A review on various attempts for in vitro propagation of human Norovirus

Abstract

Human noroviruses (HuNoV) are recognized as the primary cause for non-bacterial acute gastroenteritis. The HuNoV outbreak was firstly identified at Norwalk, Ohio and formerly known as 'winter vomiting disease' due to the illness frequently strikes during winter season. Infection of HuNoV is estimated to affects all age groups in both developed and developing country, by presenting symptoms such as nausea, vomiting, diarrhea and low-grade fever. There are approximately seven genogroups of noroviruses have been identified in which genogroup II.4 is the dominant HuNoV causing disease to human. Despite their significant impact on the economic and health burden, noroviruses remain to be poorly characterized RNA virus due to the lack of reproducible in vitro culture system for the HuNoV propagation, thus hampering understanding of its pathogenesis. Several approaches including the cultivation trials and the discovery of murine Norovirus (MuNoV) as the model system have expanded our knowledge in Norovirus biology and life cycle. However, to date there are no reliable culture system for HuNoV has been reported. The development of 3D co-culture system has shown a promising future as the improvised system that can be utilized not only for HuNoV cultivation, but also to other viruses. In this review, various attempts to cultivate the HuNoV are discussed to emphasise the future strategy in obtaining reproducible culture system. This review aims to find the gaps in the search of a reliable and reproducible propagation system thus enhancing the understanding on HuNoV biology and pathogenesis for future development of accurate detection method and vaccine production.