Rates of gonorrhoea, syphilis and chlamydia have risen
steeply at Fenway Health in Boston since 2011, according to a presentation last
week at IDWeek in New Orleans. Being HIV-positive men and using pre-exposure
prophylaxis (PrEP) to prevent HIV were associated with higher risk of getting
sexually transmitted infections (STIs), but more frequent STI testing and
treatment could potentially help reduce the numbers.
Studies of gay and bisexual men have
shown that tenofovir/emtricitabine (Truvada) PrEP reduces the
likelihood of HIV infection by more than
90% if used consistently. A common concern is that PrEP will lead people to
stop using condoms, putting them at risk for other STIs. This "risk
compensation" was not seen in clinical trials that led to approval of Truvada for HIV prevention, but it has been reported in some PrEP demonstration projects and real-world
PrEP trial participants and clients
of PrEP programmes generally do have high rates of STIs, but this is true at the
outset before they start taking Truvada.
Most studies indicate that men at highest risk for HIV – which includes those
who already do not use condoms – are most likely to seek PrEP. And in many
cities STI rates were on the rise well before PrEP became widely available.
Douglas Krakower of Beth Israel Deaconess Medical Center
and colleagues used electronic health records to analyse trends in PrEP use and
STI rates at Fenway Health, which specialises in the care of sexual and gender
A total of 19,238 men visited the clinic at least once
between 2005 and 2015. About three quarters were white, 6% were black, and 10%
were Latino. While 43% identified as gay and 3% as bisexual, just over half did
not report a sexual orientation. With regard to healthcare coverage, 62%
had private health insurance, 5% each were on Medicaid (for low-income people) and
Medicare (for seniors), and 8% reported no insurance.
About 15% of Fenway clients were HIV-positive. While
the number of people with newly diagnosed HIV infection has fallen in
Massachusetts overall, it is rising at Fenway Health, suggesting consolidation
of HIV care at this centre. In 2004, 6% of all HIV diagnoses in the state were
made at Fenway Health, rising to 14% in 2013.
From 2004 to 2014, the median CD4 cell count at
the time of antiretroviral therapy (ART) initiation rose, from 238 to 464
cells/mm3, as did the proportion of people starting ART within a
year of HIV diagnosis (from 68% to 97%) and the percentage achieving viral
suppression (from 57% to 86%).
Among HIV-negative clients, the rise in PrEP use in
over the past five years has been "very rapid and steep," according
to Krakower. The number of Fenway clients receiving prescriptions for
tenofovir/emtricitabine for PrEP rose from just five in 2011 to 960 in 2015. Last
year 14% of all men seen at the clinic for any reason ended up with a PrEP
Between 2005 and 2015, 18% of men seen at the clinic
were diagnosed with at least one bacterial STI: 7% with gonorrhoea (3%
rectal and 4% urogenital), 7% with syphilis and 9% with chlamydia. Almost all
cases occurred among men who have sex with men. By 2015, 14% of HIV-positive
people and 25% of HIV-negative PrEP clients had at least one STI. But Krakower
stressed that it is "hard to infer causality" from this type of data,
and noted that a substantial number of men who were HIV-negative and not on
PrEP got STIs as well.
Rates of all three bacterial STIs rose over time.
Syphilis increased over the entire period between 2000 and 2015, with an
accelerated rise starting around 2011. Gonorrhoea was relatively stable from
2003 to 2010, then shot up dramatically in 2011 – a "near
astronomical rise," Krakower said. Chlamydia was only reported since 2011,
showing a steady, steep increase since then. Taken together, the combined
number of bacterial STIs at Fenway rose from 162 in 2005 to 1329 in 2015.
Being HIV-positive and using PrEP were both
independently associated with a greater likelihood of being diagnosed with STIs
in a multivariate analysis (hazard ratio 2.66 and 3.43, respectively). Being
African American or of mixed race, and being on Medicaid, uninsured, or without
stable health insurance were also associated with a higher STI risk, but these
associations were not as strong.
"This work really emphasizes the need to educate
people when they are receiving PrEP about the risk of acquiring sexually
transmitted infections," said Pablo Tebas of the University of Pennsylvania at an IDWeek press briefing previewing
highlights of the meeting.
While rising STI rates among gay and bi men are a
concern, the regular clinic visits recommended for HIV-negative people on PrEP may
offer more opportunities for frequent STI testing and prompt treatment.
The US Centers for Disease Control
and Prevention PrEP guidelines recommend STI tests at least every six months, but indicate
that some people may benefit from testing more
Researchers with the PrEP
Demo Project, which enrolled at-risk gay men and transgender women in San
Francisco, Miami and Washington, DC, recently reported that 40% of chlamydia, 34% of gonorrhoea and 20% of
syphilis cases would have been missed if STI screening had been done every six
instead of every three months.
"There probably is a big population – even at a
place like Fenway where clinicians and patients are quite attuned to issues around
sexual health and PrEP – who may benefit from some more intensive screening and
counselling around PrEP, as they're not yet using it," Krakower suggested.