Introduction
Chronic norovirus (NoV) in immunocompromised individuals is associated with substantial morbidity and mortality, yet effective treatment options are limited [1]. Emerging evidence suggests that the intestinal microbiome plays a role in NoV pathogenesis and susceptibility to infection [2–4]. Given its proven efficacy in treating recurrent Clostridioides difficile infection, faecal microbiota transplant (FMT) is being evaluated for an expanding range of applications, including chronic NoV, with studies demonstrating safety in immunocompromised individuals [5].
However, outcomes have been variable. A 2017 case series reported no benefit from FMT for chronic NoV in a 32-year-old female with common variable immunodeficiency and a 65-year-old female with chronic lymphocytic leukaemia (CLL) [6]. Conversely, the first documented successful use of FMT for chronic NoV was reported in 2020 in a 68-year-old female organ-transplant recipient, who experienced complete symptom resolution and viral clearance following colonoscopic FMT [7]. More recently, a retrospective case series reported four additional successful cases of FMT for chronic NoV in immunocompromised patients, including a patient who achieved symptomatic response despite persistent viral shedding [8].
Here, we describe the case of an immunocompromised patient with debilitating chronic NoV infection who, despite successful donor microbiota engraftment after FMT, failed to achieve symptomatic improvement or viral clearance.
