Surfers and swimmers may be at a heightened risk of developing gastroenteritis due to the amount of sewage, laden with bacteria, entering the sea, according to new research.
Activities such as diving and kayaking that bring people into contact with the sea can also increase the chances of developing a number of other illnesses. These include infection of the ears, eyes, throat and nose, as well as stomach aches, scientists are claiming. The University of Exeter’s Dr Anne Leonard, who is carrying out additional research covering the risk to bathers in the United Kingdom, says current research indicates that recreational activities in coastal waters are causing an increasing number of illnesses.
Marine activities may also be increasing the chance of being infected with strains of bacteria that are resistant to antibiotics, like E. coli, which have been detected off the UK coast for the first time in large quantities by scientists. However, more research is required in order to confirm these findings, as, up to now, studies have relied upon symptoms being reported by swimmers themselves, making it uncertain whether they really were infected by these types of bacteria.
The path of the bacteria
Dr William Gaze, also of the University of Exeter, led the antibiotic resistant bacteria study, which has highlighted the extent to which a multitude of different kinds of bacteria are entering the sea. The bacteria arrive in the ocean by being passed into the sewage system via the human digestive tract, eventually entering rivers, and finally the ocean, when heavy rain causes sewers to overflow. Dr Gaze discovered that antibiotic resistant E. coli was being swallowed by swimmers and surfers in enough quantities to cause a genuine exposure risk. This makes it a real possibility that that exposure could result in infection, although that has yet to be confirmed.
A real mouthful
In a typical surfing session, participants tend to swallow about 1/6th of a litre of seawater, and that polluted water could contain up to 750 E.coli bugs that are resistant to antibiotics, according to Dr Gaze. However, there is a much lower risk of infection or exposure in the great majority of bathing waters, which have already been judged as meeting with water quality standards.
Additional research is being carried out by Gaze’s team in order to learn more about the potential health risks inherent in seawater sports. Gaze admits that very little is really known about the way in which antibiotic resistant bacteria can be spread to humans by the natural environment, or how health could be impacted by exposure to such microbes. Given that millions of people spend time on beaches every year, increasing the risk of resistant E. coli being ingested, there could be an even higher level of exposure to resistant bacteria for all water users.
Gaze’s team discovered that although just 0.12 percent of all E. coli located in coastal waters (and in rivers connected to beaches) were resistant to the important antibiotics class known as 3GCs, or third generation cephalosporins, that amount of concentration was still high enough to pose a potential exposure risk to those making use of the waters.
The Beach Bum survey
A novel experiment known as the Beach Bum survey has been devised by researchers at Exeter University, in order to learn more about the dangers to human health of ocean bacteria.
150 body-boarders and surfers, who use the ocean three times every month as a minimum, were recruited and provided with a cotton bud. The participants could then self-perform a rectal swab, and hand the results in for examination. Those results are now being analysed by Dr Anne Leonard, in a bid to see what the swabs reveal about the bacteria content in their guts. It's hoped that this analysis could yield vital information about the level of risk caused by bugs that are resistant to antibiotics in our oceans.
The study’s recruitment process was led by Andy Cummins from Surfers Against Sewage, a campaign group. Cummins says the aim is to have a clearer idea of the risks of entering the water. The study has now been completed, and the findings are expected to be published before long.