Superbugs on the shelves: diseased chicken being sold across America - The Bureau of Investigative Journalism

Although the United States Department of Agriculture (USDA) deems a certain level of salmonella and campylobacter within poultry acceptable, 12 major US poultry companies, including Perdue, Pilgrim's Pride, Koch Foods, Foster Farms and Tyson, have exceeded USDA standards for acceptable levels of salmonella multiple times since 2018, when the government began reporting contamination rates at individual plants, according to the department's records. The USDA still runs tests for campylobacter in processing plants but it is not currently tracking whether plants exceed the contamination thresholds.

Batches of poultry products with contamination rates above the limit don't have to be recalled, although plants that repeatedly exceed the thresholds can be temporarily shut down.

Separate government records also show that between January 2015 and August 2019, the same 12 major US poultry companies broke food safety rules on at least 145,000 occasions – or on average more than 80 times a day.

Poultry plant workers also claimed they have sometimes been asked to process rotten-smelling meat, have witnessed chicken tossed into grinders with dead insects and found government safety inspectors apparently asleep on the job.

"Since [the meat] comes to us really dirty, when we open the box, it's like, 'Let's see what's inside!'" alleged one worker at a Tyson plant in Springdale, Arkansas. "Sometimes it has flies, it has crickets, cockroaches in there already frozen." He claimed that when he pointed this out to the supervisors, they seemed to show little interest – and so the insects ended up being put into the grinder with the meat.

Campylobacter causes more than 100 deaths every year in America as well as 1.5 million infections. It also accounts for up to 40% of the country's cases of Guillain-Barré Syndrome, the disease that left Jayven paralysed. Yet the sale of poultry products found to be contaminated with either that or salmonella bacteria remains perfectly legal.

Canda-Alvarez is still shaken by her son's experience. "One day he's playing golf, and the next day he's completely paralysed. It was the most mind-boggling thing I've ever experienced," she said. "When they told me that it was from campylobacter I was like, 'So this bacteria that nobody knows about, that could destroy your whole life, is from chicken or poultry?'"

"That's why I tell people, you need to be careful how you cook your food or where you eat. Because you never know what could happen."

The level of salmonella and campylobacter that the USDA deems acceptable differs depending on the product. A maximum of 15.4% of chicken parts leaving a processing plant, for instance, can test positive for salmonella and the plant can still meet acceptable standards. The threshold for campylobacter is 7.7%. Many experts argue these levels are too lax.

The USDA's Food Safety and Inspection Service (FSIS) does "a very poor job of regulating the contaminants", according to Zach Corrigan, senior staff attorney at the pressure group Food & Water Watch. "This comes in the way of allowing super-fast line speeds, allowing companies to largely regulate themselves on the slaughter and then doing very little monitoring of contamination."

An FSIS spokesperson said: "FSIS is committed to reducing foodborne infections associated with FSIS-regulated products, including reduction of salmonella illnesses attributable to poultry."

Especially concerning is the increase in antibiotic-resistant strains of bacteria. The number of drug-resistant salmonella infections in the US rose from around 159,000 in 2004 to around 222,000 in 2016, according to the CDC. Campylobacter has become more resistant too: ciprofloxacin, an antibiotic commonly used to treat it, is increasingly ineffective.