Mexico pushes back on Cyclospora link

More than 11,000 people in the US have gotten sick in a major Cyclospora outbreak that the FDA linked to iceberg lettuce from central Mexico. But Mexican officials and growers are pushing back, saying no lettuce sample has tested positive for the parasite. The World's Tibisay Zea looks at the local impact in Guanajuato, the trade tensions surrounding the case, and why scientists say the exact point of contamination is still unclear. Alfonsina Avila also contributed to this report.