More than L2b in rectal lymphogranuloma venereum
Authors: Marcelo Rodríguez Fermepin, Andrea C Entrocassi, Karina A Büttner, Dolores Caffarena, Deysi López Aquino, Luciana La Rosa, Laura Svidler López
Journal: The Lancet Microbe (2021)

Lymphogranuloma venereum is a sexually transmitted infection that is caused by Chlamydia trachomatis serotypes L1, L2, or L3 and their variants. Since an outbreak of rectal lymphogranuloma venereum was reported in the Netherlands in 2003,1Nieuwenhuis RF Ossewaarde JM Götz HM et al.Resurgence of lymphogranuloma venereum in western Europe: an outbreak of Chlamydia trachomatis serovar L2 proctitis in the Netherlands among men who have sex with men.Clin Infect Dis. 2004; 1: 996-1003Crossref Scopus (254) Google Scholar many other reports from different European countries followed, always showing L2b as the most related genovar.2de Vries HJC de Barbeyrac B de Vrieze NHN et al.2019 European guideline on the management of lymphogranuloma venereum.J Eur Acad Dermatol Venereol. 2019; 33: 1821-1828Crossref PubMed Scopus (36) Google Scholar This new variant was speculated to have been imported from the USA in the 1980–90s,3Christerson L de Vries HJ de Barbeyrac B et al.Typing of lymphogranuloma venereum Chlamydia trachomatis strains.Emerg Infect Dis. 2010; 16: 1777-1779Crossref PubMed Scopus (35) Google Scholar and to date, it is the most frequent C trachomatis genovar in rectal lymphogranuloma venereum. In 2018, an outbreak of rectal lymphogranuloma venereum causing acute proctitis, particularly in men who had sex with men who were infected with HIV (as in the European outbreak), was reported in Argentina,4López LS La Rosa L Entrocassi AC Caffarena D Santos B Fermepin MR Rectal lymphogranuloma venereum, Buenos Aires, Argentina.Emerg Infect Dis. 2019; 25: 598-599Crossref PubMed Scopus (5) Google Scholar leading the Argentinian health authorities to issue an epidemiological alert. We analysed anal swabs from patients with anorectal signs or symptoms of proctitis in private practice and a public hospital. C trachomatis was detected on 47 (48·45%) of 97 samples, and lymphogranuloma venereum was detected on 39 (86·67%) of 45 typable positive samples. An unexpectedly high proportion of L1 genotype (20·51% [8 of 39]) was shown by ompA sequencing (GenBank accession number MN548736.1 to MN548759.1, MN537150.1 to MN537152.1, and MN563608.1 to MN563615.1), even when more than half of the lymphogranuloma venereum positive samples were L2b, and almost one-quarter of the samples were genotype L2, as described in European countries over the past 15 years.2de Vries HJC de Barbeyrac B de Vrieze NHN et al.2019 European guideline on the management of lymphogranuloma venereum.J Eur Acad Dermatol Venereol. 2019; 33: 1821-1828Crossref PubMed Scopus (36) Google Scholar, 5Peuchant O Touati A Sperandio C et al.Changing pattern of Chlamydia trachomatis strains in lymphogranuloma venereum outbreak, France, 2010–2015.Emerg Infect Dis. 2016; 22: 1945-1947Crossref PubMed Scopus (26) Google Scholar Notably, no circulation of L1 genotype has been reported in Europe or Australia over the past two decades.2de Vries HJC de Barbeyrac B de Vrieze NHN et al.2019 European guideline on the management of lymphogranuloma venereum.J Eur Acad Dermatol Venereol. 2019; 33: 1821-1828Crossref PubMed Scopus (36) Google Scholar Our results suggest that the lymphogranuloma venereum strains of C trachomatis causing rectal lymphogranuloma venereum were not spread equally worldwide, giving the Argentinian outbreak this unique profile. Moreover, most of the L1 ompA sequences that we analysed were almost identical (ie, just one nucleotide change) to the one described from the 1980s population of men who had sex with men in San Francisco, CA, USA, in the same survey that identified the USA as the proposed origin of the L2b strain.3Christerson L de Vries HJ de Barbeyrac B et al.Typing of lymphogranuloma venereum Chlamydia trachomatis strains.Emerg Infect Dis. 2010; 16: 1777-1779Crossref PubMed Scopus (35) Google Scholar In conclusion, rectal lymphogranuloma venereum outbreak in Buenos Aires, Argentina, has a different genovar distribution than that reported in European countries, with a high frequency of genotype L1. As has been shown over the years, more remarkably in 2020, an infection can be spread worldwide in our globally connected world. This finding is a potential warning of the possibility of the global spreading of L1 as a causative agent of rectal lymphogranuloma venereum. We declare no competing interests. The hospital's ethical committee approved the study protocol under number 201723. This study has been partly supported by Universidad de Buenos Aires grant UBACyT 20020150100223BA. ACE and KAB contributed equally. The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication. KAB, ACE, LLR, LSL, and MRF verified the data.