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1.
Nature ; 603(7902): 706-714, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35104837

RESUMO

The SARS-CoV-2 Omicron BA.1 variant emerged in 20211 and has multiple mutations in its spike protein2. Here we show that the spike protein of Omicron has a higher affinity for ACE2 compared with Delta, and a marked change in its antigenicity increases Omicron's evasion of therapeutic monoclonal and vaccine-elicited polyclonal neutralizing antibodies after two doses. mRNA vaccination as a third vaccine dose rescues and broadens neutralization. Importantly, the antiviral drugs remdesivir and molnupiravir retain efficacy against Omicron BA.1. Replication was similar for Omicron and Delta virus isolates in human nasal epithelial cultures. However, in lung cells and gut cells, Omicron demonstrated lower replication. Omicron spike protein was less efficiently cleaved compared with Delta. The differences in replication were mapped to the entry efficiency of the virus on the basis of spike-pseudotyped virus assays. The defect in entry of Omicron pseudotyped virus to specific cell types effectively correlated with higher cellular RNA expression of TMPRSS2, and deletion of TMPRSS2 affected Delta entry to a greater extent than Omicron. Furthermore, drug inhibitors targeting specific entry pathways3 demonstrated that the Omicron spike inefficiently uses the cellular protease TMPRSS2, which promotes cell entry through plasma membrane fusion, with greater dependency on cell entry through the endocytic pathway. Consistent with suboptimal S1/S2 cleavage and inability to use TMPRSS2, syncytium formation by the Omicron spike was substantially impaired compared with the Delta spike. The less efficient spike cleavage of Omicron at S1/S2 is associated with a shift in cellular tropism away from TMPRSS2-expressing cells, with implications for altered pathogenesis.


Assuntos
COVID-19/patologia , COVID-19/virologia , Fusão de Membrana , SARS-CoV-2/metabolismo , SARS-CoV-2/patogenicidade , Serina Endopeptidases/metabolismo , Internalização do Vírus , Adulto , Idoso , Idoso de 80 Anos ou mais , Enzima de Conversão de Angiotensina 2/metabolismo , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Vacinas contra COVID-19/imunologia , Linhagem Celular , Membrana Celular/metabolismo , Membrana Celular/virologia , Chlorocebus aethiops , Convalescença , Feminino , Humanos , Soros Imunes/imunologia , Intestinos/patologia , Intestinos/virologia , Pulmão/patologia , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Mutação , Mucosa Nasal/patologia , Mucosa Nasal/virologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/metabolismo , Técnicas de Cultura de Tecidos , Virulência , Replicação Viral
2.
Nature ; 596(7872): 417-422, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34192737

RESUMO

Although two-dose mRNA vaccination provides excellent protection against SARS-CoV-2, there is little information about vaccine efficacy against variants of concern (VOC) in individuals above eighty years of age1. Here we analysed immune responses following vaccination with the BNT162b2 mRNA vaccine2 in elderly participants and younger healthcare workers. Serum neutralization and levels of binding IgG or IgA after the first vaccine dose were lower in older individuals, with a marked drop in participants over eighty years old. Sera from participants above eighty showed lower neutralization potency against the B.1.1.7 (Alpha), B.1.351 (Beta) and P.1. (Gamma) VOC than against the wild-type virus and were more likely to lack any neutralization against VOC following the first dose. However, following the second dose, neutralization against VOC was detectable regardless of age. The frequency of SARS-CoV-2 spike-specific memory B cells was higher in elderly responders (whose serum showed neutralization activity) than in non-responders after the first dose. Elderly participants showed a clear reduction in somatic hypermutation of class-switched cells. The production of interferon-γ and interleukin-2 by SARS-CoV-2 spike-specific T cells was lower in older participants, and both cytokines were secreted primarily by CD4 T cells. We conclude that the elderly are a high-risk population and that specific measures to boost vaccine responses in this population are warranted, particularly where variants of concern are circulating.


Assuntos
Envelhecimento/imunologia , Vacinas contra COVID-19/imunologia , Imunidade , SARS-CoV-2/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Autoanticorpos/imunologia , Linfócitos B/citologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Vacina BNT162 , Vacinas contra COVID-19/administração & dosagem , Feminino , Pessoal de Saúde , Humanos , Imunidade/genética , Imunização Secundária , Imunoglobulina A/imunologia , Switching de Imunoglobulina , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Memória Imunológica/imunologia , Inflamação/sangue , Inflamação/imunologia , Interferon gama/imunologia , Interleucina-2/imunologia , Masculino , Pessoa de Meia-Idade , Hipermutação Somática de Imunoglobulina , Glicoproteína da Espícula de Coronavírus/imunologia , Linfócitos T/imunologia , Vacinação , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/imunologia , Vacinas de mRNA
3.
Nature ; 599(7883): 114-119, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34488225

RESUMO

The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era.


Assuntos
Evasão da Resposta Imune , SARS-CoV-2/crescimento & desenvolvimento , SARS-CoV-2/imunologia , Replicação Viral/imunologia , Anticorpos Neutralizantes/imunologia , Vacinas contra COVID-19/imunologia , Fusão Celular , Linhagem Celular , Feminino , Pessoal de Saúde , Humanos , Índia , Cinética , Masculino , Glicoproteína da Espícula de Coronavírus/metabolismo , Vacinação
4.
J Antimicrob Chemother ; 79(2): 339-348, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38153241

RESUMO

BACKGROUND: Maintenance monotherapy with ritonavir-boosted darunavir has yielded variable outcomes and is not recommended. Trial samples offer valuable opportunities for detailed studies. We analysed samples from a 48 week trial in Cameroon to obtain a detailed characterization of drug resistance. METHODS: Following failure of NNRTI-based therapy and virological suppression on PI-based therapy, participants were randomized to ritonavir-boosted darunavir (n = 81) or tenofovir disoproxil fumarate/lamivudine +ritonavir-boosted lopinavir (n = 39). At study entry, PBMC-derived HIV-1 DNA underwent bulk Protease and Reverse Transcriptase (RT) sequencing. At virological rebound (confirmed or last available HIV-1 RNA ≥ 60 copies/mL), plasma HIV-1 RNA underwent ultradeep Protease and RT sequencing and bulk Gag-Protease sequencing. The site-directed mutant T375A (p2/p7) was characterized phenotypically using a single-cycle assay. RESULTS: NRTI and NNRTI resistance-associated mutations (RAMs) were detected in 52/90 (57.8%) and 53/90 (58.9%) HIV-1 DNA samples, respectively. Prevalence in rebound HIV-1 RNA (ritonavir-boosted darunavir, n = 21; ritonavir-boosted lopinavir, n = 2) was 9/23 (39.1%) and 10/23 (43.5%), respectively, with most RAMs detected at frequencies ≥15%. The resistance patterns of paired HIV-1 DNA and RNA sequences were partially consistent. No darunavir RAMs were found. Among eight participants experiencing virological rebound on ritonavir-boosted darunavir (n = 12 samples), all had Gag mutations associated with PI exposure, including T375N, T375A (p2/p7), K436R (p7/p1) and substitutions in p17, p24, p2 and p6. T375A conferred 10-fold darunavir resistance and increased replication capacity. CONCLUSIONS: The study highlights the high resistance barrier of ritonavir-boosted darunavir while identifying alternative pathways of resistance through Gag substitutions. During virological suppression, resistance patterns in HIV-1 DNA reflect treatment history, but due to technical and biological considerations, cautious interpretation is warranted.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Inibidores da Protease de HIV , Humanos , Darunavir/farmacologia , Darunavir/uso terapêutico , Ritonavir/farmacologia , Ritonavir/uso terapêutico , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Lopinavir/farmacologia , Lopinavir/uso terapêutico , Peptídeo Hidrolases/uso terapêutico , Leucócitos Mononucleares , Infecções por HIV/tratamento farmacológico , Inibidores da Protease de HIV/farmacologia , Inibidores da Protease de HIV/uso terapêutico , Mutação , RNA/uso terapêutico , DNA/uso terapêutico , Resistência a Medicamentos , Carga Viral
5.
J Antimicrob Chemother ; 78(8): 2000-2007, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37367727

RESUMO

BACKGROUND: Due to the high prevalence of resistance to NNRTI-based ART since 2018, consolidated recommendations from the WHO have indicated dolutegravir as the preferred drug of choice for HIV treatment globally. There is a paucity of resistance outcome data from HIV-1 non-B subtypes circulating across West Africa. AIMS: We characterized the mutational profiles of persons living with HIV from a cross-sectional cohort in North-East Nigeria failing a dolutegravir-based ART regimen. METHODS: WGS of plasma samples collected from 61 HIV-1-infected participants following virological failure of dolutegravir-based ART were sequenced using the Illumina platform. Sequencing was successfully completed for samples from 55 participants. Following quality control, 33 full genomes were analysed from participants with a median age of 40 years and median time on ART of 9 years. HIV-1 subtyping was performed using SNAPPy. RESULTS: Most participants had mutational profiles reflective of exposure to previous first- and second-line ART regimens comprised NRTIs and NNRTIs. More than half of participants had one or more drug resistance-associated mutations (DRMs) affecting susceptibility to NRTIs (17/33; 52%) and NNRTIs (24/33; 73%). Almost a quarter of participants (8/33; 24.4%) had one or more DRMs affecting tenofovir susceptibility. Only one participant, infected with HIV-1 subtype G, had evidence of DRMs affecting dolutegravir susceptibility-this was characterized by the T66A, G118R, E138K and R263K mutations. CONCLUSIONS: This study found a low prevalence of resistance to dolutegravir; the data are therefore supportive of the continual rollout of dolutegravir as the primary first-line regimen for ART-naive participants and the preferred switch to second-line ART across the region. However, population-level, longer-term data collection on dolutegravir outcomes are required to further guide implementation and policy action across the region.


Assuntos
Infecções por HIV , Inibidores de Integrase de HIV , Humanos , Adulto , Estudos Transversais , Infecções por HIV/tratamento farmacológico , Compostos Heterocíclicos com 3 Anéis/uso terapêutico , Compostos Heterocíclicos com 3 Anéis/farmacologia , Oxazinas/uso terapêutico , Piridonas/uso terapêutico , Inibidores de Integrase de HIV/uso terapêutico , Inibidores de Integrase de HIV/farmacologia , Mutação , Farmacorresistência Viral/genética , Integrases/genética
6.
Parasitol Res ; 123(1): 26, 2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38072836

RESUMO

Malaria and lymphatic filariasis (LF) are two serious public health challenges in sub-Saharan Africa, and both diseases are transmitted by Anopheles mosquitoes. Successful control of both diseases requires detailed information on transmission dynamics; thus, this study investigated malaria and LF transmission indices in two (2) communities (Jidawa and Kargo) in North-West Nigeria. Anopheles mosquitoes were sampled from twenty-five (25) randomly selected houses from each of the two communities using pyrethrum spray collection (PSC). The samples were identified morphologically and molecularly characterised using polymerase chain reaction (PCR). Human biting rate (HBR), indoor resting density (IRD), sporozoite rate (SR) and entomological inoculation rate (EIR) were calculated using standard formulae. The thorax region of the collected samples were dissected and smeared; then, Plasmodium and Wuchereria bancrofti parasites were identified using microscopy. A total of 2417 Anopheles mosquitoes were collected, and all were identified morphologically as An. gambiae s.l. Further molecular identification of sibling species revealed that An. gambiae and An. arabiensis were the only sibling species present. A total of 818 Anopheles mosquitoes were screened for Plasmodium and Wuchereria bancrofti parasites. A total of 180 samples were positive for Plasmodium parasites (Jidawa = 151; Kargo = 29), and none was positive for W. bancrofti (0%). Result of entomological indices for malaria transmission showed that indoor resting density was higher in Jidawa (10 mosquitoes/room/night) while human biting rate (2.07 bites/person/night), sporozoite rate (29.3%) and entomological inoculation rate (0.61) were higher in Kargo. In total, 35.2% of the samples were blood-fed while 67.4% were parous. There is active transmission of malaria in the two communities but not LF, suggesting the effectiveness of mass drug administration for LF. Concerted efforts should be focused on malaria control as transmission of the disease persists.


Assuntos
Anopheles , Filariose Linfática , Malária , Plasmodium , Animais , Humanos , Anopheles/parasitologia , Filariose Linfática/epidemiologia , Mosquitos Vetores/parasitologia , Nigéria/epidemiologia , Esporozoítos , Wuchereria bancrofti , Distribuição Aleatória
7.
J Infect Dis ; 224(6): 989-994, 2021 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-34260717

RESUMO

The SARS-CoV-2 B.1.617 variant emerged in the Indian state of Maharashtra in late 2020. There have been fears that 2 key mutations seen in the receptor-binding domain, L452R and E484Q, would have additive effects on evasion of neutralizing antibodies. We report that spike bearing L452R and E484Q confers modestly reduced sensitivity to BNT162b2 mRNA vaccine-elicited antibodies following either first or second dose. The effect is similar in magnitude to the loss of sensitivity conferred by L452R or E484Q alone. These data demonstrate reduced sensitivity to vaccine-elicited neutralizing antibodies by L452R and E484Q but lack of synergistic loss of sensitivity.


Assuntos
COVID-19/imunologia , COVID-19/virologia , Evasão da Resposta Imune , Mutação , SARS-CoV-2/genética , Enzima de Conversão de Angiotensina 2 , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Vacina BNT162 , Vacinas contra COVID-19/imunologia , Chlorocebus aethiops , Células HEK293 , Humanos , Índia , Ligação Proteica , SARS-CoV-2/imunologia , Serina Endopeptidases , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero
8.
J Antimicrob Chemother ; 74(10): 3011-3015, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31299067

RESUMO

BACKGROUND: In sub-Saharan Africa, detecting resistance-associated mutations (RAMs) at failure of first-line ART with two NRTIs plus an NNRTI predicts improved virological responses to second-line therapy with two NRTIs plus a ritonavir-boosted PI (PI/r). This indicates residual NRTI activity in the presence of RAMs, although additional factors may contribute to the effect. OBJECTIVES: The aim of this study was to investigate the influence of pre-existing RAMs on the outcomes of maintenance monotherapy with ritonavir-boosted darunavir within a randomized trial in Cameroon. METHODS: RAMs were detected in HIV-1 DNA using PBMCs collected at initiation of darunavir/ritonavir monotherapy. Adherence was assessed by pill count and visual analogue scale (VAS). Predictors of virological failure (confirmed or last available viral load >400 copies/mL) were explored by logistic regression analysis. Trial name = MANET (NCT02155101). RESULTS: After NNRTI-based therapy, participants (n = 81) had received PI/r-based therapy for a median of 3.2 years and had a confirmed viral load <60 copies/mL and a median CD4 count of 466 cells/mm3. NRTI and NNRTI RAMs were detected in 39/60 (65.0%) and 41/60 (68.3%) HIV-1 DNA sequences, respectively. Over 48 weeks of monotherapy, 16/81 (19.8%) patients experienced virological failure. After adjusting for age, HIV-1 DNA load, adherence by VAS and RAM status, virological failure was less likely with higher VAS-measured adherence (adjusted OR 0.04, 95% CI 0.01-0.37; P = 0.004) and detectable HIV-1 DNA RAMs (adjusted OR 0.15, 95% CI 0.03-0.82; P = 0.028). CONCLUSIONS: Pre-existing NRTI and NNRTI RAMs are associated with improved virological responses to NRTI-sparing ART in sub-Saharan Africa, indicating a predictive effect that is independent of residual NRTI activity.


Assuntos
Fármacos Anti-HIV/uso terapêutico , DNA Viral/genética , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , HIV-1/efeitos dos fármacos , HIV-1/genética , Mutação/genética , Adulto , Terapia Antirretroviral de Alta Atividade/métodos , Camarões , Darunavir/uso terapêutico , Farmacorresistência Viral/efeitos dos fármacos , Quimioterapia Combinada/métodos , Feminino , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Transcriptase Reversa/farmacologia , Ritonavir/uso terapêutico , Carga Viral/efeitos dos fármacos , Carga Viral/genética
9.
Am J Trop Med Hyg ; 109(4): 890-894, 2023 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-37580023

RESUMO

Determination of previous SARS-COV-2 infection is hampered by the absence of a standardized test. The marker used to assess previous exposure is IgG antibody to the nucleocapsid (IgG anti-N), although it is known to wane quickly from peripheral blood. The accuracies of seven antibody tests (virus neutralization test, IgG anti-N, IgG anti-spike [anti-S], IgG anti-receptor binding domain [anti-RBD], IgG anti-N + anti-RBD, IgG anti-N + anti-S, and IgG anti-S + anti-RBD), either singly or in combination, were evaluated on 502 cryopreserved serum samples collected before the COVID-19 vaccination rollout in Kumasi, Ghana. The accuracy of each index test was measured using a composite reference standard based on a combination of neutralization test and IgG anti-N antibody tests. According to the composite reference, 262 participants were previously exposed; the most sensitive test was the virus neutralization test, with 95.4% sensitivity (95% CI: 93.6-97.3), followed by 79.0% for IgG anti-N + anti-S (95% CI: 76.3-83.3). The most specific tests were virus neutralization and IgG anti-N, both with 100% specificity. Viral neutralization and IgG anti-N + anti-S were the overall most accurate tests, with specificity/sensitivity of 100/95.2% and 79.0/92.1%, respectively. Our findings indicate that IgG anti-N alone is an inadequate marker of prior exposure to SARS COV-2 in this population. Virus neutralization assay appears to be the most accurate assay in discerning prior infection. A combination of IgG anti-N and IgG anti-S is also accurate and suited for assessment of SARS COV-2 exposure in low-resource settings.


Assuntos
COVID-19 , Imunoglobulina G , Humanos , SARS-CoV-2 , Vacinas contra COVID-19 , COVID-19/diagnóstico , Anticorpos Antivirais , Anticorpos Neutralizantes
10.
Sci Rep ; 13(1): 14154, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37644069

RESUMO

Male genital schistosomiasis (MGS) is hypothesized to increase seminal shedding of HIV-1. This prospective pilot study assessed seminal HIV-1 RNA shedding in men on long-term ART with and without a diagnosis of MGS. Study visits occurred at 0, 1, 3, 6 and 12 months. MGS was diagnosed by egg positivity on semen microscopy or PCR of seminal sediment. After optimization of the HIV-RNA assay, we examined 72 paired plasma and semen samples collected from 31 men (15 with and 16 without MGS) over 12 months. HIV-1 RNA was detected in 7/72 (9.7%) seminal samples and 25/72 (34.7%) plasma samples. When comparing sample pairs, 5/72 (6.9%) showed HIV-1 RNA detection only in the seminal sample. Overall, 3/31 (9.7%) participants, all with MGS, had detectable HIV-1 RNA in semen while plasma HIV-1 RNA was undetectable (< 22 copies/mL), with seminal levels ranging up to 400 copies/mL. Two participants showing HIV-1 RNA in seminal fluid from the MGS-negative group also had concomitant HIV-1 RNA detection in plasma. The findings suggest that MGS can be associated with low-level HIV-1 RNA shedding despite virologically suppressive ART. Further studies are warranted to confirm these observations and assess its implications.


Assuntos
Soropositividade para HIV , HIV-1 , Esquistossomose , Humanos , Masculino , HIV-1/genética , Projetos Piloto , Lagos , Malaui , Estudos Prospectivos , Genitália , RNA
11.
Cell Rep ; 42(8): 112991, 2023 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-37590132

RESUMO

Suboptimal responses to a primary vaccination course have been reported in the elderly, but there is little information regarding the impact of age on responses to booster third doses. Here, we show that individuals 70 years or older (median age 73, range 70-75) who received a primary two-dose schedule with AZD1222 and booster third dose with mRNA vaccine achieve significantly lower neutralizing antibody responses against SARS-CoV-2 spike pseudotyped virus compared with those younger than 70 (median age 66, range 54-69) at 1 month post booster. Impaired neutralization potency and breadth post third dose in the elderly is associated with circulating "atypical" spike-specific B cells expressing CD11c and FCRL5. However, when considering individuals who received three doses of mRNA vaccine, we did not observe differences in neutralization or enrichment in atypical B cells. This work highlights the finding that AdV and mRNA COVID-19 vaccine formats differentially instruct the memory B cell response.


Assuntos
COVID-19 , Idoso , Humanos , COVID-19/prevenção & controle , Vacinas contra COVID-19 , ChAdOx1 nCoV-19 , SARS-CoV-2 , Vacinação
12.
Hepatol Commun ; 6(11): 3036-3051, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36103301

RESUMO

There is a heavy burden of liver disease in West Africa. While the role of hepatitis B virus (HBV) infection is well recognized, less is known about the contributing role of liver steatosis and how the two interact in the context of human immunodeficiency virus (HIV) infection. Adults with HIV in Ghana underwent FibroScan measurements to determine prevalence of liver steatosis (expressed as controlled attenuation parameter [CAP]) and fibrosis (expressed as liver stiffness [LS]). We explored contributing factors in linear regression models, including demographics, lifestyle characteristics, medical history, HIV and HBV status, and measurements of metabolic syndrome. Among 329 adults (72.3% women; median age, 47 years), 322 (97.9%) were on antiretroviral therapy (median duration, 8.9 years). CD4 counts were preserved (median, 619 cells/mm3 ); plasma HIV RNA was fully suppressed in 162 (50.3%) of the treated participants. Cigarette smoking, excessive alcohol consumption, and use of traditional or herbal remedies were uncommon (6.1%, 1.8%, 3.3%, respectively). Largely undiagnosed metabolic syndrome was detected in 87 (26.4%) participants. We obtained readings indicative of ≥S2 steatosis and ≥F2 fibrosis in 43 (13.1%) and 55 (16.7%) participants, respectively. Higher CAP values were associated with metabolic syndrome and longer prior stavudine exposure. Higher LS values were associated with male sex, higher HIV RNA, and higher CAP values. Relative to people without HBV, those with HBV (n = 90) had a similar prevalence of ≥S2 steatosis but a higher prevalence of ≥F2 fibrosis (36.7% vs. 9.2%, p < 0.0001) and concomitant ≥S2 steatosis and ≥F2 fibrosis (9.1% vs. 1.3%, p < 0.001). Conclusion: Both HBV and liver steatosis pose a threat to long-term liver health among people with HIV in West Africa. Urgently required interventions include improving HIV suppression and diagnosing and managing determinants of the metabolic syndrome.


Assuntos
Coinfecção , Fígado Gorduroso , Infecções por HIV , Hepatite B , Síndrome Metabólica , Adulto , Masculino , Feminino , Humanos , Pessoa de Meia-Idade , Coinfecção/epidemiologia , Vírus da Hepatite B/genética , Estavudina , Síndrome Metabólica/epidemiologia , Cirrose Hepática/diagnóstico por imagem , Infecções por HIV/complicações , Fígado Gorduroso/diagnóstico por imagem , Hepatite B/complicações , HIV/genética , RNA , Gana/epidemiologia
13.
Nat Commun ; 13(1): 6131, 2022 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-36253377

RESUMO

Real-world data on vaccine-elicited neutralising antibody responses for two-dose AZD1222 in African populations are limited. We assessed baseline SARS-CoV-2 seroprevalence and levels of protective neutralizing antibodies prior to vaccination rollout using binding antibodies analysis coupled with pseudotyped virus neutralisation assays in two cohorts from West Africa: Nigerian healthcare workers (n = 140) and a Ghanaian community cohort (n = 527) pre and post vaccination. We found 44 and 28% of pre-vaccination participants showed IgG anti-N positivity, increasing to 59 and 39% respectively with anti-receptor binding domain (RBD) IgG-specific antibodies. Previous IgG anti-N positivity significantly increased post two-dose neutralizing antibody titres in both populations. Serological evidence of breakthrough infection was observed in 8/49 (16%). Neutralising antibodies were observed to wane in both populations, especially in anti-N negative participants with an observed waning rate of 20% highlighting the need for a combination of additional markers to characterise previous infection. We conclude that AZD1222 is immunogenic in two independent West African cohorts with high background seroprevalence and incidence of breakthrough infection in 2021. Waning titres post second dose indicates the need for booster dosing after AZD1222 in the African setting despite hybrid immunity from previous infection.


Assuntos
COVID-19 , Vacinas Virais , Anticorpos Neutralizantes , Anticorpos Antivirais , Formação de Anticorpos , COVID-19/epidemiologia , COVID-19/prevenção & controle , ChAdOx1 nCoV-19 , Gana , Humanos , Imunoglobulina G , SARS-CoV-2 , Estudos Soroepidemiológicos , Vacinação
14.
Heliyon ; 6(1): e03284, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32021938

RESUMO

Effect of storage time on the quality of smoked Oreochromis nilotius was studied. One hundred fish samples of O. niloticus (average weight 210 ± 15g) was used. Analysis carried out include: proximate, mineral composition (Ca, Na, Fe and Mg), biochemical, amino acid and sensory evaluation. Data obtained was subjected to Analysis of Variance (ANOVA) while the sensory data was subjected to nonparametric test (Kruskal Wallis test). Proximate quality, mineral, amino acid, biochemical and sensory quality of frozen O. niloticus content reduced with increase in storage period. Na and Mg were the most abundant mineral while glutamic acid and lysine were the most concentrated non-essential amino acid (NEEA) and essential amino acid (EAA) respectively. The total volatile base nitrogen (TVBN), trimethyl amine (TMA) and peroxide values (PV) obtained are within the recommended level for good quality food while NEAA and EAA are within recommended values by WHO. The amino acid scores of the fish in relation to the amino acid scoring pattern of whole hen's egg protein indicate that lysine had the highest amino acid score. No significant (χ2 = 6.624, p > 0.05) variation was observed in the score allotted for the flavor of smoked O. niloticus during storage. Smoked O. niloticus being a good source of protein, minerals and amino acids, and the quality is within good quality protein recommended by world health organization (WHO), is therefore recommended for consumption.

15.
EClinicalMedicine ; 18: 100231, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31922120

RESUMO

BACKGROUND: This prospective pilot study explored same-day point-of-care viral load testing in a setting in Ghana that has yet to implement virological monitoring of antiretroviral therapy (ART). METHODS: Consecutive patients accessing outpatient care while on ART underwent HIV-1 RNA quantification by Xpert. Those with viraemia at the first measurement (T0) received immediate adherence counselling and were reassessed 8 weeks later (T1). Predictors of virological status were determined by logistic regression analysis. Drug resistance-associated mutations (RAMs) were detected by Sanger sequencing. FINDINGS: At T0, participants had received treatment for a median of 8·9 years; 297/333 (89·2%) were on NNRTI-based ART. The viral load was ≥40 copies/mL in 164/333 (49·2%) patients and ≥1000 copies/mL in 71/333 (21·3%). In the latter group, 50/65 (76·9%) and 55/65 (84·6%) harboured NRTI and NNRTI RAMs, respectively, and 27/65 (41·5%) had ≥1 tenofovir RAM. Among 150/164 (91·5%) viraemic patients that reattended at T1, 32/150 (21·3%) showed resuppression <40 copies/mL, comprising 1/65 (1·5%) subjects with T0 viral load ≥1000 copies/mL and 31/85 (36·5%) subjects with lower levels. A T0 viral load ≥1000 copies/mL and detection of RAMs predicted ongoing T1 viraemia independently of self-reported adherence levels. Among participants with T0 viral load ≥1000 copies/mL, 23/65 (35·4%) showed resuppression <1000 copies/mL; the response was more likely among those with higher adherence levels and no RAMs. INTERPRETATION: Same-day point-of-care viral load testing was feasible and revealed poor virological control and suboptimal resuppression rates despite adherence counselling. Controlled studies should determine optimal triaging modalities for same-day versus deferred viral load testing. FUNDING: University of Liverpool, South Tees Infectious Diseases Research Fund.

17.
Open Forum Infect Dis ; 5(10): ofy251, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30377627

RESUMO

BACKGROUND: We monitored the evolution of markers of hepatitis B virus (HBV) infection in virologically suppressed HIV-positive patients switching to nucleoside reverse transcriptase inhibitor (NRTI)-sparing antiretroviral therapy within a randomized trial in Cameroon. METHODS: HBV surface antigen (HBsAg), HBV DNA, and antibodies against surface (anti-HBs), core (total anti-HBc), and e-antigen (anti-HBe) were measured retrospectively in samples collected at study entry and over 48 weeks after NRTI discontinuation. RESULTS: Participants (n = 80, 75% females) had a plasma HIV-1 RNA <60 copies/mL, a median CD4 count of 466 cells/mm3, and undetectable HBsAg and HBV DNA at study entry. After NRTI discontinuation, 3/20 (15.0%) anti-HBc-negative patients showed evidence indicative or suggestive of incident HBV infection (163 cases/1000 person-years); 6/60 (10.0%) anti-HBc-positive patients showed evidence indicative or suggestive of HBV reactivation (109 cases/1000 person-years). In one case of reactivation, anti-HBs increased from 14 to >1000 IU/L; sequencing showed HBV genotype A3 and 3 escape mutations in surface (Y100C, K122R, Y161FY). Alongside new-onset detection of HBsAg or HBV DNA, 1 patient experienced acute hepatitis and 6 patients experienced mild or marginal increases in serum transaminase levels. CONCLUSIONS: Evolving treatment strategies for sub-Saharan Africa must be accompanied by the formulation and implementation of policy to guide appropriate assessment and management of HBV status.

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