Abstract Title
Norovirus and Sapovirus Associated Chronic Diarrhea in SOT: Does Viral Load Correlate with Severity of Symptoms?
Presenter
Varalika Tyagi, University of Alberta
Co-Author(s)
'- Varalika Tyagi (1)
- Dr. Judy Qiu (2,3,4)
- Dr. Linnet Immaraj (2)
- Dr Emily Christie (1)
- Dr Kieran Halloran (1)
- Dr Carlos Cervera (1,4)
- Dr. Xiao-Li Pang (2,3)
- Dr. Dima Kabbani (1,4)
(1) Department of Medicine, University of Alberta, Edmonton, AB, Canada
(2) Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, Canada
(3) Alberta Precision Laboratory, Edmonton, AB, Canada
(4) Li Ka Shing Institute of Virology Edmonton, AB, Canada
Abstract Category
Epidemology
Abstract
Norovirus (NoV) and Sapovirus (SapV) in solid organ transplant recipients (SOTRs) are highly prevalent and cause chronic diarrhea and prolonged viral shedding. This study aims to evaluate the relationship between clinical severity and stool NoV/SapV-viral load (VL), and clinical and virologic response to different therapeutics.
Single center prospective study of adult (>18) SOTRs diagnosed with NoV or SapV. Stool samples were collected at regular intervals and participants' initial clinical samples were also tested. RNA extracts were prepared from 10% weighted-stool samples and subjected to RT-PCR to obtain cDNA (complementary DNA), and quantified using digital PCR (dPCR) assays. Total viral copies per reaction were calculated and converted per gram of stool for each sample. Clinical assessments were performed through questionnaires and chart review. Patients are followed for up to 2 years.
Since November 2023, 8 SOTRs (4 lungs, 3 kidney, 1 liver) were enrolled and provided at least one stool sample to date, median age 58.5, 88% M, with the following viruses: NoV genotype(G) GI (1), NoV GII (5) and SapV (2). Cohort characteristics are presented in table 1. Diarrhea lasting >14 days was seen in 6/8 SOTRs. Nausea/vomiting was seen in 4/8 SOTRs. Treatment included oral immunoglobulin 3/8, cholestyramine 1/8, modification in immunosuppression 6/8, antimotility 6/8, intravenous hydration 5/8. Five SOTRs required hospitalization. In the 2 SOTRs with SapV, symptoms resolved between 1-1.5 months, and follow-up VL in stool was negative. In NoV SOTRs, stool VL ranged from 1.05 x 10^6 to 2.05 x 10^10 copies/gram at enrollment and diarrhea lasted from 5 days -14 months, with NoV remaining positive in stools despite improvement of symptoms in 5/6 that had follow up stool samples. Figure shows VL of NoV in 6 SOTRs.
Preliminary data suggest a high burden of gastrointestinal symptoms and viral shedding in SOTRs with NoV. Continued enrollment, sample collection and sample testing will provide insight into the relationship between stool VL, virus type and clinical symptoms.
Single center prospective study of adult (>18) SOTRs diagnosed with NoV or SapV. Stool samples were collected at regular intervals and participants' initial clinical samples were also tested. RNA extracts were prepared from 10% weighted-stool samples and subjected to RT-PCR to obtain cDNA (complementary DNA), and quantified using digital PCR (dPCR) assays. Total viral copies per reaction were calculated and converted per gram of stool for each sample. Clinical assessments were performed through questionnaires and chart review. Patients are followed for up to 2 years.
Since November 2023, 8 SOTRs (4 lungs, 3 kidney, 1 liver) were enrolled and provided at least one stool sample to date, median age 58.5, 88% M, with the following viruses: NoV genotype(G) GI (1), NoV GII (5) and SapV (2). Cohort characteristics are presented in table 1. Diarrhea lasting >14 days was seen in 6/8 SOTRs. Nausea/vomiting was seen in 4/8 SOTRs. Treatment included oral immunoglobulin 3/8, cholestyramine 1/8, modification in immunosuppression 6/8, antimotility 6/8, intravenous hydration 5/8. Five SOTRs required hospitalization. In the 2 SOTRs with SapV, symptoms resolved between 1-1.5 months, and follow-up VL in stool was negative. In NoV SOTRs, stool VL ranged from 1.05 x 10^6 to 2.05 x 10^10 copies/gram at enrollment and diarrhea lasted from 5 days -14 months, with NoV remaining positive in stools despite improvement of symptoms in 5/6 that had follow up stool samples. Figure shows VL of NoV in 6 SOTRs.
Preliminary data suggest a high burden of gastrointestinal symptoms and viral shedding in SOTRs with NoV. Continued enrollment, sample collection and sample testing will provide insight into the relationship between stool VL, virus type and clinical symptoms.