Let me confess something straight off the stethoscope:
HIV is not that one-page topic we all tried to cram the night before our MBBS virology viva. It’s a full-blown metabolic, infectious, oncologic, and neurologic minefield.
And when that CD4 count dips below 200, we start rolling out the red carpet for the unwanted guests — the AIDS-defining illnesses.
To make sense of this alphabet soup of opportunistic invaders, I give you a mnemonic that’s as shamelessly long as the ward list on Monday morning:
AIDS-Defining Conditions Mnemonic: “O.P.P.O.R.T.U.N.I.S.T.S.”
| Letter | Condition | Clinical Insight |
|---|---|---|
| O | Oesophageal Candidiasis | Oral thrush is the appetizer; odynophagia = it’s hit the esophagus. 🍞 |
| P | Pneumocystis jirovecii Pneumonia (PJP) | Dry cough + hypoxia + ground-glass on CT. A classic. Needs TMP-SMX and oxygen. 🫁 |
| P | Progressive Multifocal Leukoencephalopathy (PML) | Caused by JC virus. Think demyelination + focal neuro deficits = neurology panic. 🧠 |
| O | Other Mycobacteria (MAC, TB) | Disseminated MAC shows up with pancytopenia, weight loss, and a vengeance. 🧬 |
| R | Retinitis (CMV) | Floaters, visual field loss — Dr. Bilal Chaudhary calls it “the fundus of doom.” 👁️ |
| T | Toxoplasmosis (CNS) | Ring-enhancing lesions on MRI. From cats, not textbooks. Treat with pyrimethamine. 🐱 |
| U | Ulcerating Herpes Simplex (Chronic) | Painful >1-month ulcers = not your average HSV flare. Biopsy if unsure. 😬 |
| N | Non-Hodgkin Lymphoma (High-grade B-cell) | Aggressive, extranodal, often CNS. Not your grandma’s lymphoma. 🧬 |
| I | Invasive Cervical Cancer | HIV speeds up HPV’s career path. Regular Pap smears = a must. 🎯 |
| S | Sarcoma (Kaposi’s) | Purple skin lesions, mucosal spots. Remember, it’s HHV-8’s signature move. 💜 |
| T | Tuberculosis (Extra-pulmonary or disseminated) | In Pakistan? Just assume it’s TB until proven otherwise. Dr. Basit Khan agrees. 🧫 |
| S | Sepsis (Recurrent Bacterial Infections) | Pneumococcus, Salmonella, and friends — frequent flyers in advanced HIV. 🌡️ |
🧑⚕️ A Real Case from Remote Zehri, Balochistan
A 36-year-old man from Zehri presented to our CCU with dry cough, fever, and desaturation despite a clear chest X-ray.
CT showed diffuse ground-glass opacities, and I knew right away: PJP.
CD4? 98. HIV? Positive.
We treated him with IV TMP-SMX and steroids, and started ART after stabilization.
And yes — it took three rounds of convincing to get Dr. Imran Baloch to believe the ECG changes weren’t cardiac. (Old habits die hard, even in HIV patients.)
📚 Exam Tip for FCPS/MRCP/PLAB Survivors
You don’t need to memorize the whole CDC list, just recognize the big-ticket OIs and malignancies.
CD4 correlation matters:
- <200: PJP, Candidiasis
- <100: Toxoplasma, Cryptococcus, CMV
- <50: MAC, PML, CMV Retinitis
And yes, always screen for TB — even if the patient came in for diarrhea.
Here’s a quick way to memorize the CD4 count and associated AIDS-defining conditions:
CD < 100 Century
- Cerebral Toxoplasmosis
- Cryptococcal meningitis
- Cryptosporidiosis (watery diarrhea)
- Candida (esophagitis)
- Cowdry A esophagitis (HSV 1)
CD < 50 MAC and Cheese
- Mycobacterium Avium Complex
- CMV (Retinitis, Colitis)
I hope that you find this medical useful in your studies/clinical practice. Happy learning! 🙂
Written with clinical caffeine, exam PTSD, and heartfelt experience by:
Dr. Aurangzaib Qambrani
MBBS | PLAB | MRCP-UK
General Medicine, Gastroenterology & CCU
Sheikh Khalifa Bin Zayed Hospital, Quetta 🏥
