Winnipeg's virology laboratory is playing a leading role in the swine flu outbreak that has been blamed for several deaths in Mexico.

The National Microbiology lab, located on Arlington Street in downtown Winnipeg, has found the 16 positive cases among specimens sent from Mexico for testing. The U.S. Centers for Disease Control have found seven positives.

About a dozen samples taken from victims in Mexico showed the virus had a genetic structure identical to that of a virus found in California earlier this week. World Health Organization spokesperson Gregory Hartl said his agency needs to determine whether the outbreaks constitute an international public health threat.

The Mexican government says 16 people who died have been confirmed as having had the new swine flu strain, and laboratories are testing samples from 44 other people who died.

Nearly 1,000 people across Mexico are sick with suspected cases of the flu, and schools in Mexico City were closed Friday to try to contain its spread.

To date, there have been no reported cases of severe respiratory illness in Manitoba associated with travel in Mexico or the southern United States, the office of Manitoba's chief provincial public health officer stated in a news release issued Friday afternoon.

Any individuals who currently have symptoms of a severe respiratory illness (fever, new or increasing cough or shortness of breath) should contact their health-care provider, stated the release. A travel history should be provided to the health-care provider.

For up-to-date information, visit the government website www.gov.mb.ca/health/publichealth. For health questions or more information on respiratory illness, Manitobans can phone Health Links at 788-8200 or toll free at 1-888-315-9257.