P1-S5.34 Diffuse distribution and extensive disassortative mixing ofChlamydia trachomatisgenotypes between ethnic groups in Paramaribo, Suriname
Authors: Bom R , van der Helm J , Sabajo L , de Vries H , Grunberg A , Bruisten S 
Published: July 2011

Background

Suriname is a multicultural society with many ethnic groups, such as Creoles and Maroons (descendants from the African diaspora due to slave trade), Indian, Javanese and Chinese (descendants from labour immigrants), Caucasian (descendants from Dutch immigrants during colonisation) and indigenous Amerindian people. The prevalence of Chlamydia trachomatis (CT) in Suriname is high (between 10 and 23% among respectively low-risk birth control and high-risk STI clinic visitors). We aim to study the influence of sexual mixing on the transmission of CT in Paramaribo, Suriname.

Methods

Samples were collected at a birth control clinic and an STI clinic in Paramaribo. Detailed questionnaires were given to visitors, concerning ethnic background, both self considered as well as that of their parents. The samples were tested with NAAT for CT. Positive samples were typed using multilocus sequence typing (MLST). Minimum spanning trees were generated and clusters were combined with the epidemiological data.

Results

We retrieved full MLST profiles for 181 of 233 samples. Eighteen ompA variants from nine different genovars were found, which were split up into 68 MLST sequence types. Although the predominant genovars were E (32.6%), F (18.8%) and D (18.8%), a remarkably large proportion was genovar I (14.4%). The sequence types of most genovars clustered together, but possible recombination events were seen for genovar B, D, E and J. The minimum spanning tree showed two large clusters for genovar E and F (30 and 19 samples each) and 28 smaller clusters (2 to 7 samples). More than half of the sequence types (38/68) consisted of singletons. When ethnicity was superimposed on the minimum spanning tree, it was diffusely distributed over all clusters (Abstract P1-S5.34 figure 1). Almost all participants (175/181) had sex partners in Suriname. Disassortative sexual mixing with other ethnical groups (having a partner from a different ethnic background) was reported by 56.0% (98/175) of the participants.

Abstract P1-S5.34 Figure 1

Ethnical background superimposed on the minimum spanning tree generated from the MLST data of 181 chlamydial infections from Paramaribo, Suriname. Depicted are the predominant ethnic groups for Chlamydia infections: Creoles are given in black, people from mixed race in grey, Maroons in dark grey and Javanese people are given in light grey. Indian, Amerindian and Caucasian people are given in white.

Conclusions

The diversity among chlamydial types within the Surinamese population was shown to be high, as about half of the sequence types were unique. The distribution of sequence types over the population seemed not to be influenced by ethnical background. This could possibly be explained by the high degree of disassortative mixing. This is in contrast to previous studies on HIV transmission in Suriname where clustering within ethnic groups was found and disassortative mixing was lacking.