Number of H7N9 cases rises to 77 in China

Chinese health officials increased the number of confirmed H7N9 avian flu cases to 77 on Monday night after adding five more cases retrospectively, according to the state-run Shanghai Daily.

The increase of 14 cases was the largest single-day increase in the spread of the deadly disease so far. Chinese health officials reported two more H7N9 fatalities, increasing the total number of reported deaths to 16, Forbes reports.

Six of the new cases were reported in Shanghai and eight were reported in China's eastern provinces. Five of the cases were reported in Zhejiang with three cases reported in Jiangsu.

Beijing and major Chinese cities in the east closed their live poultry markets and have taken other precautions to stop the spread of the virus. Prior to announcing the the new cases, Shanghai state media declared the H7N9 situation stable on Monday.

On Tuesday, the Beijing News reported that 40 percent of China's H7N9 bird flu cases involved individuals with no clear-cut contact with poultry. The newspaper said until the disease is effectively controlled, the number of cases may keep increasing.

The spread of flu has had a significant impact on China's chicken industry, which is the second largest in the world after the U.S., according to Forbes.