"When scientists couldn't prove that CFS was linked to viruses, they moved on," said Klimas. "In the next seven to eight years, research was heavily focused on hormones and the autonomic nervous system. However, with the human genome project and all the advances in genetics, there are now new tools available to look for viruses."
One reason that the virus Chia has implicated in CFS may have been so hard to pin down is the fact that it does not appear in the blood. In light of this, Chia looked for the viral proteins in the stomach tissue itself.
"We looked for the viral proteins in stomach cells of patients with CFS and of patients without CFS, who served as controls," Chia said. "We found tons of patients with CFS who had the viral proteins."
And although about 20 percent of the control patients also tested positive for the virus, they had only a small amount of it in their tissue. In contrast, the stomach cells of patients with CFS were swarming with it.
Many researchers believe that enteroviruses are not the only cause of CFS.
"There are over 15 different pathogens contributing to CFS," said Kristin Loomis, president and executive director of the HHV-6 Foundation, which funds viral research. "Enteroviruses are one, HHV-6 is another, and Epstein-Barr virus is a third."
With so many different viruses, it may seem impossible to tackle the disease. However, certain antiviral drugs have already been developed that target specific viruses and can be used to treat certain groups of CFS patients.
In one example, doctors at Stanford University School of Medicine are using the antiviral drug valganciclovir to treat CFS -- with promising results so far.
And Chia believes that as long as other scientists in the field confirm his results, drugs to fight enteroviruses will be available within five years.
"However," Klimas warned, "there are not antiviral drugs to cover all viruses. … I think we should look at treatments that make the immune system stronger and less susceptible to viral infection."
There is hope for CFS patients, Chia believes, even if it comes 20 years too late.
"I think it's a good year for CFS," he said. "Federal agencies have recognized the severity of the disease. It has been brought to the public's attention by the media, and now it's the drug companies' turn to start developing antiviral medications."