Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
J Virol Methods ; 311: 114647, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36343742

RESUMO

Accurate HIV and CD4 testing are critical in program implementation, with HIV misdiagnosis having serious consequences at both the client and/or community level. We implemented a comprehensive training and Quality Assurance (QA) program to ensure accuracy of point-of-care HIV and CD4 count testing by lay counsellors during the Botswana Combination Prevention Project (BCPP). We compared the performance of field testing by lay counsellors to results from an accredited laboratory to ascertain accuracy of testing. All trained lay counsellors passed competency assessments and performed satisfactorily in proficiency testing panel evaluations in 2013, 2014, and 2015. There was excellent agreement (99.6 %) between field and laboratory-based HIV test results; of the 3002 samples tested, 960 and 2030 were concordantly positive and negative respectively, with 12 misclassifications (kappa score 0.99, p < 0.0001). Of the 149 HIV-positive samples enumerated for CD4 count in the field using PIMA at a threshold of ≤ 350 cells/µl; there was 86 % agreement with laboratory testing, with only 21 misclassified. The mean difference between field and lab CD4 testing was - 16.16 cells/µl (95 % CI -5.4 to 26.9). Overall, there was excellent agreement between field and laboratory results for both HIV rapid test and PIMA CD4 results. A standard training package to train lay counsellors to accurately perform HIV and CD4 point-of-care testing in field settings was feasible, with point-of-care results obtained by lay counsellors comparable to laboratory-based testing.


Assuntos
Infecções por HIV , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Botsuana , Iodeto de Potássio , Infecções por HIV/diagnóstico , Infecções por HIV/prevenção & controle , Contagem de Linfócito CD4 , Pessoal de Saúde
2.
Emerg Infect Dis ; 28(13): S93-S104, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36502398

RESUMO

We used publicly available data to describe epidemiology, genomic surveillance, and public health and social measures from the first 3 COVID-19 pandemic waves in southern Africa during April 6, 2020-September 19, 2021. South Africa detected regional waves on average 7.2 weeks before other countries. Average testing volume 244 tests/million/day) increased across waves and was highest in upper-middle-income countries. Across the 3 waves, average reported regional incidence increased (17.4, 51.9, 123.3 cases/1 million population/day), as did positivity of diagnostic tests (8.8%, 12.2%, 14.5%); mortality (0.3, 1.5, 2.7 deaths/1 million populaiton/day); and case-fatality ratios (1.9%, 2.1%, 2.5%). Beta variant (B.1.351) drove the second wave and Delta (B.1.617.2) the third. Stringent implementation of safety measures declined across waves. As of September 19, 2021, completed vaccination coverage remained low (8.1% of total population). Our findings highlight opportunities for strengthening surveillance, health systems, and access to realistically available therapeutics, and scaling up risk-based vaccination.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , COVID-19/epidemiologia , Pandemias , Incidência
3.
J Acquir Immune Defic Syndr ; 91(1): 9-16, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35537094

RESUMO

BACKGROUND AND SETTING: The Botswana Combination Prevention Project demonstrated a 30% reduction in community HIV incidence through expanded HIV testing, enhanced linkage to care, and universal antiretroviral treatment and exceeded the Joint United Nations Programme on HIV/AIDS 90-90-90 targets. We report rates and characteristics of incident HIV infections. METHODS: The Botswana Combination Prevention Project was a community-randomized controlled trial conducted in 30 rural/periurban Botswana communities from 2013 to 2017. Home-based and mobile HIV-testing campaigns were conducted in 15 intervention communities, with 39% of participants testing at least twice. We assessed the HIV incidence rate [IR; number of new HIV infections per 100 person-years (py) at risk] among repeat testers and risk factors with a Cox proportional hazards regression model. RESULTS: During 27,517 py, 195 (women: 79%) of 18,597 became HIV-infected (0.71/100 py). Women had a higher IR (1.01/100 py; 95% confidence interval: 0.99 to 1.02) than men (0.34/100 py; 95% confidence interval: 0.33 to 0.35). The highest IRs were among women aged 16-24 years (1.87/100 py) and men aged 25-34 years (0.56/100 py). The lowest IRs were among those aged 35-64 years (women: 0.41/100 py; men: 0.20/100 py). The hazard of incident infection was the highest among women aged 16-24 years (hazard ratio = 7.05). Sex and age were significantly associated with incidence (both P < 0.0001). CONCLUSIONS: Despite an overall reduction in HIV incidence and approaching the United Nations Programme on HIV/AIDS 95-95-95 targets, high HIV incidence was observed in adolescent girls and young women. These findings highlight the need for additional prevention services (pre-exposure prophylaxis and DREAMS) to achieve epidemic control in this subpopulation and increased efforts with men with undiagnosed HIV.


Assuntos
Infecções por HIV , Adolescente , Antirretrovirais/uso terapêutico , Botsuana/epidemiologia , Feminino , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Humanos , Incidência , Masculino , População Rural
4.
Elife ; 112022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35229714

RESUMO

Background: Mathematical models predict that community-wide access to HIV testing-and-treatment can rapidly and substantially reduce new HIV infections. Yet several large universal test-and-treat HIV prevention trials in high-prevalence epidemics demonstrated variable reduction in population-level incidence. Methods: To elucidate patterns of HIV spread in universal test-and-treat trials, we quantified the contribution of geographic-location, gender, age, and randomized-HIV-intervention to HIV transmissions in the 30-community Ya Tsie trial in Botswana. We sequenced HIV viral whole genomes from 5114 trial participants among the 30 trial communities. Results: Deep-sequence phylogenetic analysis revealed that most inferred HIV transmissions within the trial occurred within the same or between neighboring communities, and between similarly aged partners. Transmissions into intervention communities from control communities were more common than the reverse post-baseline (30% [12.2 - 56.7] vs. 3% [0.1 - 27.3]) than at baseline (7% [1.5 - 25.3] vs. 5% [0.9 - 22.9]) compatible with a benefit from treatment-as-prevention. Conclusions: Our findings suggest that population mobility patterns are fundamental to HIV transmission dynamics and to the impact of HIV control strategies. Funding: This study was supported by the National Institute of General Medical Sciences (U54GM088558), the Fogarty International Center (FIC) of the U.S. National Institutes of Health (D43 TW009610), and the President's Emergency Plan for AIDS Relief through the Centers for Disease Control and Prevention (CDC) (Cooperative agreements U01 GH000447 and U2G GH001911).


Assuntos
Epidemias , Infecções por HIV , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/prevenção & controle , Humanos , Incidência , Masculino , Filogenia , Prevalência
5.
Clin Infect Dis ; 64(12): 1663-1669, 2017 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-28369309

RESUMO

BACKGROUND.: The OraQuick Advance Rapid HIV-1/2 Test is a point-of-care test capable of detecting human immunodeficiency virus (HIV)-specific antibodies in blood and oral fluid. To understand test performance and factors contributing to false-negative results in longitudinal studies, we examined results of participants enrolled in the Botswana TDF/FTC Oral HIV Prophylaxis Trial, the Bangkok Tenofovir Study, and the Bangkok MSM Cohort Study, 3 separate clinical studies of high-risk, HIV-negative persons conducted in Botswana and Thailand. METHODS.: In a retrospective observational analysis, we compared oral fluid OraQuick (OFOQ) results among participants becoming HIV infected to results obtained retrospectively using enzyme immunoassay and nucleic acid amplification tests on stored specimens. We categorized negative OFOQ results as true-negative or false-negative relative to nucleic acid amplification test and/or enzyme immunoassay, and determined the delay in OFOQ conversion relative to the estimated time of infection. We used log-binomial regression and generalized estimating equations to examine the association between false-negative results and participant, clinical, and testing-site factors. RESULTS.: Two-hundred thirty-three false-negative OFOQ results occurred in 80 of 287 seroconverting individuals. Estimated OFOQ conversion delay ranged from 14.5 to 547.5 (median, 98.5) days. Delayed OFOQ conversion was associated with clinical site and test operator (P < .05), preexposure prophylaxis (P = .01), low plasma viral load (P < .02), and time to kit expiration (P < .01). Participant age, sex, and HIV subtype were not associated with false-negative results. Long OFOQ conversion delay time was associated with antiretroviral exposure and low plasma viral load. CONCLUSIONS.: Failure of OFOQ to detect HIV-1 infection was frequent and multifactorial in origin. In longitudinal trials, negative oral fluid results should be confirmed via testing of blood samples.


Assuntos
Sorodiagnóstico da AIDS , Anticorpos Anti-HIV/análise , Infecções por HIV/diagnóstico , HIV-1/isolamento & purificação , Sistemas Automatizados de Assistência Junto ao Leito , Saliva/imunologia , Adulto , Botsuana/epidemiologia , Estudos Clínicos como Assunto , Reações Falso-Negativas , Feminino , Anticorpos Anti-HIV/sangue , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/genética , HIV-1/imunologia , HIV-2/genética , HIV-2/imunologia , HIV-2/isolamento & purificação , Humanos , Técnicas Imunoenzimáticas , Masculino , Reação em Cadeia da Polimerase , Profilaxia Pré-Exposição , Kit de Reagentes para Diagnóstico , Análise de Regressão , Estudos Retrospectivos , Sensibilidade e Especificidade , Tailândia/epidemiologia , Carga Viral
7.
J Acquir Immune Defic Syndr ; 73(5): 556-563, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27509251

RESUMO

OBJECTIVE: Among participants of a clinical trial to test the efficacy of tenofovir/emtricitabine in protecting heterosexual men and women living in Botswana from HIV infection, the aim was to determine (1) if sexual risk behavior, specifically condomless sex acts and number of sex partners, changed over time, (2) factors associated with condomless sex acts and number of sex partners, and (3) the effect of participant treatment arm perception on risk behavior to address the possibility of risk compensation. METHODS: A longitudinal modeling of rates of risk behaviors was used to determine if the rate of condomless sex acts (#acts/person) and rate of sex partners (#partners/person) changed over time and which factors were associated with behavior change. RESULTS: One thousand two hundred participants were analyzed over 1 year. There was a 25% decrease in the rate of sex partners among participants sexually active in the last 30 days. The rate of reported condomless sex acts was greater for males [rate ratio (RR) = 1.34; confidence interval (CI): 1.07 to 1.67] and participants whose sexual debut in years was ≤15 years of age (RR = 1.65; CI: 1.14 to 2.38) and 16-17 (RR = 1.68; CI: 1.22 to 2.31) compared with those ≥20 years. Rate of reported sex partners was greater for males (RR = 3.67; CI: 2.86 to 4.71) and participants whose age at sexual debut in years was ≤15 (RR = 2.92; CI: 2.01 to 4.22) and 16-17 (RR = 2.34; CI: 1.69 to 3.24) compared with those ≥20. There was no effect of participant treatment arm perception on risk behavior. CONCLUSIONS: Our study of preexposure prophylaxis to prevent HIV infection found no evidence of risk compensation which may have been due to participants' motivations to reduce their risk behaviors and risk-reduction counseling.


Assuntos
Infecções por HIV/prevenção & controle , Infecções por HIV/psicologia , Profilaxia Pré-Exposição/métodos , Assunção de Riscos , Comportamento Sexual , Adulto , Botsuana , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Heterossexualidade , Humanos , Masculino , Modelos Estatísticos
8.
PLoS One ; 9(4): e93034, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24714095

RESUMO

INTRODUCTION: Accurate clinical laboratory reference values derived from a local or regional population base are required to correctly interpret laboratory results. In Botswana, most reference intervals used to date are not standardized across clinical laboratories and are based on values derived from populations in the United States or Western Europe. METHODS: We measured 14 hematologic and biochemical parameters of healthy young adults screened for participation in the Botswana HIV Pre-exposure Prophylaxis Study using tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) (TDF2 Study). Reference intervals were calculated using standard methods, stratified by gender, and compared with the site-derived reference values used for the TDF2 study (BOTUSA ranges), the Division of AIDS (DAIDS) Grading Table for Adverse Events, the Botswana public health laboratories, and other regional references. RESULTS: Out of 2533 screened participants, 1786 met eligibility criteria for participation in study and were included in the analysis. Our reference values were comparable to those of the Botswana public health system except for amylase, blood urea nitrogen (BUN), phosphate, total and direct bilirubin. Compared to our reference values, BOTUSA reference ranges would have classified participants as out of range for some analytes, with amylase (50.8%) and creatinine (32.0%) producing the highest out of range values. Applying the DAIDS toxicity grading system to the values would have resulted in 45 and 18 participants as having severe or life threatening values for amylase and hemoglobin, respectively. CONCLUSION: Our reference values illustrate the differences in hematological and biochemical analyte ranges between African and Western populations. Thus, the use of western-derived reference laboratory values to screen a group of Batswana adults resulted in many healthy people being classified as having out-of-range blood analytes. The need to establish accurate local or regional reference values is apparent and we hope our results can be used to that end in Botswana.


Assuntos
Adenina/análogos & derivados , Fármacos Anti-HIV/uso terapêutico , Desoxicitidina/análogos & derivados , Infecções por HIV/sangue , Infecções por HIV/prevenção & controle , Testes Hematológicos/normas , Organofosfonatos/uso terapêutico , Adenina/uso terapêutico , Adolescente , Adulto , Botsuana/epidemiologia , Desoxicitidina/uso terapêutico , Emtricitabina , Feminino , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Humanos , Masculino , Valores de Referência , Tenofovir , Adulto Jovem
9.
PLoS One ; 9(3): e90111, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24625530

RESUMO

BACKGROUND: Tenofovir-emtricitabine (TDF-FTC) pre-exposure prophylaxis (PrEP) has been found to be effective for prevention of HIV infection in several clinical trials. Two studies of TDF PrEP among men who have sex with men showed slight bone mineral density (BMD) loss. We investigated the effect of TDF and the interaction of TDF and hormonal contraception on BMD among HIV-uninfected African men and women. METHOD: We evaluated the effects on BMD of using daily oral TDF-FTC compared to placebo among heterosexual men and women aged 18-29 years enrolled in the Botswana TDF2 PrEP study. Participants had BMD measurements at baseline and thereafter at 6-month intervals with dual-energy X-ray absorptiometry (DXA) scans at the hip, spine, and forearm. RESULTS: A total of 220 participants (108 TDF-FTC, 112 placebo) had baseline DXA BMD measurements at three anatomic sites. Fifteen (6.8%) participants had low baseline BMD (z-score of <-2.0 at any anatomic site), including 3/114 women (2.6%) and 12/106 men (11.3%) (p = 0.02). Low baseline BMD was associated with being underweight (p = 0.02), having high blood urea nitrogen (p = 0.02) or high alkaline phosphatase (p = 0.03), and low creatinine clearance (p = 0.04). BMD losses of >3.0% at any anatomic site at any time after baseline were significantly greater for the TDF-FTC treatment group [34/68 (50.0%) TDF-FTC vs. 26/79 (32.9%) placebo; p = 0.04]. There was a small but significant difference in the mean percent change in BMD from baseline for TDF-FTC versus placebo at all three sites at month 30 [forearm -0.84% (p = 0.01), spine -1.62% (p = 0.0002), hip -1.51% (p = 0.003)]. CONCLUSION: Use of TDF-FTC was associated with a small but statistically significant decrease in BMD at the forearm, hip and lumbar spine. A high percentage (6.8%) of healthy Batswana young adults had abnormal baseline BMD Further evaluation is needed of the longer-term use of TDF in HIV-uninfected persons. TRIAL REGISTRATION: ClinicalTrials.gov NCT00448669.


Assuntos
Fármacos Anti-HIV/administração & dosagem , Densidade Óssea/efeitos dos fármacos , Emtricitabina/administração & dosagem , Infecções por HIV/prevenção & controle , Profilaxia Pré-Exposição/métodos , Tenofovir/administração & dosagem , Absorciometria de Fóton , Adolescente , Adulto , Fármacos Anti-HIV/efeitos adversos , Botsuana , Controle de Doenças Transmissíveis , Emtricitabina/efeitos adversos , Feminino , Antebraço/diagnóstico por imagem , Quadril/diagnóstico por imagem , Humanos , Estudos Longitudinais , Masculino , Coluna Vertebral/diagnóstico por imagem , Tenofovir/efeitos adversos , Adulto Jovem
10.
AIDS ; 28(2): 223-6, 2014 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-24361682

RESUMO

We examined CD4 cell count and plasma viral load patterns among Botswana TDF/FTC Oral HIV Prophylaxis Trial (TDF2 study) participants who seroconverted, comparing participants assigned to receive tenofovir/emtricitabine with participants assigned to receive placebo. We also evaluated for antiretroviral drug resistance among the breakthrough HIV infections. Among nine seroconverters assigned to tenofovir/emtricitabine and 24 to placebo, there were no significant differences in their CD4 cell count or viral load profiles over time. Of the four participants who seroconverted on-study while receiving tenofovir/emtricitabine, none became infected as a result of drug-resistant HIV; moreover, no resistance mutations emerged following seroconversion.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Quimioprevenção/métodos , Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Profilaxia Pós-Exposição/métodos , Carga Viral , Adenina/análogos & derivados , Adenina/uso terapêutico , Botsuana/epidemiologia , Contagem de Linfócito CD4 , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Emtricitabina , HIV/isolamento & purificação , Infecções por HIV/imunologia , Heterossexualidade , Humanos , Organofosfonatos/uso terapêutico , Plasma/virologia , Tenofovir
11.
N Engl J Med ; 367(5): 423-34, 2012 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-22784038

RESUMO

BACKGROUND: Preexposure prophylaxis with antiretroviral agents has been shown to reduce the transmission of human immunodeficiency virus (HIV) among men who have sex with men; however, the efficacy among heterosexuals is uncertain. METHODS: We randomly assigned HIV-seronegative men and women to receive either tenofovir disoproxil fumarate and emtricitabine (TDF-FTC) or matching placebo once daily. Monthly study visits were scheduled, and participants received a comprehensive package of prevention services, including HIV testing, counseling on adherence to medication, management of sexually transmitted infections, monitoring for adverse events, and individualized counseling on risk reduction; bone mineral density testing was performed semiannually in a subgroup of participants. RESULTS: A total of 1219 men and women underwent randomization (45.7% women) and were followed for 1563 person-years (median, 1.1 years; maximum, 3.7 years). Because of low retention and logistic limitations, we concluded the study early and followed enrolled participants through an orderly study closure rather than expanding enrollment. The TDF-FTC group had higher rates of nausea (18.5% vs. 7.1%, P<0.001), vomiting (11.3% vs. 7.1%, P=0.008), and dizziness (15.1% vs. 11.0%, P=0.03) than the placebo group, but the rates of serious adverse events were similar (P=0.90). Participants who received TDF-FTC, as compared with those who received placebo, had a significant decline in bone mineral density. K65R, M184V, and A62V resistance mutations developed in 1 participant in the TDF-FTC group who had had an unrecognized acute HIV infection at enrollment. In a modified intention-to-treat analysis that included the 33 participants who became infected during the study (9 in the TDF-FTC group and 24 in the placebo group; 1.2 and 3.1 infections per 100 person-years, respectively), the efficacy of TDF-FTC was 62.2% (95% confidence interval, 21.5 to 83.4; P=0.03). CONCLUSIONS: Daily TDF-FTC prophylaxis prevented HIV infection in sexually active heterosexual adults. The long-term safety of daily TDF-FTC prophylaxis, including the effect on bone mineral density, remains unknown. (Funded by the Centers for Disease Control and Prevention and the National Institutes of Health; TDF2 ClinicalTrials.gov number, NCT00448669.).


Assuntos
Adenina/análogos & derivados , Antirretrovirais/uso terapêutico , Desoxicitidina/análogos & derivados , Infecções por HIV/prevenção & controle , HIV-1 , Organofosfonatos/uso terapêutico , Adenina/efeitos adversos , Adenina/uso terapêutico , Adolescente , Adulto , Antirretrovirais/efeitos adversos , Densidade Óssea/efeitos dos fármacos , Comportamento Contraceptivo/estatística & dados numéricos , Desoxicitidina/efeitos adversos , Desoxicitidina/uso terapêutico , Farmacorresistência Viral , Quimioterapia Combinada , Emtricitabina , Feminino , Soropositividade para HIV , HIV-1/genética , HIV-1/isolamento & purificação , HIV-2/genética , HIV-2/isolamento & purificação , Humanos , Estimativa de Kaplan-Meier , Masculino , Organofosfonatos/efeitos adversos , Modelos de Riscos Proporcionais , RNA Viral/sangue , Comportamento Sexual/estatística & dados numéricos , Tenofovir , Carga Viral , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...