HANOI (Reuters) - African swine fever outbreaks are spreading in Vietnam and could affect its food supplies and put upward pressure on inflation, according to a government document.

"The risk of wider spread of the disease is very high, and it can affect food supplies, consumer prices and the environment," said the document dated July 14, which was reviewed by Reuters.

It said 42,400 infected pigs had been culled, up by nearly five times the same period last year.

(Reporting by Khanh Vu and Phuong Nguyen; Editing by Martin Petty)