It has been my own personal project to follow H5N1 for the last 3 years simply because it interests me. Attracted to this type of information like a magnet, I've been watching this relatively new influenza virus to see where it will go, how it will change itself, and possibly change our world. I have followed its country by country outbreaks, and watched for the important viral mutations such drug resistance or changes that allowed it to more specifically target mammals.
Keeping in mind at all times that we will be cleared impacted as HCW, as well as being members of our communities, and having families of our own to care for, I wanted to start the new year by opening a single focused pandemic thread that would also look at what we are doing nationally to prepare for a future pandemic. Is this the virus to spark the next pandemic? No one can answer that question. We can look back at the past to the last few pandemics, and in particular to the most devastating one in 1918, and extrapolate useful information about them, but we can not predict the future. We can only make comparisons with our situation now, and learn what worked to lessen morbidity and mortality in those past events. And, we can look at those other viruses, and compare them with what we are seeing now. For example, H5N1 is a Type A virus. We know that all pandemics are caused by Type A viruses. It is also an avian virus. The deadly 1918 virus, H1N1 was also an avian virus.
For this thread, as in the previous threads, I will be making use of news sources, scientific studies, govt bulletins such as the MMR, as well as flu forums and blogs devoted to this subject for my sources. Because press information, particularly the foreign press, is not always available for later access when I am looking back to check recent historical information, the use of these blogs and forums are important because archived information quoting the media and all other sources is always fully and easily available there with no worries about information disappearing or no longer being available. They also fully document their sources or I would not be using them.
With this link from Avian Flu Diary, a well researched source that I highly recommend, we can read the words of outgoing HHS Secretary Leavitt on our state of preparedness. Leavitt has done an admirable job during his tenure, but admits that there is much left to do.
A scant 33 months ago, I sent my first message about a race that HHS had just begun. As I said then, it was a race against a fast-moving virulent virus with the potential to cause an influenza pandemic. Since then, we have mobilized experts and resources across the country and around the world. I now send you this final message, as I look back at the unprecedented progress we have made in energizing a national pandemic influenza preparedness movement in those 33 months.
Today, many people mistakenly think influenza pandemics are a thing of the past, but influenza has struck hard in the era of modern medicine – much harder than most people realize. And it will strike again. Pandemics are hard things to talk about. When one discusses them in advance, it sounds alarmist. After a pandemic starts, no matter how much preparation has been done, it will be inadequate.
The interesting thing about this table, is Egypt reporting 17 cases this year but no deaths. Either they've figured out how to treat it better or there not reporting all the cases.
The interesting thing about this table, is Egypt reporting 17 cases this year but no deaths. Either they've figured out how to treat it better or there not reporting all the cases.
It's very interesting, indeed because the CFR has been running at over 60% for H5N1, and now this year, we have seen a whole new demographic in Egypt. These recent cases are all toddlers with mild cases of bird flu. The adults have been primarily young women under age 40, who continue to die despite treatment with Tamiflu. No one has yet figured out why we are seeing all of these infected little kids, and why they are surviving. This was all rather alarming news just before swine flu hit the news.
This major change in the age and prognosis of victims had prompted the WHO to send in a team to Egypt to try to find out why. This may not really be a good change despite the survival of the cases. Here are some posts written in early April discussing this. See posts near the bottom of that page. We do not have any answers yet, btw.
A five-year-old Egyptian girl has contracted the highly pathogenic bird flu virus after coming into contact with infected birds, the state news agency MENA reported on Sunday.
The case brings to 69 the number of people confirmed to have contracted the H5N1 avian influenza virus in Egypt, which has been hit harder than any another country outside Asia.
This is something I hoped that we would never see, swine flu in the country with the greatest number of H5N1 bird flu cases on the planet. It is alarming to think of this very transmissible virus loose in Indonesia where bird flu is endemic with a CFR of over 80% in that country. All it would take is for one person to be co-infected with both swine flu, and bird flu for a worse case scenario of viral reasssortment which could then produce a very transmissible and very virulent new virus.
Let us hope that she did not infect anyone else on that plane. Even better, let's hope that she tests negative.
A Dutch tourist arriving in Bali with flu-like symptoms was admitted to hospital in Denpasar for treatment, tempointeraktif.com reported Sunday.
Michele Van Dorssen, a Malaysia Airlines passenger, arrived Sunday from the Netherlands via Kuala Lumpur with a fever and nausea.
Fearing she was sick with the H1N1 strain of flu, officials at Ngurah Rai International Airport immediately took her to Sanglah Hospital in Denpasar.
“We're still examining her and waiting for the lab results, because [the H1N1 flu virus] has an incubation period of three to five days,” said the hospital's Dr. Ken Wirasandhi.
UPDATE
The Indonesians are saying that she tested negative.
...there is concern that the swine H1N1 is still silently spreading (see updated map), because the vast majority of cases are mild, and require enhanced surveillance for detection, although a simple influenza A test will be more predictive of swine flu as the seasonal flu season ends in the northern hemisphere.
The above announcement by the NY lab has been echoed across the country. The testing will be selective, and a complete picture of the H1N1 spread will be lacking. This focus on the more severe cases mimics confirmations in Mexico, where the lab confirmed cases significantly underestimates the level of infections.
The focus on severe cases increases the case fatality rate. In the US there have been three reported H1N1 deaths and there has also been a death in Alberta , Canada, raising concerns that the number of fatal infections will climb significantly over the near term.
The identity between H1N1 in Mexico and the US (as well as all other countries submitting sequence data - see list of isolates here), raises concerns that the silent spread will produce frequent co-infections between swine and seasonal H1N1. These co-infections can produce genetic exchanges between human and swine isolates via reassortment and recombination.
This type of rapid genetic evolution between human and swine H1N1 raises concerns that a more virulent H1N1 will emerge in the near term, and lead to a significant rise on severe cases in the fall, when the flu season begins in the northern hemisphere.
...flu trackers here have turned their attention to the Southern Hemisphere, where flu season is just taking off.
They will be watching to see whether the new virus that has sickened and killed in a dramatic sweep fizzles this summer - or learns a few tricks before possibly rebounding here next fall.
"There's an old saying about flu viruses," said Dr. Michael Greger, director of public health and animal agriculture at the Humane Society of the United States, "if you've seen one flu virus, you've seen one flu virus. Flu viruses are so unpredictable no one knows what they'll do."
Some scientists are more confident, however, postulating that the new flu this year may be circulating in what they call a "a herald wave" - the first pass the virus makes in this hemisphere. Previous pandemic strains percolated in just such a way in the spring before taking off worldwide in the fall, or later.
"This is a new virus and we are still learning how transmission occurs," said Dr. Fatima Dagwood of the CDC's swine-virus investigation team.
The microbe lacks a virulence factor which experts say was detected in all three pandemic strains of the 20th century. But others warn that the virus could acquire such a factor as it continues around the world.
It's possible the new H1N1 may acquire resistance to the antiviral drug Tamiflu, a problem that surfaced earlier this year with commonly circulating strains of H1N1. If Tamiflu resistance occurs, then a major weapon in the Strategic National Stockpile becomes useless.
Greger calls the new swine flu virus "a game changer" because it's a product of a triple species gene swap in pigs. Genes from human, bird and porcine flu viruses "reassorted" in pigs, from which the new pathogen emerged.
All other flu viruses linked to pandemics, Greger said, have had a bird source or were bird-human hybrids. The reassorted H1N1 is not only new to science. It's new to the human immune system.
"It took only one reassortment event to create the new H1N1," said Greger. He wonders how novel the new flu virus really is. "How many more are out there?"
I like this article for its great map of how H1N1 traveled to China, Hong Kong, and Taiwan.
The Chinese mainland reported its first suspected case of A(H1N1) Sunday and health authorities quarantined seven people who flew in from North America, raising fears of a possible outbreak.
A 30-year-old man surnamed Bao has tested positive for the H1N1 virus in Sichuan province but the Ministry of Health (MOH) has not confirmed the case. That may be because MOH is conducting further tests, an expert said.
Bao flew from St Louis in the US to Tokyo on Friday. He landed in Beijing from Tokyo on flight number NW029 on Saturday, and took the U8882 flight to Chengdu, capital of Sichuan province, the same day.
Guan Yi, a microbiologist with the University of Hong Kong is famous for his discovery of the animal that was harboring the SARS virus. He is also an expert on H5N1, bird flu, and a protege of the most famous influenza specialist of all, Robert G. Webster, Division of Virology, Department of Infectious Diseases, Memphis, Tennessee. He offers an informed opinion on H1N1 and H5N1.
"This virus has been around only a few months, it is very unstable ... and we know that its presence is dramatically increasing in human population, so the chance of it meeting with H5N1 is actually increased," Guan said in an interview on Tuesday
.
"Both H1N1 and H5N1 are unstable so the chances of them exchanging genetic material are higher, whereas a stable (seasonal flu) virus is less likely to take on genetic material."
While H1N1 appears to be mild so far with many infected people recovering even without treatment, the H5N1 has a mortality rate of between 60 to 70 percent.
Experts are fearful about the emergence of a hybrid which combines the killing power of the H5N1 with the efficient transmissibility of H1N1. H5N1 is believed to be endemic in countries like China, Indonesia, Vietnam and Egypt.
The presence of H1N1 in Thailand raises concerns of co-infections of H1N1 and H5N1. Such co-infections can transfer genetic information from one genome to another, via recombination or reassortment. The swine H1N1 has already acquired human H1N1 polymorphisms circulating in seasonal flu, and additional acquisitions could increase virulence.
Increased surveillance for H1N1 which the Egyptians seem to be terrified of, will increase surveillance of bird flu in the area.
Thus far, cases have been mostly tested if there is a poultry contact confirmed. There may be many more cases of H5N1 uncovered as a result.
The above comments describe the most recent confirmed H5N1 case in Egypt. Although the pace of confirmed cases has slowed in Egypt, local media reports continue to detail the hospitalization of suspect cases, although less than 1% of hospitalized cases are PCR confirmed for H5N1.
The low confirmation rate, coupled with mild symptoms, has raised concerns of silent spread of H5N1. The recent outbreak of swine H1N1 worldwide may allow the issue of H5N1 in asymptomatic cases, or those with lower viral loads, to be resolved.
In Egypt, H5N1 testing is limited to cases claiming poultry contact. However, if a swine contact was required for H1N1 swine testing, the initial positives in the United States would have gone undetected because none of the confirmed cases had a swine contact.
The H1N1 has led to enhance surveillance, although much of the testing has been limited to travelers originating in North America. However, the heightened awareness of H1N1 may lead to broader testing. Seasonal H1N1 and H3N2, as well as swine H1N1 and avian H5N1 will all give a positive on an influenza A test. Swine H1N1 and avian H5N1 however, will not sub-type with standard reagents, which are directed against human seasonal flu.
These swine H1N1 isolates are confirmed with additional tests that are specific for swine H1N1. However, H5N1 will also test negative on the swine H1N1 test, which will signal another serotype (or evolution of the swine H1N1) and require additional testing.
Swine H1N1 Outpaces Seasonal Flu In the United States
The spike in H1N1 swine cases created a backlog at the CDC, which could be seen in a map of confirmed and probable cases (see US map). The confirmatory testing was handed off to the state labs to eliminate the backlog, but soon state labs were acknowledging that the samples tested were the tip a very large iceberg, and future testing would target more serious cases.
This movement of swine H1N1 into the human population is cause for concern. The increase over seasonal flu may be driven by the avian PB2 gene in the swine isolate. Position 627 is E, which favors growth at the higher body temperature of birds. Seasonal flu has a K at position 627, which allows for more rapid replication at a lower temperature, which is consistent with the internal temperature of a human nose in the winter.
The presence of avian PB2 may offer a selective advantage over the summer, when seasonal flu falls to barely detectable levels. However, the swine H1N1 that moves south in the upcoming months will be growing under colder conditions, which may favor the acquisition of E627K though reassortment or recombination. This change could create a more virulent H1N1 in the fall in the northern hemisphere.
Thus, the swine H1N1 may be launching a two virus strategy. The H1N1 with avian PB2 will dominate in the northern hemisphere over the summer, while the H1N1 in the southern hemisphere will acquire E627K and establish dominance during the winter months.
Thus, the spread of H1N1 is in high gear, as WHO debates if a swine H1N1 is a swine H1N1 and if a pandemic at phase 6 is really at phase 6.
The spread of swine flu appears to be slower in Europe and Asia. Of course, they had some advance warning of what was coming, and isolated the first cases quickly.
We only found the first cases here as soon as we did because of unusual circumstances. One was seen at a Navy clinic that participates in a specialized disease detection network, and the other was spotted through a specialized surveillance system set up in border communities.
So why else would there be a slower spread outside of North America. The weather? It's getting warmer, but then it was pretty darn warm in Mexico where all of this supposedly started too, wasn't it? April in Mexico is not at all cool.
CDC thinks one reason is that by the time it was discovered here it had already spread widely. The Europeans, with advance warning, were then able to contain it with aggressive use of antivirals among travelers from the affected areas.
But it wouldn't explain why this fairly transmissible virus didn't spread outside of North America before it was discovered, assuming it is true there was a lot of it around, possibly for months, before we detected it. Smothering the spark of a pandemic with antivirals was one of the hopes of many, including WHO.
It is common for flu to have a very patchy spatial distribution. Two cities in the same state can have very different flu experiences. Geographic variation seems also to hold with pandemic strains. If you add to this the difficulty in diagnosing mild or inapparent disease, I wouldn't be too confident that Europe and Asia will be spared.
Still, this is an unprecedented situation. We are watching a potential pandemic evolve in real time, something we've never seen before. Thus it's hard to compare it to anything else.
The Editors of Effect Measure are senior public health scientists and practitioners. Paul Revere was a member of the first local Board of Health in the United States (Boston, 1799). The Editors sign their posts "Revere" to recognize the public service of a professional forerunner better known for other things.
meme048
60 Posts
The interesting thing about this table, is Egypt reporting 17 cases this year but no deaths. Either they've figured out how to treat it better or there not reporting all the cases.
Maria
http://www.who.int/csr/disease/avian_influenza/country/cases_table_2009_05_06/en/index.html