RESUMEN
Remote areas of many low and middle income (LMI) countries have poor access to HIV viral load (HIV VL) testing. The SAMBA II (simple amplification-based assay) Semi-Q whole-blood test (Diagnostics for the Real World [DRW], Cambridge, UK) is a point-of-care assay, which uses leucodepletion technology to allow whole-blood testing in remote settings. A total of 1,540 consecutive HIV-positive clinic patients in Cameroon (250), United Kingdom (633), Ukraine (412), and Zimbabwe (245) donated venous blood (all countries) and finger prick blood (all except UK) for testing on SAMBA II. SAMBA II results were compared with simultaneous plasma results on the Abbott RealTime HIV-1 (Abbott Molecular, Des Plaines, IL) viral load assay and interpreted as either <1,000 RNA copies/ml or ≥1,000 RNA copies/ml. For 1,528 venous whole-blood samples tested on SAMBA II, overall percent agreement with the reference test at a cutoff HIV VL of ≥1,000 copies/ml was 96.9% (1,480/1,528; 95% confidence interval [CI], 95.9% to 97.7%), negative percent agreement was 97.7% (1,259/1,289; 95% CI, 96.7% to 98.4%), and positive percent agreement was 92.5% (221/239; 95% CI, 88.4% to 95.5%). For 854 finger prick samples, there was 95.0% (811/854; 95% CI, 93.3% to 96.3%) overall percent agreement, 98.0% (625/638; 95% CI, 96.5% to 98.9%) negative percent agreement, and 86.1% (186/216; 95% CI, 80.8% to 90.4%) positive percent agreement. These rose to 93.5% (82.1% to 98.6%), 97.6% (95.6% to 98.8%), and 95.6% (93.3% to 97.3%) after exclusion of aberrant results from the Ukraine center. These results show a high level of agreement between SAMBA-II and a laboratory-based assay. SAMBA-II has a performance that is suitable to use as a VL point-of-care assay in remote settings.
Asunto(s)
Infecciones por VIH , VIH-1 , Camerún , Infecciones por VIH/diagnóstico , VIH-1/genética , Humanos , Sistemas de Atención de Punto , ARN Viral , Sensibilidad y Especificidad , Ucrania , Reino Unido , Carga ViralRESUMEN
Although access to antiretroviral therapy for HIV infection is increasing in resource-poor countries, viral load testing for monitoring of treatment efficacy remains limited, expensive, and confined to centralized laboratories. The SAMBA HIV-1 Semi-Q Test is a nucleic acid-based amplification assay developed for viral load monitoring performed on either the semi-automated SAMBA I system for laboratory use or the fully automated SAMBA II system for point-of care use. We have assessed the performance characteristics of the SAMBA HIV-1 Semi-Q Test on SAMBA I and SAMBA II systems according to the Common Technical Specifications of the European Community's 98/79 In Vitro Diagnostic Medical Devices Directive. The sensitivity, specificity, reproducibility, and viral subtype coverage of the test were similar on the SAMBA I and SAMBA II platforms. The clinical performance on the SAMBA I system was compared with the Roche CAP/CTM assay and evaluated in-house with 130 patient specimens from London as well as in the field with 390 specimens in Kenya and Zimbabwe. The overall concordance between the SAMBA and CAP/CTM assays was 98.1%. The clinical performance of the test on the SAMBA II platform in comparison with the Abbott HIV-1 RealTime Assay was evaluated in-house with 150 specimens from Ukraine, yielding a concordance of 98.0%. The results thus show that the SAMBA HIV-1 Semi-Q Test performs equivalently on SAMBA I and SAMBA II, and they suggest that the test is suitable for implementation at the point-of-care in resource-poor regions where viral load testing is desperately needed but often unavailable.
Asunto(s)
Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Sistemas de Atención de Punto , Carga Viral/métodos , Automatización de Laboratorios/métodos , Humanos , Kenia , Londres , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Ucrania , ZimbabweRESUMEN
Ukraine is a leader in Europe in the prevalence of HIV infection. There are up to 270 thousand people, who are living with HIV. Since 1987, in Ukraine, 33,149 HIV-infected people died. During the first six months of 2013, of all the dead, who were suffering from HIV and in need of antiretroviral treatment (ART) at the time of death, 41% received treatment and only 5.7% received ART for more than one year. Specialists of Kiev Regional AIDS Center analyzed mortality among the patients of the centre, in order to determine the most frequent cause of death, set the group most at risk and to develop effective measures to reduce mortality among HIV-infected patients. In Kiev AIDS Center, 10,000 people are under medical observation and 4004 of them are taking ART. During 2013, 305 persons died: 217 were women and 88 were men which included 3 children under 14 years. Most of the dead - 272 (89%) were aged 25-49. Among the total number of the dead, 125 people (41%) were receiving ART, 53 of them (17%) were receiving ART for at least one year and 39 of them (13%) were receiving ART for less than one month. Hundred and fifty-eight people (52%) required ART and 22 (7%) did not need therapy. Hundred and ninety-two patients (63%) were in four clinical stage of HIV infection. Hundred and ten of them had HIV+TB co-infection. Twenty patients died due to TB and 12 patients died due to hepatitis b virus/hepatitis c virus (HBV/HCV). Among these patients, 87 people (39%) were taking ART and 136 persons (61%) were in need of ART, but did not get it. Nineteen patients were diagnosed with cancer. Sixteen patients, who were co-infected HIV+TB had a CD4 cell count of more than 300. Based on this analysis, we can conclude that the main causes of high mortality among HIV-infected patients in 2013 were late diagnosis of HIV, besides a large number (52%) of patients, who were in need of ART did not take it. A large number (40%) among those who died were patients co-infected with HIV+TB, HIV+HBV/HCV. This reinforces the necessity to introduce new schemes for the integrated treatment of these patients, including patients with MDR, XDR TB. Also all HIV-infected patients who died in 2013, were diagnosed multiple pathology of various organs, which demonstrates the necessity of the introduction of schemes of early diagnosis and approaches to treatment of this disease. A large number of deaths (24%) of patients receiving ART for more than a year, highlight the necessity for changes to existing treatment regimen in HIV patients, with the possibility of the development of viral resistance to certain drugs and taking into account the latest international experience in the treatment of HIV-infected patient.