Rectal infection with the STI lymphogranuloma venereum (LGV) in gay and bisexual men in central Europe is substantially under-diagnosed, according to research published in Sexually Transmitted Infections. Analysis of samples testing positive for chlamydia showed that 26% actually involved infection with LGV. In some instances, under-diagnosis led to the use of potentially suboptimal therapy.
Especially high rates of LGV – a form of chlamydia that can cause severe symptoms – were observed in men living with HIV and there was also some evidence that it was associated with travel outside the EU.
Dr Michelle Cole of Public Health England (PHE) led the research with clinics and laboratories in Austria, Croatia and Slovakia – countries in which LGV surveillance is not routinely conducted. The epidemiology of LGV among men who have sex with men in these countries was compared to the situation in the UK, where there has been robust LGV surveillance since the early 2000s.
“Our data suggest considerable under-diagnosis of LGV may be occurring across many EU countries given the number of previously unidentified LGV cases detected and the poor availability of LGV diagnostics,” comment Dr Cole and colleagues. They believe their findings are of public health significance, showing the importance of addressing barriers to LGV testing in order to optimise surveillance, diagnosis, treatment and prevention.
Epidemics of LGV among gay and bisexual men have been reported in Europe, North America and Canada. Most of the cases have involved rectal infection. Symptoms are typically more severe than with rectal chlamydia and may include proctitis, rectal bleeding, fever, tiredness and weight loss. Nonetheless, previous studies have reported that between 27 and 43% of cases are asymptomatic. If untreated, it can cause anal fistulas.
Correct diagnosis is important because of these distressing symptoms and also to ensure that people receive the correct therapy – LGV is cured by a 21-day course of the antibiotic doxycycline, whereas routine chlamydia only requires a seven-day course to achieve a cure.
The LGV epidemic among gay and bisexual men in Europe was first detected in around 2003. Over half of all documented cases are in just three countries: France, the Netherlands and the UK. The state of the epidemic in other countries, especially in central and eastern Europe, is much less clear. This is largely because surveillance and reporting systems are not in place.
Investigators from Austria, Croatia and Slovenia therefore collaborated with researchers at PHE and designed a pilot study to better describe rates of LGV in their countries.
The study involved clinics and laboratories providing sexual health care for gay and bisexual men. Rectal samples collected between 2016 and 2017 and testing positive for chlamydia were sent to PHE for testing. Stored samples from Austria (collected between 2015 and 2016) and from Croatia (taken in 2014) were also analysed.
When available, clinical and demographic data were analysed. The genetic structure of LGV was also examined to see which strains of the bacteria were circulating.
A total of 500 chlamydia-positive samples were examined. Just over a quarter (26%) tested positive for LGV.
The LGV-positivity rate was highest in Austria (79 of 166 samples; 48%). Under-diagnosis of LGV led to the provision of treatment that was potentially suboptimal. Sixty-six patients had been treated with azithromycin and cefixime, then the first-line therapy for chlamydia and gonorrhoea. The treatment given to the other 13 was not reported.
Proctitis was over twice as common among men with LGV compared to those with routine chlamydia (92% vs 41%). A higher proportion of men with LGV than chlamydia had a previous chlamydia diagnosis (36% vs 20%).
"Under-diagnosis led to the use of potentially sub-optimal therapy."
Of the 15 men diagnosed with rectal chlamydia in Croatia, three (20%) were infected with LGV. These men had been treated with a course of doxycycline that lasted for a minimum of 21 days. All three men with LGV had proctitis (compared to a quarter of men with rectal chlamydia) and reported sex abroad within the previous three months.
In Slovenia, there were six cases of rectal chlamydia, including one man (17%) with LGV. He had received 1g azithromycin, then a recommended first-line treatment for chlamydia.
In the UK, 14% of rectal chlamydia samples (45 of 313) were LGV positive. Clinical and demographic data were available for just over half of individuals with rectal chlamydia, including 22 men with LGV. All of those with LGV were treated with doxycycline for either 21 (n = 13) or seven days (n = 9).
Proctitis was reported in 52% of men with LGV compared to 12% of individuals with chlamydia. Men with LGV were twice as likely to be infected with another STI compared to men with chlamydia (63% vs 37%), and a larger proportion were HIV positive (82% vs 64%). Recent sex abroad was reported by 13% of men with LGV and by 11% of men with chlamydia. Approximately a third of individuals with LGV and a quarter of those with chlamydia reported chemsex.
Six LGV sequences were isolated. These included three previously unknown variants. The investigators suggest this diversity could be due to mixed infections leading to recombination and sampling from different transmission clusters.
“Our findings, which suggest systematic underdiagnosis of LGV in Europe, should be cause for considerable public health concern given the associated morbidity of this infection which is often misdiagnosed,” conclude the authors. “Unified infection control efforts are needed to overcome barriers to implementing LGV testing, establish effective surveillance programmes, and optimise diagnosis, treatment and prevention of LGV.”
Cole MJ et al. Substantial underdiagnosis of lymphogranuloma venereum in men who have sex with men in Europe: preliminary findings from a multicentre surveillance pilot. Sexually Transmitted Infections, 96: 137-42, 2020 (open access).