Wednesday, January 24, 2007

Cats and Dogs and Flies, Oh My!

 

# 349

 

Admittedly I was tempted to post on this last Sunday when Influenza2, on the Wiki, uncovered and translated an article in the Banjarmasan Post about Dr. Wasito and his claims that flies could carry the H5N1 virus. The translation, however, left a lot to be desired, and other than warning that flies could carry the virus, was more confusing than anything else.

 

Today, the Jakarta Post printed an English language article on Dr. Wasito. This isn’t the first time that flies have been suggested as possible vectors of the virus. In 2004, in Japan, researchers found evidence of the virus in two species of blow flies. They wrote:

 

The H5 influenza A virus genes were detected from the intestinal organs, crop, and gut of the two blow fly species, Calliphora nigribarbis and Aldrichina grahami, by reverse transcription-polymerase chain reaction for the matrix protein (M) and hemagglutinin (HA) genes. The HA gene encoding multiple basic amino acids at the HA cleavage site indicated that this virus is a highly pathogenic strain. . . . . Our results suggest it is possible that blow flies could become a mechanical transmitter of H5N1 influenza virus.

Link

 

This, from today’s Jakarta Post:

Scientist warns of bird flu in flies

Sri Wahyuni, The Jakarta Post, Yogyakarta

 

A scientist has warned the government not to place too much of the blame for bird flu on poultry as it could result in the public being unaware of the fact that other animals can also carry the virus.

 

Veterinary pathologist Wasito of Gajah Mada University's veterinary medicine told The Jakarta Post at his office in Yogykarta on Tuesday that other animals, such as cats, dogs and even files, could also carry the virus.

 

"A study we are conducting here, for example, has convincingly found that it is possible for flies to spread the bird flu virus," he said.

 

Through a series of laboratory tests involving flies collected from different parts of the country and using molecular research methods, Wasito and his colleagues found that the virus was found in the digestive and respiratory tracks of flies, along with the cuticle layers, flesh and ovum.

 

Bird flu outbreaks in Indonesia are categorized as either low pathogenic (LPAI) or highly pathogenic (HPAI).

 

The LPAI form usually attacks only the digestive and respiratory tracts, while HPAI attacks the digestive and respiratory systems along with other organs, including flesh and ovum.

 

"We do not yet dare to say whether the avian influenza we found in the flies is LPAI or HPAI. We can only say that in the flies, we also found the bird flu virus in other organs," Wasito said.

 

He said that the research had also reveled that the virus was not only found in flies taken from areas in the middle of bird flu outbreaks.

 

Wasito said the virus had also been found in flies taken from places that have been declared bird flu free. Only flies taken from locations that have never had a bird flu outbreak were always found H5N1 negative.

 

"This means that the virus in flies is still inherited in at least the 25th generation, as the research was conducted generally two years after an outbreak," said Wasito, explaining that the flies had a one-month life span.

 

He also warned that it was possible that a new type of the virus could emerge and lead to massive outbreaks of the disease in animals and humans.

 

 

While scarcely comforting, we need to remember that this appears to be very preliminary information, and that more data is needed. Dr. Wasito hasn’t proven that flies transmit the virus to other hosts; he only maintains that they can carry the virus, and have the potential to do so.

 

Dr Wasito also goes on to caution against mass vaccinations of poultry in this interview, stating that his team has uncovered `silent bird flu infections’ in seemingly healthy birds, and that applying a vaccine to an infected bird could exacerbate the problem.

 

He was also critical of the governments lack of scientific rationale when making policy regarding avian flu, stating:

 

Declaring that a particular region is bird flu free, for example, or providing a certificate announcing that a particular bird is free from bird flu, according to Wasito, were misleading and making people less aware of the danger of a possible outbreak

 

All of this simply amplifies what we’ve long known, and that is when it comes to the H5N1 virus, we don’t know much. The bird flu continues to show us new tricks, sometimes in unexpected places.

 

As far as how much stock to put in all of this, your guess is as good as mine. Flies may, or may not, play an important role in the spread of the disease.

 

We simply don’t know yet.