Understanding transmitted HIV resistance through the experience in the USA

Genotyping and Antiretroviral Drug Resistance Mutations among HIV Patients in Southern Santa Catarina, Brazil

INTRODUCTION

Therapeutic measures have been successful in increasing survival rates and quality of life of HIV/AIDS-infected people. However, some people fail to respond to antiretroviral therapy (HAART) because of viral resistance-associated mutations.

OBJECTIVE

To identify virus genotype and the presence of mutations that alter the susceptibility to HAART, and factors associated with the occurrence of these mutations.

METHODS

A cross-sectional study was conducted on adults living with HIV attending a specialized outpatient clinic in southern Santa Catarina, Brazil. The participants were interviewed and had blood samples collected for analysis. Those with detectable viral load were genotyped.

RESULTS

Out of the 629 patients recruited, 127 subjects were included due to having a detectable viral load. The most common mutations were M184V and K103N. HIV-1 subtype C was the most prevalent strain. Resistance to HAART was associated with modification in the treatment regimen (p <0.001).

CONCLUSION

This study concluded that the circulating subtype virus was subtype C and that the mutations K103N and M184V were the most prevalent strains in southern Santa Catarina, Brazil.

HIV drug resistance in the era of contemporary antiretroviral therapy: A clinical perspective

Contemporary antiretroviral therapy (ART) regimens have high barriers to the development of drug resistance. However, resistance to earlier antiretrovirals and uncommon cases of resistance to contemporary ART illustrate the continued need for good clinical management of HIV drug resistance. Here, we describe HIV drug-resistance mechanisms, the interaction of HIV drug-resistant mutations and the patterns of drug resistance to contemporary ART. We then provide guidance on the management of HIV drug resistance, including how to limit the development of resistance and manage virologic failure that is complicated by resistance. To complement this, links to resources and treatment guidelines are provided that can assist with the interpretation of HIV drug resistance test results and optimal ART selection in the clinic.

Adherence to antiretroviral therapy and associated factors among human immunodeficiency -positive patients accessing treatment at health centers in East Gojjam Zone, Northwest Ethiopia, 2019: Community-based cross-sectional study

Background

To achieve an effective treatment outcome, Antiretroviral Therapy (ART) for people living with the Human immunodeficiency virus (HIV) needs at least a 95% adherence level. The aim was to assess adherence to antiretroviral therapy and its associated factors among patients accessing treatment at Health centers in East Gojjam Zone, Northwest Ethiopia.

Methods

A community-based cross-sectional study was conducted on 770 HIV-positive patients from April 1 to May 10, 2019, in East Gojjam Zone. The study participants were selected by simple random computerized sampling methods. Primary data was collected from the patients through face-to-face interviews and home-to-home visits. Bivariable and multivariable binary logistic regression analyses were done. Independent variables with a P-value of <0.2 in bivariable binary logistic regression analysis were considered for multivariable binary logistic regression analysis. A P-value of <0.05 was used as the cut-off point for the presence of statistical significance.

Results

About 396 (51.8%) of the study participants had good adherence. Being 18-24 years old [Adjusted Odd Ratio (AOR) = 0.43; 95% CI = 0.21-0.86], having a marital status of being widowed (AOR = 0.29; 95% CI = 0.14-0.58), having a disease duration of >10 years (AOR = 0.47; 95% CI = 0.24-0.94), taking a drug regimen of Tenofovir (TDF) + Lamivudine (3 TC) + Nevirapine (NVP) (AOR = 2.94; 95% CI = 1.406.15), not being socially stigmatized (AOR = 0.52; 95% CI = 0.34-0.78), and having not encountered an opportunistic infection (AOR = 3.91; 95% CI = 2.68-5.72) were significant factors.

Conclusions

The level of adherence was low. Opportunistic infection prevention, reduction of social stigma, and other intervention activities should be strengthened to increase the level of adherence.

Time Until Loss to Follow-Up, Incidence, and Predictors Among Adults Taking ART at Public Hospitals in Southern Ethiopia

Introduction

According to the World Health Organization, more than seventeen million people were accessing ART in 2015 globally. Adherence to effective ART reduced the risk of transmitting the virus to uninfected persons. The government and other stakeholders’ focus was high to reduce the rate of loss to follow-up in HIV programs among patients who are already on ART follow-up, but its incidence rate increases from time to time.

Methods

A retrospective cohort study was conducted among the records enrolled from 1 January 2013 to 30 December 2017 at Public hospitals in Southern Ethiopia. Data were entered into Epi info V 7 and exported to STATA V 14 for analysis. The Kaplan–Meier survival curve together with a log rank test was used to estimate the survival time of the ART attending patients. Variables which had p-value <0.05 in multivariable analysis using the cox proportional hazard model were declared as statistically significant.

Results

The incidence rate of loss to follow-up from ART services among adults attending ART was 6.48 (95% CI:5.67,7.29) per 1000 person months. The cumulative survival probability at the end of the 10th, 20th, 40th and 60th follow-up month was 0.89 (95% CI:0.87,0.91), 0.82 (95% CI:0.79,0.85), 0.78 (95% CI:0.75,0.81) and 0.74 (95% CI:0.70,0.77), respectively. Distance >5 kilometers (AHR:3.71; 95% CI:2.32,5.95), not having registered phone number (AHR:2.52; 95% CI:1.76,3.60), not initiating Isoniazid (AHR:2.15; 95% CI:1.50,3.08), body mass index <18.50kg/m² (AHR:1.87; 95% CI: 1.18; 2.97) and not having primary caregiver (AHR: 2.59; 95% CI: 1.84, 3.66) were statistically significant predictors of loss to follow-up.

Conclusion

The time until loss to follow-up was high in the first 20 months of the initiation of the ART and it declines after 20 months; longer distance between home and hospital, not having registered phone number, not initiating INH, lower body mass index and not having primary caregiver were the independent predictors of loss to follow-up from ART services.

Molecular Genetics and the Incidence of Transmitted Drug Resistance Among Pre-Treatment HIV-1 Infected Patients in the Eastern Cape, South Africa

BACKGROUND

Transmitted drug resistance (TDR) remains a significant threat to Human immunodeficiency virus (HIV) infected patients that are not exposed to antiretroviral treatment. Although, combined antiretroviral therapy (cART) has reduced deaths among infected individuals, emergence of drug resistance is gradually on rise.

OBJECTIVE

To determine the drug resistance mutations and subtypes of HIV-1 among pre-treatment patients in the Eastern Cape of South Africa.

METHODS

Viral RNA was extracted from blood samples of 70 pre-treatment HIV-1 patients while partial pol gene fragment amplification was achieved with specific primers by RT-PCR followed by nested PCR and positive amplicons were sequenced utilizing ABI Prism 316 genetic sequencer. Drug resistance mutations (DRMs) analysis was performed by submitting the generated sequences to Stanford HIV drug resistance database.

RESULTS

Viral DNA was successful for 66 (94.3%) samples of which 52 edited sequences were obtained from the protease and 44 reverse transcriptase sequences were also fully edited. Four major protease inhibitor (PI) related mutations (I54V, V82A/L, L76V and L90M) were observed in seven patients while several other minor and accessory PIs were also identified. A total of 11(25.0%) patients had NRTIs related mutations while NNRTIs were observed among 14(31.8%) patients. K103N/S, V106M and M184V were the most common mutations identified among the viral sequences. Phylogenetic analysis of the partial pol gene indicated all sequences clustered with subtype C.

CONCLUSION

This study indicates that HIV-1 subtype C still predominates and responsible for driving the epidemic in the Eastern Cape of South Africa with slow rise in the occurrence of transmitted drug resistance.

Incidence and risk factors of loss to follow-up among HIV-infected children in an antiretroviral treatment program

Introduction

The success of antiretroviral treatment (ART) programs can be compromised by high rates of patient loss to follow-up (LTFU). We assessed the incidence and risk factors of LTFU in a large cohort of HIV-infected children receiving ART in Thailand.

Methods

All children participating in a multicenter cohort (NCT00433030) between 1999 and 2014 were included. The date of LTFU was 9 months after the last contact date. ART interruption was defined as ART discontinuation for more than 7 days followed by resumption of treatment. Baseline and time-dependent risk factors associated with LTFU were identified using Fine and Gray competing risk regression models with death or referral to another hospital as competing events.

Results

Of 873 children who were followed during a median of 8.6 years (interquartile range 4.5–10.6), 196 were LTFU, 73 died, and 195 referred. The cumulative incidence of LTFU was 2.9% at 1 year, 7.3% at 5 years and 22.2% at 10 years. Children aged 13 years and more had a 3-fold higher risk (95% confidence interval 2.06–4.78) of LTFU than those younger. Children who had interrupted ART within the previous year had a 2.5-fold higher risk (1.12–5.91) than those who had not. The risk of LTFU was lower in children stunted (height-for-age Z-scores <-2 SD) (0.42–0.96) or underweight (weight-for-age Z-scores <-2 SD) (0.24–0.97).

Conclusion

Adolescence, ART interruption and absence of growth deficit were associated with LTFU. These may be warnings that should draw clinicians’ attention and possibly trigger specific interventions. Children with no significant growth retardation may also be at risk of LTFU.

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.

Predictors associated with HIV/AIDS patients dropout from antiretroviral therapy at Mettu Karl Hospital, southwest Ethiopia

OBJECTIVE

The aim of this study was to determine the major risk factors of antiretroviral therapy dropout. The retrospective cohort research design was applied. 1512 HIV patients were included from Mettu Karl Hospital in Illubabor Zone, southwest part of Ethiopia from September 2005 to January 2018. Kaplan-Meier comparison and log-logistic regression accelerated failure time model were used.

RESULTS

From the log-logistic regression result, the risk of dropout for patients with primary education status was 10.58% greater as compared to illiterate (p < 0.0110). The probability of dropout for patients with marital status separated was about 16.82% higher than those patients with marital status divorced (p < 0.0070). Being merchant, farmer and daily labour had a greater risk of dropout as compared to a housewife. Most of the HIV/AIDS patients on ART were dropout in a short period due to patients separated marital status, primary education, CD4, being merchants, farmer and daily labour. Investigation on the cause of antiretroviral therapy dropout from a number of AIDS clinics in the country is highly appreciated.

Incidence and predictors of LTFU among adults with TB/HIV co-infection in two governmental hospitals, Mekelle, Ethiopia, 2009-2016: survival model approach

Background

Lost to follow-up (LTFU) negatively affects the treatment success of Anti-Retroviral Therapy (ART) and thus, increases Tuberculosis-Human Immunodeficiency Virus (TB/HIV) related morbidity, mortality and hospitalization. However, the incidence and predictors of loss to follow up (LTFU) among adults with TB/HIV co-infection have not yet well-investigated in Ethiopia. Therefore, this study was aimed at investigating the incidence and predictors of LTFU in the study setting in particular.

Methods

A facility based retrospective cohort study was employed among 305 (114 anemic and 191 normal) TB/HIV co-infected adults in two governmental hospitals (Mekelle Hospital and Ayder Comprehensive Specialized Hospital), Mekelle, Ethiopia from 2009 to 2016 and data were collected using checklist. Besides to descriptive statistics, a cox regression analysis was applied to identify statistically significant predictors of LTFU at 5% level of significance. Eventually, the Adjusted Hazard Ratio (AHR) and 95% Confidence Interval (CI) were estimated and interpreted for predictors of LTFU in the final cox model.

Results

Generally, 45 of 305 (14.8%) of TB/HIV co-infected adults were LTFU with an incidence rate of 4.5 new LTFUs per 100 Person Years (PYs) and a median follow up time of 3.1 years (Interquartile Range (IQR): 0.8–5.3 Years). Hemoglobin level ≤ 11.0 g/dl (AHR = 2.660; 95%CI: 1.459–4.848), and any history of OI/s (AHR = 3.795; 95%CI: 1.165–12.364) were risk factors of LTFU. While, adverse drug events (AHR = 0.451; 95%CI: 0.216–0.941), TB treatment completion (AHR = 0.121; 95% CI: 0.057–0.254), and being on Isoniazid Preventive Therapy (IPT) (AHR = 0.085; 95%CI: 0.012–0.628) had protective effect against LTFU.

Conclusions

One in approximately seven TB/HIV co-infected adults had experienced of LTFU with an incidence rate 4.5 LTFUs per 100 PYs. The LTFU rate was higher among adults with low baseline hemoglobin level, no adverse drug events, presence of OI/s, failure to complete TB treatment, and being not on IPT. Therefore, it is advisable to treat anemia and active TB, and preventing the occurrence of OIs including TB using IPT to reduce the incidence of LTFU among TB/HIV co-infected adults.

Prevalence and persistence of transmitted drug resistance mutations in the German HIV-1 Seroconverter Study Cohort

The prevalence of transmitted drug resistance (TDR) in antiretroviral therapy (ART)-naïve individuals remains stable in most developed countries despite a decrease in the prevalence of acquired drug resistance. This suggests that persistence and further transmission of HIV-1 that encodes transmitted drug resistance mutations (TDRMs) is occurring in ART-naïve individuals. In this study, we analysed the prevalence and persistence of TDRMs in the protease and reverse transcriptase-sequences of ART-naïve patients within the German HIV-1 Seroconverter Study Cohort who were infected between 1996 and 2017. The prevalence of TDRMs and baseline susceptibility to antiretroviral drugs were assessed using the Stanford HIVdb list and algorithm. Mean survival times of TDRMs were calculated by Kaplan-Meier analysis. The overall prevalence of TDR was 17.2% (95% CI 15.7–18.6, N = 466/2715). Transmitted NNRTI resistance was observed most frequently with 7.8% (95% CI 6.8–8.8), followed by NRTI resistance (5.0%, 95% CI 4.2–5.9) and PI resistance (2.8%, 95% CI 2.2–3.4). Total TDR (OR = 0.89, p = 0.034) and transmitted NRTI resistance (OR = 0.65, p = 0.000) decreased between 1996 and 2017 but has remained stable during the last decade. Viral susceptibility to NNRTIs (6.5%-6.9% for individual drugs) was mainly reduced, while <3% of the recommended NRTIs and PIs were affected. The longest mean survival times were calculated for the NNRTI mutations K103N (5.3 years, 95% CI 4.2–5.6) and E138A/G/K (8.0 years, 95% CI 5.8–10.2 / 7.9 years, 95% CI 5.4–10.3 / 6.7 years, 95% CI 6.7–6.7) and for the NRTI mutation M41L (6.4 years, 95% CI 6.0–6.7).The long persistence of single TDRMs indicates that onward transmission from ART-naïve individuals is the main cause for TDR in Germany. Transmitted NNRTI resistance was the most frequent TDR, showing simultaneously the highest impact on baseline ART susceptibility and on TDRMs with prolonged persistence. These results give cause for concern regarding the use of NNRTI in first-line regimens.

Contraceptive, condom and dual method use at last coitus among perinatally and horizontally HIV-infected young women in Atlanta, Georgia

Objective

To evaluate factors within the social-ecological framework associated with most or moderately effective contraception, condom and dual method use at last coitus among young, HIV-infected women in Atlanta.

Methods

This is a cross-sectional study conducted from November, 2013 until August, 2015 at the Grady Infectious Disease Clinic in Atlanta, Georgia. We recruited perinatally and horizontally HIV-infected women of ages 14–30 years to complete an audio computer-assisted self-interview. We evaluated factors within a social-ecological framework associated with most or moderately effective contraceptive use (hormonal contraception or an IUD), condom use, and dual method use (use of condom and most or moderately effective contraceptive) at last coitus.

Results

Of 103 women enrolled, 74 reported a history of sexual activity. The average age was 22.1; 89% were African American, 52% were perinatally infected, 89% received combination antiretroviral therapy, and 63% had undetectable viral loads. At last coitus, 46% reported most or moderately effective contraception, 62% reported condom use and 27% reporting dual-method use. The odds of most or moderately effective contraceptive use was significantly reduced among those with detectable viral loads (versus undetectable viral loads; aOR 0.13 [0.04, 0.38]). Older age (aOR 0.85 [0.74, 0.98] and more frequent coitus (>once/week versus < = once/week; aOR 0.24 [0.08, 0.72]) was significantly associated with reduced condom use. Having a detectable viral load (versus undetectable viral loads; aOR 0.13 [0.03, 0.69]) and more frequent coitus (>once/week versus < = once/week; aOR 0.14 [0.03,0.82]), was associated with reduced dual method use, while being enrolled in school (aOR 5.63 [1.53, 20.71]) was significantly associated with increased dual method use.

Conclusions

Most or moderately effective contraception, condom and dual method use remained inadequate in this cohort of young HIV-infected women. Individual-level interventions are needed to increase the uptake of dual methods with user-independent contraceptives.

Incidence and predictors of loss to follow up among HIV-infected adults at Pawi General Hospital, northwest Ethiopia: competing risk regression model

Objective

This study was aimed at assessing the incidence of lost-to-follow-up and its predictors among HIV-positive adults after initiation into antiretroviral therapy at Pawi General Hospital, northwest Ethiopia.

Results

The overall cumulative incidence of lost-to-follow-up after ART initiation was high, 11.6 (95% CI 9.8–13.7) per 100 adult-years follow-up time. Independent significant predictors of lost to follow up were being aged 15–28 years (aSHR = 0.44; 95% CI 0.24–0.83), being on WHO clinical stage IV (aSHR = 2.09; 95% CI 1.02–3.13); and receiving isoniazid preventive therapy (aSHR = 0.11; 95% CI 0.06–0.18).

Electronic supplementary material

The online version of this article (10.1186/s13104-018-3407-5) contains supplementary material, which is available to authorized users.

Characterization of HIV-1 subtypes and transmitted drug resistance among treatment-naive HIV-infected individuals in Zhejiang, China, 2014-2017

In recent years, transmitted drug resistance (TDR) has adversely impacted upon first-line therapy for HIV-infected individuals. To understand the current subtype distribution and TDR level in Zhejiang, China we performed phylogenetic analysis and genotypic drug resistance testing of treatment-naive HIV-infected individuals. A total of 153 HIV-1 Pol genes were successfully amplified. The distribution of HIV-1 genotypes was as follows: CRF01_AE (43.8%); CRF07_BC (37.9%); subtype B/B' (7.2%); CRF08_BC (5.2%); and others (5.9%). Drug resistance analysis demonstrated that 11.1% of isolates contained at least one NRTI or NNRTI resistance-associated mutations while 2.0% were identified to be resistant to PIs. These findings enhance our understanding of the genetic diversity of HIV-1 strains circulating in Zhejiang and provide some guidelines for HIV initial treatment therapy.

Use of Proviral DNA to Investigate Virus Resistance Mutations in HIV-infected Zimbabweans

Background:

Antiretroviral therapy (ART) to suppress HIV replication has reduced morbidity and mortality yet effectiveness of current HIV drugs is threatened by HIV drug resistance (HIVDR) mutations.

Objective:

To determine HIVDR mutations using proviral DNA from specimens of patients presenting to an HIV treatment clinic.

Methods:

DNA from 103 patients, 86 treatment-experienced, 17 treatment-naïve, were genotyped for the HIV-1C reverse transcriptase gene (RT; codons 21-304) using Sanger sequencing and sequences analyzed using Sequencher software. Resistance mutations were interpreted using Stanford HIVDR reference database.

Results:

Median age was 39 (IQR, 33-46) years and 80% of patients were female. Six-percent (n=6) had at least one HIVDR mutation, comprising NRTI-associated mutations, (M184V, T69D, T69N and V75I); NNRTI-associated mutations (G190A, K103N, V106M, Y181C) and thymidine analogue associated mutations (D67N, K70R, K219Q, L210W, M41L, T215Y). Of the six participants, with at least one HIVDR mutation, all were treatment experienced, five were on tenofovir, lamivudine and nevirapine and one was on tenofovir, lamivudine and atazanavir. There was no difference in median CD4 count and viral loads when patients were compared by presence of HIVDR mutations.

Conclusion:

We demonstrated the use of proviral DNA in HIVDR testing in adult patients and present that all the patients with various kinds of HIVDR mutations were treatment experienced, pointing to the role of drug regimens in driving viral mutations. Thus, the use of proviral DNA has potential to help provide surveillance on risk of HIVDR in HIV-infected individuals who are on treatment, which may assist in corrective treatment.

Sexual Health Knowledge in a Sample of Perinatally HIV-infected and Perinatally-exposed Uninfected Youth

This study describes sexual health knowledge in perinatally HIV-infected (PHIV+) and perinatally-exposed uninfected (PHIV-) ethnic-minority youth, ages 9-16 years, residing in NYC (n=316). Data on youth sexual health knowledge (e.g., pregnancy, STDs, birth control) and caregiver-adolescent communication about sexual health were examined. Participants in both groups answered only 35% of the sexual health knowledge questions correctly (mean=6.6/19). Higher scores were found among youth who reported more communication about sex with caregivers (vs. those who did not report talking about sex with caregivers; 8.54 vs. 5.84, p<.001) and among PHIV+ youth who were aware of their status (vs. PHIV+ youth who were not; 7.27 vs. 4.70, p<.001). Age was positively correlated with sexual health knowledge (beta=.489, p<.001). Both PHIV+ and PHIV- youth had poor sexual health knowledge, suggesting a need for sexual health education for both groups. Data suggest that interventions focused on caregiver-child risk communication may be important for prevention.

Characteristics and genotype profiles of antiretroviral-naïve patients entering a Southern US HIV outpatient clinic 2009-2012

The US city of New Orleans was ranked second in the nation for estimated HIV case rates in 2011. Opt-out testing was established at the Interim Louisiana Hospital in New Orleans in 2013. The majority of new diagnoses were referred to the HIV outpatient program. We conducted a retrospective chart review of newly referred antiretroviral-naïve patients establishing HIV care between January 2009 and June 2013 to characterise demographic and genotype profiles to assist in clinical management and needed services. Of the eligible 226 patients, 68% were men, and 88% were African American. Nearly half of the study patients were younger than 35 years of age. Forty-six percent had an initial CD4 count <200 cells/mm(3), and 39% had a HIV viral load >100,000 copies/mL. The antiretroviral class with the most common major mutation was the non-nucleoside reverse transcriptase inhibitors (NNRTIs) where K103N was the most common major NNRTI mutation at presentation. We observed that male patients showed more advanced disease with later presentation to care, confirming the need for earlier HIV diagnosis. When considering initial antiretroviral therapy, baseline genotype information is encouraged, particularly if considering a NNRTI-based regimen.

Functional label-free assays for characterizing the in vitro mechanism of action of small molecule modulators of capsid assembly

HIV capsid protein is an important target for antiviral drug design. High-throughput screening campaigns have identified two classes of compounds (PF74 and BI64) that directly target HIV capsid, resulting in antiviral activity against HIV-1 and HIV-2 laboratory strains. Using recombinant proteins, we developed a suite of label-free assays to mechanistically understand how these compounds modulate capsid activity. PF74 preferentially binds to the preassembled hexameric capsid form and prevents disruption of higher-order capsid structures by stabilizing capsid intersubunit interactions. BI64 binds only the monomeric capsid and locks the protein in the assembly incompetent monomeric form by disrupting capsid intersubunit interactions. We also used these assays to characterize the interaction between capsid and the host protein cleavage and polyadenylation specific factor 6 (CPSF6). Consistent with recently published results, our assays revealed CPSF6 activates capsid polymerization and preferentially binds to the preassembled hexameric capsid form similar to the small molecule compound, PF74. Furthermore, these label-free assays provide a robust method for facilitating the identification of a different class of small molecule modulators of capsid function.

HIV-1 transmitted drug resistance-associated mutations and mutation co-variation in HIV-1 treatment-naïve MSM from 2011 to 2013 in Beijing, China

Background

Transmitted drug resistance (TDR) is an important public health issue, because TDR-associated mutation may affect the outcome of antiretroviral treatment potentially or directly. Men who have sex with men (MSM) constitute a major risk group for HIV transmission. However, current reports are scarce on HIV TDR-associated mutations and their co-variation among MSM.

Methods

Blood samples from 262 newly diagnosed HIV-positive, antiretroviral therapy (ART)-naïve MSM, were collected from January 2011 and December 2013 in Beijing. The polymerase viral genes were sequenced to explore TDR-associated mutations and mutation co-variation.

Results

A total of 223 samples were sequenced and analyzed. Among them, HIV-1 CRF01_AE are accounted for 60.5%, followed by CRF07_BC (27.8%), subtype B (9.9%), and others. Fifty-seven samples had at least one TDR-associated mutation, mainly including L10I/V (6.3%), A71L/T/V (6.3%), V179D/E (5.4%), and V106I (2.7%), with different distributions of TDR-associated mutations by different HIV-1 subtypes and by each year. Moreover, eight significant co-variation pairs were found between TDR-associated mutations (V179D/E) and seven overlapping polymorphisms in subtype CRF01_AE.

Conclusions

To date, this work consists the most comprehensive genetic characterization of HIV-1 TDR-associated mutations prevalent among MSM. It provides important information for understanding TDR and viral evolution among Chinese MSM, a population currently at particularly high risk of HIV transmission.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0689-7) contains supplementary material, which is available to authorized users.

Contraceptive methods and risk of HIV acquisition or female-to-male transmission

Effective family planning with modern contraception is an important intervention to prevent unintended pregnancies which also provides personal, familial, and societal benefits. Contraception is also the most cost-effective strategy to reduce the burden of mother-to-child HIV transmission for women living with HIV who wish to prevent pregnancy. There are concerns, however, that certain contraceptive methods, in particular the injectable contraceptive depot medroxyprogesterone acetate (DMPA), may increase a woman's risk of acquiring HIV or transmitting it to uninfected males. These concerns, if confirmed, could potentially have large public health implications. This paper briefly reviews the literature on use of contraception among women living with HIV or at high risk of HIV infection. The Centers for Disease Control and Prevention (CDC) and the World Health Organization (WHO) recommendations place no restrictions on the use of hormonal contraceptive methods by women with or at high risk of HIV infection, although a clarification recommends that, given uncertainty in the current literature, women at high risk of HIV who choose progestogen-only injectable contraceptives should be informed that it may or may not increase their risk of HIV acquisition and should also be informed about and have access to HIV preventive measures, including male or female condoms.

Predictors of Loss to follow-up in Patients Living with HIV/AIDS after Initiation of Antiretroviral Therapy

Background:

Long-term regular follow up of ART is an important component of HIV care. Patients who are lost to follow-up (LTFU) while on treatment compromise their own health and the long-term success of ART programs.

Aim:

This study was aimed at determining the incidence and risk factors for LTFU in HIV patients on ART at ART clinic of Mizan-Aman General Hospital, Ethiopia.

Materials and Methods:

A retrospective cohort study of 2133 people living with HIV/AIDS and attending an ART clinic between 2005 and 2013 was undertaken. LTFU was defined as not taking an ART refill for a period of 3 months or longer from the last attendance for refill and not yet classified as ‘dead’ or ‘transferred-out’. The log-rank test was used to measure differences in time to LTFU between groups and Cox proportional hazards modeling was used to measure predictors of LTFU.

Results:

Of 2133 patients, 53.9% were female. The mean (SD) age of the cohort was 31.5 (8.0), 16 (2.2), and 3.8 (3.0) years for adults, adolescents, and children, respectively. Around 574 (26.7%) patients were defined as LTFU. The cumulative incidence of LTFU was 8.8 (95% CIs 8.1-9.6) per 1000 person months. Patients with regimen substitution (HR 5.2; 95% CIs 3.6-7.3), non-isoniazid (INH) prophylaxis (HR 3.7; 95% CIs 2.3-6.2), adolescent (HR 2.1; 95% CIs 1.3-3.4), and had a baseline CD₄ count < 200 cells/mm³ (HR 1.7, 95% CIs 1.3-2.2) were at higher risk of LTFU. WHO clinical stage III (HR 0.6; 95% CIs 0.4-0.9) and IV (HR 0.8; 95% CIs 0.6-1.0) patients at entry were less likely to be LTFU than clinical stage I patients. There was no significant difference in risk of LTFU in males and females.

Conclusion:

Overall, these data suggested that LTFU in this study was high. Patients phase of life, drug related factors, and clinical stages were associated with LTFU in this study. Effective control measures in the at-risk population need to be implemented to improve retention.

Prevalence of drug-resistant HIV type 1 at the time of initiation of antiretroviral therapy in Portland, Oregon

The presence of transmitted drug-resistant HIV-1 (TDR) at the time of antiretroviral therapy (ART) initiation is associated with failure to achieve viral load suppression. Rates of TDR in ART-naive patients have been reported from various parts of the world through ongoing national, regional, and global evaluations; however, surveillance of TDR in Portland, Oregon has not been previously described. We describe the prevalence of TDR in patients in the Portland area who have recently entered care. Genotypic data were obtained from plasma specimens collected between 2003 and 2009 from 165 recently identified HIV-1-positive, ART-naive adults in care at the Multnomah County Health Department. Median time from diagnosis to first genotype was 2.7 months. Mutations associated with TDR were observed in 33 (20.0%) patients. Mutations associated with resistance to nucleoside reverse transcriptase (RT) inhibitors (NRTI), nonnucleoside RT inhibitors (NNRTI), and protease inhibitors (PI) were found in 15 (9.1%), 17 (10.3%), and 5 (3.0%) patients, respectively (p=0.013 for NNRTI vs. PI, and 0.035 for NRTI vs. PI, Fisher exact test). Dual class resistance was observed in four (2.4%) patients. Predominant RT mutations included M41L, T215C or S, and K103N. The prevalence of HIV-1 with NRTI resistance-associated mutations increased from 2006 to 2008-2009 (p=0.004) based on date of diagnosis. These data indicate relatively high rates of drug resistance present prior to ART initiation among patients in the Portland area, and support continued surveillance of local trends of TDR to inform optimal individual treatment strategies and public health decisions.

Pretreatment HIV-1 drug resistance is strongly associated with virologic failure in HIV-infected patients receiving partly active antiretroviral regimens

The scale-up of antiretroviral therapy in sub-Saharan Africa has significantly reduced mortality from AIDS. Hamers et al. explores the impact of pretreatment HIV-1 drug resistance on virologic failure, immunologic response, and acquisition of drug resistance after 1 year of first-line antiretroviral therapy by longitudinally evaluating 2579 participants with pretreatment drug resistance results from the PharmAccess African Studies to Evaluate Resistance Monitoring (PASER-M) cohort. Participants with pretreatment drug resistance who were given a treatment regimen with reduced activity to at least one prescribed drug had a significantly greater risk of virologic failure and acquired drug resistance compared with both participants without pretreatment drug resistance, and participants with pretreatment drug resistance who were prescribed fully active regimens. This paper by Hamers et al. validates the need for at least three fully active antiretroviral drugs to prevent the acquisition of drug resistance and to optimize treatment success in resource limited settings.

Baseline-transmitted V106V/I/M non-nucleoside reverse transcriptase inhibitor resistance in HIV-1 subtype B infection

We report a case in which an antiretroviral therapy (ART)-naïve patient diagnosed with HIV-1 subtype B presented with baseline genotype and phenotype resistance tests, confirming a V106V/I/M nucleoside resistance mutation. The V106V/I/M mutation represents a mixture of virus strains conferring resistance to the non-nucleoside reverse transcriptase inhibitor antiretrovirals efavirenz and nevirapine. V106M mutation is not often observed as a primary resistance mutation in patients infected with HIV-1 subtype B. The patient responded well to an ART regimen consisting of tenofovir-emtricitabine and raltegravir, achieving and maintaining an undetectable HIV RNA.

Mutations in multiple domains of Gag drive the emergence of in vitro resistance to the phosphonate-containing HIV-1 protease inhibitor GS-8374

GS-8374 is a potent HIV protease inhibitor (PI) with a unique diethyl-phosphonate moiety. Due to a balanced contribution of enthalpic and entropic components to its interaction with the protease (PR) active site, the compound retains activity against HIV mutants with high-level multi-PI resistance. We report here the in vitro selection and characterization of HIV variants resistant to GS-8374. While highly resistant viruses with multiple mutations in PR were isolated in the presence of control PIs, an HIV variant displaying moderate (14-fold) resistance to GS-8374 was generated only after prolonged passaging for >300 days. The isolate showed low-level cross-resistance to darunavir, atazanavir, lopinavir, and saquinavir, but not other PIs, and contained a single R41K mutation in PR combined with multiple genotypic changes in the Gag matrix, capsid, nucleocapsid, and SP2 domains. Mutations also occurred in the transframe peptide and p6* domain of the Gag-Pol polyprotein. Analysis of recombinant HIV variants indicated that mutations in Gag, but not the R41K in PR, conferred reduced susceptibility to GS-8374. The Gag mutations acted in concert, since they did not affect susceptibility when introduced individually. Analysis of viral particles revealed that the mutations rendered Gag more susceptible to PR-mediated cleavage in the presence of GS-8374. In summary, the emergence of resistance to GS-8374 involved a combination of substrate mutations without typical resistance mutations in PR. These substrate changes were distributed throughout Gag and acted in an additive manner. Thus, they are classified as primary resistance mutations indicating a unique mechanism and pathway of resistance development for GS-8374.

Transmitted HIV resistance to first-line antiretroviral therapy in Lima, Peru

Transmission of drug-resistant HIV (TDR) has been associated with virologic failure of "first-line," nonnucleoside reverse transcriptase inhibitor (NNRTI)-based antiretroviral therapy (ART). A national ART program began in Peru in 2004. We evaluated the prevalence of TDR in individuals initiating ART and their virologic outcome during 2 years of ART. HIV-infected, ARV-naive subjects who met criteria to start ART in Lima, Peru were enrolled in a longitudinal observational study between July 2007 and February 2009. Blood plasma and cells obtained prior to ART initiation were assessed for antiretroviral (ARV) resistance by an oligonucleotide ligation assay (OLA) sensitive to 2% mutant at reverse transcriptase (RT) codons K103N, Y181C, G190A, and M184V and a subset by consensus sequencing. A total of 112 participants were enrolled; the mean CD4 was 134 ± 89 cells/μl and the median plasma HIV RNA was 93,556 copies/ml (IQR 62,776-291,364). Drug resistance mutations conferring high-level resistance to ARV were rare, detected in one of 96 (1%) evaluable participants. This subject had the Y181C mutation detected in both plasma and peripheral blood mononuclear cells (PBMCs) at a concentration of 100% by OLA and consensus sequencing; nevertheless nevirapine-ART suppressed her viral replication. Consensus sequencing of 37 (19%) participants revealed multiple polymorphisms that occasionally have been associated with low-level reductions in ARV susceptibility. A low prevalence of TDR was detected among Peruvians initiating ART. Given the increasing availability of ART, continuing surveillance is needed to determine if TDR increases and the mutant codons associated with virologic failure.

Secondary HIV prevention: novel intervention approaches to impact populations most at risk

This paper reviews recent secondary prevention interventions designed to reduce sexual risk behaviors among people living with HIV/AIDS (PLWHA). A summary of findings from previous meta-analyses and narrative reviews of interventions is provided. Next, novel HIV prevention approaches for PLWHA are reviewed. The review reports on the efficacy of interventions delivered in primary care settings or by technology-formats, interventions that also address mental health difficulties, and programs to address particular at-risk populations (eg, men who have sex with men). A critique of recent interventions for people living with HIV/AIDS is provided as well as suggestions for future research.

Comparative evaluation of the ViroSeq™ HIV-1 genotyping system and an in-house method for analysis of HIV-1 drug-resistance mutations in China

BACKGROUND AND OBJECTIVE

With the introduction of the ViroSeq™ HIV-1 Genotyping System (ViroSeq™ assay) into China, it is important to evaluate the impact of the diversity of HIV-1 genotypes found in China on the performance of the ViroSeq™ assay compared with an in-house method.

MATERIALS AND METHODS

A total of 318 plasma samples, collected from 206 HIV-1-infected patients receiving antiretroviral therapy and 112 treatment-naïve HIV-1-infected patients, were used for evaluating the concordance of genotypes, genotypic resistance mutations, and phenotypic resistance between the ViroSeq™ assay and an in-house method for analyzing HIV-1 drug resistance in China.

RESULTS

A concordance of genotypes between the ViroSeq™ assay and the in-house method was observed for the 313 samples (98.4%), using the Stanford University HIV Drug Resistance Database (Version 6.0.5). The overall concordances of drug-resistance-related mutations (DRRMs) in the HIV-1 protease (PR) and reverse transcriptase (RT) coding sequences within the HIV-1 pol gene, scored by the ViroSeq™ assay and the in-house method, were 99.5% and 98.1%, respectively. Discrepancies between the two methods were found in 38 samples assayed for protease inhibitor (PI) DRRMs, 36 samples assayed for nucleoside reverse transcriptase inhibitor (NRTI) DRRMs, and 72 samples assayed for non-nucleoside reverse transcriptase inhibitor (NNRTI) DRRMs, and 100%, 88.9%, and 87.5% of the samples with discrepancies for PI, NRTI, and NNRTI DRRMs, respectively, were genotyped as subtype B. One NNRTI mutation (the RT mutation Y318F) was reported only by the ViroSeq™ assay, and this discrepancy resulted from the difference in the pol gene lengths generated by the two systems. Furthermore, the overall concordance of phenotypic resistance was 94.7% (301/318) between the two methods.

CONCLUSION

The ViroSeq™ assay will be a useful tool for monitoring clinical drug resistance and for better management of HIV-1 patients receiving antiretroviral therapy in China.

HIV capsid is a tractable target for small molecule therapeutic intervention

Despite a high current standard of care in antiretroviral therapy for HIV, multidrug-resistant strains continue to emerge, underscoring the need for additional novel mechanism inhibitors that will offer expanded therapeutic options in the clinic. We report a new class of small molecule antiretroviral compounds that directly target HIV-1 capsid (CA) via a novel mechanism of action. The compounds exhibit potent antiviral activity against HIV-1 laboratory strains, clinical isolates, and HIV-2, and inhibit both early and late events in the viral replication cycle. We present mechanistic studies indicating that these early and late activities result from the compound affecting viral uncoating and assembly, respectively. We show that amino acid substitutions in the N-terminal domain of HIV-1 CA are sufficient to confer resistance to this class of compounds, identifying CA as the target in infected cells. A high-resolution co-crystal structure of the compound bound to HIV-1 CA reveals a novel binding pocket in the N-terminal domain of the protein. Our data demonstrate that broad-spectrum antiviral activity can be achieved by targeting this new binding site and reveal HIV CA as a tractable drug target for HIV therapy.

Although the current standard of care for Human Immunodeficiency Virus (HIV) is high, viral resistance has emerged to every drug currently in the clinic, in some cases rendering the entire class ineffective for patients. A new class of antiretroviral drugs would be effective against strains of HIV-1 that are resistant to any existing drug and would expand the therapeutic options available to patients. Capsid is the primary structural protein of HIV and a critical part of the viral replication cycle, both in the assembly of viral particles and in the infection of host cells. We report a new class of antiretrovirals that targets HIV-1 capsid and demonstrate that it is active at two critical stages in the viral replication cycle. These compounds were consistently effective against a range of clinical strains of HIV-1, from various sub-types, as well as HIV-2. Finally, the compounds bind in a unique pocket on capsid that has not previously been highlighted as a drug binding site. We believe this new class of antiretrovirals can serve as a starting point for the development of a new generation of HIV-1 therapeutics and, more generally, underscores the potential of capsid as a therapeutic target.

High rate of loss to clinical follow up among African HIV-infected patients attending a London clinic: a retrospective analysis of a clinical cohort

Background

Long-term regular clinic follow up is an important component of HIV care. We determined the frequency and characteristics of HIV-infected patients lost to follow up from a London HIV clinic, and factors associated with loss to all HIV follow up in the UK.

Methods

We identified 1859 HIV-infected adults who had registered and attended a London clinic on one or more occasions between January 1997 and December 2005. Loss to follow up was defined as clinic non-attendance for one or more years. Through anonymized linkage with the Survey of Prevalent HIV Infections Diagnosed and Health Protection Scotland, national databases of all HIV patients in care in the UK up to December 2006, loss-to-follow-up patients were categorized as Transfers (subsequently received care at another UK HIV clinic) or UKLFU (no record of subsequent attendance at any HIV clinic in the UK). Logistic regression analysis was used to identify factors associated with UKLFU for those both on highly active antiretroviral therapy (HAART) and not on HAART.

Results

In total, 722 (38.8%) of 1859 patients were defined as lost to follow up. Of these, 347 (48.1%) were Transfers and 375 (51.9%), or 20.2% of all patients, were UKLFU. Overall, 11.9% of all patients receiving HAART, and 32.2% not receiving HAART were UKLFU. Among those on HAART, risk factors for UKLFU were: African heterosexual female (OR = 2.22, 95% CI: 1.11-4.56) versus white men who have sex with men; earlier year of HIV clinic registration (1997-1999 OR: 3.51, 95% CI: 1.97-6.26; 2000-02 OR: 2.49, 95% CI: 1.43-4.32 vs. 2003-2005); CD4 count of < 200 versus > 350 cells/mm³ (OR = 1.99, 95% CI:1.05-3.74); and a detectable viral load of > 400 copies/ml (OR = 5.03, 95% CI: 2.95-8.57 vs. ≤ 400 copies/ml) at last clinic visit.

Among those not receiving HAART, factors were: African heterosexual male (OR = 3.91, 95% CI: 1.77-8.64) versus white men who have sex with men; earlier HIV clinic registration (2000-2002 OR: 2.91, 95% CI: 1.77-4.78; 1997-1999: OR: 5.26, 95% CI: 2.71-10.19); and a CD4 count of < 200 cells/mm³ (OR: 3.24, 95% CI: 1.49-7.04).

Conclusions

One in five HIV-infected patients (one in three not on HAART and one in nine on HAART) from a London clinic were lost to all clinical follow up in the UK. Black African ethnicity, earlier year of clinic registration and advanced immunological suppression were the most important predictors of UKLFU. There is a need for all HIV clinics to establish systems for monitoring and tracing loss-to-follow-up patients, and to implement strategies for improving retention in care.

Adolescents and HIV: prevention and clinical care

The incidence of HIV infection has increased to alarming proportions among minority youth, in particular among young men who have sex with men and among teenage girls. The unique socioeconomic, behavioral, and emotional vulnerability of adolescents for sexually transmitted diseases, including HIV, requires early identification of HIV infection for linkage to care. Differences in the clinical and psychosocial presentations of youth with perinatally versus behavioral acquired HIV infection are important and influence the acceptance of illness, self-efficacy, and antiretroviral treatment adherence. The ideal multidisciplinary team approach of culturally sensitive services for youth integrates clinical care, psychosocial and peer support interventions, transition planning, primary and secondary prevention, as well as comprehensive reproductive adolescent health services.