Background: GII. 4 is the predominant norovirus genotype worldwide. Challenge models involving humans have shown the association of human histo-blood group antigens (HBGAs) and susceptibility to infection with Norwalk virus (GI VSports手机版. 1 norovirus), but the association of HBGAs and infection with other noroviruses is based on results of epidemiological studies. We performed the first GII. 4 challenge study involving humans and prospectively evaluated the relationship between HBGAs and norovirus infection and associated illness. .

Methods: Forty healthy adults (23 secretors and 17 nonsecretors of HBGAs) were challenged with 5 10(4) reverse-transcription polymerase chain reaction (RT-PCR) units of GII. 4 norovirus. Subjects were assessed daily for clinical illness, and stool specimens were evaluated for norovirus by RT-PCR. Infection was defined by detection of norovirus and/or seroconversion to GII. 4 antibody V体育安卓版. .

Results: Of the 23 secretors, 16 (70%) were infected with norovirus, 13 (57%) became ill (characterized by vomiting and/or diarrhea), and 12 (52%) developed norovirus-associated illness. In contrast, only 1 nonsecretor (5. 9%) became ill, and another nonsecretor shed virus for a single day (P < . 001 for each variable, compared with secretors) V体育ios版. Infection occurred in secretors regardless of ABO blood group. Illness was mild to moderate in severity and lasted 1-3 days. .

Conclusions: Secretor status determined the susceptibility to norovirus GII. 4 challenge. This human challenge model should be useful for evaluating norovirus vaccines and antiviral agents. Clinical trials registration. NCT01322503 VSports最新版本. .