The port backups that have paralyzed food shipments around the world for weeks aren’t getting much better. In fact, in some places, they’re getting worse.

In the Philippines, officials at a port that’s a key entry point for rice said earlier this week the terminal was at risk of shutting as thousands of shipping containers pile up because lockdown measures are making them harder to clear. Meanwhile, curfews in Guatemala and Honduras, known for their specialty coffees, are limiting operating hours at ports and slowing shipments. And in parts of Africa, which is heavily dependent on food imports, there aren’t enough workers showing up to help unload cargoes.

The port choke-points are just the latest example of how the virus is snarling food production and distribution across the globe. Trucking bottlenecks, sick plant workers, export bans and panic buying have all contributed to why shoppers are seeing empty grocery store shelves, even amid ample supplies. Food moves from farm to table through a complicated web of interactions. So problems for even just a few ports can ripple through to create troubling slowdowns. For example, wheat grown in Europe can be shipped off to India, where it’s processed into naan bread for eventual export into the American market. Disruptions along the way are causing heavy delays.

And there’s the threat that things could get much worse if port problems spread. Just a handful countries, for instance, export the bulk of the world’s rice and wheat, staple sources of calories. Soybeans from South America help keep the planet’s livestock fed, and the vast majority of cocoa supplies are shipped out of small section of West Africa.

Even countries like the U.S., a key food exporter, depend on imports for things like wine, spices, cheese and out-of-season produce — that’s how you can make avocado toast year-round.

U.S. frozen-foods company Saffron Road relies on Indian shipments for naan and other products. A three-week lockdown on the nation’s 1.3 billion people has brought transportation of goods within its borders to a near halt, and the government sparked confusion when it told all major ports that the virus was a valid reason to halt some operations.