# Late-Onset HSV-2 Encephalitis in a Kidney Transplant Recipient: A Rare Case Report

## TL;DR

A kidney transplant recipient developed HSV-2 encephalitis three years post-transplant and recovered after acyclovir treatment, highlighting the importance of early diagnosis and PCR testing.

## Contribution

This case report presents a rare late-onset HSV-2 encephalitis in a kidney transplant recipient and underscores the value of PCR diagnostics in atypical presentations.

## Key findings

- HSV-2 encephalitis occurred three years post-transplant in a kidney recipient.
- PCR testing of cerebrospinal fluid confirmed the diagnosis and guided effective treatment.
- The patient achieved full neurological recovery after acyclovir therapy.

## Abstract

Infections are an important cause of morbidity and mortality in renal transplant recipients. Among the viral pathogens encountered in this population, herpes simplex virus (HSV), a member of the Alphaherpesvirinae subfamily, has an important place. HSV type 2 infections in this immunosuppressed population are primarily due to viral reactivation. While HSV-2 frequently presents as genital herpes or remains asymptomatic, in rare cases, it can lead to severe neurological manifestations, such as encephalitis, particularly in the early post-transplant period with a reported mortality rate of up to 40%. We present the case of a 49-year-old male who, three years after kidney transplantation, developed acute neurological symptoms, including aphasia and disorientation. Polymerase chain reaction (PCR) analysis of cerebrospinal fluid (CSF) identified HSV-2 as the causative pathogen, enabling a swift and accurate diagnosis. The patient was promptly treated with intravenous acyclovir, adjusted for renal function, resulting in complete neurological recovery and subsequent negative follow-up CSF PCR results. This case emphasizes the vital role of PCR diagnostics as the gold standard for confirming viral encephalitis, particularly in immunosuppressed patients, where atypical presentations can complicate diagnosis. It also highlights the importance of considering HSV-2 encephalitis in the differential diagnosis even beyond the immediate post-transplant period. Early recognition and management, facilitated by the multidisciplinary approach, are critical for improving outcomes in this vulnerable patient population.