positive. Further studies reveal plasma HIV viral load is >250,000 copies/mL and CD4 lymphocyte count is 150 cells/mm³. After discussing the results and need for treatment, the patient agrees to start antiretroviral therapy. An additional medication to prevent opportunistic infections is also planned. This added treatment is most likely being used to prevent infection from which of the following pathogens?

Quizplus · Accepted Answer

Eductional Objective: Patients with advanced HIV and low CD4 counts are at risk for opportunistic infections and require antimicrobial prophylaxis. Pneumocystis jiroveci pneumonia prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMX) is indicated when CD4 count is <200/mm³.

A 46-Year-Old Woman Comes to the Office to Be Tested