The Malaysian Ministry of Health reported the H7N9 case was an "imported" case of avian flu and the virus has not been detected in poultry in Malaysia.
Human infections with a new H7N9 virus were first reported in China last March. Since that time, 337 cases had been detected in China as of Tuesday. Most H7N9 infections are believed to result from exposure to infected poultry or contaminated environments. No evidence of sustained, ongoing person-to-person spread of H7N9 has been found, the Health Ministry said.
The Centers for Disease Control and Prevention in Atlanta said the new H7N9 virus has not been detected in people or birds in the United States.
"The detection of H7N9 in a traveler from China to Malaysia does not change the risk assessment for this virus. The most important factor in the public health risk assessment is the transmissibility of the virus. There is no evidence of sustained, ongoing person-to-person spread of H7N9," the CDC said in a statement.
However, the Malaysia case underscores the importance of international surveillance for H7N9 and other influenza viruses with pandemic potential, the CDC said.
"H7N9 also might spread to poultry in neighboring countries and human cases associated with poultry exposure also may be detected in those neighboring countries. Most concerning about this situation is the possibility that this virus could gain the ability to spread easily and sustainably among people, triggering a global outbreak of disease or pandemic," the CDC said.
"The CDC is following the H7N9 situation closely and coordinating with domestic and international partners. The U.S. government has been providing funding to support international surveillance for H7N9 and other influenza viruses with pandemic potential."