Research Interests

Characterization of novel enteric viruses

Our laboratory is actively pursuing the identification of novel viruses that may be causal agents of human diarrhea. Diarrhea is the 3rd leading infectious cause of death in the world, with ~40% of all cases of unknown etiology. Application of microarray and high throughput sequencing strategies have lead to the identification of multiple novel viruses in stool specimens. These include members of the families Astroviridae, Picornaviridae, Parvoviridae and Nodaviridae. For example, we have recently identified 7 novel members of the astrovirus family (Astroviruses MLB1, MLB2, MLB3, VA1, VA2, VA3 and VA4).

Of course detection of a virus in stool does not necessarily mean it is a human pathogen. We are working to answer questions such as: Do these novel viruses cause human diarrhea? Do they cause disease elsewhere but are shed in stool? In support of this hypothesis, we recently detected AstV-MLB2 in the serum of a child with febrile disease, suggesting that astroviruses can disseminate outside the GI tract. Other studies have identified AstV-VA1 in brain tissue of encephalitis patients. To address these questions, we have developed the first culture system for AstV-VA1 and further demonstrated that neural cells can support infection by astroviruses. Ongoing studies aim to fulfill Koch's postulates and to define mechanisms of pathogenesis and immune control.