WASHINGTON (AP) — U.S. health inspectors are still struggling to address a massive backlog of pharmaceutical plants that went uninspected during disruptions caused by COVID-19.

That’s according to an analysis of government data by the Associated Press.

The data shows roughly 2,000 drug manufacturing sites around the world have not had a Food and Drug Administration inspection for quality since before the pandemic.

The FDA considers plants that have gone more than five years without an inspection to be a significant risk.

Agency officials say their work has been hampered by difficulties recruiting and retaining inspectors, who face a grueling schedule of overseas travel.