Combination antiretroviral therapy failure and HIV super-infection

First line antiretroviral treatment failure and associated factors among people living with HIV in northwest Ethiopia

BACKGROUND

Anti-retroviral treatment enhances the immune status and reduces unwanted outcomes. However, development of treatment failure and drug resistance raises concern over lifelong treatments to chronic diseases such as HIV/AIDS.

OBJECTIVES

This study determined proportion of treatment failure (TF) and identified factors associated with TF among people living with human immunodeficiency virus (HIV) in Bahir Dar, Northwest Ethiopia.

METHODS

Facility based cross sectional study was carried out from November, 2017 to April, 2018. Sociodemographic and clinical data were collected using structured questioner. Blood sample was collected and analyzed for viral load, complete blood count (CBC), liver and kidney function test and CD4 count. A patient is declared as treatment failure when viral load value is higher than 1000 RNA copies/ml in two consecutive viral load analyses within three months interval. Data were entered and analyzed using SPSS version 23. To identify factors associated with TF, logistic regressions model was employed.

RESULTS

A total of 430 people who had six months and above antiretroviral treatment (ART) follow up were enrolled in the study. Of these, 57.9% were females & the mean age was 38 years. The mean month of ART follow up was 83 months. In the first viral load analysis, 106 (24.7%) of the cohort were virologically failed. These failed people were followed for 3 months with intensive adherence support; then second viral load analysis showed a viralogical failure among 65 people of the second cohort. Thus, the overall viralogical failure or TF was 15.1%. The re-suppression rates were 41(38.7%). Male gender, people with history of drug discontinuation, poor adherence, irregular time of drug intake, multiple sexual practice showed significant association with TF. Moreover, base line and current CD4 counts of <200 cells/ml also demonstrated significant association with TF.

CONCLUSION

Significant proportion of treatment failure was reported in the present study. Moreover, behavioral factors such as drug discontinuation, poor adherence, multiple sexual partner were associated with treatment failure. Hence, to avoid TF, regular patient counseling and monitoring should be in place. To identify the predictors for treatment failure, further follow-up study is desirable.

Immunological and virological characteristics of human immunodeficiency virus type 1 superinfection: implications in vaccine design

Superinfection is frequently detected among individuals infected by human immunodeficiency virus type I (HIV-1). Superinfection occurs at similar frequencies at acute and chronic infection stages but less frequently than primary infection. This observation indicates that the immune responses elicited by natural HIV-1 infection may play a role in curb of superinfection; however, these responses are not sufficiently strong to completely prevent superinfection. Thus, a successful HIV-1 vaccine likely needs to induce more potent and broader immune responses than those elicited by primary infection. On the other hand, potent and broad neutralization responses are more often detected after superinfection than during monoinfection. This suggests that broadly neutralizing antibodies are more likely induced by sequential immunization of multiple different immunogens than with only one form of envelope glycoprotein immunogens. Understanding why the protection from superinfection by immunity induced by primary infection is insufficient and if superinfection can lead to cross-reactive immune responses will be highly informative for HIV-1 vaccine design.

HIV Type 1 transmission networks among men having sex with men and heterosexuals in Kenya

We performed a molecular phylogenetic study on HIV-1 polymerase sequences of men who have sex with men (MSM) and heterosexual patient samples in Kenya to characterize any observed HIV-1 transmission networks. HIV-1 polymerase sequences were obtained from samples in Nairobi and coastal Kenya from 84 MSM, 226 other men, and 364 women from 2005 to 2010. Using Bayesian phylogenetics, we tested whether sequences clustered by sexual orientation and geographic location. In addition, we used trait diffusion analyses to identify significant epidemiological links and to quantify the number of transmissions between risk groups. Finally, we compared 84 MSM sequences with all HIV-1 sequences available online at GenBank. Significant clustering of sequences from MSM at both coastal Kenya and Nairobi was found, with evidence of HIV-1 transmission between both locations. Although a transmission pair between a coastal MSM and woman was confirmed, no significant HIV-1 transmission was evident between MSM and the comparison population for the predominant subtype A (60%). However, a weak but significant link was evident when studying all subtypes together. GenBank comparison did not reveal other important transmission links. Our data suggest infrequent intermingling of MSM and heterosexual HIV-1 epidemics in Kenya.

Behavioral and molecular tracing of risky sexual contacts in a sample of Chinese HIV-infected men who have sex with men

Contact tracing, coupled with molecular epidemiologic investigation, is especially useful for identifying an infection with few cases in the population, such as human immunodeficiency virus (HIV) infection in China. No such research is available on Chinese men who have sex with men (MSM). From 2008 to 2010 in Taizhou Prefecture in China, every newly diagnosed HIV-infected MSM was invited to participate as an "index case" in a contact tracing survey by providing contact information for up to 8 sexual contacts, who themselves were approached to receive voluntary HIV counseling and testing. Those who tested HIV-positive were then subjected to another contact tracing survey. This process was repeated until no more sexual contacts were reported or tested positive. A total of 100 HIV-infected MSM served as "index cases," including the initial 49 cases identified through routine surveillance programs and 51 cases from the present survey. Traced MSM exhibited little willingness to receive voluntary counseling and testing. CRF01_AE (HIV type 1) was the dominant subtype. Seven of 49 independent sexual networks were deemed HIV transmission clusters. Fear of stigma or discrimination may deter Chinese MSM from receiving voluntary counseling and testing. Nonetheless, the integration of behavioral network analysis and HIV phylogenetic analysis provides enhanced evidence for developing tailored prevention strategies for HIV-infected MSM.

Perceptions of superinfection risk among gay men with diagnosed HIV who have unprotected anal intercourse

This paper explores how men who have sex with men (MSM) with diagnosed HIV who engage in unprotected anal intercourse (UAI) perceive the potential risk of superinfection and how they respond to it. Semistructured interviews were carried out with 42 MSM recruited via community-based agencies throughout England and Wales. The interviews examined sexual risk taking and the ways in which men sought to manage the risks they perceived. All participants had heard of superinfection and one-third considered it a personal risk when they had UAI with men with the same sero-status. The risk of being superinfected with HIV was often situated among a number of other concerns that men felt they needed to manage when having sex. There was significant uncertainty about the likelihood of acquiring an additional strain of HIV, which was exacerbated by competing, and often conflicting, advice from a variety of expert sources. Men frequently drew upon lay and expert understandings of viral load and infectiousness to rationalize engagement in UAI with other diagnosed positive men. HIV health-care providers should seek to find consensus on how to discuss superinfection with MSM, taking account of the array of other physical and social risks associated with sex.

Multiple HIV-1 infections with evidence of recombination in heterosexual partnerships in a low risk Rural Clinical Cohort in Uganda

We report on the frequency of multiple infections, generation of recombinants and consequences on disease progression in 35 HIV-1 infected individuals from 7 monogamous and 6 polygamous partnerships within a Rural Clinical Cohort in Uganda. The env-C2V3, gag-p24 and pol-IN genes were sequenced. Single genome amplified half genome sequences were used to map recombination breakpoints. Three participants were dually infected with subtypes A and D, one case with subtype A and A/D recombinant and the fifth with 2 phylogenetically distinct A/D recombinants. Occurrence of A/D recombination was observed in two multiple infected individuals. Rate of late stage WHO events using Cox regression was 3 times greater amongst multiple infected compared to singly infected individuals (hazard ratio 3.35; 95% CI 1.09, 10.3; p = 0.049). We have shown that polygamous relationships involving subtype discordant partnerships was a major contributor of multiple infections with generation of inter subtype recombinants in our cohort.

An RNAi in silico approach to find an optimal shRNA cocktail against HIV-1

Background

HIV-1 can be inhibited by RNA interference in vitro through the expression of short hairpin RNAs (shRNAs) that target conserved genome sequences. In silico shRNA design for HIV has lacked a detailed study of virus variability constituting a possible breaking point in a clinical setting. We designed shRNAs against HIV-1 considering the variability observed in naïve and drug-resistant isolates available at public databases.

Methods

A Bioperl-based algorithm was developed to automatically scan multiple sequence alignments of HIV, while evaluating the possibility of identifying dominant and subdominant viral variants that could be used as efficient silencing molecules. Student t-test and Bonferroni Dunn correction test were used to assess statistical significance of our findings.

Results

Our in silico approach identified the most common viral variants within highly conserved genome regions, with a calculated free energy of ≥ -6.6 kcal/mol. This is crucial for strand loading to RISC complex and for a predicted silencing efficiency score, which could be used in combination for achieving over 90% silencing. Resistant and naïve isolate variability revealed that the most frequent shRNA per region targets a maximum of 85% of viral sequences. Adding more divergent sequences maintained this percentage. Specific sequence features that have been found to be related with higher silencing efficiency were hardly accomplished in conserved regions, even when lower entropy values correlated with better scores. We identified a conserved region among most HIV-1 genomes, which meets as many sequence features for efficient silencing.

Conclusions

HIV-1 variability is an obstacle to achieving absolute silencing using shRNAs designed against a consensus sequence, mainly because there are many functional viral variants. Our shRNA cocktail could be truly effective at silencing dominant and subdominant naïve viral variants. Additionally, resistant isolates might be targeted under specific antiretroviral selective pressure, but in both cases these should be tested exhaustively prior to clinical use.

Transmission networks of HIV-1 among men having sex with men in the Netherlands

OBJECTIVE

To obtain insight in the HIV-1 transmission networks among men having sex with men (MSM) in the Netherlands.

DESIGN

A phylogenetic tree was constructed from polymerase sequences isolated from 2877 HIV-1 subtype B-infected patients monitored as part of the AIDS Therapy Evaluation in the Netherlands (ATHENA) nationwide observational cohort.

METHODS

For MSM with a known date of infection, the most similar sequences were selected as potential transmission pairs when they clustered with bootstrap value of at least 99%. Time from infection to onward transmission was estimated as the median time between dates of infection for each transmission pair. The source of infections with a resistant strain was traced using the entire phylogenetic tree.

RESULTS

Of sequences from 403 MSM with a known date of infection between 1987 and 2007, 175 (43%) formed 63 clusters. Median time to onward transmission was 1.4 years (interquartile range 0.6-2.7). Twenty-four (6%) MSM carried a virus with resistance-related mutations, 13 of these were in eight clusters together with sequences from 28 other patients in the entire phylogenetic tree. Six clusters contained sequences obtained from 29 men all presenting the same resistance-related mutations.

CONCLUSION

From our selection of likely transmission pairs, we conclude that onward transmission of HIV-1 from infected MSM in the Netherlands happens both during and after primary infection. Transmission of resistant strains from the antiretroviral therapy-treated population is limited, but strains with resistance-related mutations have formed subepidemics.

Concurrent sexual partnerships among individuals in HIV sero-discordant heterosexual couples

The objective of the study was to assess the level at which individuals in HIV discordant couples engage in concurrent sexual partnerships and factors associated with this risk of transmitting HIV. By using data from a group of HIV discordant heterosexual couples (n = 145), we examined the frequency of concurrent sexual partners and factors associated with such partnerships. The prevalence of concurrent partnerships with heterosexual partners was 16%. Fewer than half of individuals with concurrent partnerships reported that their main study partner knew about these relationships. Of individuals involved in concurrent partnerships, 30% reported inconsistent condom use in these relationships. Unmarried individuals in new HIV sero-discordant relationships were particularly at risk for concurrent partnerships. In conclusion, more frequent HIV testing may complement increased attention to communication, disclosure and condom use in this population that is especially vulnerable to acquiring and transmitting HIV infection.