Julianne R Brown1, Sunando Roy2, Helena Tutill2, Rachel Williams2, Judith Breuer3. 1. Microbiology, Virology and Infection Prevention and Control, Great Ormond Street Hospital for Children NHS Foundation Trust, UK. Electronic address: Julianne.brown@nhs.net. 2. Infection and Immunity, University College London, UK. 3. Microbiology, Virology and Infection Prevention and Control, Great Ormond Street Hospital for Children NHS Foundation Trust, UK; Infection and Immunity, University College London, UK.
Abstract
BACKGROUND: Norovirus causes chronic infections in immunocompromised patients with considerable associated morbidity. It is not known whether chronic infections involve super- or re-infections or relapses. OBJECTIVES: To retrospectively investigate whether longitudinal sampling in chronically infected patients demonstrates persistent infection with the same virus, or super- or re-infection. STUDY DESIGN: Norovirus full genomes were generated from 86 longitudinal samples from 25 paediatric patients. Consensus sequences were used for phylogenetic analysis and genotyping. RESULTS: Super-infections occurred in 17% of chronically infected patients who were continuously PCR positive; including two with mixed norovirus infections. The median duration of infection was 107days longer in those with super-infections; however this was not statistically significant. A third of patients with interrupted norovirus shedding continued to be infected with the same virus despite up to 2 months of PCR negative stools, classified as a relapse. The majority (67%) of patients with interrupted shedding were re-infected with a different genotype. CONCLUSIONS: Chronically infected patients who are continuously PCR positive are most likely to remain infected with the same virus; however super-infections do occur leading to mixed infection. Patients with interrupted shedding are likely to represent re-infection with a different genotype, however relapsing infections also occur. Our findings have implications for infection control as immunosuppressed patients remain susceptible to new norovirus infections despite current or recent infection and may continue to be infectious after norovirus is undetectable in stool. The relevance to children without co-morbidities remains to be determined.
BACKGROUND: Norovirus causes chronic infections in immunocompromised patients with considerable associated morbidity. It is not known whether chronic infections involve super- or re-infections or relapses. OBJECTIVES: To retrospectively investigate whether longitudinal sampling in chronically infectedpatients demonstrates persistent infection with the same virus, or super- or re-infection. STUDY DESIGN: Norovirus full genomes were generated from 86 longitudinal samples from 25 paediatric patients. Consensus sequences were used for phylogenetic analysis and genotyping. RESULTS:Super-infections occurred in 17% of chronically infectedpatients who were continuously PCR positive; including two with mixed norovirus infections. The median duration of infection was 107days longer in those with super-infections; however this was not statistically significant. A third of patients with interrupted norovirus shedding continued to be infected with the same virus despite up to 2 months of PCR negative stools, classified as a relapse. The majority (67%) of patients with interrupted shedding were re-infected with a different genotype. CONCLUSIONS:Chronically infectedpatients who are continuously PCR positive are most likely to remain infected with the same virus; however super-infections do occur leading to mixed infection. Patients with interrupted shedding are likely to represent re-infection with a different genotype, however relapsing infections also occur. Our findings have implications for infection control as immunosuppressed patients remain susceptible to new norovirus infections despite current or recent infection and may continue to be infectious after norovirus is undetectable in stool. The relevance to children without co-morbidities remains to be determined.
Authors: Li-An K Brown; Christopher Ruis; Ian Clark; Sunando Roy; Julianne R Brown; Adriana S Albuquerque; Smita Y Patel; Joanne Miller; Mohammed Yousuf Karim; Samir Dervisevic; Jennifer Moore; Charlotte A Williams; Juliana Cudini; Fernando Moreira; Penny Neild; Suranjith L Seneviratne; Sarita Workman; Christos Toumpanakis; Claire Atkinson; Siobhan O Burns; Judith Breuer; David M Lowe Journal: J Allergy Clin Immunol Date: 2019-08-13 Impact factor: 10.793
Authors: Louisa F Ludwig-Begall; Elisabetta Di Felice; Barbara Toffoli; Chiara Ceci; Barbara Di Martino; Fulvio Marsilio; Axel Mauroy; Etienne Thiry Journal: Viruses Date: 2021-05-02 Impact factor: 5.048