Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 45
Filter
Add more filters

Country/Region as subject
Publication year range
1.
BMC Infect Dis ; 24(1): 833, 2024 Aug 16.
Article in English | MEDLINE | ID: mdl-39148016

ABSTRACT

BACKGROUND: Hepatitis B virus (HBV) and human immunodeficiency virus (HIV) co-infection are significant public health issues, despite the availability of an effective HBV vaccine for nearly three decades and the great progress that has been made in preventing and treating HIV. HBV and HIV both modulate micro-ribonucleic acids (microRNA) expression to support viral replication. The aim of this study was to describe the pattern of microRNA expression in patients coinfected with chronic HBV and HIV with varying disease severity, as indicated by Hepatitis B e antigen (HBeAg) status, HBV viral load, alanine transaminase (ALT) levels, and HIV viral load. METHODS: Plasma microRNAs, specific to HBV, were measured by quantitative real-time polymerase chain reaction (qRT-PCR) in HBV and HIV-negative healthy controls (n = 23) and patients coinfected with chronic HBV-HIV (n = 50). MicroRNA expression levels were compared between patients with high vs low HBV viral load, HBeAg positive vs HBeAg negative, high vs low ALT levels, and high vs low HIV viral load. Additionally, HBV viral load, ALT levels, and HIV viral load were correlated with microRNA expression levels. RESULTS: Significantly higher expression levels of selected microRNAs were observed in chronic HBV-HIV coinfected patients compared to healthy controls. Significantly higher expression levels of hsa-miR-122-5p, hsa-miR-192-5p, and hsa-miR-193b-3p were observed in patients with high HBV viral load compared with low HBV viral load patients, and the levels of these microRNAs were correlated with HBV viral load levels. Significantly higher levels of hsa-miR-15b-5p and hsa-miR-181b-5p were observed in HBeAg-negative patients. CONCLUSION: This study demonstrates the potential use of hsa-miR-15b-5p, hsa-miR-122-5p, hsa-miR-181b-5p, hsa-miR-192-5p and hsa-miR-193b-3p as additional diagnostic biomarkers in chronic HBV disease progression.


Subject(s)
Coinfection , HIV Infections , Hepatitis B virus , Hepatitis B, Chronic , MicroRNAs , Viral Load , Humans , Hepatitis B, Chronic/virology , Hepatitis B, Chronic/blood , Hepatitis B, Chronic/complications , MicroRNAs/blood , MicroRNAs/genetics , HIV Infections/complications , HIV Infections/virology , HIV Infections/blood , HIV Infections/epidemiology , Male , Coinfection/virology , Coinfection/epidemiology , Coinfection/blood , Female , Adult , South Africa/epidemiology , Hepatitis B virus/genetics , Middle Aged , Hepatitis B e Antigens/blood , Prevalence , Young Adult , Alanine Transaminase/blood
2.
Lancet ; 399(10323): 437-446, 2022 01 29.
Article in English | MEDLINE | ID: mdl-35065011

ABSTRACT

BACKGROUND: The SARS-CoV-2 omicron variant of concern was identified in South Africa in November, 2021, and was associated with an increase in COVID-19 cases. We aimed to assess the clinical severity of infections with the omicron variant using S gene target failure (SGTF) on the Thermo Fisher Scientific TaqPath COVID-19 PCR test as a proxy. METHODS: We did data linkages for national, South African COVID-19 case data, SARS-CoV-2 laboratory test data, SARS-CoV-2 genome data, and COVID-19 hospital admissions data. For individuals diagnosed with COVID-19 via TaqPath PCR tests, infections were designated as either SGTF or non-SGTF. The delta variant was identified by genome sequencing. Using multivariable logistic regression models, we assessed disease severity and hospitalisations by comparing individuals with SGTF versus non-SGTF infections diagnosed between Oct 1 and Nov 30, 2021, and we further assessed disease severity by comparing SGTF-infected individuals diagnosed between Oct 1 and Nov 30, 2021, with delta variant-infected individuals diagnosed between April 1 and Nov 9, 2021. FINDINGS: From Oct 1 (week 39), 2021, to Dec 6 (week 49), 2021, 161 328 cases of COVID-19 were reported in South Africa. 38 282 people were diagnosed via TaqPath PCR tests and 29 721 SGTF infections and 1412 non-SGTF infections were identified. The proportion of SGTF infections increased from two (3·2%) of 63 in week 39 to 21 978 (97·9%) of 22 455 in week 48. After controlling for factors associated with hospitalisation, individuals with SGTF infections had significantly lower odds of admission than did those with non-SGTF infections (256 [2·4%] of 10 547 vs 121 [12·8%] of 948; adjusted odds ratio [aOR] 0·2, 95% CI 0·1-0·3). After controlling for factors associated with disease severity, the odds of severe disease were similar between hospitalised individuals with SGTF versus non-SGTF infections (42 [21%] of 204 vs 45 [40%] of 113; aOR 0·7, 95% CI 0·3-1·4). Compared with individuals with earlier delta variant infections, SGTF-infected individuals had a significantly lower odds of severe disease (496 [62·5%] of 793 vs 57 [23·4%] of 244; aOR 0·3, 95% CI 0·2-0·5), after controlling for factors associated with disease severity. INTERPRETATION: Our early analyses suggest a significantly reduced odds of hospitalisation among individuals with SGTF versus non-SGTF infections diagnosed during the same time period. SGTF-infected individuals had a significantly reduced odds of severe disease compared with individuals infected earlier with the delta variant. Some of this reduced severity is probably a result of previous immunity. FUNDING: The South African Medical Research Council, the South African National Department of Health, US Centers for Disease Control and Prevention, the African Society of Laboratory Medicine, Africa Centers for Disease Control and Prevention, the Bill & Melinda Gates Foundation, the Wellcome Trust, and the Fleming Fund.


Subject(s)
COVID-19/physiopathology , Hospitalization/statistics & numerical data , SARS-CoV-2/genetics , Severity of Illness Index , Adolescent , Adult , COVID-19/epidemiology , COVID-19/virology , COVID-19 Nucleic Acid Testing , Child , Child, Preschool , Female , Genome, Viral , Humans , Information Storage and Retrieval , Logistic Models , Male , Middle Aged , Multivariate Analysis , Odds Ratio , South Africa/epidemiology , Young Adult
3.
Nanotechnology ; 33(40)2022 Jul 11.
Article in English | MEDLINE | ID: mdl-35700711

ABSTRACT

Active targeting is a promising approach for the treatment of viral infections. In particular, site-specific formulations for the treatment of HIV infection may overcome challenges associated with current ARV regimens. In this study we explored active targeting by synthesizing a gold nanoparticle construct decorated with an anti-CD4 cyclic peptide. The aim was to demonstrate selectivity of the system for the CD4 receptor and to deliver the RNA payload into T-lymphocytes. Colloidal gold nanoparticles functionalized withN-succinimidyl 3-(2-pyridyldithio) propionate (SPDP) were formed by a one-pot synthesis method where thiol modified polyethyleneimine (PEI) was mixed with chloroauric acid. PEI-SPDP AuNPs (gold nanoparticles) were conjugated to an anti-CD4 peptide and loaded with RNA. We measured toxicity and uptake using TZM-bl and HeLa cells. Our findings show that the nanoparticles bind selectively to CD4 + cells. UV-vis characterisation of the nanoparticles revealed a surface plasmon resonance (SPR) peak at 527 nm, corresponding to a 6 nm diameter. HRTEM of the complete nanoparticles visualised circular shaped particles with average diameter of ∼7 nm. The polydispersity index was calculated to be 0.08, indicating monodispersity of complete NPS in solution. Through the pyridine-2-thione assay each nanoparticle was calculated to carry 1.37 × 105SPDP molecules available for peptide binding. Flow cytometry showed that 13.6% of TZM-bl cells, and 0.14% of HeLa cells retained fluorescence after an overnight incubation, an indication of system binding. No internal RNA delivery was demonstrated. Further work is required to improve internalization.


Subject(s)
HIV Infections , Metal Nanoparticles , Nanoparticles , Gold , HeLa Cells , Humans , Metal Nanoparticles/chemistry , Nanoparticles/chemistry , Peptides/pharmacology , Polyethyleneimine/chemistry , RNA , T-Lymphocytes
4.
J Med Virol ; 91(7): 1217-1223, 2019 07.
Article in English | MEDLINE | ID: mdl-30840773

ABSTRACT

BACKGROUND: Parvovirus B19 (PVB19) is transmitted via transfusion of blood and blood products. PVB19 is resistant to viral inactivation methods, which poses a threat to blood safety. We investigated the prevalence of PVB19 antibodies and DNA in healthy blood donors from the South African National Blood Bank Service to evaluate the necessity of PVB19 DNA testing. STUDY DESIGN AND METHOD: A retrospective analysis of 1500 residual plasma specimens from healthy blood donors from the SANBS repository were screened in mini-pools of 20 for PVB19 DNA using a quantitative polymerase chain reaction (PCR). Positive pools were resolved by individual viral load testing and screened for PVB19 immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies to correlate viral loads with serological status. PVB19 IgG prevalence was determined by testing 90 randomly selected specimens from the 1500 plasma specimens. RESULTS: The prevalence of PVB19 IgG, IgM and IgG, and DNA was 62.2%, 0.06%, and 0.9%, respectively. Fourteen of the 1500 blood donor specimens received, had detectable PVB19 viral loads. Nine of the fourteen donors with detectable viral loads were PVB19 IgG seropositive. The PVB19 viral loads ranged from 1.81 to 5.32 log IU/mL. Four of the fourteen viraemic donors had a viraemia >10 4 IU/mL. CONCLUSION: We have demonstrated a low prevalence of PVB19 DNA in SANBS blood donors. The predominance of low-level viraemia and the presence of PVB19 antibodies, suggests that the risk of transfusion transmission of PVB19 among SANBS donors may be relatively low.


Subject(s)
Antibodies, Viral/blood , Blood Donors , Parvoviridae Infections/diagnosis , Parvovirus B19, Human/isolation & purification , Adolescent , Adult , DNA, Viral/isolation & purification , Female , Healthy Volunteers , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Parvoviridae Infections/epidemiology , Prevalence , Retrospective Studies , South Africa/epidemiology , Viral Load , Viremia , Young Adult
5.
J Med Virol ; 91(10): 1797-1803, 2019 10.
Article in English | MEDLINE | ID: mdl-31180137

ABSTRACT

Occult hepatitis B virus (HBV) infection (OBI) is defined as the presence of HBV DNA in the liver with or without detectable HBV DNA in the serum of individuals testing HBV surface antigen (HBsAg) negative using currently available assays. The prevalence of OBI among patients receiving hemodialysis (HD) treatment remains poorly characterized in South Africa despite the high prevalence of HBV. We sought to determine the prevalence of OBI in HD units in tertiary hospitals of KwaZulu-Natal and to characterize the HBV S gene mutations potentially responsible for OBI. A cross-sectional descriptive study of residual diagnostic plasma samples from 85 HBsAg-negative patients receiving HD treatment was included. The PreS/S gene was amplified with a nested HBV polymerase chain reaction for downstream next-generation sequencing, to determine the viral genotype and identify S gene mutations associated with OBI. Nine of the 85 samples had OBI, based on detectable HBV DNA. The point prevalence of OBI was 10.6% (95% control interval: 5.5%-19.1%). Phylogenetic analysis of the samples with OBI showed that all belonged to genotype A. Three (~33%) samples had mutations in the major hydrophilic region (MHR) within the S gene, three (~33%) had mutations within the S gene but outside the MHR, whilst the remaining three had no mutations observed. The prevalence of OBI in HBsAg-negative patients undergoing HD was 10.6%, suggesting that OBI is a clinically significant problem in patients with HD in this region. The screening methods for HBV infection need to be revised to include nucleic acid testing.


Subject(s)
Hepatitis B virus/isolation & purification , Hepatitis B/diagnosis , Hepatitis B/epidemiology , Adult , Amino Acid Sequence , Cross-Sectional Studies , Female , Genotype , Hemodialysis Units, Hospital , Hepatitis B virus/genetics , Humans , Male , Phylogeny , Renal Dialysis , South Africa/epidemiology , Viral Load , Viral Proteins
6.
J Med Virol ; 89(6): 1080-1087, 2017 06.
Article in English | MEDLINE | ID: mdl-27918839

ABSTRACT

Cytomegalovirus (CMV) pneumonitis is a significant cause of morbidity and mortality of children in Africa. The current practice for diagnosing CMV pneumonitis in this setting is based on interpretation of clinical, laboratory, and radiological findings. There is a need for a sensitive and specific laboratory test to objectively distinguish between patients with CMV pneumonitis and those with CMV infection, and non-CMV pneumonia. In this study, we compared plasma and non-bronchoscopic bronchoalveolar lavage (NBBAL) CMV viral loads in patients with CMV pneumonitis and those with CMV infection and non-CMV pneumonia. Receiver operator characteristic curve analysis was used to establish a threshold and assess utility of viral loads in the diagnosis of CMV pneumonitis. We assessed the urea dilution method, and expression of viral loads relative to the total amount of extracted nucleic acids in correcting for NBBAL dilution. CMV quantification in NBBAL specimens was more predictive of CMV pneumonitis than blood CMV quantification. The threshold of 4.03 log IU/ml in NBBAL specimens has good predictive value and can be used to guide management of infants with suspected CMV pneumonitis. Adjusting for dilution of NBBAL specimens by using the urea dilution method or by expressing the viral load relative to the total nucleic acids extracted did not provide additional analytical benefits. J. Med. Virol. 89:1080-1087, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Bronchoalveolar Lavage Fluid/virology , Cytomegalovirus Infections/diagnosis , Cytomegalovirus/isolation & purification , Pneumonia/diagnosis , Viral Load , Blood/virology , Female , Humans , Infant , Male , Predictive Value of Tests , ROC Curve
7.
J Med Virol ; 87(10): 1662-7, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25940687

ABSTRACT

Although the rates of vertical transmission of HIV in the developing world have improved to around 3% in countries like South Africa, resistance to antiretrovirals (ARV) used in Prevention of Mother-to-Child transmission (pMTCT) strategies may thwart such outcomes and affect the efficacy of future ARV regimens in mothers and children. This study conducted in Durban, South Africa, between 2010 and 2013 found a high rate of nevirapine (NVP) resistance among women receiving Zidovudine (AZT) from 14 weeks gestation, single dose nevirapine (sd NVP) at the onset of labor and a single dose of coformulated Tenofovir/Emtricitabine (TDF/FTC) postpartum. Using Sanger sequencing, high and intermediate levels of nevirapine (NVP) resistance were detected in 15/44 (34%) and in 1/44 (2%) of women tested, respectively. Most subjects selected the K103N mutation (22% (10/45) of all patients and 66% (10/15) of those with high-level NVP resistance). Such rate of NVP resistance is comparable to studies where only sd NVP was used. In conclusion, a post-partum single-dose TDF/FTC tail does not prevent the selection of NNRTI resistance in women receiving pre-partum ZDV and intrapartum sd NVP to prevent mother-to-child HIV-1 transmission.


Subject(s)
Anti-HIV Agents/administration & dosage , Deoxycytidine/administration & dosage , Emtricitabine/administration & dosage , HIV Infections/transmission , HIV-1/drug effects , Infectious Disease Transmission, Vertical/prevention & control , Reverse Transcriptase Inhibitors/pharmacology , Tenofovir/administration & dosage , Zidovudine/administration & dosage , Adult , Antiretroviral Therapy, Highly Active , Child , Deoxycytidine/therapeutic use , Drug Administration Schedule , Drug Resistance, Viral , Emtricitabine/therapeutic use , Female , HIV Infections/drug therapy , HIV Infections/prevention & control , HIV Infections/virology , HIV-1/genetics , HIV-1/pathogenicity , Humans , Infectious Disease Transmission, Vertical/statistics & numerical data , Mothers , Mutation/drug effects , Nevirapine/administration & dosage , Nevirapine/therapeutic use , Postpartum Period , Pregnancy , Pregnancy Complications, Infectious/drug therapy , Pregnancy Complications, Infectious/prevention & control , Pregnancy Complications, Infectious/virology , Reverse Transcriptase Inhibitors/administration & dosage , Reverse Transcriptase Inhibitors/therapeutic use , Sequence Analysis, DNA , South Africa , Tenofovir/therapeutic use , Viral Load
8.
PLOS Glob Public Health ; 4(5): e0003224, 2024.
Article in English | MEDLINE | ID: mdl-38805477

ABSTRACT

South Africa rolled out dolutegravir (DTG) as first-line antiretroviral therapy (ART) in December 2019 to overcome high rates of pretreatment non-nucleoside reverse transcriptase inhibitor drug resistance. In the context of transition to DTG-based ART, this study spatiotemporally analysed detectable HIV viral loads (VLs) prior to- and following DTG rollout in public-sector healthcare facilities in KwaZulu-Natal (KZN) province, the epicentre of the HIV epidemic in South Africa. We retrospectively curated a HIV VL database using de-identified routine VL data obtained from the National Health Laboratory Service for the period January 2018 to June 2022. We analysed trends in HIV viraemia and mapped median log10 HIV VLs per facility on inverse distance weighted interpolation maps. We used Getis-Ord Gi* hotspot analysis to identify geospatial HIV hotspots. We obtained 7,639,978 HIV VL records from 736 healthcare facilities across KZN, of which 1,031,171 (13.5%) had detectable VLs (i.e., VLs ≥400 copies/millilitre (mL)). Of those with detectable VLs, we observed an overall decrease in HIV VLs between 2018 and 2022 (median 4.093 log10 copies/mL; 95% confidence interval (CI) 4.087-4.100 to median 3.563 log10 copies/mL; CI 3.553-3.572), p<0.01 (median test). The downward trend in proportion of HIV VLs ≥1000 copies/mL over time was accompanied by an inverse upward trend in the proportion of HIV VLs between 400 and 999 copies/mL. Moreover, specific coastal and northern districts of KZN had persistently higher VLs, with emergent hotspots demonstrating spatial clustering of high median log10 HIV VLs. The overall decrease in HIV VLs over time shows good progress towards achieving UNAIDS 95-95-95 targets in KZN, South Africa. The DTG-transition has been associated with a reduction in VLs, however, there is a need for pre-emptive monitoring of low-level viraemia. Furthermore, our findings highlight that specific districts will need intensified HIV care despite DTG rollout.

9.
J Med Virol ; 85(12): 2065-71, 2013 Dec.
Article in English | MEDLINE | ID: mdl-23959597

ABSTRACT

Human immunodeficiency virus 2 (HIV-2) is found predominantly in West Africa. It is not unlikely, however, that HIV-2 may also be found in South Africa, due to the influx of immigrants into this country. It is important to distinguish between HIV-1 and HIV-2 since the clinical courses and treatment responses of these viruses are different. Routine serological methods for diagnosing HIV do not differentiate between HIV-1 and -2 infections, while rapid tests, viral load quantification and PCR are HIV-type--specific. The objective of this study was to describe the seroprevalence and molecular epidemiology of HIV-2 in KwaZulu-Natal, one of the regions with the highest HIV prevalence in the world and home of the two largest harbors in South Africa. HIV-1 positive samples were screened for antibodies against HIV-2, using a rapid test. The confirmation of HIV-2 positive samples was done by PCR. Of the 2,123 samples screened, 319 (15%) were identified as positive by the rapid test. None of these samples were confirmed positive by PCR. To explore this discrepancy in the results, a subset (n = 52) of the rapid HIV-2 positive samples was subjected to Western blotting. Thirty-seven (71%) of these were positive, yielding an overall HIV-2 seroprevalence of 10.6%. Three out of 28 (10.7%) Western blot positive samples were positive by a Pepti-LAV assay. This discrepancy between serological and molecular confirmation may be attributed to non-specific or cross-reacting antibodies. The use of rapid tests and Western blots for HIV-2 diagnosis in South Africa should be interpreted with caution.


Subject(s)
HIV Infections/epidemiology , HIV-1/classification , HIV-2/classification , False Positive Reactions , HIV Infections/diagnosis , HIV Seroprevalence , Humans , Prevalence , South Africa/epidemiology
10.
Curr HIV Res ; 21(5): 279-289, 2023.
Article in English | MEDLINE | ID: mdl-37881079

ABSTRACT

INTRODUCTION: A "Shock and Kill" strategy has been proposed to eradicate the HIV latent viral reservoir. Effective Latency Reversal Agents (LRA) are a key requirement for this strategy. The search for LRAs with a novel mechanism of action is ongoing. This is the first study to propose aptamers for the reactivation of HIV. OBJECTIVE: The purpose of this study was to identify an aptamer that potentially reactivates HIV via the NF-κß pathway, specifically by binding to IkB and releasing NF-κß. METHODS: Aptamer selection was performed at Aptus Biotech (www.aptusbiotech.es), using ikB human recombinant protein with His tag bound to Ni-NTA agarose resin using the SELEX procedure. Activation of NF-κß was measured by SEAP Assay. HIV reactivation was measured in JLat cells using a BD FACS-Canto™ II flow cytometer. All flow cytometry data were analyzed using Kaluza analyzing software. RESULTS: Clones that had equivalent or greater activation than the positive control in the SEAP assay were regarded as potential reactivators of the NF-κß pathway and were sequenced. The three ikb clones namely R6-1F, R6-2F, and R6-3F were found to potentially activate the NF-κß pathway. Toxicity was determined by exposing lymphocytes to serial dilutions of the aptamers; the highest concentration of the aptamers that did not decrease viability by > 20% was used for the reactivation experiments. The three novel aptamers R6-1F, R6-2F, and R6-3F resulted in 4,07%, 6,72% and 3,42% HIV reactivation, respectively, while the untreated control showed minimal (<0.18%) fluorescence detection. CONCLUSION: This study demonstrated the reactivation of latent HIV by aptamers that act via the NF-κß pathway. Although the effect was modest and unlikely to be of clinical benefit, future studies are warranted to explore ways of enhancing reactivation.


Subject(s)
HIV Infections , HIV-1 , Humans , Virus Activation , Virus Latency , HIV Infections/drug therapy , HIV-1/physiology , CD4-Positive T-Lymphocytes
11.
Afr J Lab Med ; 12(1): 2065, 2023.
Article in English | MEDLINE | ID: mdl-37434993

ABSTRACT

Background: KwaZulu-Natal ranked second highest among South African provinces for the number of laboratory-confirmed cases during the second wave of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. The seroprevalence of SARS-CoV-2 among certain vulnerable groups, such as people living with HIV in KwaZulu-Natal, is unknown. Objective: The study aimed to determine the prevalence of SARS-CoV-2 immunoglobulin G (IgG) in HIV-positive versus HIV-negative patients. Methods: This was a retrospective analysis of residual clinical blood specimens unrelated to coronavirus disease 2019 (COVID-19) submitted for diagnostic testing at Inkosi Albert Luthuli Central Hospital, Durban, from 10 November 2020 to 09 February 2021. Specimens were tested for SARS-CoV-2 immunoglobulin G on the Abbott Architect analyser. Results: A total of 1977/8829 (22.4%) specimens were positive for SARS-CoV-2 antibodies. Seroprevalence varied between health districts from 16.4% to 37.3%, and was 19% in HIV-positive and 35.3% in HIV-negative specimens. Seroprevalence was higher among female patients (23.6% vs 19.8%; p < 0.0001) and increased with increasing age, with a statistically significant difference between the farthest age groups (< 10 years and > 79 years; p < 0.0001). The seroprevalence increased from 17% on 10 November 2020 to 43% on 09 February 2021 during the second wave. Conclusion: Our results highlight that during the second COVID-19 wave in KwaZulu-Natal a large proportion of people living with HIV were still immunologically susceptible. The reduced seropositivity in people with virological failure further emphasises the importance of targeted vaccination and vaccine response monitoring in these individuals. What the study adds: This study contributes to data on SARS-CoV-2 seroprevalence before and during the second wave in KwaZulu-Natal, South Africa, which has the highest HIV prevalence globally. Reduced seropositivity was found among people living with HIV with virological failure, highlighting the importance of targeted booster vaccination and vaccine response monitoring.

12.
Curr Mol Pharmacol ; 15(1): 143-158, 2022.
Article in English | MEDLINE | ID: mdl-33881977

ABSTRACT

There are no available antivirals for many viruses or strains, while current antivirals are limited by toxicity and drug resistance. Therefore, alternative strategies, such as RNA interference (RNAi) are required. RNAi suppresses gene expression of any mRNA, making it an attractive candidate for antiviral therapeutics. Studies have evaluated siRNAs in a range of viruses, with some showing promising results. However, issues with stability and delivery of siRNAs remain. These issues may be minimized by modifying the siRNA structure, using an efficient delivery vector and targeting multiple regions of a virus's genome in a single dose. Finding these solutions could accelerate the progress of RNAi-based antivirals. This review highlights selected examples of antiviral siRNAs, limitations of RNAi and strategies to overcome these limitations.


Subject(s)
Viruses , Antiviral Agents , RNA Interference , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Viruses/genetics , Viruses/metabolism
13.
Curr HIV Res ; 20(1): 7-19, 2022.
Article in English | MEDLINE | ID: mdl-34503417

ABSTRACT

Human Immunodeficiency Virus (HIV) infection continues to be a significant health burden in many countries around the world. Current HIV treatment through a combination of different antiretroviral drugs (cART) effectively suppresses viral replication, but drug resistance and crossresistance are significant challenges. This has prompted the search for novel targets and agents, such as nucleic acid aptamers. Nucleic acid aptamers are oligonucleotides that attach to the target sites with high affinity and specificity. This review provides a target-by-target account of research into anti-HIV aptamers and summarises the challenges and prospects of this therapeutic strategy, specifically in the unique context of HIV infection.


Subject(s)
Aptamers, Nucleotide , HIV Infections , Nucleic Acids , Aptamers, Nucleotide/pharmacology , Aptamers, Nucleotide/therapeutic use , Humans , Nucleic Acids/pharmacology , Nucleic Acids/therapeutic use , Oligonucleotides/pharmacology , Oligonucleotides/therapeutic use , Virus Replication
14.
Viruses ; 14(4)2022 04 10.
Article in English | MEDLINE | ID: mdl-35458518

ABSTRACT

To understand the problem of persistent Hepatitis B virus (HBV) viraemia in HIV/HBV co-infected patients on HBV-active antiretroviral therapy (ART), we assessed the rate of HBV virological response in patients on HBV-active ART in KwaZulu-Natal, South Africa, and analysed factors associated with persistent HBV viraemia. One hundred and fifty eligible participants with a chronic HBV diagnosis, with or without HIV coinfection, were enrolled and followed up after 6 months. The HBV pol gene was sequenced by next-generation sequencing and mutations were determined using the Stanford HBVseq database. Logistic regression analysis was used to assess factors associated with HBV viraemia at 6-month follow-up. The mean duration of HBV-active ART was 24 months. Thirty-seven of one hundred and six (35%) participants receiving HBV-active ART for longer than 6 months had virological failure. Advanced immunosuppression with CD4+ cell counts <200 cells/µL was independently associated with persistent HBV viraemia, aOR 5.276 (95% CI 1.575−17.670) p = 0.007. A high proportion of patients on HBV-active ART are unsuppressed, which will ultimately have an impact on global elimination goals. Better monitoring should be implemented, especially in HIV-coinfected patients with low CD4+ cell counts and followed by early HBV drug-resistance testing.


Subject(s)
Coinfection , HIV Infections , Hepatitis B virus , Hepatitis B , Viral Replicase Complex Proteins , Viremia , Antiretroviral Therapy, Highly Active/adverse effects , CD4 Lymphocyte Count , DNA, Viral/genetics , HIV Infections/complications , HIV Infections/drug therapy , Hepatitis B virus/genetics , Humans , Mutation , South Africa/epidemiology , Viral Load , Viral Replicase Complex Proteins/genetics , Viremia/genetics
15.
Viruses ; 14(5)2022 04 21.
Article in English | MEDLINE | ID: mdl-35632596

ABSTRACT

Human cytomegalovirus (HCMV) can cause significant end-organ diseases such as pneumonia in HIV-exposed infants. Complex viral factors may influence pathogenesis including: a large genome with a sizeable coding capacity, numerous gene regions of hypervariability, multiple-strain infections, and tissue compartmentalization of strains. We used a whole genome sequencing approach to assess the complexity of infection by comparing high-throughput sequencing data obtained from respiratory and blood specimens of HIV-exposed infants with severe HCMV pneumonia with those of lung transplant recipients and patients with hematological disorders. There were significantly more specimens from HIV-exposed infants showing multiple HCMV strain infection. Some genotypes, such as UL73 G4B and UL74 G4, were significantly more prevalent in HIV-exposed infants with severe HCMV pneumonia. Some genotypes were predominant in the respiratory specimens of several patients. However, the predominance was not statistically significant, precluding firm conclusions on anatomical compartmentalization in the lung.


Subject(s)
Cytomegalovirus Infections , HIV Infections , Pneumonia , Cytomegalovirus/genetics , Cytomegalovirus Infections/epidemiology , HIV Infections/complications , Humans , Infant , South Africa/epidemiology
16.
J Glob Antimicrob Resist ; 29: 468-475, 2022 06.
Article in English | MEDLINE | ID: mdl-34785393

ABSTRACT

OBJECTIVES: In low-middle-income countries, increasing levels of HIV drug resistance (HIVDR) on second-line protease inhibitor (PI)-based regimens are a cause for concern given the limited drug options for third-line antiretroviral therapy (ART). We conducted a retrospective analysis of routine HIV-1 genotyping laboratory data from KwaZulu-Natal, South Africa, to describe the frequency and patterns of HIVDR mutations and their consequent impact on standardised third-line regimens. METHODS: This was a cross-sectional analysis of all HIV-1 genotypic resistance tests conducted by the National Health Laboratory Service in KwaZulu-Natal (January 2015 to December 2016) for adults and adolescents (age ≥10 years) on second-line PI-based ART with virological failure. We assigned a third-line regimen to each record based on a national treatment algorithm and calculated the genotypic susceptibility score (GSS) for that regimen. RESULTS: Of 348 samples analysed, 287 (82.5%) had at least one drug resistance mutation (DRM) and 114 (32.8%) had at least one major PI DRM. Major PI resistance was associated with longer duration on second-line ART (aOR per 6-months = 1.11, 95% CI 1.04-1.19) and older age (aOR = 1.03, 95% CI 1.01-1.05). Of 112 patients requiring third-line ART, 12 (10.7%) had a GSS of <2 for the algorithm-assigned third-line regimen. CONCLUSION: One-third of people failing second-line ART had significant PI DRMs. A subgroup of these individuals had extensive HIVDR, where the predicted activity of third-line ART was suboptimal, highlighting the need for continuous evaluation of outcomes on third-line regimens and close monitoring for emergent HIV-1 integrase inhibitor resistance.


Subject(s)
Anti-HIV Agents , HIV Infections , HIV-1 , Adolescent , Adult , Anti-HIV Agents/pharmacology , Anti-HIV Agents/therapeutic use , Child , Cross-Sectional Studies , Drug Resistance, Viral/genetics , HIV Infections/drug therapy , HIV-1/genetics , Humans , Protease Inhibitors/pharmacology , Retrospective Studies , South Africa
17.
Nat Commun ; 13(1): 5860, 2022 10 04.
Article in English | MEDLINE | ID: mdl-36195617

ABSTRACT

Omicron lineages BA.4 and BA.5 drove a fifth wave of COVID-19 cases in South Africa. Here, we use the presence/absence of the S-gene target as a proxy for SARS-CoV-2 variant/lineage for infections diagnosed using the TaqPath PCR assay between 1 October 2021 and 26 April 2022. We link national COVID-19 individual-level data including case, laboratory test and hospitalisation data. We assess severity using multivariable logistic regression comparing the risk of hospitalisation and risk of severe disease, once hospitalised, for Delta, BA.1, BA.2 and BA.4/BA.5 infections. After controlling for factors associated with hospitalisation and severe outcome respectively, BA.4/BA.5-infected individuals had a similar odds of hospitalisation (aOR 1.24, 95% CI 0.98-1.55) and severe outcome (aOR 0.72, 95% CI 0.41-1.26) compared to BA.1-infected individuals. Newly emerged Omicron lineages BA.4/BA.5 showed similar severity to the BA.1 lineage and continued to show reduced clinical severity compared to the Delta variant.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , Humans , SARS-CoV-2/genetics , South Africa/epidemiology
18.
Biol Trace Elem Res ; 199(8): 3159-3176, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33029761

ABSTRACT

Globally, viral diseases continue to pose a significant threat to public health. Recent outbreaks, such as influenza, coronavirus, Ebola, and dengue, have emphasized the urgent need for new antiviral therapeutics. Considerable efforts have focused on developing metal nanoparticles for the treatment of several pathogenic viruses. As a result of these efforts, metal nanoparticles are demonstrating promising antiviral activity against pathogenic surrogates and clinical isolates. This review summarizes the application of metal nanoparticles for the treatment of viral infections. It provides information on synthesis methods, size-related properties, nano-bio-interaction, and immunological effects of metal nanoparticles. This article also addresses critical criteria and considerations for developing clinically translatable nanosized metal particles to treat viral diseases.


Subject(s)
Metal Nanoparticles , Antiviral Agents/therapeutic use , Metals
19.
Future Microbiol ; 16: 1401-1414, 2021 12.
Article in English | MEDLINE | ID: mdl-34812046

ABSTRACT

Cytomegalovirus pneumonia has repeatedly been described in the context of HIV-exposed uninfected and HIV-infected infants. Despite its significant role in the etiology of childhood pneumonia, there is still a paucity of literature generally, and specifically in Africa, suggesting that it might be a neglected disease. Emerging evidence highlights the importance of postnatal transmission through breastmilk. The pathogenetic significance of the multiplicity of strains acquired through repeated re-infections in early infancy is unknown. The development of cheap, accurate diagnostic tools and safe, effective antivirals and the maintenance of effective prevention and treatment of pediatric HIV are needed to manage cytomegalovirus pneumonia in low-resource settings.


Subject(s)
Cytomegalovirus Infections , HIV Infections , Pneumonia , Africa/epidemiology , Child , Cytomegalovirus , Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/drug therapy , Cytomegalovirus Infections/epidemiology , HIV Infections/complications , HIV Infections/epidemiology , Humans , Infant , Infectious Disease Transmission, Vertical/prevention & control
SELECTION OF CITATIONS
SEARCH DETAIL