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1.
PLOS Glob Public Health ; 4(1): e0001770, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38170720

RESUMEN

Hepatitis C self-testing (HCVST) is emerging as an additional strategy that could help to expand access to HCV testing. We conducted a study to assess the usability and acceptability of two types of HCVST, oral fluid- and blood-based, among the general population and men who have sex with men (MSM) in Malaysia. An observational study was conducted in three primary care centres in Malaysia. Participants who were layman users performed the oral fluid- and blood-based HCVST sequentially. Usability was assessed by calculating the rate of errors observed, the rate of difficulties faced by participants as well as inter-reader (self-test interpreted by self-tester vs interpreted by trained user) and inter-operator concordances (self-test vs test performed by trained user). The acceptability of HCV self-testing was assessed using an interviewer-administered semi-structured questionnaire. Participants were also required to read contrived test results which included "positive", "negative", and "invalid". There was a total of 200 participants (100 general population, 100 MSM; mean age 33.6 ± 14.0 years). We found a high acceptability of oral fluid- and blood-based HCVST across both general population and MSM. User errors, related to timekeeping and reading within stipulated time, were common. However, the majority of the participants were still able to obtain and interpret results correctly, including that of contrived results, although there was substantial difficulty interpreting weak positive results. The high acceptability of HCVST among the participants did not appreciably change after they had experienced both tests, with 97.0% of all participants indicating they would be willing to use HCVST again and 98.5% of them indicating they would recommend it to people they knew. There was no significant difference between the general population and MSM in these aspects. Our study demonstrates that both oral fluid- and blood-based HCVST are highly acceptable among both the general population and MSM. Both populations also showed comparable ability to conduct the tests and interpret the results. Overall, this study suggests that HCVST could be introduced as an addition to existing HCV testing services in Malaysia. Further studies are needed to establish the optimal positioning of self-testing alongside facility-based testing to expand access to HCV diagnosis in the country.

2.
BMJ Open ; 13(12): e071198, 2023 12 28.
Artículo en Inglés | MEDLINE | ID: mdl-38154882

RESUMEN

OBJECTIVES: In 2019, the WHO released guidelines on HIV testing service (HTS). We aim to assess the adoption of six of these recommendations on HIV testing strategies among African countries. DESIGN: Policy review. SETTING: 47 countries within the WHO African region. PARTICIPANTS: National HTS policies from the WHO African region as of December 2021. PRIMARY AND SECONDARY OUTCOME MEASURES: Uptake of WHO recommendations across national HTS policies including the standard three-test strategy; discontinuation of a tiebreaker test to rule in HIV infection; discontinuation of western blotting (WB) for HIV diagnosis; retesting prior to antiretroviral treatment (ART) initiation and the use of dual HIV/syphilis rapid diagnostic tests (RDTs) in antenatal care. Country policy adoption was assessed on a continuum, based on varying levels of complete adoption. RESULTS: National policies were reviewed for 96% (n=45/47) of countries in the WHO African region, 38% (n=18) were published before 2019 and 60% (n=28) adopted WHO guidance. Among countries that had not fully adopted WHO guidance, not yet adopting a three-test strategy was the most common reason for misalignment (45%, 21/47); of which 31% and 22% were in low-prevalence (<5%) and high-prevalence (≥5%) countries, respectively. Ten policies (21%) recommended the use of WB and 49% (n=23) recommended retesting before ART initiation. Dual HIV/syphilis RDTs were recommended in 45% (n=21/47) of policies. CONCLUSIONS: Many countries in the African region have adopted WHO-recommended HIV testing strategies; however, efforts are still needed to fully adopt WHO guidance. Countries should accelerate their efforts to adopt and implement a three-test strategy, retesting prior to ART initiation and the use of dual HIV/syphilis RDTs.


Asunto(s)
Infecciones por VIH , Sífilis , Humanos , Femenino , Embarazo , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/tratamiento farmacológico , Sífilis/diagnóstico , Sífilis/epidemiología , Sífilis/tratamiento farmacológico , Políticas , Antirretrovirales/uso terapéutico , Organización Mundial de la Salud , Algoritmos , Prueba de VIH
3.
Clin Infect Dis ; 77(8): 1137-1156, 2023 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-37648655

RESUMEN

BACKGROUND: Many people who have a positive hepatitis C virus (HCV) antibody (Ab) test never receive a confirmatory HCV RNA viral load (VL) test. Reflex VL testing may help address this problem. We undertook a systematic review to evaluate the effectiveness of reflex VL testing compared with standard nonreflex approaches on outcomes across the HCV care cascade. METHODS: We searched 4 databases for studies that examined laboratory-based reflex or clinic-based reflex VL testing approaches, with or without a nonreflex comparator, and had data on the uptake of HCV RNA VL test and treatment initiation and turnaround time between Ab and VL testing. Both laboratory- and clinic-based reflex VL testing involve only a single clinic visit. Summary estimates were calculated using random-effects meta-analyses. RESULTS: Fifty-one studies were included (32 laboratory-based and 19 clinic-based reflex VL testing). Laboratory-based reflex VL testing increased HCV VL test uptake versus nonreflex testing (RR: 1.35; 95% CI: 1.16-1.58) and may improve linkage to care among people with a positive HCV RNA test (RR: 1.47; 95% CI: .81-2.67) and HCV treatment initiation (RR: 1.03; 95% CI: .46-2.32). The median time between Ab and VL test was <1 day for all laboratory-based reflex studies and 0-5 days for 13 clinic-based reflex testing. CONCLUSIONS: Laboratory-based and clinic-based HCV reflex VL testing increased uptake and reduced time to HCV VL testing and may increase HCV linkage to care. The World Health Organization now recommends reflex VL testing as an additional strategy to promote access to HCV VL testing and treatment. CLINICAL TRIALS REGISTRATION: PROSPERO CRD42021283822.


Asunto(s)
Hepatitis C , Humanos , Hepatitis C/diagnóstico , Hepacivirus/genética , Carga Viral , Reflejo , ARN
4.
PLOS Glob Public Health ; 3(4): e0001667, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37018166

RESUMEN

Globally, there are approximately 58 million people with chronic hepatitis C virus infection (HCV) but only 20% have been diagnosed. HCV self-testing (HCVST) could reach those who have never been tested and increase uptake of HCV testing services. We compared cost per HCV viraemic diagnosis or cure for HCVST versus facility-based HCV testing services. We used a decision analysis model with a one-year time horizon to examine the key drivers of economic cost per diagnosis or cure following the introduction of HCVST in China (men who have sex with men), Georgia (men 40-49 years), Viet Nam (people who inject drugs, PWID), and Kenya (PWID). HCV antibody (HCVAb) prevalence ranged from 1%-60% across settings. Model parameters in each setting were informed by HCV testing and treatment programmes, HIV self-testing programmes, and expert opinion. In the base case, we assume a reactive HCVST is followed by a facility-based rapid diagnostic test (RDT) and then nucleic acid testing (NAT). We assumed oral-fluid HCVST costs of $5.63/unit ($0.87-$21.43 for facility-based RDT), 62% increase in testing following HCVST introduction, 65% linkage following HCVST, and 10% replacement of facility-based testing with HCVST based on HIV studies. Parameters were varied in sensitivity analysis. Cost per HCV viraemic diagnosis without HCVST ranged from $35 2019 US dollars (Viet Nam) to $361 (Kenya). With HCVST, diagnosis increased resulting in incremental cost per diagnosis of $104 in Viet Nam, $163 in Georgia, $587 in Kenya, and $2,647 in China. Differences were driven by HCVAb prevalence. Switching to blood-based HCVST ($2.25/test), increasing uptake of HCVST and linkage to facility-based care and NAT testing, or proceeding directly to NAT testing following HCVST, reduced the cost per diagnosis. The baseline incremental cost per cure was lowest in Georgia ($1,418), similar in Viet Nam ($2,033), and Kenya ($2,566), and highest in China ($4,956). HCVST increased the number of people tested, diagnosed, and cured, but at higher cost. Introducing HCVST is more cost-effective in populations with high prevalence.

5.
Lancet Gastroenterol Hepatol ; 8(3): 253-270, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36706775

RESUMEN

BACKGROUND: Point-of-care (POC) hepatitis C virus (HCV) RNA nucleic acid test viral load assays are being used increasingly as an alternative to centralised, laboratory-based standard-of-care (SOC) viral load assays to reduce loss to follow-up. We aimed to evaluate the impact of using POC compared with SOC approaches on uptake of HCV RNA viral load testing and treatment, and turnaround times from testing to treatment along the HCV care cascade. METHODS: We searched PubMed, Embase, and Web of Science for studies published in English between Jan 1, 2016, and April 13, 2022. We additionally searched for accepted conference abstracts (2016-20) not identified in the main search. The contacts directory of the WHO Global Hepatitis Programme was also used to solicit additional studies on use of POC RNA assays. We included studies if they evaluated use of POC HCV RNA viral load with or without a comparator laboratory-based SOC assay, and had data on uptake of viral load testing and treatment, and turnaround times between these steps in cascade. We excluded studies with a sample size of ten or fewer participants. The POC studies were categorised according to whether the POC assay was based onsite at the clinic, in a mobile unit, or in a laboratory. Studies using the POC assay or comparator SOC assays were further stratified according to four models of care: whether HCV testing and treatment initiation were performed in the same or different site, and on the same or a different visit. The comparator was centralised, laboratory-based HCV RNA SOC assays. For turnaround times, we calculated the weighted median of medians with 95% CIs. We analysed viral load testing and treatment uptake using random-effects meta-analysis. The quality of evidence was rated using the GRADE framework. This study is registered with PROSPERO, CRD42020218239. FINDINGS: We included 45 studies with 64 within-study arms: 28 studies were in people who inject drugs, were homeless, or both; four were in people incarcerated in prison; nine were in the general or mixed (ie, includes high-risk groups) populations; and four were in people living with HIV. All were observational studies. The pooled median turnaround times between HCV antibody test and treatment initiation was shorter with onsite POC assays (19 days [95% CI 14-53], ten arms) than with either laboratory-based POC assays (64 days [64-64], one arm) or laboratory-based SOC assays (67 days [50-67], two arms). Treatment uptake was higher with onsite POC assays (77% [95% CI 72-83], 34 arms) or mobile POC assays (81% [60-97], five arms) than with SOC assays (53% [31-75], 12 arms); onsite and mobile POC assay vs SOC assay p=0·029). For POC and SOC arms, higher RNA viral load testing uptake was seen with the same-site models for testing and treatment than with different-site models (all within-category p≤0·0001). For onsite and mobile POC arms, there was higher treatment uptake for same-site than different-site models (within-category p<0·0001). Four studies had direct within-study POC versus SOC comparisons for RNA viral load testing uptake (pooled relative risk 1·11 [95% CI 0·89-1·38]), and there were ten studies on treatment uptake (1·32 [1·06-1·64]). Overall, the quality of evidence was rated as low. INTERPRETATION: Compared with use of laboratory-based SOC HCV viral load testing, the use of POC assays was associated with reduced time from antibody test to treatment initiation and increased treatment uptake. The effect of POC viral load testing is greatest when positioned within a simplified care model in which testing and treatment are provided at the same site, and, where possible, on the same day. POC HCV RNA viral load testing is now recommended in WHO guidelines as an alternative strategy to laboratory-based viral load testing. FUNDING: Unitaid.


Asunto(s)
Infecciones por VIH , Hepatitis C , Humanos , Sistemas de Atención de Punto , Hepacivirus/genética , ARN/uso terapéutico , Carga Viral , Infecciones por VIH/tratamiento farmacológico , Hepatitis C/diagnóstico , Hepatitis C/tratamiento farmacológico
6.
BMC Infect Dis ; 22(1): 738, 2022 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-36109704

RESUMEN

BACKGROUND: People who inject drugs (PWID) are disproportionally affected by hepatitis C virus (HCV) infection and many remain undiagnosed. HCV self-testing (HCVST) may be an effective approach to increase testing uptake, but has rarely been used among PWID. We assessed the usability and acceptability of HCVST among PWID in Kenya. METHODS: We conducted a cross-sectional study nested within a cohort study between August and December 2020 on Kenya's North Coast region. Participants were handed a prototype oral fluid HCVST kit and asked to conduct the test relying on the instructions for use. Usability was assessed by documenting errors made and difficulties faced by participants. Acceptability was assessed using an interviewer-administered semi-structured questionnaire. RESULTS: Among 150 participants, 19% were female and 65.3% had primary level education or lower. 71.3% made at least one error, 56.7% experienced some difficulty during at least one step, and the majority of participants (78%) required assistance during at least one step of the procedure. Most common errors occurred when placing the tube into the stand (18%), collecting the oral fluid sample (24%) and timing of reading results (53%). There was a strong association between presence of symptoms of opiate withdrawals and observed errors (94% vs 62%; p = 0.016) in a sub-group of 74 participants assessed. Inter-reader and inter-operator concordance were 97.7% (kappa: 0.92) and 99.2% (kappa: 0.95), respectively. Acceptability assessed by asking whether participants would choose to use HCVST prior to and after conducting HCVST was 98% and 95%, respectively. CONCLUSIONS: We found a high acceptability of oral fluid HCVST among PWID. User errors were common and were associated with the presence of withdrawal symptoms among users. Despite errors, most participants were able to obtain and interpret results correctly. These findings suggest that this group of users may benefit from greater messaging and education including options to receive direct assistance when self-testing for HCV.


Asunto(s)
Consumidores de Drogas , Hepatitis C , Alcaloides Opiáceos , Abuso de Sustancias por Vía Intravenosa , Estudios de Cohortes , Estudios Transversales , Femenino , Hepacivirus , Hepatitis C/complicaciones , Hepatitis C/diagnóstico , Hepatitis C/epidemiología , Humanos , Kenia/epidemiología , Masculino , Proyectos Piloto , Autoevaluación , Abuso de Sustancias por Vía Intravenosa/complicaciones
7.
BMC Infect Dis ; 22(1): 510, 2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35641908

RESUMEN

BACKGROUND: Hepatitis C virus self-testing (HCVST) is an additional approach that may expand access to HCV testing. We conducted a mixed-methods cross-sectional observational study to assess the usability and acceptability of HCVST among people who inject drugs (PWID), men who have sex with men (MSM) and transgender (TG) people in Tbilisi, Georgia. METHODS: The study was conducted from December 2019 to June 2020 among PWID at one harm reduction site and among MSM/TG at one community-based organization. We used a convergent parallel mixed-methods design. Usability was assessed by observing errors made and difficulties faced by participants. Acceptability was assessed using an interviewer-administered semi-structured questionnaire. A subset of participants participated in cognitive and in-depth interviews. RESULTS: A total of 90 PWID, 84 MSM and 6 TG were observed performing HCVST. PWID were older (median age 35 vs 24) and had a lower level of education compared to MSM/TG (27% vs 59%). The proportion of participants who completed all steps successfully without assistance was 60% among PWID and 80% among MSM/TG. The most common error was in sample collection and this was observed more often among PWID than MSM/TG (21% vs 6%; p = 0.002). More PWID requested assistance during HCVST compared to MSM/TG (22% vs 8%; p = 0.011). Acceptability was high in both groups (98% vs 96%; p = 0.407). Inter-reader agreement was 97% among PWID and 99% among MSM/TG. Qualitative data from cognitive (n = 20) and in-depth interviews (n = 20) was consistent with the quantitative data confirming a high usability and acceptability. CONCLUSIONS: HCVST was highly acceptable among key populations in Georgia of relatively high educational level, and most participants performed HCVST correctly. A significant difference in usability was observed among PWID compared to MSM/TG, indicating that PWID may benefit from improved messaging and education as well as options to receive direct assistance when self-testing for HCV.


Asunto(s)
Infecciones por VIH , Hepatitis C , Minorías Sexuales y de Género , Abuso de Sustancias por Vía Intravenosa , Adulto , Estudios Transversales , Georgia (República)/epidemiología , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Hepacivirus , Hepatitis C/diagnóstico , Hepatitis C/epidemiología , Hepatitis C/psicología , Homosexualidad Masculina , Humanos , Masculino , Autoevaluación , Abuso de Sustancias por Vía Intravenosa/psicología
8.
Diagnostics (Basel) ; 12(5)2022 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-35626411

RESUMEN

Despite the widespread availability of curative treatment with direct-acting antivirals, a significant proportion of people with HCV remain undiagnosed and untreated. New point-of-care (PoC) HCV RNA assays that can be used in clinical settings may help expand access to testing and treatment. This study aimed to evaluate the diagnostic performance of PoC HCV viral load assays compared to laboratory-based testing. Methods: We searched three databases for studies published before May 2021 that evaluated PoC HCV RNA assays against a laboratory NAT reference standard (Prospero CRD42021269022). Random effects bivariate models were used to summarize the estimates. Stratified analyses were performed based on geographic region, population (PWID, etc.), and specimen type (serum/plasma or fingerstick; fresh or frozen). We used the GRADE approach to assess the certainty of the evidence. Results: A total of 25 studies were eligible. We evaluated five different commercially available viral load assays. The pooled sensitivity and specificity were 99% (95% CI: 98−99%) and 99% (95% CI: 99−100%), respectively. High sensitivity and specificity were observed across different assays, study settings (including LMICs and HICs), and populations. There was a small but statistically significant reduction in sensitivity for fingersticks compared to serum or plasma samples (98% vs. 100%, p < 0.05), but the specificity was similar between frozen and fresh samples. The evidence was rated as moderate-high certainty. Conclusions: PoC HCV viral load assays demonstrate excellent diagnostic performance in various settings and populations. The WHO now recommends using PoC HCV viral load assays as an additional strategy to promote access to confirmatory viral load testing and treatment.

9.
BMC Infect Dis ; 21(1): 1064, 2021 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-34649503

RESUMEN

BACKGROUND: In 2018, Rwanda launched a 5-year hepatitis C virus (HCV) elimination plan as per the World Health Organization global targets to eliminate HCV by 2030. To improve awareness of HCV status, strategies are needed to ensure easy access to HCV testing by as-yet unreached populations. HCV-self-testing, an innovative strategy, could further increase HCV testing uptake. This assessment explores perceptions around HCV self-testing among members of the public and healthcare workers in Rwanda. METHODS: A qualitative study was undertaken in Masaka District Hospital, comprising individual interviews, group interviews and participatory action research (PAR) activities. Purposive and snowball sampling methods guided the selection of informants. Informed consent was obtained from all participants. A thematic analysis approach was used to analyse the findings. RESULTS: The participants comprised 36 members of the public and 36 healthcare workers. Informants appreciated HCV self-testing as an innovative means of increasing access to HCV testing, as well as an opportunity to test privately and subsequently autonomously decide whether to seek further HCV care. Informants further highlighted the need to make HCV self-testing services free of charge at the nearest health facility. Disadvantages identified included the lack of pre/post-test counselling, as well as the potential psychosocial harm which may result from the use of HCV self-testing. CONCLUSION: HCV self-testing is perceived to be an acceptable method to increase HCV testing in Rwanda. Further research is needed to assess the impact of HCV self-testing on HCV cascade of care outcomes.


Asunto(s)
Hepatitis C , Autoevaluación , Personal de Salud , Hepatitis C/diagnóstico , Humanos , Rwanda , Uganda
10.
BMC Infect Dis ; 21(1): 609, 2021 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-34171990

RESUMEN

BACKGROUND: The prevalence of hepatitis C virus (HCV) among people who inject drugs (PWID) continues to be a major public-health burden in this highly stigmatised population. To halt transmission of HCV, rapid HCV self-testing kits represent an innovative approach that could enable PWID to know their HCV status and seek treatment. As no HCV test has yet been licenced for self-administration, it is crucial to obtain knowledge around the factors that may deter or foster delivery of HCV self-testing among PWID in resource-constrained countries. METHODS: A qualitative study to assess values and preferences relating to HCV self-testing was conducted in mid-2020 among PWID in the Bishkek and Chui regions of Kyrgyzstan. Forty-seven PWID participated in 15 individual interviews, two group interviews (n = 12) and one participatory action-research session (n = 20). Responses were analysed using a thematic analysis approach with 4 predefined themes: awareness of HCV and current HCV testing experiences, and acceptability and service delivery preferences for HCV self-testing. Informants' insights were analysed using a thematic analysis approach. This research received local ethics approval. RESULTS: Awareness of HCV is low and currently PWID prefer community-based HCV testing due to stigma encountered in other healthcare settings. HCV self-testing would be accepted and appreciated by PWID. Acceptability may increase if HCV self-testing: was delivered in pharmacies or by harm reduction associations; was free of charge; was oral rather than blood-based; included instructions with images and clear information on the test's accuracy; and was distributed alongside pre- and post-testing counselling with linkage to confirmatory testing support. CONCLUSIONS: HCV self-testing could increase awareness of and more frequent testing for HCV infection among PWID in Kyrgyzstan. It is recommended that peer-driven associations are involved in the delivery of any HCV self-testing. Furthermore, efforts should be maximised to end discrimination against PWID at the healthcare institutions responsible for confirmatory HCV testing and treatment provision.


Asunto(s)
Autoevaluación Diagnóstica , Hepatitis C/diagnóstico , Prioridad del Paciente , Abuso de Sustancias por Vía Intravenosa , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Reducción del Daño , Hepacivirus/aislamiento & purificación , Hepatitis C/complicaciones , Hepatitis C/epidemiología , Hepatitis C/psicología , Humanos , Kirguistán/epidemiología , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud/psicología , Aceptación de la Atención de Salud/estadística & datos numéricos , Prioridad del Paciente/psicología , Prioridad del Paciente/estadística & datos numéricos , Prevalencia , Autoevaluación , Pruebas Serológicas/métodos , Valores Sociales , Abuso de Sustancias por Vía Intravenosa/diagnóstico , Abuso de Sustancias por Vía Intravenosa/epidemiología , Abuso de Sustancias por Vía Intravenosa/psicología , Abuso de Sustancias por Vía Intravenosa/virología , Encuestas y Cuestionarios , Adulto Joven
11.
Diagnostics (Basel) ; 11(5)2021 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-33921930

RESUMEN

Point-of-care diagnostics have the potential to increase diagnosis and linkage to care and help reach the WHO targets to eliminate hepatitis C virus (HCV) by 2030. Here, we evaluated the diagnostic accuracy of Genedrive HCV ID assay for the qualitative detection of HCV RNA in decentralized settings in two low- and middle-income countries using fresh plasma specimens from 426 participants. The Abbott RealTime HCV assay was used as the gold standard. Genedrive HCV ID assay was conducted by different users. Users also completed questionnaires to assess the usability of Genedrive. At detection thresholds of 12 IU/mL or 30 IU/mL, 1000 IU/mL, and 2362 IU/mL, the sensitivity was 96.2% (95% CI: 92.7-98.4), 100% (98.2-100), and 100% (98.2-100), respectively; the specificity was 99.5% (95% CI: 97.4-100), 99.5% (97.5-100), and 98.7% (96.1-100), respectively. All genotypes detected using the gold-standard assay were also detected with Genedrive. Users found Genedrive easy to use. Genedrive is a simple and accurate test to confirm chronic HCV infection in decentralized, real-life, resource-limited settings. This novel diagnostic tool could contribute to closing the current gap in HCV diagnosis.

12.
J Clin Virol ; 137: 104783, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33711695

RESUMEN

INTRODUCTION: Dried blood spots (DBS) have potential to improve access to screening for antibodies to hepatitis C virus (HCV). However, although several studies on off-label use of DBS have been performed, to date no HCV antibody serology test is formally approved for use with DBS. This study evaluated the performance of the INNOTEST® HCV Ab IV enzyme immunoassay in paired DBS and plasma samples, to determine whether DBS may be added to the intended use. METHODS: Adults with no history of HCV treatment were prospectively enrolled from two sites in Ukraine. DBS were prepared from fingerstick whole blood (fDBS) and venous whole blood (vDBS) samples. Undiluted and serially diluted DBS and plasma samples were tested. RESULTS: Samples from 149 HCV positive and 151 HCV negative participants were included. Sensitivity and specificity of the INNOTEST® HCV Ab IV assay were both 100 % (95 % confidence intervals 95.7-100) for samples collected on fDBS or vDBS compared with plasma as the reference standard. In all undiluted samples, negative and positive percentage agreement and overall rate of agreement were 100 % between all sample types (Cohen's kappa coefficient of 1). In serially diluted samples, agreement was high (>95 %) between fDBS and vDBS, and as expected, positive percentage agreement between both DBS sample types and plasma was lower (>66 %). CONCLUSIONS: Performance of the INNOTEST® HCV Ab IV assay in DBS was acceptable, thus whole blood collected on DBS may represent an alternative sample type for this assay in settings where venous blood collection is not possible.


Asunto(s)
Hepacivirus , Hepatitis C , Adulto , Pruebas con Sangre Seca , Hepatitis C/diagnóstico , Anticuerpos contra la Hepatitis C , Humanos , Técnicas para Inmunoenzimas
13.
Lancet HIV ; 7(7): e514-e520, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32473102

RESUMEN

Patients with advanced HIV disease have a high risk of mortality, mainly from tuberculosis and cryptococcal meningitis. The advanced HIV disease management package recommended by WHO, which includes diagnostics, therapeutics, and patient psychosocial support, is barely implemented in many different countries. Here, we present a framework for the implementation of advanced HIV disease diagnostics. Laboratory and point-of-care-based reflex testing, coupled with provider-initiated requested testing, for cryptococcal antigen and urinary Mycobacterium tuberculosis lipoarabinomannan antigen, should be done for all patients with CD4+ cell counts of 200 cells per µL or less. Implementation of the advanced HIV disease package should be encouraged within primary health-care facilities and task shifting of testing to lay cadres could facilitate access to rapid results. Implementation of differentiated antiretroviral therapy delivery models can allow clinicians enough time to focus on the management of patients with advanced HIV disease. Efficient up-referral and post-discharge systems, including the development of patient-centric advanced HIV disease literacy, are also crucial. Implementation of the advanced HIV disease package is feasible at all health-care levels, and it should be part of the core of the global response towards ending AIDS as a public health threat.


Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/diagnóstico , Antirretrovirales/uso terapéutico , Antígenos Fúngicos/inmunología , Infecciones por VIH/diagnóstico , Implementación de Plan de Salud , Tuberculosis/diagnóstico , África del Sur del Sahara/epidemiología , Cuidados Posteriores , Instituciones de Atención Ambulatoria , Recuento de Linfocito CD4 , Infecciones por VIH/complicaciones , Infecciones por VIH/mortalidad , Humanos , Alta del Paciente , Pruebas en el Punto de Atención
14.
PLoS One ; 15(4): e0230453, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32243435

RESUMEN

BACKGROUND: In sub-Saharan Africa, a third of people starting antiretroviral therapy and majority of patients returning to HIV-care after disengagement, present with advanced HIV disease (ADH), and are at high risk of mortality. Simplified and more affordable point-of-care (POC) diagnostics are required to increase access to prompt CD4 cell count screening for ambulatory and asymptomatic patients. The Visitect CD4 Lateral Flow Assay (LFA) is a disposable POC test, providing a visually interpreted result of above or below 200 CD4cells/mm3. This study evaluated the diagnostic performance of this index test. METHODS: Consenting patients above 18years of age and eligible for CD4 testing were enrolled in Nsanje district hospital (Malawi), Gutu mission hospital (Zimbabwe) and Centre hopitalier de Kabinda (DRC). A total of 708 venous blood samples were tested in the index test and in the BD FACSCount assay (reference test method) in the laboratories (Phase 1) to determine diagnostic accuracy. A total of 433 finger-prick (FP) samples were tested on the index test at POC by clinicians (Phase 2) and a self-completed questionnaire was administered to all testers to explore usability of the index test. RESULTS: Among 708 patients, 67.2% were female and median CD4 was 297cells/mm3. The sensitivity of the Visitect CD4 LFA using venous blood in the laboratory was 95.0% [95% CI: 91.3-97.5] and specificity was 81.9% [95% CI: 78.2-85.2%]. Using FP samples, the sensitivity of the Visitect CD4 LFA was 98.3% [95% CI: 95.0-99.6] and specificity was 77.2% [95% CI: 71.6-82.2%]. Usability of the Visitect CD4 LFA was high across the study sites with 97% successfully completed tests. Due to the required specific multiple incubation and procedural steps during the Visitect CD4 LFA testing, few health workers (7/26) were not confident to manage testing whilst multi-tasking in their clinical work. CONCLUSIONS: Visitect CD4 LFA is a promising test for decentralized CD4 screening in resource-limited settings, without access to CD4 testing and and it can trigger prompt management of patients with AHD. Lay health cadres should be considered to conduct Visitect CD4 LFA testing in PHCs as well as coordinating all other POC quality assurance.


Asunto(s)
Recuento de Linfocito CD4/métodos , Infecciones por VIH/diagnóstico , Tamizaje Masivo , Adulto , Femenino , Infecciones por VIH/epidemiología , Humanos , Malaui/epidemiología , Persona de Mediana Edad , Pruebas en el Punto de Atención , Pruebas Serológicas , Zimbabwe/epidemiología
15.
J Acquir Immune Defic Syndr ; 82(1): 96-104, 2019 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-31408452

RESUMEN

BACKGROUND: To assess the performance and suitability of dried blood spot (DBS) sampling using filter paper to collect blood for viral load (VL) quantification under routine conditions. METHODS: We compared performance of DBS VL quantification using the Biocentric method with plasma VL quantification using Roche and Biocentric as reference methods. Adults (≥18 years) were enrolled at 2 health facilities in Eswatini from October 12, 2016 to March 1, 2017. DBS samples were prepared through finger-prick by a phlebotomist (DBS-1), and through the pipetting of whole venous blood by a phlebotomist (DBS-2) and by a laboratory technologist (DBS-3). We calculated the VL-testing completion rate, correlation, and agreement, as well as diagnostic accuracy estimates at the clinical threshold of 1000 copies/mL. RESULTS: Of 362 patients enrolled, 1066 DBS cards (DBS-1: 347; DBS-2: 359; DBS-3: 360) were tested. Overall, test characteristics were comparable between DBS-sampling methods, irrespective of the reference method. The Pearson correlation coefficients ranged from 0.67 to 0.82 (P < 0.001) for different types of DBS sampling using both reference methods, and the Bland-Altman difference ranged from 0.15 to 0.30 log10 copies/mL. Sensitivity estimates were from 85.3% to 89.2% and specificity estimates were from 94.5% to 98.6%. The positive predictive values were between 87.0% and 96.5% at a prevalence of 30% VL elevations, and negative predictive values were between 93.7% and 95.4%. CONCLUSIONS: DBS VL quantification using the newly configured Biocentric method can be part of contextualized VL-testing strategies, particularly for remote settings and populations with higher viral failure rates.


Asunto(s)
Infecciones por VIH/sangre , Infecciones por VIH/diagnóstico , Plasma/virología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Carga Viral/métodos , Adulto , Recolección de Muestras de Sangre , Pruebas con Sangre Seca/métodos , Esuatini , Femenino , VIH-1/genética , Humanos , Masculino , ARN Viral/sangre , Sensibilidad y Especificidad , Pruebas Serológicas
16.
BMC Infect Dis ; 18(1): 570, 2018 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-30428850

RESUMEN

BACKGROUND: Viral load (VL) testing is being scaled up in resource-limited settings. However, not all commercially available VL testing methods have been evaluated under field conditions. This study is one of a few to evaluate the Biocentric platform for VL quantification in routine practice in Sub-Saharan Africa. METHODS: Venous blood specimens were obtained from patients eligible for VL testing at two health facilities in Swaziland from October 2016 to March 2017. Samples were centrifuged at two laboratories (LAB-1, LAB-2) to obtain paired plasma specimens for VL quantification with the national reference method and on the Biocentric platform. Agreement (correlation, Bland-Altman) and accuracy (sensitivity, specificity) indicators were calculated at the VL thresholds of 416 (2.62 log10) and 1000 (3.0 log10) copies/mL. Leftover samples from patients with discordant VL results were re-quantified and accuracy indicators recalculated. Logistic regression was used to compare laboratory performance. RESULTS: A total of 364 paired plasma samples (LAB-1: n = 198; LAB-2: n = 166) were successfully tested using both methods. The correlation was high (R = 0.82, p < 0.01), and the Bland-Altman analysis showed a minimal mean difference (- 0.03 log10 copies/mL; 95% CI: -1.15 to 1.08). At the clinical threshold level of 3.0 log10 copies/mL, the sensitivity was 88.6% (95% CI: 78.7 to 94.9) and the specificity was 98.3% (95% CI: 96.1 to 99.4). Sensitivity was higher in LAB-1 (100%; 95% CI: 71.5 to 100) than in LAB-2 (86.4%; 95% CI: 75.0 to 94.0). Most upward (n = 8, 2.2%) and downward (n = 11, 3.0%) misclassifications occurred at the 2.62 log threshold, with LAB-2 having a 16 (95% CI: 2.26 to 113.27; p = 0.006) times higher odds of downward misclassification. After retesting of discordant leftover samples (n = 17), overall sensitivity increased to 93.5% (95% CI: 85.5 to 97.9) and 97.1% (95% CI: 90.1 to 99.7) at the 2.62 and 3.0 thresholds, and specificity increased to 98.6% (95% CI: 96.5 to 99.6) and 99.0% (95% CI: 97.0 to 99.8) respectively. CONCLUSIONS: The test characteristics of the Biocentric platform were overall comparable to the national reference method for VL quantification. One laboratory tended to misclassify VL results downwards, likely owing to unmet training needs and lack of previous hands-on practice.


Asunto(s)
Infecciones por VIH/diagnóstico , VIH-1/genética , ARN Viral/sangre , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Carga Viral/métodos , Adolescente , Adulto , Pruebas Diagnósticas de Rutina/economía , Pruebas Diagnósticas de Rutina/métodos , Pruebas Diagnósticas de Rutina/normas , Esuatini , Femenino , Infecciones por VIH/sangre , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Sistemas de Atención de Punto/economía , Sistemas de Atención de Punto/normas , Valor Predictivo de las Pruebas , ARN Viral/análisis , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Pruebas Serológicas , Manejo de Especímenes/métodos , Carga Viral/genética , Adulto Joven
17.
Infect Dis Clin North Am ; 32(2): 425-445, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29778264

RESUMEN

The world has embraced the call for global elimination of hepatitis C virus by 2030. The unprecedented speed of therapeutic development and increased access to direct-acting antivirals has made elimination a possibility. We must screen hundreds of millions of people to diagnose and treat those currently infected. Global access to hepatitis C virus diagnostics will be a keystone to success. Key challenges must be overcome and systems optimized to ensure widespread access to existing diagnostics. Although promising technologies may soon transform the landscape, innovative strategies are needed to stimulate investment and accelerate the development of point-of-care hepatitis C virus diagnostics.


Asunto(s)
Hepacivirus/aislamiento & purificación , Hepatitis C/diagnóstico , Técnicas de Diagnóstico Molecular/tendencias , Sistemas de Atención de Punto , Antivirales/uso terapéutico , Erradicación de la Enfermedad/instrumentación , Erradicación de la Enfermedad/métodos , Salud Global , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepatitis C/tratamiento farmacológico , Hepatitis C/epidemiología , Humanos , Técnicas de Diagnóstico Molecular/economía , Técnicas de Diagnóstico Molecular/métodos , Abuso de Sustancias por Vía Intravenosa/complicaciones , Abuso de Sustancias por Vía Intravenosa/virología
18.
PLoS One ; 13(3): e0193577, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29499042

RESUMEN

BACKGROUND: HIV Viral Load and Early Infant Diagnosis technologies in many high burden settings are restricted to centralized laboratory testing, leading to long result turnaround times and patient attrition. GeneXpert (Cepheid, CA, USA) is a polyvalent near point-of-care platform and is widely implemented for Xpert MTB/RIF diagnosis. This study sought to evaluate the operational feasibility of integrated HIV VL, EID and MTB/RIF testing in new GeneXpert platforms. METHODS: Whole blood samples were collected from consenting patients due for routine HIV VL testing and DBS samples from infants due for EID testing, at three rural health facilities in Zimbabwe. Sputum samples were collected from all individuals suspected of TB. GeneXpert testing was reserved for all EID, all TB suspects and priority HIV VL at each site. Blood samples were further sent to centralized laboratories for confirmatory testing. GeneXpert polyvalent testing results and patient outcomes, including infrastructural and logistical requirements are reported. The study was conducted over a 10-month period. RESULTS: The fully automated GeneXpert testing device, required minimal training and biosafety considerations. A total of 1,302 HIV VL, 277 EID and 1,581 MTB/RIF samples were tested on a four module GeneXpert platform in each study site. Xpert HIV-1 VL testing was prioritized for patients who presented with advanced HIV disease, pregnant women, adolescents and suspected ART failures patients. On average, the study sites had a GeneXpert utilization rate of 50.4% (Gutu Mission Hospital), 63.5% (Murambinda Mission Hospital) and 17.5% (Chimombe Rural Health Centre) per month. GeneXpert polyvalent testing error rates remained lower than 4% in all sites. Decentralized EID and VL testing on Xpert had shorter overall median TAT (1 day [IQR: 0-4] and 1 day [IQR: 0-1] respectively) compared to centralized testing (17 days [IQR: 13-21] and 26 days [IQR: 23-32] respectively). Among patients with VL >1000 copies/ml (73/640; 11.4%) at GMH health facility, median time to enhanced adherence counselling was 8 days and majority of those with documented outcomes had re-suppressed VL (20/32; 62.5%). Median time to ART initiation among Xpert EID positive infants at GMH was 1 day [IQR: 0-1]. CONCLUSION: Implementation of near point-of-care GeneXpert platform for integrated multi-disease testing within district and sub-district healthcare settings is feasible and will increase access to VL, and EID testing to priority populations. Quality management systems including monitoring of performance indicators, together with regular on-site supervision are crucial, and near-POC test results must be promptly actioned-on by clinicians for patient management.


Asunto(s)
Infecciones por VIH/diagnóstico , Sistemas de Atención de Punto , Tuberculosis/diagnóstico , Adulto , Antirretrovirales/uso terapéutico , Automatización , Estudios de Factibilidad , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , VIH-1/metabolismo , Humanos , Masculino , Esputo/microbiología , Tuberculosis/microbiología , Carga Viral , Zimbabwe
19.
PLoS One ; 10(12): e0144656, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26670929

RESUMEN

BACKGROUND: The Xpert® MTB/RIF (Xpert) is an automated molecular test for simultaneous detection of tuberculosis (TB) and rifampicin resistance, recommended by the World Health Organization as the preferred diagnostic method for individuals presumed to have multi-drug resistant TB (MDR-TB) or HIV-associated TB. We describe the performance of Xpert and key lessons learned during two years of implementation under routine conditions in 33 projects located in 18 countries supported by Médecins Sans Frontières across varied geographic, epidemiological and clinical settings. METHODS: Xpert was used following three strategies: the first being as the initial test, with microscopy in parallel, for all presumptive TB cases; the second being only for patients at risk of MDR-TB, or with HIV- associated TB, or presumptive paediatric TB; and the third being as the initial test for these high-risk patients plus as an add-on test to microscopy in others. Routine laboratory data were collected, using laboratory registers. Qualitative data such as logistic aspects, human resources, and tool acceptance were collected using a questionnaire. FINDINGS: In total, 52,863 samples underwent Xpert testing from April 2011 to December 2012. The average MTB detection rate was 18.5%, 22.3%, and 11.6% for the three different strategies respectively. Analysis of the results on samples tested in parallel showed that using Xpert as add-on test to microscopy would have increased laboratory TB confirmation by 49.7%, versus 42.3% for Xpert replacing microscopy. The main limitation of the test was the high rate of inconclusive results, which correlated with factors such as defective modules, cartridge version (G3 vs. G4) and staff experience. Operational and logistical hurdles included infrastructure renovation, basic computer training, regular instrument troubleshooting and maintenance, all of which required substantial and continuous support. CONCLUSION: The implementation of Xpert was feasible and significantly increased TB detection compared to microscopy, despite the high rate of inconclusive results. Xpert implementation was accompanied by considerable operational and logistical challenges. To further decentralize diagnosis, simpler, low-cost TB technologies well-suited to low-resource settings are still urgently needed.


Asunto(s)
Pruebas Diagnósticas de Rutina , Farmacorresistencia Bacteriana , Juego de Reactivos para Diagnóstico , Rifampin/uso terapéutico , Tuberculosis/diagnóstico , Tuberculosis/tratamiento farmacológico , Adulto , Niño , Farmacorresistencia Bacteriana/efectos de los fármacos , Humanos , Rifampin/farmacología , Factores de Riesgo , Esputo/microbiología , Encuestas y Cuestionarios , Resultado del Tratamiento
20.
Bull World Health Organ ; 93(9): 623-30, 2015 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-26478626

RESUMEN

OBJECTIVE: To estimate the proportion of invalid results generated by a CD4+ T-lymphocyte analyser used by Médecins Sans Frontières (MSF) in field projects and identify factors associated with invalid results. METHODS: We collated 25,616 CD4+ T-lymphocyte test results from 39 sites in nine countries for the years 2011 to 2013. Information about the setting, user, training, sampling technique and device repair history were obtained by questionnaire. The analyser performs a series of checks to ensure that all steps of the analysis are completed successfully; if not, an invalid result is reported. We calculated the proportion of invalid results by device and by operator. Regression analyses were used to investigate factors associated with invalid results. FINDINGS: There were 3354 invalid test results (13.1%) across 39 sites, for 58 Alere PimaTM devices and 180 operators. The median proportion of errors per device and operator was 12.7% (interquartile range, IQR: 10.3-19.9) and 12.1% (IQR: 7.1-19.2), respectively. The proportion of invalid results varied widely by country, setting, user and device. Errors were not associated with settings, user experience or the number of users per device. Tests performed on capillary blood samples were significantly less likely to generate errors compared to venous whole blood. CONCLUSION: The Alere Pima CD4+ analyser generated a high proportion of invalid test results, across different countries, settings and users. Most error codes could be attributed to the operator, but the exact causes proved difficult to identify. Invalid results need to be factored into the implementation and operational costs of routine CD4+ T-lymphocyte testing.


Asunto(s)
Artefactos , Recuento de Linfocito CD4/métodos , Sistemas de Atención de Punto , Recolección de Muestras de Sangre , Humanos , Competencia Profesional , Análisis de Regresión , Estudios Retrospectivos
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