Poultry farmers in China have lost about 20 billion yuan (3.3 billion U.S. dollars) due to H7N9 bird flu infections, said the Ministry of Agriculture (MOA) on Wednesday. Sales and prices of poultry products have slumped badly on the back of H7N9 infections. "There is insufficient proof that the virus is transmitted from poultry to humans directly, so it is safe to eat poultry products that are bought through formal channels and quarantined," said Zhang Zhongqiu, MOA chief veterinary officer, as quoted by China News Agency (Xinhua). H7N9 has not been detected in any poultry farm, said Zhang, adding that there were genetic differences between human and avian viruses, as laboratory studies have shown. The authorities found 88 positive samples among more than 1.6 million collected in ten cities and provinces including Shanghai, according to Zhang. H7N9 bird flu has killed 19 in China this year, and human infections stood at 96 on Monday, according to the Chinese Center for Disease Control and Prevention.