The article highlights the fear of an African swine fever (ASF) outbreak in the United States, driven by the movement of undocumented migrants from the Dominican Republic and Haiti, both of which have seen ASF outbreaks. As a precaution, Puerto Rico, a US territory, has banned the shipment of pork to the US, and is monitoring its ports and airports to prevent the disease from entering the country. However, the difficulty of controlling illegal migration routes at sea poses a challenge in fully preventing the spread of ASF. The article underscores the serious nature of ASF, which is hard to eradicate and highly contagious, leading to the mass destruction of pigs in affected areas.