The SARS conspiracy theory began to emerge during the severe acute respiratory syndrome (SARS) outbreak in China in the spring of 2003, when Sergei Kolesnikov, a Russian scientist and a member of the Russian Academy of Medical Sciences, first publicized his claim that the SARS coronavirus is a synthesis of measles and mumps.
According to him, this combination cannot be formed in the natural world and thus the SARS virus must have been produced under laboratory conditions. Earlier, another Russian scientist, Nikolai Filatov, head of Moscow's epidemiological services, had commented that the SARS virus was probably man-made. However, these claims were premature because the type of virus causing SARS has been proven by independent labs to be a coronavirus, but measles and mumps are paramyxoviruses that differ from coronavirus structurally and in the method of infection, making it implausible that a coronavirus was created from two paramyxoviruses.
The widespread reporting of claims by Kolesnokov and Filatov caused controversy in many Chinese internet discussion boards and chat rooms. Many Chinese believed that the SARS virus could be a biological weapon manufactured by the United States, who perceived China's rise as a potential threat to its dominance and superiority in the world. The failure to find the source of the SARS virus further convinced these people and many more that SARS was artificially synthesised and spread by some individuals and even governments. Circumstantial evidence suggests that the SARS virus crossed over to humans from Asian palm civets ("civet cats"), a type of animal that is often killed and eaten in Guangdong, where SARS was first discovered. However, civet cats are extensively used in food production without causing SARS in their handlers.
Supporters of the conspiracy theory suggest that SARS caused the most serious harm in mainland China, Hong Kong, Taiwan and Singapore, regions where most Chinese reside, while the United States, Europe and Japan were not much affected. However, the highest mortality from SARS outside of China occurred in Canada where 43 died. Conspiracists further point out that SARS has an average mortality rate of around 10% around the world, but no one died in the United States from SARS, despite the fact that there were 8 confirmed cases out of 27 probable cases (10% of 8 people is less than 1 person). Regarding reasons why SARS patients in the United States experienced a relatively mild illness, the U.S. Centers for Disease Control has explained that anybody with fever and a respiratory symptom who had traveled to an affected area was included as a SARS patient in the U.S., even though many of these were found to have had other respiratory illnesses.
In October 2003, Tong Zeng, a Chinese lawyer and a volunteer in a 1998 Chinese-American medical cooperation program, published a book that again speculated that SARS could be a biological weapon developed by the United States against China. In the book, Tong disclosed that in the 1990s, many American research groups collected thousands of blood and DNA samples and specimens of mainland Chinese (including 5,000 DNA samples from twins) through numerous joint research projects carried out in China. These samples were then sent back to the United States for further research, and could be used in developing biological weapons targeting Chinese. These samples came from 22 provinces in China, all of which were hit by SARS in 2003. Only provinces like Yunnan, Guizhou, Hainan, Tibet, and Xinjiang were left out, and all these provinces suffered less severely during the SARS outbreak. The author suspects that Japan is also involved, as many Japanese factories in Guangdong in the 1990s made it compulsory for all workers to have blood tests in the factory annually, rather than asking workers to go to local hospitals for blood tests and a proper physical examination. However, Tong Zeng admits that these are only speculations, and he does not have any concrete proof from the study of the virus's genetic sequence.
The scientists named above expressed the possibility that the SARS virus was man-made. Those who argue it is a natural disease mention that the human variant of the SARS coronavirus has been fully gene sequenced and that the genome has been made globally available. Naysayers insist there has been no evidence found of genetic engineering in the genome. The SARS coronavirus is novel, they say, but this only implies it has mutated or was previously undiscovered, not that it is genetically engineered. Epidemiologists in support of the theory say it implies artificial introduction of the disease into the population. Some, mostly Americans, disregard the Chinese and Russian scientists' research as merely propaganda and an impossibility. In the U.S. media has thus far dismissed the issue, calling it a political move and portraying the supporters of the hypothesis as unintelligent or insane.
Coronaviruses similar to SARS have been found in bats in China, suggesting they may be their natural reservoir. However scientists report that the genome of the coronavirus is similar to SARS only in structural and method of infection. The version of SARS which effect bats "can be detected only in anal swabs" and does not share any symptoms found in the human version of SARS. These missing symptoms resemble that of measles and mumps, which some, mostly Russian and Chinese, believe is a clear sign of the well understood field of gene splicing.