7 December 2019 | New Scientist | 15Dating apps Blood donation
Chris Stokel-Walker Alice Klein
TINDER doesn’t seem to be as good
at finding you a partner as you
might think. An analysis of the
match-making service has found
that most people don’t meet up
with others through the app and
the chances of meeting someone
interested in a long-term
relationship are relatively low.
Trond Viggo Grøntvedt at the
Norwegian University of Science
and Technology and his colleagues
surveyed 269 students in Norway
who said they were current or
former Tinder users. About 60 per
cent of the students were women.
People reported that, on average,
they had been matched to more
than 100 people during their time
using the app. But only about half of
the participants said they had ever
actually met a match in person. The
likelihood that a study participant
would use Tinder to meet a potential
partner was the same for men and
women (Evolutionary Psychological
Science, doi.org/df79).
Only about 25 per cent of study
participants said they had used
the app to meet someone interested
in a long-term relationship.
Grøntvedt’s team also discovered
that some 20 per cent of people
had used Tinder to meet a partner
for a one-night stand – although the
participants reported they were as
likely to have a one-night stand with
someone they met via other means.
Tinder might not be an efficient
way of meeting a long-term
committed partner, says Grøntvedt.
“But this is one study from Norway,”
he cautions. “We need to see more
cross-cultural studies.”
Gareth Tyson at Queen Mary
University of London is sceptical
that Tinder has had much effect on
dating. “Tinder may not be rewriting
the fundamentals of modern dating:
similar patterns continue, simply
in a new arena,” he says.
Tinder didn’t respond to New
Scientist’s request for comment. ❚
Tinder may not
be much good for
finding a partner
NEW rules that make it easier
for gay and bisexual men in the
UK to donate blood have been
found to be safe, but equal rights
campaigners say they don’t go
far enough to eliminate
discrimination.
Most rich countries,
including the US and Australia,
only allow men who have sex
with men to donate blood if
they have abstained from sex
for at least 12 months, because
men in these countries have a
higher risk of getting HIV and
hepatitis from sex. In the US, for
example, two-thirds of new HIV
infections result from male-to-
male sexual contact.
All donated blood is tested
before it is used, but it takes
time for recent HIV and
hepatitis infections to become
detectable, which is why most
countries ask that higher-risk
donors avoid sex for a period
of time before giving blood.
However, modern screening
tests can detect HIV and
hepatitis within one month
of a person being infected.
In November 2017, England,
Scotland and Wales shortened
the time that men who have sexwith men have to abstain from
sex before donating blood to
three months, on the guidance
of the UK’s Advisory Committee
on the Safety of Blood, Tissues
and Organs.
Two years in, this change
hasn’t compromised the safety
of the UK’s donor blood supply,
says Katy Davison of Public
Health England, who presented
the first data at a meeting
of the AABB internationalblood bank association in
San Antonio, Texas.
There was no significant
rise in infected blood. Out of
2 million blood donations made
in the UK in 2018, seven tested
positive for HIV, compared with
six in 2017. These donations
were discarded and no one
received HIV-infected blood,
she told the meeting.
In addition, 89 blood
donations tested positive for
hepatitis in 2018, comparedwith 102 the previous year.
Blood transfusions resulted in
one person becoming infected
with hepatitis B and another
with hepatitis E, but this was
below the required rate of no
more than one infection per
1 million transfusions.
Several other countries have
followed the UK’s lead. Canada
moved to a three-month
abstinence period in June,
and France, Denmark and the
Netherlands have approved
four-month abstinence periods.
However, activist group
Freedom to Donate says these
new rules are still discriminatory
because they group people
together based on sexuality
rather than individual
behaviour. It wants governments
to introduce individualised risk
assessments that would allow
men who have sex with men
with low-risk sexual behaviour –
like those in monogamous
relationships or who always use
protection – to donate blood
without having to abstain.
One major question that
needs to be addressed before
individualised risk assessments
can be introduced more widely
is whether people taking pre-
exposure prophylaxis (PrEP)
drugs can safely donate blood,
says Brian Custer at US blood
research institute Vitalant.
These medicines lower the
risk of getting HIV from sex by
about 99 per cent when taken
properly. But HIV can still be
contracted if PrEP is taken
inconsistently, and the virus
may not show up in screening
tests because PrEP reduces
the viral load in the blood,
says Custer. ❚UK’s new blood donor
rules are safe
BE
RND^ VOGEL
/GETTY^ IMAGESThere has been no rise
in HIV or hepatitis in
donated blood3 months
How long gay and bisexual men
are asked not to have sex before
donating blood in the UK