Pandemic flu strain at our back door with Mexico?
Scott McPherson
in Politics and government, influenza and infectious diseases
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Same strain of swine flu found in Mexico, US.
The "Mexican flu" has taken a huge leap in the American press today, with everyone, including the Drudge Report, headlining the outbreak. In fact, the Drudge headline trumpets Outbreak!on its front page. The link is to a Breitbart.com story from French news service AFP of this morning.
This is not trivial, nor is it something that is being overblown. In a matter of days, this report- starting with the curious report of two San Diego-area youths who contracted swine flu in March -- has now blown up into a full-fledged crisis Down South.
So in a matter of days -- DAYS! -- we have gone from Zero to:
1. Novel strain of influenza
2. Suspected human-to-human transmission (see below)
3. No immunity in the general population
4. Only one continent (not for long, I fear).
We do not know its virulence. We do not know its exact genetic makeup other than it is a fusion of European and Asian avian and swine and human genes. But we do know that it may have passed under our surveillance net as an "untyped Influenza A strain," only to be revealed by going back and re-testing the samples (read below).
Earlier today, Breitbart/AFP reported:
The government of Mexico City said Friday it was launching a massive vaccination campaign against swine flu, after authorities said they were probing 45 deaths and 943 possible infections from the virus. (bold mine)
Reuters has weighed in with a chilling story of the seven confirmed US swine flu infections. Excerpts below:
In the United States, the CDC reported the new strain of swine flu on Tuesday in a boy and a girl from California's two southernmost counties.
Now, five more cases have been found via normal surveillance for seasonal influenza. None of the patients, whose symptoms closely resembled seasonal flu, had any direct contact with pigs.
Two of the new cases were among 16-year-olds at the same school in San Antonio "and there's a father-daughter pair in California," Schuchat said. The boy whose case was reported on Tuesday had flown to Dallas, but the CDC has found no links to the other Texas cases.
The agency will issue daily updates at http://www.cdc.gov/flu/swine/investigation.htm.
HUMAN TO HUMAN
"We believe at this point that human-to-human spread is occurring," Schuchat said. "That's unusual. We don't know yet how widely it is spreading ... We are also working with international partners to understand what is occurring in other parts of the world."
The CDC's Dr. Nancy Cox said virus samples from the seven appear to carry genes from swine flu, avian flu and human flu viruses from North America, Europe and Asia. (bold mine)
"We haven't seen this strain before, but we hadn't been looking as intensively as we have," Schuchat said. "It's very possible that this is something new that hasn't been happening before."
Surveillance for and scrutiny of influenza has been stepped up since 2003, when H5N1 bird flu reappeared in Asia. Experts fear this strain, or another strain, could spark a pandemic that could kill millions.
The influenza A strain is an H1N1, the same subtype as one of the seasonal flu viruses now circulating. Now that the normal influenza season is waning, it may be easier to spot cases of the new swine flu, Schuchat said.
The CDC is asking doctors to think about the possibility of swine flu when patients appear with flu-like symptoms, to take a sample and send it to state health officials or the CDC for testing.
Cox said the CDC is already preparing a vaccine against the new strain, just in case.
"This is standard operating procedure," he said.
A vaccine will take months. It would be very interesting to see if the existing vaccine makers can quickly turn around and begin making enough swine H1N1 vaccine to do any good.
The best article I have seen to date is from MSNBC, so I include excerpts here for you to read and get caught up.
Deadly outbreak in Mexico caused by swine flu
All 7 U.S. victims recovered but more cases expected; source a mystery msnbc.com news services updated 11:25 a.m. ET, Fri., April 24, 2009
The unique strain of swine flu found in seven people in California in Texas has been connected to the deadly flu that has broken out in Mexico, killing as many as 60 people, NBC News has confirmed. (bold mine)
The strain has never been seen before and is raising fears of a possible pandemic.
The World Health Organization said it was concerned at what it called 800 "influenza-like" cases in Mexico, and also about the confirmed outbreak of a new strain of swine flu in the United States.
Mexico canceled classes for millions of children in its sprawling capital city and surrounding area on Friday after authorities noticed a higher number of flu-like deaths than normal in recent weeks.
"It is a virus that mutated from pigs and then at some point was transmitted to humans," Health Minister Jose Angel Cordova told the Televisa network.
He put the death toll at 16 confirmed cases and dozens of other suspected deaths. WHO estimates about 60 people have died in the country.
U.S. health experts said Thursday they expect to find more cases of the swine flu as they check people who had contact with seven California and Texas residents diagnosed with the illness.
All of the seven U.S. victims recovered from the flu that combines pig, bird and human viruses in a way that researchers have not seen before, the U.S. Centers for Disease Control and Prevention said.
The cases are a growing medical mystery because it's unclear how they caught the virus. The CDC said none of the seven people were in contact with pigs, which is how people usually catch swine flu. And only a few were in contact with each other.
Still, health officials said it's not a cause for public alarm: The five in California and two in Texas all recovered, only one person was hospitalized and testing indicates some mainstream antiviral medications seem to work against the virus.
Dr. Anne Schuchat of the CDC said officials believe it can spread human-to-human, which is unusual for a swine flu virus.
The CDC is checking people who have been in contact with the seven confirmed cases, who all became ill between late March and mid-April.
Because of intensive searching, it's likely health officials will find additional cases, said Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases.
Unique combo virus
CDC officials detected a virus with a unique combination of gene segments that have not been seen in people or pigs before. The bug contains human virus, avian virus from North America and pig viruses from North America, Europe and Asia.
Health officials have seen mixes of bird, pig and human virus before, but never such an intercontinental combination with more than one pig virus in the mix.
Scientists keep a close eye on flu viruses that emerge from pigs. The animals are considered particularly susceptible to both avian and human viruses and a likely place where the kind of genetic reassortment can take place that might lead to a new form of pandemic flu, said Dr. John Treanor, an infectious disease specialist at the University of Rochester Medical Center.
The virus may be something completely new, or it may have been around for a while but was only detected now because of improved lab testing and disease surveillance, CDC officials said.
The virus was first detected in two children in southern California — a 10-year-old boy in San Diego County and a 9-year-old girl in neighboring Imperial County.
The cases were detected under unusual circumstances. One was seen at a Navy clinic that participates in a specialized disease detection network, and the other was caught through a specialized surveillance system set up in border communities, CDC officials said.
On Thursday, investigators said they had discovered five more cases. That includes a father and his teenage daughter in San Diego County, a 41-year-old woman in Imperial County who was the only person hospitalized, and two 16-year-old boys who are friends and live in Guadalupe County, Texas, near San Antonio.
Puzzling cases
The Texas cases are especially puzzling. One of the California cases — the 10-year-old boy — traveled to Texas early this month, but that was to Dallas, about 270 miles northeast of San Antonio. He did not travel to the San Antonio area, Schuchat said.
The two 16-year-olds had not traveled recently, Texas health officials said.
The swine flu's symptoms are like those of the regular flu, mostly involving fever, cough and sore throat, though some of the seven also experienced vomiting and diarrhea.
CDC are not calling it an outbreak, a term that suggests ongoing illnesses. It's not known if anyone is getting sick from the virus right now, CDC officials said.
It's also not known if the seasonal flu vaccine that Americans got last fall and early this year protects against this type of virus. People should wash their hands and take other customary precautions, CDC officials said.
The Associated Press and Reuters contributed to this report.
URL: http://www.msnbc.msn.com/id/30386163/
And the always-good Canadian Pres has offered up its take:
Swine flu cases in US, mystery ailment in Mexico have experts scrambling
Laboratories in Atlanta and Winnipeg are looking at clinical specimens trying to determine if the mounting number of human cases of swine flu - seven and counting - in California and Texas, and an unusual explosion of severe respiratory illnesses in Mexico are pieces of the same puzzle or confusing coincidences.
Even on its own the human infections with swine flu viruses are significant enough to have experts wondering whether the world is watching the start of a flu pandemic.
But official pronouncements are being crafted with caution by authorities, who remember all too well the 1976 swine flu scare - a feared pandemic that didn't materialize.
The World Health Organization, which has been monitoring the situation, said at this point it does not believe the threat of a pandemic - the first since the 1968 Hong Kong flu - has risen.
"We would not see any evidence yet for this being a phase change," said WHO spokesman Gregory Hartl, referring to the organization's six step pandemic alert scale. The world is currently at phase 3 - occasional human cases with a novel flu virus - because of ongoing sporadic human infections with the H5N1 avian flu virus.
"We never want to overestimate or underestimate something, so we're following it closely," Hartl said from Geneva. "But as of the moment we see no evidence to change the global pandemic phase."
The U.S. Centers for Disease Control, which earlier in the week revealed they had found two human cases of swine flu, announced Thursday that the number of confirmed cases has risen to seven. There are two clusters, a father-daughter pairing and two 16 year old boys who attended the same school.
Symptoms are similar to seasonal flu, though there are more reports of vomiting and diarrhea that is seen with regular flu. All of the cases have recovered, though one person required hospitalization. It appears none of the cases had contact with pigs.
"We believe at this point that human-to-human spread is occurring," said Dr. Anne Schuchat, director of the CDC's national centre for immunization and respiratory diseases. (bold mine)
"That's unusual. (Really? - Scott.) We don't know yet how widely it's spreading. And we certainly don't know the extent of the problem."
Genetic sequencing done to date reveals a seemingly unique influenza A virus of the H1N1 subtype made up of a distinctive mix of swine, bird and human flu virus genes. There have been no reports of this virus in pigs, said Dr. Marie Gramer, a swine flu expert with the University of Minnesota's college of veterinary medicine.
"It doesn't seem to be very similar to anything that is currently circulating, from what I have," said Gramer, who has an extensive library of swine flu virus isolates.
The CDC said they expect to confirm more cases in coming days as contacts of the cases are checked and doctors and clinics are put on notice the CDC wants samples of flu viruses that can't be identified by standard methods.
They also cautioned they can't currently tell if the events unfolding represent something new or something that happens occasionally but which has gone unnoticed in the past.
"We have improved and intensified influenza surveillance over the past few years. So it certainly is possible that events like this occurred in the past and we simply didn't detect them," said Dr. Nancy Cox, head of the CDC's influenza division.
The first of the known cases fell ill on March 28 and the most recent developed symptoms last Sunday. Most of the cases have been children or teenagers, though two are adults. Ages range from nine to 54 years. They live in and around San Diego and in San Antonio, Tex., cities that are nearly 3,000 kilometres apart. Except for the family pairing and the school mates, there don't appear to be links among the cases.
No infections with this virus have been found in Canada, Canadian authorities said.
Nor does it seem that any cases of an unusually severe respiratory illness plaguing parts of Mexico have turned up in this country, said Dr. Danielle Grondin, assistant deputy minister for the Public Health Agency of Canada.
One person from Ontario was ill after returning from Mexico but Grondin said it seemed unlikely the illness was related to the apparent outbreak, which is affecting mainly young, previously healthy adults. (bold mine)
Alerts that have been sent out to health providers and public health officials in Canada say 20 deaths have been associated with the outbreak, which seems to be centred around central Mexico and Mexico City.
Grondin said Canada would issue a travel advisory warning Canadians who plan to travel to Mexico of the problem, though it was not released Thursday.
And she said the National Microbiology Laboratory in Winnipeg is testing samples from Mexico looking for the cause or causes of the illnesses. Samples were also en route Thursday to the CDC's labs in Atlanta, Cox said.
Copyright © 2009 The Canadian Press. All rights reserved.
OK, you're all caught up! That's why you come here, right?
No word on whether or not Tamiflu helps this H1N1 variant. In light of the failure of Tamiflu against H1N1 in the past two seasons, I am not optimistic. But it can always be hoped that this hybrid currently ciurculating in Mexico and the American Southwest might not contain the Tamiflu-resistant gene.
At least not for now.
Everyone needs to pay very close attention to this rapidly-developing situation.
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