One of the scientists who discovered Ebola has warned that China is under threat from the deadly virus because of the huge number of Chinese workers in Africa. Professor Peter Piot also made the grim prediction that Ebola would claim thousands more lives in the months ahead. "It will get worse for a while, and then hopefully it will get better when people are isolated," said Piot, who is in Hong Kong for a two-day symposium. "What we see now is every 30 days there is a doubling of new infections." He estimated the epidemic would last another six to 12 months. West Africa is experiencing the worst Ebola outbreak in history. Cases have also been recorded in the United States, Germany, Spain, Norway, France and Britain. So far, 10,141 suspected cases have been reported and the death toll stands at 4,922. "In Africa, there are many Chinese working there. So that could be a risk for China in general, and I assume that one day [an outbreak of Ebola in China] will happen," said Piot, director of the London School of Hygiene and Tropical Medicine. He also said that infection control measures at mainland hospitals were not always "up to standard", which put public health at great risk. Piot stressed the importance of training people to spot at-risk air passengers before they boarded. And he said voluntary surveillance measures at Chek Lap Kok airport in Hong Kong were not effective enough. "Widespread screening [of arrivals] in airports is not that effective, to be honest … the most cost-effective method is to screen people before they take the plane." A patient feared to have Ebola in Hong Kong tested negative in a preliminary test yesterday. The 39-year-old man, who had been in Nigeria from October 13 to 20, went to Prince of Wales Hospital before being transferred to the Infectious Disease Centre at Princess Margaret Hospital. Piot said the best way to bring Ebola under control was the use of "safe and cheap" blood tests that took as little as 10 minutes. Ebola is transmitted through contact with bodily fluids, and Piot said there was no scientific evidence that the virus would become airborne. The World Health Organisation has warned there could be 10,000 new cases a week by December if governments worldwide do not act. It said the earliest a vaccine could be made available was the middle of next year. Piot said that three pharmaceutical firms were working on vaccines, and the results of an early trial of one drug may be available by February. He hoped that confidence could be built among people in Ebola-stricken countries to receive the vaccines. UN Secretary General Ban Ki-moon said last week a "massive surge in assistance" was needed to supply more protective equipment, mobile laboratories and medical workers. China has sent a new batch of protective gear and equipment to seven African countries. Watch: What is the Ebola virus?