Lymphogranuloma Venereum in the era of PrEP: are we heading for another epidemic?
Professor David Templeton.
Professor Templeton presented a paper on the transmission dynamics of rectal LGV. He gave information regarding the prevalence of infection being significantly more prevalent in gay and bisexual men (GBM) and even more significantly higher in HIV positive men. He posed the question ‘Is it all behaviour or does immunodeficiency play a role?’
The research he had looked at suggested a differing theory of CT transmission (including the LGV serovars) this being the role of ano-oral transmission from gut reservoirs of infection passed through faecal-oral contamination. In comparison to the thinking that it might be past via rimming and fisting. CT can be transmitted from the urethra of men into the throat of their partners, it then is carried through the gut (the gut with it’s down-regulation of inflammatory responses allows CT to survive), it then infects the rectal mucosa and sets up a persisting infection (that then might lead to symptomatic or asymptomatic carriage of LGV or CT.)
This has been suggested by several authors that I found in the reference list of the paper Professor Templeton was quoting – The Enigma of Lymphogranuloma Venereum Spread in Men Who Have Sex With Men: Does Ano-Oral Transmission Play a Role? de Vries, Sexually Transmitted Diseases 43, 7, 2016. Some of the work is based on animal models – where animal CT and ‘LGV – like’ infections occur and persist in the GIT and are not cleared with macrolide treatments.
There are some studies by one author who looked at infection in babies at risk of CT infection at birth and how long it took for the infection to get to the anus of the baby and the vagina of the baby girls – postulating that the infection had to travel through the gut and then through feacal contamination enter the vagina. (for further information read Hidden in Plain Sight: Chlamydial Gastrointestinal Infection and Its Relevance to Persistence in Human Genital Infection Rank & Yeruva, Infection and Immunity 2014 ;82 :4, 1362–1371.
In practice this has implications for testing and treatment as rectal CT and LGV are vastly different to uro-genital infection. Therefore non-sexual health clinicians must ask about sexual practices (or just test every orifice in both men and women), GBM with proctitis or procto-colitis who get sent to Gastro-enterologist must have an anal swab first (symptomatic LGV can present as Crohns Disease for example and be missed) and any GBM with ano-rectal CT infection should have their sample sent for LGV serovar testing. The research is suggesting that heterosexual transmission of LGV is very unusual however continuing vigilance and surveillance is needed to detect shifts in infection dynamics within our community.