Unfortunately, it's a scenario that's becoming increasingly common on cruise ships. So common, in fact, that the National Institutes of Health's Western Regional Center of Excellence (RCE) for Biodefense and Emerging Infectious Diseases awarded a two-year $280,000 grant to a pair of University of Houston professors who are studying what has commonly been dubbed the "Cruise Ship Virus."
This RCE is part of a national network of 10 other centers that support research focused on countering threats from bioterror agents and emerging infectious diseases. Each is comprised of a consortium of universities and complementary research institutions serving a specific geographical region. UH and the Baylor College of Medicine (BCM) are part of region VI, encompassing institutions in Texas, New Mexico, Oklahoma, Arkansas and Louisiana.
The centers, located throughout the United States, are building and maintaining a strong scientific infrastructure to support multifaceted research and development activities that promote the next generation of therapeutics, vaccines and diagnostics for Category A, B and C pathogens posing threats as agents of bioterrorism.
The two faculty members from UH's Cullen College of Engineering ?Paul Ruchhoeft, assistant professor of electrical and computer engineering, and Richard Willson, professor of chemical engineering ?are working with Dr. Robert L. Atmar, associate professor of medicine, molecular virology and microbiology, from the Baylor College of Medicine to combat the Norwalk virus.
This insidious, highly infectious disease is an intestinal illness that causes nausea, diarrhea, vomiting and stomach cramps. The research conducted at UH and BCM may save a number of people from a vacation nightmar e through the creation of a quick, accurate test for the "Cruise Ship Virus." One of the difficulties in treating Norwalk is that it is very hard to diagnose with traditional methods.
"The current tests take a long time," Ruchhoeft said. "If we can build a diagnostic tool that mimics something like the pregnancy test in speed and ease of use, we could create a platform for rapid detection of this virus and other pathogens."
The tool Ruchhoeft and Willson are building will rely on the disease protein/antibody relationship that occurs in the human body. As with all diseases, when an individual is infected with the Norwalk virus, the human immune system creates antibody proteins that bond only with proteins that are specific to that disease.
Under Ruchhoeft and Willson's plan, a biological sample from a suspected Norwalk victim will be placed on a glass slide covered with Norwalk antibodies provided by BCM. An attempt will be made to wash away the sample, but if the virus is present in the sample, it will bond with the antibody and remain on the slide.
The next step of the test relies on retroreflectors, specially designed cubes that reflect light back to its point of origin, that are used on the macroscale for items such as reflective vests and lane markers on roads. Ruchhoeft, however, will create retroreflectors that measure just a few micrometers wide.
Three sides of the reflectors will be covered with reflective material and will be populated with the Norwalk antibody. These retroreflectors will be dispensed onto the slide. If Norwalk is present on the slide from the previous protein/antibody bond, the retroreflectors will bond with it. If not, they will all be washed away when the slide is rinsed.
An optical device will then shine a strong light on the slide. If, due to the protein/antibody bond, the retroreflectors remain on the slide, they will clearly reflect the light, indicating the p resence of Norwalk. If no light is reflected, then no protein/antibody bond has occurred and the patient does not have the Norwalk virus.
"This process may seem complicated, but it is actually much simpler than current tests for Norwalk," Ruchhoeft said. "By having the virus bridge the cube to the surface, you don't need to go through complex sample preparation steps, like extracting DNA, amplifying it and so forth. You could envision making a system work at a doctor's office or at an entry point to the cruise ship."
The ease with which Norwalk is spread makes it important to the field of biodefense, as well, which is a key point with the RCE helping to fund this research. According to Ruchhoeft, while the center is certainly interested in a more effective diagnostic tool for Norwalk, it foresees using this approach for other diseases, as well.
"If someone else has the antibody for other pathogens, then we can use it to coat the retroreflectors," Ruchhoeft said. "If we're successful in detecting the Norwalk virus, it opens up the possibility of creating a similar diagnostic tool for a variety of other infectious diseases."