Lu Hongzhou, an infectious disease specialist at Fudan University in Shanghai, told the state-controlled Global Times tabloid that nasal or throat swabs could cause “uncomfortable reactions,” leading to subpar samples. He acknowledged that fecal samples could replace anal swabs, to prevent similar discomfort.
But other experts — including in China — have questioned the need for anal samples. The Global Times quoted another expert, Yang Zhanqiu, as saying that nasal and throat swabs are still the most effective because the virus is contracted through the respiratory tract.
Benjamin Cowling, a public health professor at the University of Hong Kong, said in an interview that even if someone did test positive on an anal swab but not a respiratory one, he or she would likely not be very contagious.
“The value of detecting people with the virus is to stop transmission,” Professor Cowling said. “If someone has got an infection but they’re not contagious to anyone else, we didn’t need to detect that person.”
A spokesman for the Chinese Foreign Ministry said this week that the government would make “science-based adjustments” to its containment policies.