Calicivirus, schmalicivirus

I mentioned previously that a new virus had been found that's associated with prostate cancer. Several ongoing studies are finding tons of new species of microbes, and we're learning more about the diversity that is around us every day. And though most of these newly-discovered organisms won't harm us, some just might.

A new study (summarized here points to a calicivirus (genus Vesivirus, a relative of the Norovirus that has gotten much attention recently as the cause of gastroenteritis on cruise ships) as a potential cause of human illness. Vesivirus has an oceanic reservoir and has been previously found to infect fish, seals, shellfish, swine, cattle, and primates, but it was thought this infection--and especially disease--was rare in humans. Maybe not.

In the paper (reference below), investigators examined sera from blood donors and did enzyme assays of the blood to detect antibodies to the Vesivirus, as well as used several different nucleic acid methods to detect viral RNA in the blood. They make a case for higher seroprevalence to the virus in persons with elevated ALT (alanine aminotransferase, an enzyme used to test whether the liver is damaged. Liver damage or disease-->high ALT), but it's a bit thin. They also found RNA specific to Vesivirus in several different sera, suggesting viral presence in the blood (viremia). When they sequenced these fragments, they were found to be close to viruses found in the ocean reservoir--so does this mean that all the people infected acquired it from the ocean? (Or from ocean animals--shellfish, etc.) Is it circulating in some unknown reservoir apart from oceanic ecosystems? Does it actually play any role in liver pathology in humans?

Dunno the answers to any of those--but it's another one of those areas to keep an eye on.

Reference:

Smith AW et al. 2006. Vesivirus viremia and seroprevalence in humans. J Medical Virology. 78:693-01.