iTEM Solution Virology - Automated virus detection and identification via digital TEM image analysis

Gastroenteritis viruses
Viruses cause epidemic outbreaks such as the ”winter vomiting disease”  in many countries every year. Detecting and identifying of the known gastroenteritis viruses and other unknown viruses have all become of critical global interest.
Identification of viruses with PCR (Polymerase Chain Reaction) and ELISA (Enzyme-Linked Immunosorbent Assay) can be troublesome due to frequent virus mutation rates, spurred by the hundreds of millions of new infections occurring every year. This problem can be avoided by visually identifying specific virus structures in TEM images. However, conventional TEM analysis is manual and relies heavily on specialists with extensive experience to be able to diagnose quickly and reliably. These persons can identify viruses due to their morphology (shape, size) within minutes irrespective of the virus in question. The problem is that the TEM-based method requires experienced virologists. Hospitals and other diagnostic centers such as national centers for infectious disease control, however, need to have an objective, automatic method for detecting and identifying these viruses.

Automated virus identification
iTEM Solution Virology fulfills the various requirements for such an automated virus identification and analysis system for differentiating the four different types of viruses responsible for typical gastrointestinal diseases (Astrovirus, Novovirus, Adenovirus, and Rotavirus) with high identification accuracy. Standard negative staining protocols guarantee completion of TEM sample preparation in less than five minutes. This means that it takes only a few minutes to prepare samples of patients potentially infected with gastro viruses and observe them in the TEM. The iTEM software controls all hardware components like microscope, motorized stage and TEM camera and guarantees simple and fast image acquisition. As Astrovirus and Norovirus are of similar size, as well as Adenovirus and Rotavirus are, they can hence not be distinguished between solely based on sizes. Furthermore, TEM images have a highly structured background and the distinguishing texture features are close to the resolution limits. Therefore a robust differentiation of viruses is only possible by analyzing structural features on the surface of the virus. The virus identification software implemented in iTEM Solution Virology is based on an extensive set of structural surface features, derived from virus particles detected. iTEM Solution Virology contains information of structural features of various virus types drawn from sample images of representative viruses. This information is used to automatically identify a virus in the TEM image.  The analytical findings are presented in a written report along with primary analytical data in a format compatible with standard software.