CMV encephalitis in an immune-competent patient

After being admitted to hospital with atypical chest pain, a 61-year-old woman was noted to become lethargic and confused. She also developed global dysphasia. MRI was suggestive of encephalitis, and lumbar puncture was positive for cytomegalovirus (CMV) PCR. The patient was treated with intravenous ganciclovir and subsequent oral valganciclovir and she gradually made a reasonable recovery. While this infection is usually closely linked to immunosuppression, the patient was found to be HIV negative, and was not on any immunosuppressive therapy. Going through the patient's medical history revealed two possible risk factors which might have led to the development of CMV encephalitis: immunosuppression secondary to underlying poorly controlled diabetes mellitus; and previous admission to the intensive care unit which might have lead to CMV reactivation.