A small study by researchers in Italy has found that COVID-19 patients who were tested for the novel coronavirus at a hospital there in May had fewer virus particles than those who were tested a month earlier. The researchers offered some theories for the lower "viral load", including that lockdown measures may have reduced patients' exposure to the virus, but their study did not provide evidence to explain their finding. Another Italian doctor said last month that "the virus clinically no longer exists in Italy", suggesting the interaction between the virus and its human host had changed.