Suarez reacts after clashing with Italy’s Chiellini. (Reuters)

New Delhi, June 25: Those inclined to defend Uruguayan football striker Luis Suarez might want to cite a census of human bites from New York City 35 years ago that had documented 12 per cent presumably accidental bites incurred during sports.

But sports psychologists suspect Suarez’s alleged bite on the shoulder of Italian defender Giorgio Chiellini during a World Cup clash in Brazil on Tuesday — if confirmed, his third bite on an opponent on a football field in five years — represents a bad way of coping with stress.

“Competitive sports are highly passionate and players with poor emotional intuitions can find themselves drifting into fairly bizarre and often unsporting behaviour,” Adam Naylor, a sports psychologist at Boston University, told The Telegraph.

Naylor, who has spent over a decade educating professional sportspersons, including some Olympians, said the incident with Suarez could be seen as a maladaptive way of coping with stress in the sports arena.

Psychologists and psychiatrists have known for long that increased frustration can in some people at times lead to increased or unregulated aggression. “When frustration crosses a tipping point, it may trigger aggression,” said Madhusudan Solanki, a psychiatrist at the Saket City Hospital, New Delhi.

“But the level of that tipping point and the manifestation of that aggression depends on the personality,” Solanki added. “Both are different for different people.”

Suarez has been in similar trouble on the football field before. He was suspended in 2010 by his club for biting an opponent. In 2013, he was suspended again after he bit Chelsea’s Branislav Ivanovic.

Medical studies from the West suggest that human bite injuries account for about one in 1,000 visits to emergency medicine departments. Five years ago, a study in the UK documented 421 bites over a four-year period — about one bite every three days.

In one of the largest studies on the subject, a team of doctors in New York City analysed 892 human bites reported to medical institutions across the city in 1979, analysing sites of injuries and the circumstances, if recorded, in which the bites had occurred.

The doctors, who documented the circumstances in 464 of the 892 bites, found aggressive activities — fighting, police arrests and mugging — accounted for 72 per cent of the bites. Playing sports or games accounted for the largest proportion — 12 per cent — of non-aggressive bites. Their study, published in the journal Public Health Reports, had also found humans were the third most common source of bites, after dogs and cats.

Human behaviour specialists say biting is only one among several manifestations of aggressive behaviour. “There is a continuum — some people might shout and abuse or kick things around or, on the sports field, push people,” Solanki said.

Such behaviour signals what psychologists call poor impulse control when coping with adversity. “We can’t say exactly why he (Suarez) does this but, on the football field, he’s likely to be experiencing stress and his coping mechanism might be to cause injury rather than deal with the stress mentally,” said Chris Harwood, reader in applied sports psychology at the University of Loughbourough.

“Suarez would have been under pressure,” said Rhonda Cohen, a sports and exercise psychologist at Middlesex University in the UK. “He was frustrated and reverted to an instinctual behaviour of biting.”

Some medical studies suggest that one in five human bite injuries is likely to lead to infection. Human bites may transmit microbes by exposing the biter’s oral mucosa to the blood of the victim, and the bite wound to the biter’s saliva. A research study published in 2007 cited a bacterial load in human saliva at about 900 million microorganisms per ml.

How a bite should be treated depends on the severity of the bite. Doctors have observed that the use of antibiotics after bites can significantly reduce the risk of infection. While studies have documented four instances where people became positive for hepatitis B virus after bites, most doctors believe the evidence for such transmission is inadequate.

Photographs taken during Tuesday’s match showed Suarez on the ground holding his teeth immediately after the incident, a Reuters report from Brazil said today.

The world football body, Fifa, said it had initiated disciplinary proceedings against Suarez. Fifa said Suarez and the Uruguayan football association had until 5pm Brasilia time on Wednesday to “provide their position and any documentary evidence they deem relevant”.