Chongqing- A new material to kill the African swine fever virus (ASFV) has successfully developed in southwestern China's Chongqing Municipality. It uses the "photosynthesis" of semiconductor materials to kill viruses. This is the first "material disinfection" to replace "drug disinfection" in the global animal husbandry industry. This method is environmentally friendly, and the cost is only one-fifth of the traditional method.

This is a semiconductor photocatalytic sterilization and disinfection material based on the principle of photocatalytic reaction, which has been mass-produced and promoted in Chongqing's pig industry.

Impact of the ASFV

In 2018, the introduction and spread of African swine fever (ASF) in China and through many areas in Southeast Asia underscored the importance of animal diseases in economics and trade in the region, according to Evaluating Losses Associated with African Swine Fever in the People's Republic of China and Neighboring Countries released by Asia Development Bank in 2020.

The report indicated that China raises approximately 50% of the world's pigs, an industry worth over $128 billion. The industry is an essential component of the national economy and a source of livelihood and food security for much of the population. 

The results indicate direct costs of ASF on China and neighboring countries of $55 billion–$130 billion. Of this, $28 billion–$46 billion were attributed to initial losses to disease and culling, $4 billion–$7 billion to the cost of replacement breeding animals, and $23 billion–$77 billion in revenue forgone.

"ASFV has brought huge losses to the pig industry. It has high infectivity and high fatality rate and can survive in abnormally cold or hot climates for a long time," said Fu Lizhi, a Chongqing Academy of Animal Science researcher.

Fu introduced that the elimination of ASFV mainly relies on chemical solvents in the past, such as caustic soda and strong acid, which are harmful to the environment and the human body.

National Chongqing (Rongchang) Pig Big Data Center. (iChongqing file photo)

New material born in Chongqing

In March last year, the Chongqing Academy of Animal Sciences united with the National Pig Technology Innovation Center and Chongqing Shenmeng New Material Technology Co., Ltd. formed a scientific research team, relying on the annual output of 800,000 pigs in Rongchang District, to carry out aquaculture clinical experiments with new material.

"It can be imagined as a kind of 'photosynthesis,' the titanium dioxide is used as a semiconductor photocatalytic material, and the hydroxyl groups and free radicals generated under visible light are used to destroy the synthesis of viral DNA, thereby realizing the killing," said Fu.

"This is the first time to apply the technology to inactivate ASFV in the world," Fu added.

"We have adjusted the concentration and composition ratio of the disinfection materials countless times so that it can effectively fight against the ASFV and greatly reduce the mortality rate of infected pigs," said Du Jinxing, deputy general manager of Shenmeng.

Furthermore, the disinfectant can effectively kill viruses such as porcine reproductive and respiratory syndrome (PRRS) and avian influenza. Meanwhile, it will automatically form an adhesive and long-lasting film. And this film provides whole life cycle protection for pigs.

"Traditionally, the farm needs to be disinfected every three or four days, and each pig will cost about 20 yuan (about 3.15 U.S. dollars) during the process. However, when we change into photocatalytic sterilization, the sterilization rate could be maintained at about 99.8% after spraying for ten days. The cost is only about 4 yuan (about 0.63 U.S. dollars)," said Du.

The technology has passed the third-party scientific testing of the Chinese Academy of Agricultural Sciences. Chongqing Academy of Animal Science and Shenmeng will promote this new material to benefit farmers.