Seroepidemiology and phylogenetic analysis of human herpesvirus type 8 in injection drug users and men who have sex with men in northern Taiwan

Abstract

Objectives: Human herpesvirus 8 (HHV-8) is transmissible and causes Kaposi’s sarcoma and other malignancies. This study analyzed the seroepidemiology and phylogeny of HHV-8 among 515 injection drug users (IDUs) and 229 men who have sex with men (MSM) in Taiwan.

Methods: Blood and peripheral mononuclear cells were analyzed for HHV-8 seroprevalence using enzyme-linked immunosorbent and immunofluorescence assays. Viral loads were measured using a real-time PCR assay. Phylogenetic analysis of the K1 gene was performed using nested PCR and DNA sequencing.

Results: HHV-8 infection rate was higher in MSM (24.9%) than in IDUs (3.8%). The rate of HHV-8 infection was higher in HIV-1-positive patients (32.8%, MSM; 5.5%, IDUs) than in HIV-1 negative patients. HHV-8 load was not significantly different between HHV-8 seropositive and seronegative patients. HHV-8 genotypes C and A variants were detected at frequencies of 80% and 20%, respectively, among IDUs; and genotypes C, D, E, and A were detected at frequencies of 55.6%, 11.1%, 11.1%, and 5.6%, respectively, among MSM. Variants of K1 amino acid residues 54–84 were detected in most IDUs and MSM.

Conclusions: HHV-8 prevalence was significantly higher among MSM than among IDUs. Evolution of the K1 gene occurred in HHV-8 variants of IDUs and MSM.

Keywords: HHV-8; HIV-1; IDU; MSM; phylogeny; seroepidemiology.

Figure 1.

Predicted phylogenetic distribution of a 561-bp segment of HHV-8 K1 amplified from MSM and IDUs with HIV(+) among a background of GeneBank sequences representing the major ORF K1 subtypes. Linear unrooted phylogenetic dendrograms were generated using the neighbor-joining method. Bootstrapping of 1000 replicates is indicated as a percentage at major branch points, and P values are labeled on each node (*P < 0.05 and **P < 0.01). The genetic distance, size scale = 0.02 (2% divergence) is indicated. •: BC-1 (primary effusion B lymphoma cells, positive control); ▲: IDUs (TYKS 1, 5, 17–19); ♦: MSM (TPE-VGH, TYKS 7–13, 20–22); ▪: MSM (MVDCI, TYKS 2–4, 6, 4–16, 23); TYKS, Taiwan Yang-Ming University Kaposi’s sarcoma associated virus; MVDCI, Taipei-Municipal Venereal Disease Control Institution; TPE-VGH, Taipei-Veterans General Hospital.

Figure 2.

Sequence analyses of the K1 variable region, VRI loop, identify genotypic diversity in HHV-8 detected in IDUs and MSM. The K1 region was PCR-amplified from PBMC DNAs, sequenced, and aligned with representative K1 genotypes. Dashes indicate identities.