FRIDAY, Aug. 3 (HealthDay News) -- Only 29 human cases of a new strain of "swine" flu have been identified in two years, but the U.S. Centers for Disease Control and Prevention is making sure it's prepared should the H3N2 strain become more widespread.
"This virus is still principally a swine virus, but it doesn't seem to have onward spread. It's still not a human virus," Dr. Joseph Bresee, from the CDC's influenza division, stressed during a noon press conference Friday.
"Even so, a H3N2 candidate vaccine has been prepared and clinical trials are being planned for this year," he said.
The reason the CDC is concerned about this particular virus is that it contains an element seen in the pandemic 2009 swine flu strain, H1N1, which may make it more likely for the virus to spread from person-to-person.
All 29 cases were infected with strains of H3N2 "that contained the matrix (m) gene from the influenza A H1N1 pandemic virus," Bresee explained. "This 'm' gene may confer increased transmissibility to and among humans, compared with other variant influenzas viruses."
In addition, the virus appears to have become more active recently, the CDC said. "The virus was first detected in humans in July 2011, and since then there have been 29 total cases of H3N2 variant virus detected, including the 16 cases occurring in the last three weeks," Bresee said.
Of the 12 cases reported this week, 10 were from Ohio and one each came from Hawaii and Indiana, the CDC said.
According to Bresee, "29 cases of infection with this H3N2 virus since 2011 is a significant increase for these types of viruses that we have seen in recent years."
Flu viruses commonly circulate in pigs, Bresee noted. But they are generally different from those that spread to people. Sometimes these viruses can spread to people, however, which happens most often when someone comes into close conta
All rights reserved