Molecular epidemiology of HIV-1 infection in Taiwan from 2005 to 2008: further spread of CRF07_BC and emergence of CRF07_BC/subtype B dual infection

Geographic Transmission and Epidemic History of HIV-1 CRF01_AE, CRF07_BC, and HCV Subtype-6w among Taiwanese Persons Who Inject Drugs

Persons who inject drugs (PWID) and their risk-related behaviors (e.g., unprotected sex and sharing needles/syringes/other injection equipment) have caused severe public health problems, especially in the rapid spread of HIV-1 and HCV. Here, we reconstructed the epidemic history of HIV-1 circulating recombinant form (CRF) 01_AE, CRF07_BC, and HCV subtype-6w among Taiwanese PWID. The timescales were estimated using phylogenetic and Bayesian coalescent analyses. The results revealed that CRF01_AE started to circulate in the Taiwanese PWID population in central Taiwan at 1992.5 (95% credible region: 1988.8–1995.9) and spread to other regions of Taiwan, while CRF07_BC was first identified in southern Taiwan at 2000.0 (95% CR: 1997.8–2002.2) and then spread northward to central-northern Taiwan. All HCV-6 strains were from Asia (that is, China, Myanmar, Taiwan, and Vietnam) and originated in 1928.1 (95% CR: 1890.2–1966.0). Furthermore, subtype-6w isolates from different regions of Taiwan appeared to share a common source that existed in the mid-1990s (95% CR: 1985.0–2001.8) or thereabouts. The routes of drug trafficking and the resulting high prevalence of HIV-1/HCV co-infections among PWID might have contributed to the virus transmission and promoted its spread worldwide. Long-term monitoring and policy implementation in at-risk populations would be useful for disease control.

Sex stratification of the trends and risk of mortality among individuals living with HIV under different transmission categories

We retrospectively examined 33,142 persons living with HIV (PLWH) in Taiwan from a nationwide database to assess sex-stratified trends and risk of all-cause mortality under different transmission categories from 1984 to 2016. Overall, 61.25% were men who have sex with men (MSM), 14.37% were men who have sex with women (MSW), 18.32% were male persons who inject drugs (M-PWID), 3.30% were women who have sex with men (WSM), and 2.74% were female PWID (F-PWID). All-cause mortality (per 100 person-years) among heterosexual people and PWID was higher in men (4.04 and 3.39, respectively) than in women (2.93 and 2.18, respectively). In each sex-stratified transmission category, the all-cause mortality reduced substantially from 1984–1996 to 2012–2016, but evolved distinctly from 2007–2011 to 2012–2016. Since 2007–2011, the decline in all-cause mortality has slowed notably in the groups with sexually transmitted HIV, but has increased in PWID, surpassing even that among groups with sexually transmitted HIV in 2012–2016. PLWH with sexually transmitted HIV had lower risks of all-cause mortality than PWID, regardless of sex. Sex and transmission category did not interact significantly on all-cause mortality. Understanding the reasons for the distinct evolving trends of all-cause mortality in each transmission category serves as a reference for developing strategies to reduce mortality in PLWH in Taiwan further.

The impact of Taiwan's implementation of a nationwide harm reduction program in 2006 on the use of various illicit drugs: trend analysis of first-time offenders from 2001 to 2017

Background

After implementing a nationwide harm reduction program in 2006, a dramatic decline in the incidence of human immunodeficiency virus (HIV) infection among people with injection drug use (IDU) was observed in Taiwan. The harm reduction program might have sent out the message discouraging the choice of IDU among illicit drug users in early stage. Based on the yearly first-time offense rates from 2001 to 2017, this study aimed to examine (1) whether the nationwide implementation of the harm reduction program in 2006 led to changes in first-time offenders’ use of heroin; (2) whether the intervention had a similar effect on the use of other illicit drugs; and (3) whether the effect of the intervention was limited to the first-time offenders of young age groups.

Methods

Yearly first-time illicit-drug offense rates from 2001 to 2017 in Taiwan were derived from two national databases for drug arrests that were verified using urine tests: the Criminal Record Processing System on Schedule I/II Drugs and the Administrative Penalty System for Schedule III/IV Substances. A hierarchy of mutually exclusive categories of drug uses was defined by the drug with the highest schedule level among those tested positive in an arrest. Segmented regression analyses of interrupted time series were used to test for the impact of the 2006 intervention.

Results

There was a decrease of 22.37 per 100,000 in the rate for heroin but no detectable level changes in that for methamphetamine or ecstasy after the 2006 intervention in Taiwan. There were baseline decreasing trends in the first-time offense rate from 2001 to 2017 for heroin and ecstasy and an increasing trend for methamphetamine, with the slopes not altered by the 2006 intervention. The postintervention decrease in the first-time offense rate for heroin was detectable among offenders less than 40 years old.

Conclusions

Our results indicate a diffusion effect of the 2006 intervention on decreasing heroin use among young offenders and have policy implications for better prevention and treatment for different age groups.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12954-021-00566-5.

Epidemiological and phylogenetic analysis for non-B subtypes of human immunodeficiency virus type 1 in Busan, Korea

Recent data on non-B subtypes’ epidemiology among patients infected with human immunodeficiency virus-1 (HIV-1) in Korea are lacking. We aimed to assess the changing trends in the epidemiology of non-B subtypes of HIV-1 in Korea using phyloepidemiological analyses. We analyzed the demographic records and sequencing data obtained from genotypic drug resistance tests between 2005 and 2019 from 517 patients infected with HIV attending a tertiary care hospital in Busan, Korea. Subtyping and phylogenetic analyses with reference sequences were performed. Additionally, transmission clusters were identified via maximum-likelihood trees. Non-B subtypes accounted for 21.3% of the 517 sequences. CRF01_AE (52.7%) was the most common non-B subtype, followed by CRF02_AG (16.4%), A1 (11.8%), and C (5.5%). The prevalence of non-B subtypes decreased from 36.4 to 13.4% by 2009, while it increased to 27.4% between 2015 and 2019. Among patients with non-B subtypes, the proportion of overseas sailors decreased from 66.7 to 7.5%; contrarily, the proportion of men-who-have-sex-with-men (MSM) increased from 0 to 46.9% over the study period. We identified 8 transmission clusters involving non-B subtypes, with sizes ranging from 2 to 4 patients, including 3 clusters containing MSM. Our results highlight the changes in the epidemiological trends of non-B subtypes of HIV-1 in Korea.

Different Trends of Distinct Time Points of AIDS Events Following HIV Diagnosis in Various At-risk Populations: A Retrospective Nationwide Cohort Study in Taiwan

Introduction

Acquired immune deficiency syndrome (AIDS) events at distinct time points after human immunodeficiency virus (HIV) diagnosis require various AIDS prevention strategies. However, no nationwide epidemiological surveillance studies have been conducted to explore the trends of distinct AIDS event time points in various at-risk populations. The aim of this study was to explore the issues and characterize the determinants of AIDS status after HIV diagnosis.

Methods

This nationwide cohort study enrolled HIV-positive Taiwanese during 1984–2016. AIDS events were classified into three time points (≤ 3, 4–12, > 12 months) by their occurrence time after HIV diagnosis. The periods of HIV/AIDS diagnosis were divided into six categories according to the calendar year of HIV/AIDS diagnosis: 1984–1991, 1992–1996, 1997–2001, 2002–2006, 2007–2011, and 2012–2016. HIV-positive Taiwanese during 1984–2011 were then selected to determine the factors associated with four AIDS statuses within 5 years after HIV diagnosis (no AIDS, AIDS ≤ 3 months, within 4–12 months, > 12 months) using multinomial logistic regression.

Results

Of 33,142 cases, we identified 15,254 (46%) AIDS events. The overall AIDS incidence (events/100 person-years) peaked during 1992–1996 (20.61), then declined, and finally stabilized from 2002 (8.96–9.82). The evolution of the proportion of distinct time points of AIDS events following HIV diagnosis changed significantly in heterosexuals and intravenous drug users (IDUs) during 1984–2016 (decline at ≤ 3 months in IDUs, decline at 4–12 months in IDUs, and increase at > 12 months in heterosexuals and IDUs) but not among men who have sex with men (MSM). Time points at ≤ 3 months remained at > 50% among MSM and at > 55% among heterosexuals. In multinomial logistic regression, IDUs (vs. men who have sex with men; MSM) had a lower risk of all AIDS statuses; heterosexuals (vs. MSM) had a higher risk of AIDS events ≤ 3 months after HIV diagnosis.

Conclusion

The magnitude of AIDS in Taiwan has been stable since 2002. Enhancing early diagnosis among people with sexual contact and optimizing the HIV care continuum among heterosexuals and IDUs should be priorities for further AIDS prevention strategies.

Non-opioid recreational drug use and a prolonged HIV outbreak among men who have sex with men in Taiwan: An incident case-control study, 2006-2015

BACKGROUND/PURPOSE

Limited data are available on the role of illicit non-injecting drug use in a prolonged HIV outbreak that predominantly affected men who have sex with men (MSM) in Taiwan since 2006. We aimed to assess associations between specific types of drug use and incident HIV infections in this outbreak.

METHODS

We conducted a retrospective case-control study among MSM clients at voluntary counselling and testing (VCT) service at National Taiwan University Hospital (Taipei, Taiwan). We used BED IgG-capture enzyme immunoassay to identify incident HIV infection (cases), individually matched to HIV-negative MSM clients (controls) by HIV testing date. We used a structured questionnaire to obtain the information on illicit drug use and sexual risk behaviors.

RESULTS

From a total of 15,305 MSM client visits during 2006-2015, 387 cases were matched to 1012 controls. Use of inhaled nitrites (adjusted odds ratio [aOR] 2.1), MDMA (aOR 2.9), amphetamines (aOR 1.6), and ketamine (aOR 1.5) were independently associated with incident HIV infection. Polydrug (≥2 drugs) use was associated with the highest risk (aOR 4.3; 95% CI 2.6-7.2). While the proportion of MSM VCT clients who reported use of any recreational drug remained stable during 2006-2015 (average: 9.7%, P: 0.38), there was a shift in specific types of drug use, from MDMA/ketamine to inhaled nitrites/amphetamine, after 2011 (all Ps < 0.05).

CONCLUSION

Non-opioid recreational drugs use is associated with incident HIV infection in this prolonged HIV outbreak. There is an urgent need to formulate an effective public health response to mitigate the risk.

Molecular Characterization of HIV-1 Minority Subtypes in Hong Kong: A Recent Epidemic of CRF07_BC among the Men who have Sex with Men Population

BACKGROUND

Over the past years, an increasing trend was noticed for non-B and non- CRF01_AE HIV-1 strains prevalence in Hong Kong.

OBJECTIVE

In this study, we aimed at using the available HIV-1 pol sequences collected from 1994 to 2013 through our local antiretroviral resistance surveillance program to investigate the molecular epidemiology and evolution of HIV-1 minority subtypes in Hong Kong. We also aimed at investigating their potential association and impact of those transmission risk groups.

METHODS

A total of 2,315 HIV-1 partial pol sequences were included. HIV-1 genotypes were determined by REGA Genotyping Tool and phylogenetic analysis with reference sequences. The viral evolutionary rates and time of the most common ancestor (tMRCA) were estimated by Bayesian Markov Chain Monte Carlo (MCMC) interference.

RESULTS

Apart from the two prevalent HIV-1 genotypes in Hong Kong (subtype B,41.6%, CRF01_AE,40.5%), phylogenetic analysis revealed a broad viral diversity including CRF07_BC(5.1%), subtype C(4.5%), CRF02_AG(1.1%), CRF08_BC(0.8%), subtype A1(0.8%), subtype G(0.4%), subtype D(0.4%), CRF06_cpx(0.4%), subtype F(0.1%), CRF12_BF(0·04%) and other recombinants(4.5%). The top five minority subtypes were further analyzed which demonstrated distinct epidemiological and phylogenetic patterns. Over 70% of subtypes A1, C and CRF02_AG infections were circulated among non-Chinese Asians or African community in Hong Kong and were mainly transmitted between heterosexual regular partners. Instead, over 90% of CRF07_BC and CRF08_BC patients were Chinese. An epidemic cluster was identified in CRF07_BC and estimated to expand from 2002 onwards based on skyline plot and molecular clock analysis.

CONCLUSION

Our results highlighted the emergence of CRF07_BC epidemic in local MSM community, public health interventions targeting the community should be further enhanced to tackle the epidemic.

Source identification of HIV-1 transmission in three lawsuits Using Ultra-Deep pyrosequencing and phylogenetic analysis

BACKGROUND/PURPOSE

Intentional transmission of HIV-1 is a crime. Identifying the source of transmission between HIV-1 infected cases using phylogenetic analysis has limitations, including delayed examinations after the initiation of infection and ambiguity of phyletic relationships. This study was the first to introduce phylogenetic tree Results as forensic evidence in a trial in Taiwan.

METHODS

Three lawsuit cases from different district courts in Taiwan were chosen for this study. We identified the source of transmission between individuals in each lawsuit based on the maximum likelihood and Bayesian phylogenetic tree analyses using the HIV-1 sequences from molecular cloning and ultra-deep pyrosequencing (UDPS). Two gene regions of the HIV genome, env and gag, were involved.

RESULTS

The results of phylogenetic analysis using sequences from molecular cloning were clear and evidential enough in lawsuits 1 and 3. Due to the delayed sampling time, the result of sequences from molecular cloning in lawsuit 2 was ambiguous. Combined with the analyzed result of sequences from UDPS and epidemiological information, the source of transmission in lawsuit 2 was further identified.

CONCLUSION

Hence phylogenetic analyses cannot exclude the possibility of unsampled intermediaries, the data interpretation should be more careful and conservative, and it should not be considered as the only evidence for the source identification in a trial without epidemiological or serological information. The evaluation of the introduced UDPS method in the identification of transmission source has shown that the validity and evidential effects were still limited and need further optimization.

Phylogenetic transmission clusters among newly diagnosed antiretroviral drug-naïve patients with human immunodeficiency virus-1 in Korea: A study from 1999 to 2012

Population-level phylogenetic patterns reflect both transmission dynamics and genetic changes, which accumulate because of selection or drift. In this study, we determined whether a longitudinally sampled dataset derived from human immunodeficiency virus (HIV)-1-infected individuals over a 14-year period (1999–2012) could shed light on the transmission processes involved in the initiation of the HIV-1 epidemic in Korea. In total, 927 sequences were acquired from 1999 to 2012; each sequence was acquired from an individual patient who had not received treatment. Sequences were used for drug resistance and phylogenetic analyses. Phylogenetic and other analyses were conducted using MEGA version 6.06 based on the GTR G+I parameter model and SAS. Of the 927 samples, 863 (93.1%) were classified as subtype B and 64 were classified as other subtypes. Phylogenetic analysis demonstrated that 104 of 927 patient samples (11.2%) were grouped into 37 clusters. Being part of a transmission cluster was significantly associated with subtype-B viruses, infection via sexual contact, and the infection of young males. Of all clusters, three (~8.1%) that comprised 10 individual samples (22.2% of 45 individuals) included at least one member with total transmitted drug resistance (TDR). In summary, HIV transmission cluster analyses can integrate laboratory data with behavioral data to enable the identification of key transmission patterns to develop tailored interventions aimed at interrupting transmission chains.

AIDS-related opportunistic illnesses and early initiation of HIV care remain critical in the contemporary HAART era: a retrospective cohort study in Taiwan

BACKGROUND

No study has reported the epidemiology of AIDS-related opportunistic illnesses (AOIs) in patients with newly diagnosed HIV infection in Taiwan in the past decade. Understanding the current trends in AOI-related morbidity/mortality is essential in improving patient care and optimizing current public health strategies to further reduce AOIs in Taiwan in the era of contemporary highly active antiretroviral therapy (HAART).

METHODS

Eligible patients were evaluated at two referral centers between 2010 and 2015. The patients were stratified by date of diagnosis into three periods: 2010-2011, 2012-2013, and 2014-2015. The demographics, HIV stage at presentation according to the United States CDC 2014 case definition, laboratory variables, and the occurrence of AOIs and associated outcomes were compared among the patients. Logistic regression and Cox regression were respectively used to identify variables associated with the occurrence of AOIs within 90 days of HIV enrollment and all-cause mortality.

RESULTS

Over a mean observation period of 469 days, 1264 patients with newly diagnosed HIV with a mean age of 29 years and mean CD4 count of 275 cells/μL experienced 394 AOI episodes in 290 events. At presentation, 37.7% of the patients had AIDS; the frequency did not significantly differ across groups. The overall proportion of AOIs within the study period was 21.0%, and no decline across groups was observed. The majority of AOIs (91.7%) developed within 90 days of enrollment. All-cause and AOI-related mortality did not significantly differ across groups. Throughout the three study periods, AOIs remained the main cause of death (47/56, 83.9%), especially within 180 days of enrollment (40/42, 95.2%). A CD4 cell count of < 200 cells/μL at presentation was associated with increased adjusted odds of an AOI within 90 days [adjusted odds ratio, 40.84; 95% confidence intervals (CI), 12.59-132.49] and an elevated adjusted hazard of all-cause mortality (adjusted hazard ratio, 11.03; 95% CI, 1.51-80.64).

CONCLUSIONS

Despite efforts toward HIV prevention and management, early HIV care in Taiwan continues to be critically affected by AOI-related morbidity and mortality in the era of contemporary HAART. Additional targeted interventions are required for the earlier diagnosis of patients with HIV.

AIDS incidence trends at presentation and during follow-up among HIV-at-risk populations: a 15-year nationwide cohort study in Taiwan

BACKGROUND

Although Taiwan has implemented several important interventions for various HIV-at-risk populations to combat the HIV epidemic, little is known regarding AIDS incidence at presentation and during follow-up among the various HIV-at-risk populations in Taiwan. A better understanding of AIDS incidence trends would help improve patient care and optimize public health strategies aimed at further decreasing HIV-related morbidity and mortality.

METHODS

Data from Taiwan Centers for Disease Control-operated Notifiable Diseases Surveillance System and Taiwan National Health Insurance Research Database (1998-2012) was divided into five cohort periods (consecutive 3-year groups). Logistic regression was employed to identify factors associated with AIDS incidence at presentation. Time-dependent Cox regression was used to identify factors associated with AIDS incidence during the follow-up period.

RESULTS

Of 22,665 patients [mean age: 32 years; male (93.03%)], 6210 (27.4%) had AIDS incidence over 2 (1.16) [median (interquartile range)] years of follow-up. AIDS developed in ≤3 months of HIV diagnosis in 73.6% AIDS patients. AIDS incidence trends at presentation and during follow-up differed according to HIV transmission routes over the five periods: AIDS at presentation increased in the sexual contact groups (P < 0.001 for homosexuals/heterosexuals; 0.648 for bisexuals) but decreased to a nadir in period 3 and then increased slightly in period 5 (P < 0.001) in people who injected drugs (PWIDs). AIDS incidence during the follow-up period increased from period 1 to a peak in period 3 or 4, before declining slightly in period 5, in the sexual contact groups (P < 0.001 for homosexuals/heterosexuals; 0.549 for bisexuals). However, it increased throughout the five periods in PWIDs (P < 0.001). Older age, sexual contact group versus PWIDs, high versus low income level, cohort periods, and HIV diagnosis regions helped predict AIDS at presentation and during follow-up.

CONCLUSIONS

Disparities in AIDS incidence trends in various HIV-at-risk populations reflect different sociodemographic variables of HIV exposure and the adopted HIV prevention strategies. This study suggests the urgent need for tailored strategies aimed at specific populations at presentation and during follow-up.

Overview of HIV molecular epidemiology among people who inject drugs in Europe and Asia

HIV strains continuously evolve, tend to recombine, and new circulating variants are being discovered. Novel strains complicate efforts to develop a vaccine against HIV and may exhibit higher transmission efficiency and virulence, and elevated resistance to antiretroviral agents. The United Nations Joint Programme on HIV/AIDS (UNAIDS) set an ambitious goal to end HIV as a public health threat by 2030 through comprehensive strategies that include epidemiological input as the first step of the process. In this context, molecular epidemiology becomes invaluable as it captures trends in HIV evolution rates that shape epidemiological pictures across several geographical areas. This review briefly summarizes the molecular epidemiology of HIV among people who inject drugs (PWID) in Europe and Asia. Following high transmission rates of subtype G and CRF14_BG among PWID in Portugal and Spain, two European countries, Greece and Romania, experienced recent HIV outbreaks in PWID that consisted of multiple transmission clusters including subtypes B, A, F1, and recombinants CRF14_BG and CRF35_AD. The latter was first identified in Afghanistan. Russia, Ukraine, and other Former Soviet Union (FSU) states are still facing the devastating effects of epidemics in PWID produced by A_FSU (also known as IDU-A), B_FSU (known as IDU-B), and CRF03_AB. In Asia, CRF01_AE and subtype B (Western B and Thai B) travelled from PWID in Thailand to neighboring countries. Recombination hotspots in South China, Northern Myanmar, and Malaysia have been generating several intersubtype and inter-CRF recombinants (e.g. CRF07_BC, CRF08_BC, CRF33_01B etc.), increasing the complexity of HIV molecular patterns.

Characterization of the Near Full-Length Genome of a Novel HIV-1 CRF01_AE/CRF07_BC Recombinant in an Injection Drug User from Southern Taiwan

HIV-1 CRF07_BC became prevalent in Taiwan after the epidemic among injection drug users (IDUs). We describe a unique recombinant form (URF) consisting of CRF01_AE and CRF07_BC (named URF_0107-H8) genes detected from an IDU. The 8.8 kb near full-length genome of URF_0107-H8 had a CRF01_AE backbone with two CRF07_BC fragments in the reverse transcriptase and integrase region [RT-Int; HXB2 nucleotide (nt) positions 2942-4709] and within the envelop (nt 8467-8722) gene. Phylogenetic analyses revealed that its 1.8 kb RT-Int sequence clustered with those of CRF07_BC strains from Taiwan, while sequences of CRF01_AE portions were more similar to those of Central African origin than contemporaneous CRF01_AE isolates in Taiwan or prevalent in East or Southeast Asia. Recombination breakpoints and phylogenetic relationships of URF_0107-H8 were different from those of CRF01_AE/CRF07_BC URFs previously reported from China. This highlighted the importance of continual monitoring of genetic evolution of HIV strains and the emergence of new recombinants.

Prevalence of different HIV-1 subtypes in sexual transmission in China: a systematic review and meta-analysis

Sexual transmission has become the primary route of HIV transmission in China. Therefore, a comprehensive overview of HIV-1 subtype distribution is necessary for the prevention and control of the HIV epidemic. The present study aimed to provide a comprehensive prevalence estimate of different HIV-1 subtypes in sexual transmission in China. We conducted a systematic literature review for studies of HIV-1 subtypes in English and Chinese through several databases. Eligible articles were screened and selected by two authors independently. Random-effects model were applied to calculate the pooled prevalence of different HIV-1 subtypes, and subgroup analyses examined prevalence estimates across time, locations, and populations. A total of 130 eligible studies were identified, including 18 752 successfully genotyped samples. The pooled prevalence of CRF01_AE, subtype B, CRF07_BC, CRF08_BC, and subtype C were 44·54% (95% CI 40·81-48·30), 18·31% (95% CI 14·71-22·17), 16·45% (95% CI 13·82-19·25), 2·55% (95% CI 1·56-3·73), 0·37% (95% CI 0·11-0·72), respectively. The prevalence of subtype B in sexual transmission decreased, while the prevalence of CRF01_AE and CRF07_BC in sexual transmission, and CRF08_BC in heterosexual transmission increased. There is significant variation in HIV-1 subtype distribution between regions. The distribution of HIV-1 subtypes and circulating recombinant forms have changed significantly. The high genetic variability of HIV-1 poses a significant challenge for disease control and surveillance in China.

Molecular Epidemiology of HIV-1 Infection among Men who Have Sex with Men in Taiwan in 2012

The number of men who have sex with men (MSM) infected with HIV-1 in Taiwan has increased rapidly in the past few years. The goal of this study was to conduct a molecular epidemiological study of HIV-1 infection among MSM in Taiwan to identify risk factors for intervention. Voluntary counseling program and anonymous testing were provided to patrons at 1 gay bar, 7 night clubs and 3 gay saunas in Taipei and New Taipei Cities in 2012. HIV-1 subtypes were determined using gag subtype-specific PCR and phylogenetic analysis by env sequences. Recent HIV-1 infection was determined using LAg-Avidity EIA. In-depth interviews and questionnaires were used to identify risk factors. The prevalence and incidence of HIV-1 among MSM in Taiwan were 4.38% (53/1,208) and 3.29 per 100 person-years, respectively. Of 49 cases genotyped, 48 (97.9%) were infected with subtype B and 1 with CRF01_AE (2%). Phylogenetic analysis of 46 HIV-1 strains showed that 25 (54.4%) subtype B strains formed 9 clusters with each other or with other local strains. The CRF01_AE case clustered with a reference strain from a Thai blood donor with bootstrap value of 99. Multivariate logistic regression analysis showed that risk factors associated with HIV-1 infection included use of oil-based solution as lubricant (vs. saliva or water-based lubricants, OR= 4.23; p <0.001); exclusively receptive role (vs. insertive role, OR= 9.69; p <0.001); versatile role (vs. insertive role, OR= 6.45; p= 0.003); oral sex (vs. insertive role, OR= 11.93; p= 0.044); times of sexual contact per week (2-3 vs. zero per week, OR= 3.41; p= 0.021); illegal drug use (OR= 4.12; p <0.001); and history of sexually transmitted diseases (OR= 3.65; p= 0.002). In conclusion, there was no new HIV-1 subtype or circulating recombinant form responsible for the increase of HIV-1 among MSM in Taiwan in 2012. Misuse of oil-based solution as lubricant is a new risk factor identified among MSM in Taiwan. The Taiwan's Centers for Disease Control has created a video (www.youtube.com/watch?v=BinExvvOTMM&feature=iv&src_vid=BW81-PfmY3E&annotation_id=annotation_2436493705) to correct such misconception in its AIDS prevention campaign.

Patients infected with CRF07_BC have significantly lower viral loads than patients with HIV-1 subtype B: mechanism and impact on disease progression

The circulating recombinant form (CRF) 07_BC is the most prevalent HIV-1 strain among injection drug users (IDUs) in Taiwan. It contains a 7 amino-acid deletion in its p6gag. We conducted a cohort study to compare viral loads and CD4 cell count changes between patients infected with subtype B and CRF07_BC and to elucidate its mechanism. Twenty-one patients infected with CRF07_BC and 59 patients with subtype B were selected from a cohort of 667 HIV-1/AIDS patients whom have been followed up for 3 years. Generalized estimated equation was used to analyze their clinical data and the results showed that patients infected with CRF07_BC had significantly lower viral loads (about 58,000 copies per ml less) than patients with subtype B infection (p = 0.002). The replicative capacity of nine CRF07_BC and four subtype B isolates were compared and the results showed that the former had significantly lower replicative capacity than the latter although all of them were CCR5- tropic and non-syncytium inducing viruses. An HIV-1-NL4-3 mutant virus which contains a 7 amino-acid deletion in p6gag (designated as 7d virus) was generated and its live cycle was investigated. The results showed that 7d virus had significantly lower replication capacity, poorer protease-mediated processing and viral proteins production. Electron microscopic examination of cells infected with wild-type or 7d virus demonstrated that the 7d virus had poorer and slower viral maturation processes: more viruses attached to the cell membrane and higher proportion of immature virions outside the cells. The interaction between p6gag and Alix protein was less efficient in cells infected with 7d virus. In conclusion, patients infected with CRF07_BC had significantly lower viral loads than patients infected with subtype B and it may due to the deletion of 7 amino acids which overlaps with Alix protein-binding domain of the p6gag.

Diverse forms of HIV-1 among Burmese long-distance truck drivers imply their contribution to HIV-1 cross-border transmission

BACKGROUND

The China-Myanmar border is a particularly interesting region that has very high prevalence of and considerable diversity of HIV-1 recombinants. Due to the transient nature of their work, long-distance truck drivers (LDTDs) have a comparatively high potential to become infected with HIV-1 and further spread virus to other individuals in the area they travel within. In this study, we hypothesized that Burmese LDTDs crossing the China-Myanmar border frequently may potentially be involved in the cross-border transmission of HIV, and contribute to the extremely high prevalence of HIV-1 inter-subtype recombinants in this border region.

METHODS

A molecular epidemiology study was conducted among 105 Burmese LDTDs between 2008 and 2010. HIV-1 genetic fragments including p17, pol, vif-vpr, vpr-env, and C2V3 were amplified and sequenced. The subtype characterization and HIV-1 transmission were determined by both phylogenetic and phylogeographic analyses.

RESULTS

Diverse forms of HIV-1, including subtypes CRF01_AE (41.9%), C (8.6%), B (4.8%), CRF02_AG (1.0%), and inter-subtype recombinants (33.3%), as well as dual infection (10.5%), were detected among the tested LDTDs. Phylogeographic analyses based on pure subtype revealed that 77.8% Burmese LDTDs acquired HIV-1 infection in Yunnan, and the others in Myanmar. Both the C-related and CRF01_AE-related recombinants from these LDTDs appeared to have close genetic relationship with those from IDUs in Myanmar and Dehong.

CONCLUSIONS

Burmese LDTDs may contribute to HIV-1 transmission along the China-Myanmar border. The results may provide some new perspective for understanding the on-going generation and prevalence of HIV-1 recombinants in the border region.

Cancer incidence in a Nationwide HIV/AIDS patient cohort in Taiwan in 1998-2009

BACKGROUND

The aims of this study were to investigate the cancer incidence and risk in HIV/AIDS patients relative to the general population in Taiwan.

METHODS

Using Taiwan's National Health Insurance Research Database, 15,269 HIV/AIDS patients were identified between 1998 and 2009. Gender-specific incidence densities (IDs) of both AIDS-defining cancers (ADC) and non-AIDS-defining cancers (NADC) after HIV infection were calculated. Age-, sex-, and period-adjusted standardized incidence rates (SIRs) were obtained using 1.8 million people from the general population as controls.

RESULTS

A total of 1117 male and 165 female HIV/AIDS patients were diagnosed with cancer. Non-Hodgkin lymphoma (n = 196; ID = 328.79/100,000 person-years) and cervical cancer (n = 50; ID = 712.08/100,000 person-years) were the most common ADCs, whereas liver cancer (n = 125; ID = 184.52/100,000 person-years) and colon cancer (n = 11; ID = 156.66/100,000 person-years) were the most common NADCs in males and females, respectively. Period-adjusted gender-specific ADC and NADC rates decreased from more than 1500 cases/100,000 person-years to less than 500 cases/100,000 person-years (P < 0.001 for trend). SIRs of ADCs and NADCs also decreased. However, relative to the general population, increased SIRs were still seen for most cancers, many of which had an infectious etiology. The highest SIRs in ADCs and NADCs were seen in Kaposi sarcoma [SIR = 298.0, 95% confidence interval (CI): 258.16 to 343.85] and anal cancer (SIR = 19.10, 95% CI: 12.80 to 27.50).

CONCLUSION

This study showed that although the cancer incidence rates have significantly decreased in the highly active antiretroviral therapy era, HIV/AIDS patients were still at increased risk of ADCs and most NADCs. Cancer screening, especially for infection-related NADCs, should therefore be promoted.

Inferring viral population structures using heteroduplex mobility and DNA sequence analyses

Heteroduplex mobility (HMA) and tracking assays (HTA) are used to assess genetic relationships between DNA molecules. While distinguishing relationships between clonal or nearly clonal molecules is relatively straightforward, inferring population structures is more complex. To address this issue, HIV-1 quasispecies with varying levels of diversity were studied using both HTA and DNA sequencing. Viral diversity estimates and the temporal features of virus evolution were found to be generally concordant between HTA and DNA sequencing. In addition, the distribution of pairwise differences and the rates of virus divergence were similar between the two methods. These findings support the use of HTA to characterize variant populations of DNA and strengthen previous inferences concerning the evolution of HIV-1 over the course of infection.