No transmitted drug resistance to HIV integrase strand-transfer inhibitors after their scale-up in Estonia in 2017

OBJECTIVES

In Eastern Europe HIV-1 transmitted drug resistance (TDR) data, especially in integrase (IN) region is limited. In Estonia INSTI (Integrase Strand Transfer Inhibitors) TDR has been studied only prior to the INSTI scale-up in late 2010s. Current study aimed to determine the levels of protease (PR), reverse transcriptase (RT) and IN surveillance drug resistance mutations (SDRMs) among newly diagnosed patients in Estonia in 2017.

METHODS

Study included 216 newly diagnosed HIV-1 individuals from January 1 until December 31, 2017 in Estonia. Demographic and clinical data were obtained from the Estonian Health Board, Estonian HIV Cohort Study (E-HIV) and clinical laboratories' databases. The PR-RT and IN regions were sequenced and analyzed for SDRMs and subtype determination.

RESULTS

Seventy-one percent (151/213) of available HIV-positive samples were successfully sequenced. The overall level of TDR was 7.9% (12/151; 95% CI 4.4-13.8%); no dual or triple class resistance was detected. No major INSTI mutations were found. The distribution of SDRMs for NNRTI, NRTI and PI was 5.9% (9/151), 1.3% (2/151) and 0.7% (1/151), respectively. The predominant NNRTI mutation was K103N. CRF06_cpx was predominant variant (59%) in Estonian HIV-1 population followed by subtype A (9%) and subtype B (8%).

CONCLUSION

Although no major INSTI mutations were found, close monitoring of INSTI SDRMs is needed considering the extensive use of the first and second-generation INSTIs. PR-RT TDR is slowly rising in Estonia indicating the need for continuous surveillance in the future. Low genetic barrier NNRTIs should be avoided in the treatment regimens.

Norovirus strains among children aged 0-18 years hospitalized with acute gastroenteritis in Estonia 2015-2016

Norovirus (NoV) is the leading cause of acute gastroenteritis (AGE) in many countries that have introduced universal rotavirus mass vaccination. This is the first study to report data on NoV strains in Estonia. We recruited 2249 children aged 0-18 years hospitalized for AGE in Estonian hospitals from February 1, 2015 to August 31, 2016. Norovirus gastroenteritis (NoVGE) was diagnosed in 14.5% (n = 325) cases. Stool sample for RNA extraction and genotyping was available in 86% (n = 280) of NoVGE cases (2015, n = 91; 2016, n = 189). Dominant capsid types detected in 75% (n = 210) samples were, GII.4 (63.8%, n = 134), GII.3 (15.2%, n = 32), GII.17 (6.7%, n = 14), and GII.6 (5.2%, n = 11). Prevailing RNA polymerase types found in 77% (n = 215) samples were GII.P31 (51.1%, n = 110), GII.P21 (17.7%, n = 38), GII.P4 (11.2%, n = 24), and GII.P7 (6.5%, n = 14). Both regions were typeable for 67% (n = 189) of samples. Most prevalent strains were GII.4Sydney_2012[P31] (48.7%, n = 92), GII.3[P21] (15.3%, n = 29), GII.4Sydney_2012[P4] (5.8%, n = 11) and GII.17[P17] (5.8%, n = 11). Simpson's diversity index showed a significant difference between the age groups 1-4 and 5-9 years: D 0.64 (95% confidence interval [CI]: 0.55-0.73) versus 0.83 (95% CI: 0.81-0.86), respectively (p = 0.03). An accurate understanding of NoV strain diversity is important for control and preventive measures, especially in the postrotavirus vaccine era.

Dynamics of hepatitis C epidemic among people living with HIV in Estonia based on Estonian HIV cohort study

Background

Estonia has a typical Eastern European HIV epidemic where the most frequent co-infection is chronic hepatitis C (HCV). We aimed to describe the changes in HCV prevalence, the distribution of HCV genotypes (GT), and HCV treatment in Estonian people living with HIV over 15 years.

Methods

We used data of subjects included to the Estonian HIV Cohort Study (E-HIV) before 31st of December 2015. We compared two time periods—first, 1st of January 2000 to 31st of December 2008 when the HIV epidemic was mostly spreading among people who inject drugs (PWID) and second, 1st of January 2009 to 31st of December 2015 when HIV started to emerge to the general population.

Results

Of 4422 HIV positives 3708 (84%) had information about their HCV serostatus; 2706 (61%) were HCV seropositive, of latter 1625 (60%) were HCV RNA positive, 239 (9%) had their HCV GT determined, and 141 (5%) received treatment for HCV. The dominating subtypes were 1b (42%) and 3a (37%) followed by 1a (16%), and the few cases of 2 (1.5%). HCV prevalence was 1.5 times (95% CI 1.4–1.6) higher in subjects diagnosed with HIV in first as compared to those diagnosed in second period (84% vs 56%, respectively). There were more men and the median age at HIV diagnosis was lower in HIV/HCV co-infected than in HIV mono-infected patients (70% vs 47% and 24 years vs. 30 years, respectively; both p < 0.001).

Conclusion

There is a decrease in HCV prevalence but it remains high among HIV positive PWID, suggesting that there is need for improvement of harm reduction programs among PWID.

Stable level of HIV transmitted drug resistance in Estonia despite significant scale-up of antiretroviral therapy

BACKGROUND

Due to the widespread use of non-nucleoside reverse transcriptase inhibitors (NNRTI) as part of first-line therapies to curb the human immunodeficiency virus (HIV) epidemic in Eastern-European countries, transmitted drug resistance (TDR) is of serious concern in this region. Therefore, TDR and its associated risk factors were investigated among newly diagnosed HIV-1 subjects in Estonia.

METHODS

This nationwide observational study included all newly diagnosed HIV-1 subjects from January 1 until December 31, 2013. Demographic and clinical data were collected using the national surveillance system and the Estonian HIV-positive patient database (E-HIV). Starting from RNA, the HIV-1 protease (PR) and reverse transcriptase (RT) region was sequenced and surveillance drug resistance mutations (SDRM) were determined. Sequences from previous studies in Estonia and from public databases were included to study epidemic trends and to determine TDR clusters by phylogenetic analysis.

RESULTS

Out of 325 newly diagnosed HIV-1 infections, 224 were successfully sequenced (68%). As in previous studies from Estonia, the circulating recombinant form CRF06_cpx was the most prevalent HIV subtype (164/224, 74%). Fifteen strains displayed SDRM, giving a TDR rate of 6.7% (95% CI 3.9; 11.0). The most common SDRMs were associated with NNRTI (10/15, 4.5%), followed by PI (3/15, 1.3%) and NRTI (2/15, 0.9%). K103 N (8/15, 53%) was the most common SDRM. The level of TDR and mutational patterns were comparable to previous years. Twenty-six transmission clusters containing Estonian sequences were observed, of which 23/26 belonged to CRF06_cpx and 2/26 displayed evidence of TDR. The only risk factor associated with the presence of TDR was imprisonment (OR 5.187, CI 1.139-25.565, p = 0.034).

CONCLUSIONS

TDR remained stable at a moderate level in Estonia, K103N is the main SDRM with only one transmission-pair detected. We suggest screening for TDR at the time of diagnosis or prior to antiretroviral treatment initiation to tailor first-line regimens accordingly.

SUMMARY

The third consecutive transmitted drug resistance (TDR) study demonstrated a stable TDR in Estonia. TDR reached 6.7% (moderate level) in 2013, with imprisonment being the only associated risk factor. Few drug resistance-associated transmission clusters were identified.

Association of IFNλ4 rs12979860 polymorphism with the acquisition of HCV and HIV infections among people who inject drugs

We investigated the presence of a single-nucleotide polymorphism designated rs12979860 in the interferon λ4 (IFNλ4) gene among 345 people who inject drugs (PWID) and 495 blood donors to evaluate associations between the rs12979860 genotypes and human immunodeficiency virus/hepatitis C virus (HIV/HCV). The rs12979860 TT genotype was over-represented among HIV+ PWID than HIV- PWID and blood donors (16% vs 8% and 10%, P = 0.03, respectively). PWID with TT genotype had approximately twice the probability of being HIV+ (odds ratio [OR], 2.19; 95% confidence interval [CI], 1.11 to 4.33) than PWID without TT. Every additional year of intravenous drug use (IVDU) decreased the OR 1.16 times (OR, 0.86; 95% CI, 0.75 to 0.98). This suggests that rs12979860 TT increases susceptibility to HIV and this impact decreases with increasing duration of IVDU.

Prevalence and genotypes of GBV-C and its associations with HIV infection among persons who inject drugs in Eastern Europe

We aimed to determine the rate of GBV-C viremia, seropositivity, and genotypes among people who inject drugs (PWID) and healthy volunteers in Estonia and to evaluate associations between GBV-C and sociodemographic factors, intravenous drug use, co-infections. The study included 345 Caucasian PWID and 118 healthy volunteers. The presence of GBV-C RNA (viremia) was determined by reverse transcriptase-nested PCR in 5' long terminal repeat. PCR products were sequenced and genotyped by phylogenetic analysis. GBV-C seropositivity was determined by ELISA. One third of PWID (114/345) and 6% (7/118) of healthy volunteers (OR = 7.8, 95% CI = 3.5-20.5, P < 0.001) were GBV-C viremic. In PWID group, 79% of sequences belonged to subtype 2a, 19% to subtype 2b, and two remained unclassified. In healthy volunteers, six out of seven sequences belonged to subtype 2a and one to subtype 2b. We found HIV+ PWID to have two times increased odds of being GBV-C viremic compared to HIV- PWID (62% vs. 38%; OR = 2.13, 95% CI = 1.34-3.36, P = 0.001). In addition, odds of being GBV-C viremic decreased with increasing age (OR = 0.94, 95% CI = 0.90-0.98, P = 0.001). HIV positivity remained associated with GBV-C viremia in multivariate analysis after adjustment for age (OR = 2.23, 95% CI = 1.39-3.58, P = 0.001). GBV-C seropositivity was similar among PWID and healthy volunteers (2.3% vs. 1.7%, respectively; OR = 1.4, 95% CI =0.3-13.5, P = 1). In an Eastern European country we demonstrated that GBV-C viremia is common among PWID, but uncommon among healthy volunteers, and GBV-C seropositivity is infrequent among both groups. Similarly to other European countries and USA, GBV-C 2a is the most common genotype in Estonia. J. Med. Virol. 89:632-638, 2017. © 2016 Wiley Periodicals, Inc.

T Cell Distribution in Relation to HIV/HBV/HCV Coinfections and Intravenous Drug Use

Intravenous drug use (IDU) is one of the most important transmission routes for blood borne viruses, including human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV). These infections alter the subset distributions of T cells; however, knowledge of such effects during HIV, HBV, and or HCV coinfection is limited. Therefore, we aimed to evaluate any associations between T cell distribution and the presence of HIV, HBV, and HCV coinfections among persons who inject drugs (PWID). Blood samples from 88 Caucasian PWID (mean age 30; 82% male) and 47 age-matched subjects negative for all three infections (mean age of 29; 83% male) were analyzed. The T cell markers CD3, CD4, CD8, CD45RA, CCR7, HLA-DR, and CCR5 were assessed using flow cytometry. Of the PWID, 40% were HIV+HBV+HCV+, 20% HBV+HCV+, 19% HCV+, and 13% negative for all three infections. The HIV+HBV+HCV+ PWID had lower percentages of CD4⁺ and higher percentages of CD8⁺ cells compared to triple negative PWID (p < 0.001 in all cases). The only difference between HBV+HCV+ with triple negative PWID was the lower CD4⁺ cell percentages among the former (52.1% and 58.6%, p = 0.021). Triple negative PWID had higher immune activation and number of CCR5⁺ cells compared to the controls. We suggest that the altered T cell subset distribution among PWID is mainly triggered by HIV infection and or IDU, while HBV and or HCV seropositivity has minimal additional effects on CD4⁺ cell distribution.

A CCL5 Haplotype Is Associated with Low Seropositivity Rate of HCV Infection in People Who Inject Drugs

OBJECTIVE

The role of CC chemokine receptor 5 (CCR5) and its ligand CCL5 on the pathogenesis of HIV infection has been well studied but not for HCV infection. Here, we investigated whether CCL5 haplotypes influence HIV and HCV seropositivity among 373 Caucasian people who inject drugs (PWID) from Estonia.

METHODS

Study included 373 PWID; 56% were HIV seropositive, 44% HCV seropositive and 47% co-infected. Four CCL5 haplotypes (A-D) were derived from three CCL5 polymorphisms (rs2107538/rs2280788/rs2280789) typed by Taqman allelic discrimination assays. The data of CCR5 haplotypes were used from our previous study. The association between CCL5 haplotypes with HIV and/or HCV seropositivity was determined using logistic regression analysis.

RESULTS

Possessing CCL5 haplotype D (defined by rs2107538A/rs2280788G/rs2280789C) decreased the odds of HCV seropositivity compared to those not possessing it (OR = 0.19; 95% CI 0.09-0.40), which remained significant after adjustment to co-variates (OR = 0.08; 95% CI 0.02-0.29). An association of this haplotype with HIV seropositivity was not found. In step-wise logistic regression with backward elimination CCL5 haplotype D and CCR5 HHG*1 had reduced odds for HCV seropositivity (OR = 0.28 95% CI 0.09-0.92; OR = 0.23 95% CI 0.08-0.68, respectively) compared to those who did not possess these haplotypes, respectively.

CONCLUSIONS

Our results suggest that among PWID CCL5 haplotype D and CCR5 HHG*1 independently protects against HCV. Our findings highlight the importance of CCL5 genetic variability and CCL5-CCR5 axis on the susceptibility to HCV.

Human T-lymphotropic virus types 1 and 2 are rare among intravenous drug users in Eastern Europe

BACKGROUND

In Europe, human T-lymphotropic virus (HTLV) type 2 mainly occurs among intravenous drug users (IDUs) with prevalence up to 15% and HTLV-1 among general population with prevalence <1%. However, there is no data regarding the prevalence of HTLV-1 or HTLV-2 in Eastern European IDUs population where HIV prevalence is relatively high. We aimed to determine the prevalence and genotypes of HTLV-1/HTLV-2 among IDUs and healthy volunteers in Estonia.

METHODS

The study included 345 IDUs and 138 healthy volunteers. The presence of HTLV-1/HTLV-2 was determined by nested PCR; positive and negative controls were used in every PCR run.

RESULTS

The analysed IDUs resembled the IDUs of HIV epidemic in Estonia: mainly male (79%) with median age of 30years (interquartile range [IQR] 25-34), and prolonged duration of intravenous drug usage (11years; IQR 7-14). The prevalence exposure to blood-borne viral infections was high - 50% were HIV positive, 88% hepatitis C positive, 67% hepatitis B positive. Of IDUs, 64% reported receptive needle sharing in the past and 18% at least once a month during last six months. None of the IDUs carried HTLV-1 but there was a case of HTLV-2 (prevalence 0.3%; 95% CI 0.1-1.6). All healthy volunteers were HTLV-1 and HTLV-2 PCR negative.

CONCLUSION

This is the first study investigating the prevalence of HTLV-1/HTLV-2 among high risk population and healthy volunteers in Eastern European region. Our results suggest that despite other widely spread blood-borne infections (e.g. HIV, HBV, HCV) HTLV-1 and HTLV-2 are rare among IDUs in Estonia.

Prevalence of drug resistance mutations in HAART patients infected with HIV-1 CRF06_cpx in Estonia

HIV-1 drug resistance mutations (DRMs) and substitutions were assessed after the failure of the first line non-nucleoside reverse transcriptase inhibitors (NNRTIs) + 2 nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) treatment regimens (efavirenz [EFV] + lamivudine[3TC] + zidovudine [ZDV] vs. EFV + 3TC + ddI) among the HIV-1 CRF06_cpx infected subjects in Estonia. HIV-1 genomic RNA was sequenced; DRMs and amino acid substitutions were compared in 44 treatment naïve and 45 first-line NNRTI + 2 NRTI treatment failed patients consisting of EFV + 3TC + ZDV (n = 17) and EFV + 3TC + didanosine[ddI] (n = 21) therapy failed sub-populations. At least one DRM was found in 78% of treatment experienced patients. The most common NRTI mutations were M184V (80%), L74V (31%), L74I (17%), K219E (9%), and M184I (9%), NNRTI mutations were K103N (83%), P225H (14%), L100I (11%), and Y188L (11%), reflecting generally the similar pattern of DRMs to that seen in treatment failed subtype B viruses. Sub-population analysis revealed that EFV + 3TC + ddI failed patients had more DRMs compared to EFV + 3TC + ZDV failed patients, especially the ddI DRM L74IV and several additional NNRTI DRMs. Additionally, CRF06_cpx specific mutation E179V and substitutions R32K, K122E, and V200AE were also detected in treatment experienced population. After the failure of the first-line EFV + 3TC + ddI therapy HIV-1 CRF06_cpx viruses develop additional NRTI and NNRTI mutations compared to EFV + 3TC + ZDV regimen. Therefore the usage of EFV + 3TC + ddI in this subtype decreases the options for next regimens containing abacavir, and NNRTI class agents.

Influence of interleukin 10 polymorphisms -592 and -1082 to the HIV, HBV and HCV serostatus among intravenous drug users

BACKGROUND

Interleukin 10 (IL-10) is a multifunctional cytokine produced by macrophages, monocytes, and T-helper cells. Two polymorphisms at positions -592 and -1082 have been associated with HIV susceptibility. However, their associations with susceptibility to HIV and its co-infections among intravenous drug users (IDUs) are largely unknown.

METHODS

A total of 345 IDUs were recruited. Of the 173 HIV negative IDUs, 20 were classified as highly exposed HIV seronegative subjects (HESNs). A control group consisted of 496 blood donors; all HIV, HCV, and HBV negative. The IL-10-592C/A and -1082A/G were determined using TaqMan allelic discrimination assay.

RESULTS

Of the IDUs, 50% were HIV positive, 89% HCV positive, 67% HBV positive and 41% had triple infection. IL-10-592C allele and -1082A allele were the most common and the -1082AG/-592CC was the most common genotype pair. All HESNs exhibited -1082A allele as compared to 81.4% of the HIV positive IDUs and 79% of donors (p=0.029 and p=0.019, respectively). None of HESNs had GG/CC genotype pair compared with 18.6% of HIV positive IDUs and 21.0% of donors (p=0.029 and p=0.019, respectively). The possession of -592AC and genotype pair AG/AC were associated with the decreased odds of HBV infection (OR=0.28; 95% CI 0.09-0.87; p=0.028 and OR=0.19; 95% CI 0.06-0.61; p=0.052, respectively).

CONCLUSIONS

The presence of low producing IL-10-1082A and -592A alleles and their containing genetic variants protect highly exposed IDUs against acquisition of HIV and HBV infections.

Transmitted drug resistance is still low in newly diagnosed human immunodeficiency virus type 1 CRF06_cpx-infected patients in Estonia in 2010

The presence of transmitted drug resistance (TDR) in treatment-naive HIV-1-positive subjects is of concern, especially in the countries of the former Soviet Union in which the number of subjects exposed to antiretrovirals (ARV) has exponentially increased during the past decade. We assessed the rate of TDR among newly diagnosed subjects in Estonia in 2010 and compared it to that in 2008. The study included 325 subjects (87% of all subjects tested HIV positive from January 1 to December 31, 2010). Of the 244 sequenced viral genomic RNA in the reverse transcriptase (RT) region 214 were CRF06_cpx, nine were subtype A1, three (one each) were subtype B and subtype C, CRF02_AG, and CRF03_AB; 15 viruses remained unclassified as putative recombinant forms between CRF06_cpx and subtype A1. HIV-1 TDR mutations in 2010 and 2008 (n=145) occurred at similar frequency in 4.5% (95% CI 2.45; 7.98) and 5.5% (95% CI 1.8; 9.24) of the patients, respectively. In 2010, 2.5% (6/244) of the sequences harbored nonnucleoside reverse transcriptase inhibitor (NNRTI) (K103N and K101E), 1.6% (4/244) nucleoside reverse transcriptase inhibitor (NRTI) (M41L, M184I, and K219E), and 0.4% (1/244) protease inhibitor (PI) (V82A) mutations. Our findings indicate that in spite of the increased consumption of ARVs the rate of TDR in Estonia has remained unchanged over the past 3 years. Similar stabilizing or even decreasing trends have been described in Western Europe and North America albeit at higher levels and in different socioeconomic backgrounds.

Association between TLR3 rs3775291 and resistance to HIV among highly exposed Caucasian intravenous drug users

BACKGROUND

TLR3 recognizes dsRNA and triggers immune responses against RNA and DNA viruses. A polymorphism in TLR3, rs3775291 (Leu412Phe), has been associated with the increased susceptibility to enteroviral myocarditis, protection against tick-borne encephalitis virus and HIV-1 infection. We investigated Caucasian intravenous drug users (IDUs) and blood donors in order to evaluate the associations between TLR3 genotypes and susceptibility to HIV infection.

MATERIALS AND METHODS

A total of 345 Caucasian IDUs were recruited, 50% of them were HIV positive, 89% HCV and 77% HBV positive. Based on their history of needle sharing, 20 of the HIV negative IDUs were classified as highly exposed HIV seronegatives (HESNs), 68 as non-HESNs and 85 as unexposed. The control group consisting of 497 blood donors tested negative for all three viruses. TLR3 rs3775291 were determined by using TaqMan Allelic Discrimination Assay.

RESULTS

The TLR3 rs3775291 T allele frequency was similar among the HIV negative and HIV positive IDUs and blood donors - 36%, 31% and 34%, respectively. The frequency of persons possessing at least one TLR3 rs3775291 T allele was significantly higher in HESNs compared with blood donors and HIV positive IDUs (80% vs. 55%; p=0.037 and 80% vs. 53%; p=0.031, respectively). In the univariate analysis, persons who possessed at least one T allele had reduced odds of being HIV seropositive (OR=0.29, 95% CI=0.09-0.90). This association remained significant (OR=0.25, 95% CI=0.07-0.87) after the adjustment for other co-variates (HCV, HBV serostatus and duration of intravenous drug use).

CONCLUSIONS

The TLR3 rs3775291 T allele has a protective effect against HIV infection among HESNs IDUs.