"It's a potential pandemic because it is infecting people." said Margaret Chan,the Director-General of the World Health Organization (WHO), about the unknown and strange flu that has killed at least 149 people in Mexico and may have infected up to a thousand.

The alarm is also coming from the U.S., where the virus has infected height people. The Center for Disease Control and Prevention (CDC) has warned that the spread of the virus appears to be out of control.

"Be prepared for the worst. The situation is very serious and we are very concerned, and we do not know if we can contain the spread of this virus" said the director of CDC's Public Health, Anne Schuchat.