Chinese and American scientists have achieved a breakthrough on the SARS front by isolating a live SARS-like virus from bats that is highly similar to the human virus that erupted in Asia in 2002 and 2003 and caused a global pandemic.

This new study, published in Nature, comes after nine years of research by an international team of 14 Chinese, four American and two Australian scientists.

"The finding will allow us to further conduct detailed studies to create control measures to thwart outbreaks and provide opportunities for vaccine development," Shi Zhengli, a senior scientist of the Wuhan Institute of Virology at the Chinese Academy of Sciences, told China Daily.

The research got started in 2004, just after the SARS pandemic was brought under control. Before this research, cat-like civets were demonstrated to be a direct source - but not the original source - of the 2002-2003 SARS virus outbreak.

The American and Australian scientists had been working on bat viruses for a long time in South Asia and Australia and expanded their work into 2004 into China.

The group in Wuhan worked on virus detection, isolation and function. The American group together with the group in Wuhan collected samples and epidemiological data analysis; the Australian team worked on virus pathogenesis.

In 2005, the researchers reported the discovery of a SARS-like coronavirus in horseshoe bats which had a high similarity to human SARS virus. But there is still missing direct link to the human SARS virus.

The international team continued the investigation and found a number of SARS-like coronaviruses in horseshoe bats, mostly from China.

Shi said the biggest challenge was isolating the virus, which was also the most exciting moment of their scientific breakthrough.

"We made many modifications to the protocol," he said. "Isolating the virus provided important evidence in clarifying the origin of the SARS coronavirus. It's not easy to isolate a coronavirus from samples collected from wildlife."

The international team will continue exploring viruses in bats and other wildlife, and keep an eye out for newly emerging infectious diseases that arise from wildlife, he said.

"This work shows that these viruses can directly infect humans and validates our assumption that we should be searching for viruses of pandemic potential before they spill over to people," said co-author and UC-Davis professor Jonna Mazet, co-director of Predict, a project of USAID's Emerging Pandemic Threats program. Predict, which partially supported the study, is designed to target surveillance of wildlife populations and identify potential pandemic viruses before they emerge.

"The discovery that bats may directly infect humans has enormous implications for public health control measures," said co-senior author Peter Daszak, president of EcoHealth Alliance.

Public health measures need to be created to reduce the risk of transmission, he said.

He also noted the study carries lessons for the recent outbreak of Middle East Respiratory Syndrome coronavirus, which likely originated in Saudi Arabian bats.

Contact the writer at chenjia@chinadailyusa.com

(China Daily USA 11/04/2013 page2)