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As H7N9 Infections Wane, MERS-CoV Claims Thirtieth Victim

Coronaviruses get their name from the crown-like spikes on their surface. (via WikiMedia Commons)

Coronaviruses get their name from the crown-like spikes on their surface. (via WikiMedia Commons)

With the winter flu season now over in the Northern Hemisphere, we can safely say that the feared global pandemic from the newly emerged H7N9 flu virus did not occur. As the weather in China warms up, cases are dwindling in the manner usually seen for any flu virus:

After months of mounting concern, Chinese health officials are breathing a sigh of relief: no new human cases of H7N9 have been reported in the country in more than a week. The milestone marks the first time since March, when the H7N9 outbreak first began, that human cases haven’t continued to increase.

In the week beginning May 13, one previously infected patient succumbed to the virus, according to a statement issued on Monday by China’s National Health and Family Planning Commission. That death brings the H7N9 fatality toll to 36, with 130 confirmed cases in total.

Vigilance will be needed next fall to see if the virus is now lurking, ready to re-emerge once weather conditions are more favorable.

Unfortunately, the situation with another emerging virus is not improving. The newly named (pdf) Middle East Respiratory Syndrome Coronavirus (MERS-CoV) still bears watching since the death toll from this virus has now reached 30:

Three more people have died in Saudi Arabia from the new SARS-like coronavirus, bringing the worldwide death toll to 30, the World Health Organization (WHO) said on Friday.

Saudi health officials also told the WHO of a new case in the eastern province of al-Ahsa, increasing the number of cases worldwide to 50, WHO spokesman Glenn Thomas told reporters at a news conference in Geneva.

As shown in the schematic above, coronaviruses get their name from the crown-like spikes on their surface. The common cold is caused by various members of the coronavirus family.

Another coronavirus that got headlines in the past was the virus causing Severe Acute Respiratory Syndrome, or SARS. That virus was first identified in 2003. This otherwise informative description of the virus and its outbreak that resulted in over 8000 cases and 750 deaths states that SARS is “here to stay”, but the CDC, in this backgrounder on coronaviruses, notes that there have been no reported cases of SARS since 2004.

From the link above where MERS-CoV was given its new name, we get more information on the virus (references removed): Read more

H7N9 Continues Slow Spread, Animal Reservoir Still Uncertain

A steady, but slow and at least for now, not accelerating, spread of the new H7N9 bird flu virus continues. Although infection of poultry in markets in Shanghai has been confirmed and thousands of birds culled, ongoing work on the virus has yet to provide what appears to be a full description of how the virus spreads in animal hosts and gets transmitted to humans.

The latest figures from China put the death toll at 9 and the number of confirmed cases at 28 people infected. The question of whether the virus can be passed from one person to another is still under intense investigation, and two possible family clusters are being investigated. WHO spokesman Gregory Hartl was quoted by Xinhua:

“At this point, there is no evidence of sustained human to human transmission,” he said, adding that there are some “suspected but not yet confirmed cases of perhaps very limited transmission between close family members.”

“They are still being investigated,” he said.

Hartl told Xinhua one of the suspected family clusters was in Shanghai, with three family members having similar symptoms and one of them being confirmed of H7N9.

The confirmed case died, so has another suspected family member, according to Hartl.

The other suspected family cluster, which included two family members with one of them being confirmed, was in Jiangsu Province, he said.

Hartl said that even if the infection of H7N9 is confirmed in other family member, further investigations are still needed to make sure whether that’s a human to human transmission between constant and close contacts or an infection with virus from the same environmental source.

That final point from Hartl illustrates the difficulties that scientists face in developing a full description of how the disease is transmitted. At the same time that we do not yet know fully which animals are the reservoir from which humans are infected, we are simultaneously trying to determine whether family members are passing the virus to one another. That question is complicated by the fact that because the family members live in close proximity to one another but by definition also are exposed to the same local environment, multiple family members could have been infected from the same animal source or one family member could have passed the disease to another.

Moving to the question of the animal host, the same Xinhua article that quotes Hartl also informs us that no pigs have been found to be infected with the virus. Recall that large numbers of pig carcasses had been disposed of in rivers in the same areas of China around the same time H7N9 emerged, so some scientists wondered whether the virus arose in pigs and caused those deaths. There were also observations of dead birds. Xinhua has new information on analysis of bird infections: Read more

Shanghai Culls Poultry as H7N9 Spreads, But Relevant US Research Remains Suspended Due to Security Theater

Partial screen capture of the home page of the Chinese news agency Xinhua (http://www.xinhuanet.com/english/), showing the culling of poultry in Shanghai.

Partial screen capture of the home page of the Chinese news agency Xinhua (http://www.xinhuanet.com/english/), showing the culling of poultry in Shanghai.

Yesterday saw a number of developments in the ongoing story of the emerging H7N9 virus in the Shanghai region of China, as the virus was identified in pigeons being sold at a meat market and the culling of all poultry at that market was initiated. One close associate of an infected person still is being monitored in isolation after developing possible symptoms of the virus and might turn out to be the first case of person to person transfer of the virus. Meanwhile, the CDC already has started work in the US that could lead to a vaccine.

As I pointed out yesterday, key questions to be addressed in understanding how dangerous this virus will be revolve around the issue of how the virus jumps from one host to another and whether it acquires the ability to transfer from one person to another. Sadly, the most directly relevant research in the US on these questions remains suspended due to a cowardly display of security theater by the National Science Advisory Board for Biosecurity. Back in late 2011, I wrote about this board asking two prominent scientific journals to censor work that had been approved for publication. The work eventually was published, but only after a hiatus of about six months. As I pointed out at that time, the fears expressed by NSABB were then shown to be entirely unfounded.

In their report online today on the latest developments in the H7N9 emergence, CNN provided a link at the bottom of their story to this story they published back in January, with the headline “Bird flu research resumes — but not in U.S.” From that report:

 Drama surrounding research on the deadly H5N1 avian flu continues, as 40 scientists urge work on the virus to continue in countries that have established guidelines on the safety and aims of the research. The United States is not among them.

This new correspondence, a letter from researchers published Wednesday in the journals Science and Nature, comes after a “voluntary pause” in the research, which scientists announced in January 2012.

/snip/

In many countries, those objectives have been achieved, according to the letter, and researchers who have permission from their governments to continue this research should do so.

Ah, but the US never misses out on an opportunity to over-play its hand when it comes to security theater, so the work hasn’t restarted here:

But the United States has been unclear about how long it will be before it issues official guidelines for conditions under which H5N1 transmission research can continue, the letter says. As such, laboratories in the United States and facilities abroad that receive U.S. funding should not proceed with their transmission studies.

Back when the NASBB first proposed to censor the work that had been done, I had this to say (emphasis added):

However, in the case of the bird flu version of influenza virus, the basic flu virus is found worldwide and undergoes rapid changes. The fact that flu virus changes rapidly suggests that, as mentioned in the snippet above from ScienceInsider, a version similar [to] that developed in the controversial experiment could even arise naturally. Those who would suppress publication of details on how Fouchier’s group developed the pathogenic virus would prevent responsible researchers repeating the work in order to develop an effective treatment for the virus.  Since the virus could arise naturally, preventing work on a treatment is completely irresponsible.

In the CNN article, we have this from one of the scientists whose work has been put on hold (emphasis added again):

“It’s so easily mutated, so the risk exists in nature already, and not doing the research is really putting us in danger,” Kawaoka said at a press conference Wednesday.

While NSABB was busily subjecting us to needless security theater, nature produced what could be the virus for which scientists were trying to prepare us. They were working with the H5N1 virus to address the very questions of host-jumping and person to person transmission that now lie at the heart of the H7N9 emergence. In the best of all worlds, H7N9 will turn out not spread quickly enough to turn into a deadly pandemic. In that good scenario, H7N9 will serve as a wake-up call to once again free the hands of researchers to carry out work that is vital to understanding deadly bird flu virus outbreaks. The alternative is too terrible to consider. If we see widespread death from H7N9, we will be left to wonder how many of those deaths could have been prevented if this important research had not been suspended.

H7N9: A New Influenza Virus Emerges

This post is in two parts. The first part deals with the news that a new flu virus has emerged. The second part, which comes below the fold, provides a bit of biological and public health information to help put the news into perspective.

According to the latest reports I can find, there are now three confirmed deaths and ten confirmed cases of people infected with a new strain of Type A (bird) influenza virus that has been designated H7N9. All cases have been in eastern China. The good news is that there is not yet evidence to suggest that this virus can spread from one person to another (although that question has not yet been fully answered), which is a prerequisite for a pandemic. The bad news, though, is that the animal host from which the infections were acquired has not been identified.

Earlier this week, Laurie Garrett began assembling what is known about the emerging cases of H7N9 infection and putting those cases into the context of mysterious mass die-offs of pigs and birds in the same general region of China (Garrett is asking important questions here since previous flu pandemics have come from swine or bird hosts):

By the end of March, at least 20,000 pig carcasses and tens of thousands of ducks and swans had washed upon riverbanks that stretch from the Lake Qinghai area all the way to the East China Sea — a distance roughly equivalent to the span between Miami and Boston. Nobody knows how many more thousands of birds and pigs have died, but gone uncounted as farmers buried or burned the carcasses to avoid reprimands from authorities.

While environmental clean-up and agricultural authorities scrambled to remove the unsightly corpses and provide the anxious public with less-than-believable explanations for their demise, a seemingly separate human drama was unfolding. On Feb. 19, a man identified by Xinhua, China’s state news agency, only as Li, an 87-year old retiree, was hospitalized in Shanghai with severe respiratory distress and pneumonia. On March 4, Li went into severe cardio-respiratory failure and succumbed.

On Feb. 27, a man identified only as Wu, a 27-year-old butcher or meat processor, fell ill with respiratory distress, was hospitalized, and died on March 10. The day Wu succumbed a third individual, a 35-year-old woman identified as Han, was hospitalized in the city of Nanjing, though she came from distant Chuzhou City, in Anhui province, about 300 miles northwest of Shanghai. Han is reportedly in critical condition, in intensive care. To date, no connection between the three individuals has been found.

The key question of whether person-to-person transmission of the virus can occur is made somewhat murky by the family of Li:

The elderly Li may have been part of a family cluster of illness, as his 55-year old son died of pneumonia in March, and another 67-year-old son suffered respiratory distress, but has survived.

On March 31 — Easter in the United States — China’s newly created National Health and Family Planning Commission (which includes the former Ministry of Health) announced that 87-year-old Li, Wu, and Han all were infected with a form of influenza denoted as H7N9 — a type of flu never previously known to infect human beings. The commission insisted that Li’s two sons (one dead, the other a survivor) were not infected with the flu virus — their ailments were reportedly coincidental, though they occurred at the same time as the elder Li’s demise.

Garrett goes on to point out that Chinese authorities have blamed a non-influenza virus for the pig deaths, but she casts some doubt on this claim, since the virus cited by the Chinese is known to kill young piglets but not adult pigs. The dead pigs found tossed into rivers primarily were adults.

Garrett rightly states that our knowledge of what is going on here is highly dependent on the accuracy of the tests that authorities are carrying out:

If the pigs, people, and birds have died in China from H7N9, it is imperative and urgent that the biological connection be made, and extensive research be done to determine how widespread human infection may be. Shanghai health authorities have tested dozens of people known to have been in contact with Wu and Li, none of whom have come up positive for H7N9 infection. Assuming the tests are accurate, the mystery of Li and Wu’s infections only deepens. Moreover, if they are a “two of three,” meaning two dead, of three known cases, the H7N9 virus is very virulent.

“At this point, these three are isolated cases with no evidence of human-to-human transmission”, the WHO representative in China, Dr. Michael O’Leary, told reporters on Monday. But, O’Leary added, the possibility of a family cluster of illness could not be ruled out, and, “We don’t know yet the causes of illness in the two sons, but naturally, if three people in one family acquire severe pneumonia in a short period of time, it raises a lot of concern.”

 

The key phrase above is “Assuming these tests are accurate”. When a new virus emerges, it is difficult to know what tests to conduct to detect the virus and how to conduct those tests. More detail is clearly needed to know what level of confidence can be placed on the Chinese claim that Li’s family members were not infected with the same virus that killed him.

Garrett puts these questions into more context in the Reuters article linked above:

However, China has yet to find any animals infected with H7N9, meaning how the humans got it remains a mystery.

“We know that it was originally a bird virus. We also know that it has taken on some genetic attributes that are not seen in bird viruses,” Laurie Garrett, Senior Fellow for Global Health at the Council for Foreign Relations, told Reuters in New York.

“In other words, it seems to have adapted somehow to mammals, to humans. How that happened, we don’t know,” added Garrett.

 

Update: Via Twitter, Laurie Garrett points out that Chinese authorities now have evidence that pigeons in Shanghai have been infected with a version of the H7N9 virus that is a genetic match to the viruses isolated from humans, so pigeons may be the source. More can be read here.

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