Lymphogranuloma venereum in Portugal: unusual events and new variants during 2007

Several European countries identified an ongoing LGV outbreak, particularly among men who have sex with men (MSM). In Portugal, no particular surveillance measures were launched. Nonetheless, circulating LGV strains could eventually be detected through the routine Chlamydia trachomatis ompA genotyping procedure held in the Portuguese National Institute of Health (NIH).

During 2007, 178 Chlamydia trachomatis specimens were genotyped through amplification and automated-sequencing of ompA. Sequences of 891bp (nt142-nt1032) were aligned with currently available chlamydial sequences from GenBank to identify the corresponding genotype.

Eight Chlamydia trachomatis specimens matched LGV-genotypes (7 "L2" and 1 mixed E+L2 undetermined variant). These specimens were identified in samples collected from 4 women and 4 men. One HIV(+) MSM presented LGV related symptoms, while the other infected persons were either asymptomatic or presented no clear LGV symptoms. All samples revealed ompA sequences different from the L2/434 reference strain and from the L2b/144276, which is the most frequently described genotype during the recent LGV outbreak.

The detection of 7 LGV specimens during 2007 in contrast with their absence over the previous 5 years. The LGV infected individuals do not seem to be related to any sexual networks of MSM, contrarily to those described in other European countries. Moreover, all Lisbon LGV specimens revealed unusual ompA sequences that differentiate them from the currently reported LGV infections in Europe. The results of the current study further justify an attentive surveillance of LGV strains infecting different populations and the study of their relation with clinical aspects and disease patterns.