OIE: H5N1 Detected In Crows Again – India

Indian House Crow – Photo Credit Wikipedia

 

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While China, Cambodia, Vietnam, and South Korea have garnered most of the avian flu headlines this winter, the H5N1 virus remains endemic in other countries as well, including much of Asia and parts of the Middle East.  In many of these regions, surveillance and reporting is less than optimal, so the true extent of this virus is hard to measure.

 

Although debate over the incidence and importance of wild birds spreading the avian flu virus remains contentious (see India: The H5N1 & Migratory Birds Debate), we have often seen wild and migratory birds test positive for the H5N1 virus.   

 

In addition to having infected more than 20 mammalian species, the H5N1 virus has been detected in more than 150 different types of wild birds (See USGS List of Species Affected by H5N1 (Avian Influenza)).

 

Waterfowl (ducks & geese) and gallinaceous birds (turkeys, grouse, chickens & quail) are most often associated with carriage of the H5N1 virus, but terrestrial birds such as crows, starlings, pigeons, and sparrows are also known to carry, and shed, the virus as well (see 2007’s EID Journal  Role of Terrestrial Wild Birds in Ecology of Influenza A Virus (H5N1).

 

As far back as 2008, we saw reports out of India of crows dying from the H5N1 virus. A little over two years ago India was again plagued with numerous wild bird die offs that were blamed on the avian flu virus (see Media Report: H5N1 Killing Crows In Jharkhand).

 

By mid-December of 2011 the Indian Veterinary Research Institute (IVRI), Bhopal, confirmed that the H5N1 virus was behind at least some of these deaths. (see EpiSouth eweb_195_15_12__11.pdf). Over the next few months, even more reports came in, involving thousands of dead birds (see The Kolkata Crow Mystery & H5N1: A Murder Of Crows) that spread across several northern states.

 

On February  6th, 2012 official notification was made to the OIE of H5N1 virus detections in crows from four states; Jharkhand, Maharashtra, Orissa, and Bihar.

 

While India has reported a number of H5N1 outbreaks in Poultry since then - and at least one die off in pigeons (see Nov. 2012 Pigeon Droppings) - reports of the virus in wild birds have been noticeably absent the past 18 months.

 

At least, until this week, when the OIE was notified of two dead house crows from Keonjhar District, in Orissa state in Eastern India that were found to be infected with the virus.

 

 

Two dead house crows may not seem terribly important, but as the study below indicates, changes in the behavior of the virus in the wild can sometimes be a tip off that something is changing with the virus. This from just last October, in the Archives of Virology:

 

Investigating a crow die-off in January–February 2011 during the introduction of a new clade of highly pathogenic avian influenza virus H5N1 into Bangladesh

Salah Uddin Khan, LaShondra Berman, Najmul Haider, Nancy Gerloff, Md Z. Rahman, Bo Shu, Mustafizur Rahman, Tapan Kumar Dey, Todd C. Davis, Bidhan Chandra Das . . . .

Abstract

We investigated unusual crow mortality in Bangladesh during January-February 2011 at two sites. Crows of two species, Corvus splendens and C. macrorhynchos, were found sick and dead during the outbreaks. In selected crow roosts, morbidity was ~1 % and mortality was ~4 % during the investigation. Highly pathogenic avian influenza virus H5N1 clade 2.3.2.1 was isolated from dead crows.

All isolates were closely related to A/duck/India/02CA10/2011 (H5N1) with 99.8 % and A/crow/Bangladesh/11rs1984-15/2011 (H5N1) virus with 99 % nucleotide sequence identity in their HA genes. The phylogenetic cluster of Bangladesh viruses suggested a common ancestor with viruses found in poultry from India, Myanmar and Nepal. 

<SNIP>

Continuation of surveillance in wild and domestic birds may identify evolution of new avian influenza virus and associated public-health risks.

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As the H5N1 virus continues to evolve into new clades or strains, its behavior across various species is likely to change as well. Two years ago, in Differences In Virulence Between Closely Related H5N1 Strains, we looked at a study that found that genetically similar strains can exhibit significantly different pathogenicity in specific hosts.

 

Making any perceived change in how the virus presents or spreads worth noting.

NDTV: Video Report On India’s Crow Deaths

 

 

 

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NDTV or New Delhi Television, is a commercial broadcast network in India that features a good deal of English language programming.

 

Today they’ve uploaded a news video to their YouTube channel reporting on fresh concerns over the deaths of thousands of crows across several Indian states (see H5N1: A Murder Of Crows).

 

`Science reporting’ via the mass media often suffers from a lack of scientific specificity, and occasionally indulges in a bit of speculation as well. 

 

I think it’s fair to say that this media report contains a bit of both. The opening monologue reads:

 

After remaining clean for five years, India saw an outbreak of avian influenza or bird flu in the eastern states early this year. But this time there is the threat of a possible new virus circulating in the environment. Over 6000 crows have died across several states. Only 20 samples have shown up positive for bird flu. The rest have died of unidentified causes. After ignoring the problem, the government is now moving quickly to work out an emergency outbreak plan to identify the virus and contain the epidemic.

 

You will find a short interview with FAO  representative John Weaver, calling for an epidemiological investigation into these bird deaths and the testing for pathogens other than H5N1 that may be contributing to these crow deaths.

 

Bird flu virus changing DNA, 6000 crows dead

 

 

While an interesting report, a few caveats to consider:

 

The opening statement that `After remaining clean for five years, India saw an outbreak of avian influenza or bird flu in the eastern states early this year’ seems a dubious start, since India has reported outbreaks of the H5N1 virus to the OIE every year since 2006.

 

Similarly, the claim `Over 6000 crows have died across several states. Only 20 samples have shown up positive for bird flu. The rest have died of unidentified causes.’ gives the impression that all 6000 crows were tested for bird flu.  Something I’ve not seen reported.

 

And lastly, the headline Bird flu virus changing DNA,  6000 crows dead - in the absence of genetic tests  showing mutations -  appears to be highly speculative (not to mention the fact that influenza is an RNA virus).

 

 

Despite these limitations, this report illustrates that more than three months after thousands of crows began dying mysteriously across several Indian states, we still know surprisingly little about the cause or causes.

The Kolkata Crow Mystery

 

Indian House Crow – Photo Credit Wikipedia

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Roughly two months ago crows by the hundreds (some say thousands) began falling from their perches and dying in Jharkhand, India. 

 

By mid-December the Indian Veterinary Research Institute (IVRI), Bhopal, confirmed that it was the H5N1 virus that was behind these deaths. (see EpiSouth Bulletin eweb_195_15_12__11.pdf).

 

You can find additional AFD coverage of this event in Media Report: H5N1 Killing Crows In Jharkhand  and several from Crofsblog, including India: ‘New bird flu strain killed Jharkhand crows’.

 

Today the Times of India is reporting (h/t Emily on FluTrackers) that after ignoring dying crows in the capital city of Kolkata for weeks, West Bengal authorities are finally launching an investigation.

 

Govt gets cracking on crow deaths

TNN | Jan 29, 2012, 07.36AM IST

 

KOLKATA: After ignoring the mysterious crow deaths in the city for nearly two months, the state government flew into action mode on Saturday and sent scientists to Rabindra Sarovar to gather carcasses and blood samples.

TOI on Friday first reported on crows dropping dead all over the city.

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Somewhat remarkably, two weeks after the discovery of H5N1 in Jharkhand crows, India declared itself to be bird flu free, leading to some highly critical media coverage (see Dying crows deny India is bird flu free).

 

There are other possible causes of the crow deaths in Kolkata; insecticides, accidental poisoning, and Newcastle disease to name a few.

 

But with the recent positive test results in neighboring Jharkhand positive for H5N1, concerns are running high that the virus may be behind these deaths as well.

Media Report: H5N1 Killing Crows In Jharkhand

 

Photo Credit – Wikipedia

 

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More than two weeks after the first reports started coming in that hundreds of dead crows have been found in the eastern Indian state of Jharkhand, we now have a report that lab tests have finally confirmed the presence of the H5N1 virus.

 

Initial reports raised concerns over the possibility of avian flu, as in this November 29th report from the Deccan Herald.

 

Dead crows in Jharkhand raise fears of avian virus

Ranchi, Nov 29, (IANS):

Crows are dropping dead in cities and towns across Jharkhand since the last fortnight due to a mysterious disease. The state authorities have warned people not to touch the dead birds as they could be carrying a contagious avian virus.

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The following day, the Times of India carried this report.

 

Bird flu-like virus killing Jharkhand crows

Jaideep Deogharia, TNN Dec 1, 2011, 12.48AM IST

RANCHI: The Centre has sent an alert to the Jharkhand government to remain cautious about a possible poultry infection, after a mysterious bird flu-like virus is believed to have killed between 500 and 1,000 crows in Jamshedpur, Bokaro and parts of Hazaribagh. Though an official intimation from the Union animal husbandry department is still to reach the state, a study on the crow deaths conducted at the animal disease laboratory in Bhopal found a virus resembling that of bird flu. However, the study allays fears about cattle, poultry and humans being infected because the virus was detected only in the brain of the dead crows.

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This is a story that flublogia, including FluTrackers, has been following for several weeks. You’ll find more than 30 posts on FT regarding this story in this thread.

 

Over the past 10 days we’ve seen conflicting reports, with some attributing these bird deaths to bird flu, and others saying the cause was still undetermined.

 

Today it is being widely reported in the media (see here, and here) that laboratory testing in Bhopal has apparently detected the H5N1 virus in some of these dead birds.

 

 

Bird Flu killing crows in Jharkhand

Dec 15, 2011 |

In a worrying development, hundreds of crows have died in Jharkhand due to bird flu, a government official said Thursday.

 

The crows first started dying mysteriously last month in Jamshedpur district. This was followed by their deaths in Ranchi, Bokaro, Khuti, Sahebganj and other districts of the state.

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I’ve looked for, but have not yet found, any official announcement from the Indian Government or on the Jharkhand government website.