Substantial numbers of British adults find new sexual partners while travelling abroad, find two studies, published online in the journal Sexually Transmitted Infections.
And it's not just all about the young; plenty of older men and women have sex with new partners while travelling overseas, the figures indicate, prompting the authors of one of the studies to call for safer sex information to be routinely provided in pre-departure travellers' health advice, regardless of age, destination, or reason for travel.
In the first study, the researchers analysed responses to the third British National Survey of Sexual Attitudes & Lifestyles (Natsal-3), carried out between 2010 and 2012 among more than 15,000 16-74 year olds living in Britain.
In all, 12,530 people said they had had at least one sexual partner within the preceding five years.
Of these, one in 10 men and one in 20 women -- 1071 altogether -- said they had had sex with a new partner while travelling overseas during this time. Among those aged 35 and older, the equivalent figures were one in 20 men and one in 40 women -- numbers which are likely to rise in tandem with the increase in 'healthy ageing' and partnership break-down, suggest the researchers.
Reporting sex with a new partner while travelling overseas was strongly associated with higher numbers of partners, overall, and other 'risky' behaviours, such as not using a condom, illicit drug use, and excess alcohol, the responses showed.
And both men and women who had sex with new partners while overseas were more likely to say they been to a sexual health clinic, had been tested for HIV, or been diagnosed with a sexually transmitted infection within the past five years.
Nearly three quarters of the men (just under 72%) and over half (almost 58.5%) of the women reported having sex with at least one new partner from outside the UK while overseas.
This group was more likely to report higher numbers of partners and concurrent partnerships. And men in this group were also much more likely to report paying for sex.
Around one in four (26%) men who reported new non-UK partners said they had paid for sex within the past five years and had ever paid for sex outside the UK. And older men (35-74) were more likely than younger men (37% vs 19%) to report this. They also averaged more (three) partners than those not paying for sex (average of one).
The researchers emphasise that the survey did not mine information on condom use or the acquisition of sexually transmitted infections while overseas, but they nevertheless conclude that their data indicate little change over the past decade.
"At a population level, those reporting new partners while overseas continue to be a high risk group, being more likely to report sexual risk behaviours as well as potentially harmful health behaviours, including drug and alcohol use," which, in turn can increase the risks of unsafe sex, they write.
"This argues for the importance of holistic travel advice, addressing sex in the context of broader health behaviours," they say. And it should include older people too.
Referring to the numbers of older people having sex with new partners while overseas, they suggest: "These proportions are likely to increase as older people maintain good health, have the financial means to travel, and are now more likely to experience partnership breakdown, and so older age groups should also be considered for health promotion messages by health professionals when consulting for travel advice."
A second study in the journal draws on the responses of 2013 backpackers visiting the Thai islands of Koh Phangan and Koh Tao in 2013. It found differences in safer sex practices among travellers of different nationalities.
Almost two thirds of all the respondents (61.5%) were travelling without a long term sexual partner, and well over a third (39%) said they had had sex with a new partner during the trip--usually other backpackers from other countries, although men were more likely than women to have had sex with a local person.
But nearly 37% reported no or inconsistent condom use, with Brits and Swedes the most likely to say this -- echoing patterns of sexually transmitted infections in both countries, which have some of the highest reported rates of chlamydia in Europe, the researchers point out.
German backpackers were less likely than Brits to engage in unsafe sex, but they were also less likely to acquire new partners, while Canadians were most likely to report a new sexual partner, but also more likely to say they had used a condom.
While condom use was associated with a greater likelihood of safer sex, a third of those who said they had packed condoms, didn't always use them.
The researchers concede that the limited geographical coverage of the survey mean the findings might not reflect the behaviour of all young travellers, but they suggest that backpackers are a group worth targeting to promote safer sex while travelling.
"In an era of growing antibiotic resistance and continuing HIV transmission, targeting unsafe sex in backpackers has the potential to reduce STI [sexually transmitted infection] incidence internationally," they conclude.
In an editorial linked to both studies, Drs Alberto Matteelli and Susanna Capone, of the Infectious and Tropical Diseases Clinic, University of Brescia, Italy, say that international travel has increased dramatically in recent decades. And they point to its "huge" potential to boost sexual mixing between different nationalities and the consequent spread of antibiotic resistant strains of bacteria.
"The consequences on STIs could be substantial. STIs have uneven geographical distribution, and travellers may act as bridges between high-burden and low-burden countries," they write, citing the example of how syphilis was thought to have been introduced to Europe from the Americas by Columbus and the conquistadors.
"Unfortunately, we do not have any patented intervention of any kind, with proven efficacy in changing human behaviours towards lower risk sexual practices while travelling," they point out. Research in this area is urgently needed as the impact of a new effective approach "would have the highest probability of being transformational," they suggest.