Management of CMV encephalitis with persistent CSF CMV DNA in a patient with HIV: a case report of successful treatment with ganciclovir–foscarnet combination therapy

Cytomegalovirus (CMV) is a common opportunistic pathogen in immunocompromised individuals and can lead to significant mortality and morbidity via end-organ involvements. CMV related multiorgan involvement including encephalitis is rare and difficult to manage. We presented a case with multiorgan involvement of CMV including encephalitis, colitis, and pneumonia in a patient with HIV, in whom neurological symptoms worsened under ganciclovir monotherapy but responded to a combination therapy of ganciclovir and foscarnet. A 30-year-old male was admitted to the hospital with complaints of cough and shortness of breath. Anti-HIV test was found to be positive. CD4+ T-cell count was 4 cells/mm³. A chest CT scan revealed extensive ground-glass opacities, and CMV PCR was positive in the bronchoalveolar lavage. During follow-up, the patient developed diarrhea, dysarthria, and seizures. CMV viral inclusion bodies were identified in colon biopsy samples, and CSF CMV DNA was positive. Brain MRI findings were consistent with CMV encephalitis. Pulmonary and gastrointestinal symptoms improved with ganciclovir, but neurological symptoms worsened. Despite no detected ganciclovir resistance, foscarnet was added on day 16 due to persistent high CSF CMV DNA levels and worsening neurological status. On the second day of the combination therapy, his seizures ceased, neurological symptoms improved. On the second month, CSF CMV DNA levels become undeceteable and he was able to return to his normal daily life. Maintenance therapy with valganciclovir continued nine months until the patient’s CD4+ T-cell count exceeded 100 cells/mm³. This case underscores the potential benefits of ganciclovir–foscarnet combination therapy in patients with CMV encephalitis. It also highlights the role of serial CSF CMV DNA monitoring in guiding therapeutic decisions and assessing treatment response in severe cases. We suggest that ganciclovir-foscarnet combination therapy may offer a therapeutic advantage over monotherapy in treating CMV encephalitis, even in the absence of ganciclovir resistance.