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PJP Breakthrough Non-Adherence — SCE Infectious Diseases MCQ

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EasyHIV MedicinePJP Breakthrough Non-AdherenceSCE Infectious Diseases

A 35-year-old man with HIV on ART develops a first episode of Pneumocystis jirovecii pneumonia despite being on Co-trimoxazole prophylaxis 960 mg daily. His CD4 is 150 cells/µL. What is the most common reason for PJP breakthrough on prophylaxis?

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Correct answer: D — Non-adherence to Co-trimoxazole — this is by far the most common reason for PJP breakthrough; true Co-trimoxazole-resistant PJP is extremely rare

PJP breakthrough on Co-trimoxazole prophylaxis is almost always due to non-adherence (missed doses, drug holidays). True Co-trimoxazole-resistant PJP (via DHPS mutations) is described but remains rare. Non-adherence should be addressed sensitively: explore barriers (side effects, pill burden, mental health, forgetfulness), simplify the regimen if possible, and consider directly observed therapy. If genuine Co-trimoxazole intolerance is the issue, alternative prophylaxis (Dapsone, Atovaquone, nebulised Pentamidine) should be prescribed.

Reference: BHIVA 2022 – OI guidelines; Cochrane 2019 – PJP prophylaxis