Any disease with average transmissibility < T c cannot cause sustained transmission within a population and will thus be limited to small outbreaks.
In spite of the substantial variation we observed within H5N1 and H7N9 subtypes, our results show that, statistically, isolates more transmissible in ferrets are more likely to be capable of sustained transmission in humans.
There hasn't been anything sustained, though, and I think there would be real advantages to starting a sustained transmission.
The WHO Pandemic Influenza Phases system requires evidence of sustained transmission between human beings in two distinct parts of the planet at the same time.
The World Health Organisation said it expected more infections in South Korea, but stressed that there was "no evidence of sustained transmission in the community".
Although isolated instances of person-to-person transmission appear to have occurred since 1997, sustained transmission has not been observed.
Phase 6, the highest level of pandemic alert, is characterized by widespread disease and sustained transmission of the virus between humans.
"There is absolutely no evidence of sustained transmission of avian influenza virus between people," Phyllis Kozarsky, a consultant to the centers on the migration of infectious diseases, said last week in a conference call with travel industry professionals.
However, recent detection of human cases with a local strain of ZIKV indicates there is sustained transmission of the virus within the region34, emphasizing a need for wildlife surveillance in this region.
What we know is that it is not common that there is sustained transmission in people.
"But I don't think we're going to have sustained transmission in the U.S., primarily because of our lifestyle.
