A Boston-bound United Airlines flight was diverted on Sunday mid-air over a 'biohazard' issue.

United Airlines flight 2477 departed from Houston at 9:39 a.m. CT on Sunday destined for Boston, but was forced to reroute when a customer became sick, the airline told DailyMail.com.

The plane, a Boeing 737-800, was diverted to Washington Dulles International Airport, landing at 1:36 p.m. ET, according to FlightAware. 

'Especially with this kind of being a biohazard, I think we need to get this plane on the ground ASAP,' a pilot on board said to air traffic control in audio shared on X.

Despite the on board drama, known of the 155 passengers or six crew members required medical assistance after the plane landed in the nation's capital. 

'The crew is vomiting and passengers all around are asking for masks, etc.

'I talked to the crew and it sounds like it's quite bad back there.' 

'The aircraft is currently undergoing a deep clean and we are working to get customers on their way to Boston soon,' United said. 

Flight tracking shows the aircraft is set to leave Dulles and continue its journey to Boston at 3:40 p.m. ET. 

A biohazard event is generally classified as exposure to a biological substance such as feces, vomit or blood, that could harm a person's health. 

In September 2023, a dramatic biohazard incident forced a Delta Airbus A350 en route from Atlanta to Barcelona was forced to turn back after a passenger suffered an horrific bout of diarrhea. 

The outbreak prompted a five-hour clean-up operation, with carpets being torn up and vanilla scented disinfectant being deployed. 

One disturbed passenger took to social media, saying that her partner reported that the offending excrement had been dribbling down the aisle. 

The woman, known as Dee W on X, said: 'My partner was on that flight! It was pretty bad. It was dribbled down the aisle, smelled horrible. 

Sunday's incident not the first incident to occur on the route this year. 

In March, the United Airlines flight 2477, veered off the runway when the pilot failed to slow down enough. 

That incident forced the evacuation of the 161 passengers and six crew members.

The summer of bizarre incidents on board flights amid the vacation season shows no signs of letting up.  

On July 9, a passenger bit a chunk of fabric out of a United Airlines flight attendant's shirt and told an 'old lady' she should 'go back to Russia' during a mid-fight meltdown.

The woman was on United Airlines Flight 762 from Miami to Newark but barely made it off the runway before she became unruly over a petty toilet squabble.

Video recorded by another traveler began after the crew restrained her wrists with zip-ties and she was wrestling with three of them.

Suddenly she bit one of their shoulders, tearing off a piece of fabric and letting it float to the floor in front of the shocked plane.

'Stop touching me... let go of me, I'm a f**king girl, are you trying to kill me?' she shouted afterwards.

The video cuts to the woman, now with her hands zip-tied behind her back and standing in the aisle, yelling at everyone not to fly United.

'These people have an attitude problem and they don't f**king do their jobs. They're handcuffing me. Why are you handcuffing me?' she yelled.

'Why b***h? Why the f**k are you handcuffing me? Why, why, why?'

A passenger told her to stop yelling and she told her 'go back to Russia, old lady', then let out a steady stream of expletives and told her 'I'll f**king kill you, b***h'.

Audio from the plane caught the woman yelling: 'You're a disgrace, piece of s**t, I wish I could f**king spit on you right now.'

'Don't do that, don't do that,' a male flight attendant warned her. 'You are insulting everyone on this aircraft.'

Everyone on the plane clapped when she was kicked off after the flight diverted to Orlando and was delayed three-and-a-half hours. 

In April, a United Airlines flight was forced to divert after a dog pooped in the first class aisle. 

The messy incident was captured by Reddit user gig_wizard, who said they were on the five-hour Flight 422 from Houston to Seattle on Friday, April 7, when the incident occurred.

'Dog had messy accident in the aisle right in first class,' the passenger wrote alongside the photo. 

The Reddit user said the flight was diverted to Dallas Fort Worth International Airport, where the ground crew spent over two hours trying to clean the carpet with paper towels, noting the smell made them ill.

'Gate agents kept yelling at passengers and the cabin crew,' they continued.

'The smell never quite went away.'

The multi-hour cleaning effect was ultimately unsuccessful, after the first class toilet was declared unusable.

'The dog mess was apparently unresolved in there,' the passenger wrote. 'Food went bad while on the ground so very few snacks left.'

In an email to DailyMail.com, United Airlines confirmed that the incident had occurred but declined to share any other details.