Wednesday, April 29, 2009

Swine Flu V: Sequence Analysis

Via ProMED-mail: sequence analysis indicates that swine flu may be entirely domestic and porcine, despite previous reports linking it to human and bird flus as well as Asian swine flu strains.

"...the NA and M genes are most closely related to corresponding genes from influenza viruses isolated in swine population in Eurasia."
However, the NA and M genes from 2 swine virus isolates from America are also closely related to the novel H1N1 virus (A/swine/Virginia/670/1987, A/swine/Virginia/67a/1987), if a reasonable nucleotide substitution rate is accepted. Thus, H1N1 from Mexico may be a swine flu virus strain of entirely American origin, possibly even of relatively ancient origin.

Tuesday, April 28, 2009

Swine Flu IV: The Return of the Typhoid Traveller

Via Healthmap on Twitter: ABC Australia reports on the search for fellow passengers of three New Zealander students with swine flu.

There are more updates on the pig farming connection, Israel's cases, Connecticut's suspected cases, and California's deaths and state of emergency in my twitter feed.

Monday, April 27, 2009

Swine Flu III: Mexico Timeline

Via Effect Measure by way of The Pump Handle: the blog Biosurveillance reports on Veratect's extensive timeline of swine flu in Mexico, starting with an incident in Canada on March 30th.

At Veratect, we operate two operations centers based in the United States (one in the Washington, DC area and one in Seattle, WA) that provide animal and human infectious disease event detection and tracking globally. Both operations centers are organizationally modeled after our National Weather Service using a distinct methodology inspired by the natural disaster and meteorology communities. Our analysts handle information in the native vernacular language and have been thoroughly trained in their discipline, which include cultural-specific interpretation of the information.
March 30
Veratect reported that a 47-year-old city attorney for Cornwall was hospitalized in a coma at Ottawa General Hospital following a recent trip to Mexico. Family members reported the individual voluntarily reported to the hospital after gradually feeling ill upon returning from his trip on 22 March.

Of special note are the pig farming connection on April 6th, the Semana Santa [Holy Week] connection under the heading "Large mass gatherings", and Veratect's new Twitter feed.

Sunday, April 26, 2009

Swine Flu II

Although no pigs have become ill and no patients have reported contact with pigs, the new swine/avian/human influenza mix coming out of Mexico has been dubbed "swine flu." Since Mexican health officials first admitted the problem on Thursday, swine flu has been detected in California, Texas, Kansas, New York City, and Nova Scotia. Suspected cases are currently under investigation in British Columbia, France, Spain, Israel, and New Zealand, mainly in tourists returning from Mexico. No fatalities have been reported outside of Mexico (where the case count now stands at approximately 1500 with over 80 fatalities).

The Associated Press reports that the WHO has declared the outbreak in North America to be a "public health emergency" with "pandemic potential."

The CDC has a page up summarizing the current investigation.

A ProMED poster notes that like this one, the Spanish Flu first appeared at the end of the flu season, but came back with a vengeance for the next one:

The 1st cases of that agent showed up in May 1918 in an army base in Kansas -- it went quiet over the summer -- and started ravaging the globe in early fall that year.

Also, someone is maintaining a Google map of the outbreak.

Friday, April 24, 2009

Swine-Bird Flu

Via an unnamed source: The BBC reports on a rash of deaths in Mexico from a new strain of flu with both swine and bird elements.

Fifty-seven people had died in Mexico City from flu-like symptoms, [WHO spokeswoman Fadela Chaib] said, and another three in San Luis Potosi in central Mexico. There are around 800 suspected cases, she said.
Health Minister Jose Angel Cordova said the virus had "mutated from pigs and then at some point was transmitted to humans".
The strain of flu had been confirmed in at least 16 deaths, with 44 others being tested, the government said.
It urged people to take preventative measures such as not shaking hands or sharing crockery.
In the US, experts say the seven people who fell ill across two states were suffering from a new form of swine flu that combined pig, bird and human viruses.
"This is the first time that we've seen an avian strain, two swine strains and a human strain," Dave Daigle, a spokesman for the CDC, told AFP.
The CDC said none of the seven victims had been in contact with pigs, which is how people usually catch swine flu.