Referral: A Summary Of Worldwide H5N1 Cases in 2011

 

 

 

# 6048

 

One of the senior moderators at FluTrackers, who goes by the moniker Laidback Al, has put together an impressive overview of human H5N1 cases reported during the year just past.

 

Al, who is well known at FluTrackers for his skill with maps and charts, uses visual representations of the data to good effect here.

 

I’ve posted just a snippet from the abstract and smaller versions of a couple of his graphics below, but I encourage everyone to go to the thread and read it in its entirety.

 

This is as fine of an overview of the situation as you are apt to find anywhere, and I’ve already downloaded a copy and put in into the reference folder on my desktop.

 

It’s a keeper, and highly recommended.

 

 

A Summary of Worldwide Human H5N1 Cases in 2011

Laidback Al, Senior Moderator, www.FluTrackers.com
January 1, 2012

Abstract – In 2011, 59 human cases of H5N1 were reported from around the world, a 23% increase over 2010. Five countries reported cases in 2011, Bangladesh, Cambodia, China, Egypt, and Indonesia. Almost half of the 59 cases (about 45%) were children under 10 years old. The fatality rate did not appreciably decline in 2011, about half of all the reported cases died. Four small family clusters were noted during the year. The source of exposure for all of the cluster cases has been reported as exposure to sick and dying poultry. None of these clusters resulted in sustained human to human transmission. Based on an analysis of the 2011 data, the potential for a virulent H5N1 pandemic has not diminished.

(Continue . . . )

The Passing Parade Of 2011 – Pt. 2

 

 

 

# 6036

 

Over the past year I’ve posted more than 900 blogs, dozens of which looked at some of the latest research into influenza and other emerging infectious diseases.

 

Since these studies oft times make an initial splash only to get lost in the passing parade of new reports, today I’ve some brief summaries (with links back to the original blogs) on some of the research of 2011 I believe is deserving of a second look.

 

This is the second such roundup, the first one may be accessed at this link.

 

 

Last April in Lancet Study: NDM-1 In New Delhi Water Supply, we saw a report authored by Timothy Walsh, Janis Weeks , David M Livermore, and Mark A Toleman that looked for – and found – bacteria carrying the NDM-1 enzyme in New Delhi's drinking water supply.

 

We’ve a press release on this study, issued by Cardiff University, that gives the highlights of the research, but the `money quote’ (emphasis mine) buried about halfway down is:

 

Resistant bacteria were found in 4 per cent of the water supplies and 30 per cent of the seepage sites. The researchers identified 11 new species of bacteria carrying the NDM-1 gene, including strains which cause cholera and dysentery.

 

Below is a link to the Lancet study, which you can read in its entirety (a free registration is required).

 

 

The Lancet Infectious Diseases, Early Online Publication, 7 April 2011

doi:10.1016/S1473-3099(11)70059-7

Dissemination of NDM-1 positive bacteria in the New Delhi environment and its implications for human health: an environmental point prevalence study

Prof Timothy R Walsh PhD , Janis Weeks BS, David M Livermore PhD , Mark A Toleman PhD

 

Again in April, we saw research seeking to answer the question over why there was such a wide variance in death rates around the world with the 1918 Spanish influenza. 

 

In 2006, in a Lancet journal (doi:10.1016/S0140- 6736(06) 69895-4) article cited as much as a 30-fold difference in mortality rates around the world:

 

Estimation of potential global pandemic influenza mortality on the basis of vital registry data from the 1918—20 pandemic: a quantitative analysis

Christopher JL Murray , Alan D Lopez , Brian Chin , Dennis Feehan , Kenneth H Hill

Excess mortality ranged from 0·2% in Denmark to 4·4% in India. Since there was some under-registration of mortality in India, total pandemic mortality could have been even higher.

 

 

This wide disparity in mortality rates – much of it based on anecdotal accounts – has long intrigued researchers.  This new study from the Norwegian Institute of Public Health that attempts to answer some of these questions.

 

What they found was that the mortality rate varied nearly 100 fold between remote, rural regions and urban populations, and that in the more remote areas, older persons were just as susceptible to the virus as those who were younger.

 

This study appears in the Journal Epidemics.

Geography May Explain Adult Mortality from the 1918–20 Influenza Pandemic

Original Research Article
Pages 46-60
Svenn-Erik Mamelund

 

The theory that a similar H1 virus circulated prior to 1890 – and that provided some immunity to those over the age of 30 – is bolstered by this study.

 

 

Given the current flap over the H5N1 experiments conducted by Ron Fouchier in the Netherlands and Yoshihiro Kawaoka  at the University of Wisconsin (see The Biosecurity Debate On H5N1 Research) the next two studies deserve a second look as well.

 

 

Simplified Illustration of a Serial Passage Experiment. 

 

In H5N1: A Rite Of Passage we looked at how serial passage studies are conducted, and at one in particular that appeared in the Journal of Animal and Veterinary Advances that looked at increases in pathogenicity (in mice) of two H5N1 viruses after six serial passages in quail.

 

The study is called:

 

The Pathogenicity Variation of Two Quail-Origin H5N1 HPAV to BALB/c Mice after Six Passages in Quail

Hailiang Sun, Peirong Jiao, Yuqiang Cheng, Runyu Yuan, Pengfei Cui, Liming Jin, Chaoan Xin and Ming Liao

 

Another study, profiled in PNAS: Reassortment Potential Of Avian H9N2, looked at the reassortment potential of the avian H9N2 virus and H1N1. Research was done using ferrets whose respiratory physiology is considered relatively close to humans.

 

Compatibility of H9N2 avian influenza surface genes and 2009 pandemic H1N1 internal genes for transmission in the ferret model

J. Brian Kimble, Erin Sorrell,  Hongxia Shao,  Philip L. Martin, and Daniel Roberto Perez

 

(Excerpt from the abstract)

Four reassortant viruses were generated, with three of them showing efficient respiratory droplet transmission. Differences in replication efficiency were observed for these viruses; however, the results clearly indicate that H9N2 avian influenza viruses and pH1N1 viruses, both of which have occasionally infected pigs, have the potential to reassort and generate novel viruses with respiratory transmission potential in mammals.

 

 

The entire study is available online, and open access.

 

 

And in Study: Prior Antibiotic Use & MRSA In Children Canadian researchers, examining 13 years worth of data from the UK’s General Practice Research Database (GPRD), came up with what they called  a `robust association’ between a prior history of antibiotic use and rates of CA-MRSA (Community Acquired Methicillin Resistant Staph Aureus) infection in children.

The study appeared Aug. 1st  in the Archives of Pediatrics & Adolescent Medicine.

 

Antibacterial Drugs and the Risk of Community-Associated Methicillin-Resistant Staphylococcus aureus in Children

Verena Schneider-Lindner, MD, MSc; Caroline Quach, MD, MSc; James A Hanley, PhD; Samy Suissa, PhD

Arch Pediatr Adolesc Med. Published online August 1, 2011. doi:10.1001/archpediatrics.2011.143

 

What these researchers found was that while nearly half of children with MRSA in this study had no recent history of antibiotic use, the adjusted relative risk (RR) of developing MRSA was 3.5 times higher among children who had received antibiotic treatment in the previous 30-180 days before infection.

 

And that relative risk increased substantially among children who received more than one course of antibiotics.

 

To find more blogs specific to research you can use the RESEARCH quick link on my sidebar.

 

As news is often slow during the holiday season, over the next couple of weeks I plan to post one or two more retrospectives on the news and research of the year that was.

The Passing Parade Of 2011

 

 

# 6018

 

 

Over the past year I’ve posted more than 900 blogs, dozens of which looked at some of the latest research into influenza and other emerging infectious diseases.

 

Since these studies oft times make an initial splash only to get lost in the passing parade of new reports, I thought I’d post some quick summaries (with links back to the original blogs) on some of the research of 2011 I believe is deserving of a second look.

 

 

In January of 2011 we saw a study published in IDSA’s Clinical Infectious Diseases journal that looked at the use of convalescent plasma in treating severe H1N1 infection.  The study was called:

 

Convalescent Plasma Treatment Reduced Mortality in Patients With Severe Pandemic Influenza A (H1N1) 2009 Virus Infection

Ivan FN Hung, Kelvin KW To, Cheuk-Kwong Lee,Kar-Lung Lee, Kenny Chan, Wing-Wah Yan, Raymond Liu,Chi-Leung Watt, Wai-Ming Chan, Kang-Yiu Lai,Chi-Kwan Koo, Tom Buckley,Fu-Loi Chow,Kwan-Keung Wong, Hok-Sum Chan, Chi-Keung Ching, Bone SF Tang,Candy CY Lau,Iris WS Li, Shao-Haei Liu, Kwok-Hung Chan, Che-Kit Lin, and Kwok-Yung Yuen

 

Convalescent plasma is created by collecting blood from those who been infected, and have since recovered, and through a process called plasmapheresis, the blood cells are removed from the blood plasma.

 

Convalescent plasma, which contains antibodies against the infection could, theoretically, be used as either a treatment for someone already infected, or as a temporary prophylactic, to prevent infection.

 

In my  blog (see CID Journal: Convalescent Plasma Therapy For Severe H1N1) I also looked at the history of using convalescent plasma in the treatment of H5N1 in China.

 

Also in January we saw a study that appeared in the CDC’s EID Journal, that looks at the potential for the 2009 H1N1 virus to reassort with other currently circulating flu viruses and create a more virulent flu strain.

 

Possible Increased Pathogenicity of Pandemic (H1N1) 2009 Influenza Virus upon Reassortment

Eefje J.A. Schrauwen, Sander Herfst, Salin Chutinimitkul, Theo M. Bestebroer, Guus F. Rimmelzwaan, Albert D.M.E. Osterhaus, Thijs Kuiken, and Ron A.M. Fouchier

 

The authors concluded:

 

We conclude that the pandemic (H1N1) 2009 virus has the potential to reassort with seasonal influenza virus A (H1N1) and influenza virus A (H3N2) and that such reassortment events could result in viruses with increased pathogenicity in ferrets.

 

And while not quite as envisioned by this study, within a few months we were to learn of a reassortment between a swine H3N2 virus, and the 2009 pandemic H1N1 virus (see CIDRAP: New Details In The trH3N2 Story).

 

In my blog on this study (EID Journal: H1N1 Reassortment Possibilities), I also referenced another study from 2010 (mBio: A/H1N1 Potential For Mutation) that looked at the potential for the 2009 H1N1 virus to become more pathogenic through the more common process; antigenic `drift’.

 

 

 

In late February we saw a report in PNAS that looked at research out of China where scientists - using reverse genetics – had created 127 hybrid viruses out of the H9N2 and 2009 H1N1 viruses  in the laboratory and tested them on mice for compatibility, replication ability, and virulence.

 

They found that half of the hybrid viruses were biologically `fit’ as far as replication goes, and 8 hybrids were significantly more pathogenic than either of their parental viruses (see PNAS: Reassortment Of H1N1 And H9N2 Avian viruses).

 

High genetic compatibility and increased pathogenicity of reassortants derived from avian H9N2 and pandemic H1N1/2009 influenza viruses

Yipeng Sun,Kun Qin, Jingjing Wang, Juan Pu, Qingdong Tang, Yanxin Hu, Yuhai Bi,Xueli Zhao, Hanchun Yang, Yuelong Shu, and Jinhua Liu

 

This research, albeit with far less lethal parental flu strains, is not so very different from the work on the H5N1 virus conducted by Ron Fouchier and Yoshihiro Kawaoka (see The Biosecurity Debate On H5N1 Research) that has caused so much furor in the press over the past few months.

 

 

While the month of March was understandably dominated by the news of the devastating earthquake, tsunami, and nuclear accident in Japan, we did look at a few studies, including Study: Longevity Of Viruses On PPEs.

 

 

Appearing in the Japanese journal Environmental Health and Preventative Medicine. researchers inoculated various fomites (masks, gloves, gowns, wooden and steel desktops) with laboratory grown H1N1, and then tested the surfaces after 1, 8, and 24 hrs for the presence of the virus (HA titer & 50% tissue culture infective dose (TCID₅₀)/mL were measured).

 

Environmental Health and Preventive Medicine

Volume 15, Number 6, 344-349, DOI: 10.1007/s12199-010-0149-y

Maintenance of influenza virus infectivity on the surfaces of personal protective equipment and clothing used in healthcare settings

Hiroko Sakaguchi, Koji Wada, Jitsuo Kajioka, Mayumi Watanabe, Ryuichi Nakano, Tatsuko Hirose, Hiroshi Ohta and Yoshiharu Aizawa

 

The results indicate that all surfaces tested harbored viable H1N1 viruses for at least 8 hours, with some surfaces infectious for more than 24 hours. These test results extend the window of infectivity from fomites considerably beyond what has previously been reported.

 

There were many other studies of note during the first quarter of 2011, including a Eurosurveillance look at the D222G/N mutation in the 2009 H1N1 virus, the IOM update on the use of PPEs for healthcare workers when facing pandemic influenza and other viral respiratory illnesses.

 

To browse blogs specific to research you can use the RESEARCH quick link on my sidebar.

 

As news is often slow during the holiday season, over the next couple of weeks I plan to post a couple of more retrospectives on the news and research of the year that was.