January 9, 2024

 

Blow flies potential carriers of avian influenza virus, according to Japanese research team

 

 

Blow flies may be carriers of avian influenza viruses, a Japanese research team said recently, as Japan grapples with infections that have led to widespread bird culls and driven up food prices.

 

With new outbreaks reported late last year following heavy cullings the previous season, the team led by Ryosuke Fujita, an associate professor at Kyushu University's Graduate School of Bioresource and Bioenvironmental Sciences, is urging chicken farms to use insect-proof nets to contain the spread of the virus.

 

In December 2022, the team analysed around 650 blowfly samples collected from some 30 locations in the city of Izumi, Kagoshima Prefecture, where bird flu cases were confirmed, and found traces of the avian influenza virus in up to about 15% of the flies' digestive systems.

 

Researchers think the flies could be picking up the virus from the carcasses and excrement of infected birds, thereby becoming a carrier for the pathogen.

 

Calliphora nigribarbis, more commonly known as blow flies, are found across Japan. During the winter egg-laying period, the flies seek out bird excrement and animal carcasses for nutrients.

 

Blow flies measure about 1.5-2 centimeters in length and tend to travel within a range of 1-2 kilometers a day. Though often found around poultry houses, the insects usually hide from plain sight.

 

During the previous avian flu season that began in late 2022, Japan carried out its largest-ever bird culling, pushing up the cost of eggs and other poultry products.

 

Beginning in November last year, outbreaks were confirmed in the prefectures of Saga and Kagoshima, as well as Ibaraki, Saitama and Gunma prefectures. By the end of December, some 80 wild birds had been infected with the virus nationwide.

 

Current measures taken by the Japanese poultry industry to prevent avian flu outbreaks involve using nets and animal traps to stop wild birds and other small animals from entering poultry farming facilities, as well as disinfection procedures for workers and vehicles.

 

Fujita called for expanding preventative measures, such as increasing the use of bug nets, saying: "By taking measures against flies, we could lower the risk of infections."

 

- The Japan Times