![]() However, we recorded variations of intensity of the strip test. For both RDTs our results only include data from participants above the age of 2 years in order to exclude false test-positivity due to the presence of maternal antibodies.Īccording to the manufacturer’s instructions for both assays, any test result with visible lines in both test control areas, regardless of intensity, were considered reactive. Results of the third survey are not reported here, they were only used when needed to verify results from the two previous surveys. During the second and third annual survey round, where the STAT-PAK RDT was used for HIV screening, we collected 2.7 ml of blood from all participants above 2 years of age, thus all our STAT-PAK RDT results were obtained from plasma samples. In most cases this smaller amount of blood did not supply sufficient plasma, so that HIV testing in children below 6 years was mostly done using whole blood. In these cases, 300 µl of blood were collected after finger prick, using microvettes (Sarstedt, Nürnbrecht, Germany). However, venae puncture was not possible in all participants, and especially problematic in younger children. 2.7 ml of blood were collected by venae puncture from participants above the age of 6 years. Collected data further included socio-economic characteristics of the study participants, previous and current medical history, as well as individual knowledge regarding different diseases.ĭuring the first survey (2006/2007) the Determine RDT was used to screen for HIV-1 infection. Study participants were visited annually for specimen and data collection, including an HIV rapid test. Subsequently, 10% of all households in the study sites were randomly selected, which resulted in a cohort of approximately 18,000 individuals of all age groups and both sexes. The urban, semi-urban and rural study sites were carefully chosen in order to reflect the geographic diversity of the Region, from altitudes of about 475 meters above sea level near Lake Nyassa, to over 2300 meters. The EMINI project (Establishment of the infrastructure to Evaluate and Monitor the Impact of New Interventions), a population based cohort study, investigated the prevalence and incidence of HIV in 9 selected communities with a total population of ∼171,000 people. The manufacturer’s information applies to the time of the study today both tests are manufactured and sold by Alere, formerly named Inverness Medical Professional Diagnostics, Princeton, NJ.ĭata for this study were collected between May 2006 and June 2008 in the Mbeya Region in Tanzania. The two tests are referred to below as the “Determine” RDT and the “STAT-PAK” RDT, in order to improve the readability of this article. ![]() Here we evaluate the diagnostic test performance for HIV testing of the Determine HIV 1/2 and the HIV 1/2 STAT-PAK (Chembio Diagnostics Systems, Medford, NY, USA) RDTs in a general population cohort in South West Tanzania where, in contrast to previous studies, children and adults of both genders were included. Especially the Determine HIV 1/2 test received very diverse reports regarding its specificity which ranged from 91.7% to above 99%, ,, ,. However, it seems that the diagnosis of HIV by RDT is challenged by confounding regional factors. Because they allow for real-time, point-of-care HIV testing, individuals can receive their test result during a single clinic visit which is likely to increase the uptake of VCT, , especially in Sub Saharan Africa, where in some settings more than two weeks may be needed for laboratory results to become available. All four RDTs are less expensive than ELISA or Western Blot tests, require little or no equipment, can be stored at room temperature and are easy to use and to read. A fourth HIV rapid test, HIV 1/2 STAT-PAK (Chembio Diagnostics Systems, Medford, NY, USA) is used in neighbouring countries mainly as a confirmatory test. The Uni-Gold™ HIV-1/2 (Trinity Biotech, Bray Ireland) is used as a final test if results are discrepant. Until recently the National guidelines for VCT in Tanzania recommended using the SD Bioline HIV 1/2 3.0 (Standard Diagnostics, Kyonggi-do, Korea) as a screening test, with initial reactive samples re-tested using the Determine HIV 1/2 test (Abbott Laboratories, Abbott Park, IL). Since then RDTs have been widely used throughout Africa and the developing world for blood safety screening, surveillance and in prenatal or voluntary counselling and testing (VCT) centres. The World Health Organisation (WHO) Global Programme on AIDS first recommended the use of simple rapid detection tests (RDTs) for HIV in 1992.
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