HIV-1 CRF07_BC Infections, Injecting Drug Users, Taiwan

To date Taiwans human immunodeficiency virus type 1 (HIV-1) epidemic has primarily spread via sexual contact. The subtype B and circulating recombinant form (CRF) 01_AE account for > 95% of all infections. However since 2003 Taiwan has experienced a major outbreak of CRF07_BC among injecting drug users (IDUs). The first wave of HIV-1 infections in Taiwan can be traced to the early 1980s when a group of hemophilia patients received imported HIV-1-contaminated antihemophilia medications. By the time these medications had been replaced by heat-treated factor VIII concentrates at least 53 patients had contracted HIV-1 infections. (excerpt)

. The Taiwan CDC received reports of 1,241 IDUs diagnosed with HIV-1 infections from January 1 to July 31, 2005; these account for >75% of all reported HIV- Since all inmates are routinely tested for HIV-1 in detention centers, and all infected inmates are separated from HIV-1-seronegative inmates, the potential of HIV-1 transmission in prisons is remote. We therefore suggest that the Taiwanese IDU population and its HIV-1 seropositive rate have both increased rapidly in the past few years.
To identify the primary HIV-1 strains in the current epidemic, we collected blood specimens from HIV-1-infected inmates in 3 detention centers (1 each located in the northern, central and southern regions of Taiwan). HIV-1 subtypes were determined by polymerase chain reaction, DNA sequencing, and phylogenetic analyses of pol or env genes. Our results indicate that 145 (96%) of 151 IDUs were infected with CRF07_BC and 6 (4%) were infected with subtype B; 97% of the CRF07_BC cases were diagnosed in 2003 or 2004. According to our phylogenetic analysis of the env gene, the Taiwanese CRF07_BC strains clustered with CRF07_BC strains drawn from IDUs in China (Figure).
CRF07_BC is a recombinant of the B′ and C subtypes. Several studies have suggested that CRF07_BC originated in China's Yunnan Province, with subtype B′ from Thailand mixing with subtype C from India before moving northwestward to Xinjiang Province along a major Chinese heroin trafficking route (4)(5)(6). To our knowledge, this is the first report of a large group of IDUs in northeastern Asia having CRF07_BC infections. It may have followed another drug trafficking route from Yunnan Province to southeast China, moving through Guangxi Province and Hong Kong to Taiwan (7-9). In a bid to combat skyrocketing HIV/AIDS infection rates among IDUs, the Taiwan CDC has proposed a 5-year harm reduction program to the Republic of China Executive Yuan.

Acknowledgments
We thank Yi-Ru Chang for her technical assistance, the Sequencing Core

Chlamydialike Organisms and Atherosclerosis
To the Editor: Chlamydophila pneumoniae causes pneumonia, but its role in the pathogenesis of atherosclerosis is controversial (1)(2)(3)(4). The role of C. pneumoniae in atherosclerosis is supported by seroepidemiologic studies and detection in atherosclerotic lesions by polymerase chain reaction (PCR), immunohistologic analysis, culture, and electron microscopy (2,3). However, these results were not confirmed by other serologic or PCR-based studies (4). Meijer et al. evaluated abdominal aortic aneurysm biopsy specimens and detected C. pneumoniae membrane antigen more frequently than lipopolysaccharide antigens but did not detect heat shock protein 60 (1). In addition, they could not amplify or detect specific C. pneumoniae DNA by PCR and fluorescence in situ hybridization (1). They hypothesized that this discrepancy may result from a chlamydialike organism present in aortic samples that has surface antigens similar to those of C. pneumoniae.
Parachlamydia acanthamoebae and Neochlamydia hartmanellae are chlamydialike organisms that share ≈86% 16S rRNA sequence similarity with C. pneumoniae (5). Like C. pneumoniae, they have elementary and reticulate bodies visible by electron microscopy (6). Neochlamydiarelated DNA (GenBank accession no. AF097191) has been amplified from 5 different arterial samples, including 1 aortic aneurysm (7), and a relationship (p = 0.009) between cerebral hemorrhage and serologic evidence of Parachlamydia infection has been reported (8). Therefore, we investigated the role of Parachlamydia in pathogenesis of atherosclerosis by using a molecular approach.
We analyzed 78 surgical samples from 27 patients undergoing aortic or carotid surgery for atherosclerotic disease at Hôpital Nord in Marseille from June 1, 2003, to December 31, 2003. The study was approved by the local ethics committee, and written informed consent was obtained from all participants. Demographic and clinical data were prospectively recorded.
Sequences were analyzed with BLAST (http://www.ncbi.nlm.nih. gov/BLAST/) using gap existence and extension penalties of 5 and 2, respectively. Results were considered positive only when the sequence of the amplified product exhibited a best BLAST hit with a chlamydialike organism. Statistical analyses were performed with STATA software (Stata Corporation, College Station, TX, USA).
A positive PCR result was obtained with samples from 5 (18.5%) of 27 patients (Table). Three sequences had a best BLAST hit with the sequence of Parachlamydia sp. UV7 (GenBank accession no. AJ715410), with a sequence similarity ranging from 99% to 100%. The other 2 sequences had 98% sequence similarity with Neochlamydia-related symbiont TUME-1 (GenBank accession no. AF098330). PCR positivity was not associated with age, sex, or location of the atherosclerotic lesion.
All patients with positive PCR results were >68 years of age. Patients without cardiovascular risk factors were more likely than those with >1 risk factor to have positive PCR results (p = 0.023). Despite the small number of patients in this study, this association was also confirmed in a multivariate logistic regression model adjusted for sex and previous cardiovascular disease (odds ratio 0.035, 95% confidence interval 0.001-0.94).
These findings suggest that Parachlamydia and Neochlamydia are associated with atherosclerosis. In addition, these obligate intracellular