New York CNN Business  — 

Americans across the country are stocking up on hand sanitizer, cleaning wipes, toilet paper and other products to prepare for the spread of coronavirus.

Long lines at stores and panic buying on cleaning products throughout the country are stretching American retailers’ ability to keep up with demand. Shoppers are posting pictures on social media of lines snaking around Costco and empty shelves of sanitizers at CVS, Walgreens and other drug stores.

“Very, very busy!” Costco (COST) chief financial officer Richard Galanti said in an email Saturday. Costco (COST) was the top stock on the S&P 500 Monday. Walmart (WMT), Walgreens (WBA) and other retail stocks also jumped.

“It does feel like there is a little bit of panic buying going on,” said Doug Baker, vice president of industry relations at trade group Food Marketing Institute. Retailers are “trying to follow the bouncing ball as quickly as they can.”

Analysts predict the shopping frenzy will increase revenue for retailers early in the year. For the four weeks ending on February 22, sales of hand sanitizer increased 73%, thermometers grew by 47% and medical masks increased 319% compared with the same period last year, according to Nielsen.

“We would expect to see a noticeable benefit to [sales] from accelerated traffic and basket growth as shoppers stock up on food and other essentials,” Cowen analyst Oliver Chen said in a note to clients Tuesday.

Increased demand is testing retailers and grocers’ supply chains, however. Unlike a hurricane or natural disaster, which is usually a regional event, coronavirus panic buying has spread nationally.

“The pattern we’re seeing is more along the lines of what you would see as people prepare for a major storm where certain categories, such as cleaning supplies, would be in high demand,” a spokesperson for Walmart said. The company is working closely with suppliers to “help meet the needs of customers.”

Dennis Curtin, spokesperson for Weis Markets, a grocer with 200 stores in the northeast, said that Weis was increasing its focus on securing private-branded hand sanitizer in stores because national manufacturers were running low.

“We are working to keep our shelves packed with products similar to when a blizzard is being called for and folks know they might be stuck at home,” said Andrea Karns, vice president of sales and marketing at Karns Foods, a family-owed chain of nine stores in Pennsylvania. Karns has increased orders from its suppliers to stock up on inventory.