Diagnosing Human Immuno-Deficiency Virus (HIV) infection at the early stages is very important in HIV/AIDS disease surveillance. A rapid diagnostic test (RDT) is a medical diagnostic test kit that is quick and easy to perform [1]. Rapid (point-of-care) tests can be conducted away from specialized laboratory facilities and give results in less than 15 minutes [2]. Although RDT kits have the lowest detection ability, they remain the preferred assay for HIV testing in many countries [3]. The performance of HIV RDT kits differ with brand(s), therefore, are used in combination to give accurate diagnosis [4]. HIV testing is a critical step that helps to control HIV prevalence and incidence in a population (Harries et al., 2010). HIV positive cases were initially diagnosed negative due to poor RDT sensitivity [5]. Other conducted studies in sub- Saharan Africa revealed that 3% of individuals undergoing HIV testing are at a risk of receiving false negative results and advised a follow-up post transfusion HIV testing for blood recipients to monitor sero-conversion [6].
Owusu-ofori et al. proposed that Ghana complement serologic rapid test with Nucleic Acid Test (NAT) in pre-donation screening of blood donors. Nevertheless, NAT comes with a lot of technical and economic limitation [7]. This leaves the country in equipoise since studies on the affordable HIV RDT kits are reporting varying sensitivity and specificity with test specimen types [8].
Several rapid tests have been developed in various countries, and most of them have not been extensively evaluated. A lot of attempts have been made to determine how sensitive the HIV RDTs are to the viruses, however, its sensitivity to the less common virus, HIV-2, has received little attention [9].
This study was designed to compare the sensitivities of First Response HIV-1-2, OraQuick Advance (OraSure/Launch), and Multisure MP Diagnostics to HIV-2 to help in accurate diagnosis and proper administration of therapy to patients.
It has been determined that persons infected with HIV-2 have a longer asymptomatic phase, higher CD4 cell counts, lower viral RNA levels, and slower progression to AIDS than HIV-1 infection [10]. Though HIV-2 has a higher mutation rate, it does not have a selective advantage over HIV-1[10]. Once persons with HIV-2 infection have progressed to clinical AIDS, the manifestations are similar to those of persons with AIDS from HIV-1 infection [11].
Testing of HIV can be done by a health care provider using a Rapid Diagnostic Test kit. A rapid diagnostic test (RDT) is a medical diagnostic test kit that is quick and easy to perform [1]. RDTs are suitable for preliminary or emergency medical screening and for use in medical facilities with limited resources [12]. Rapid (point-of-care) tests can be conducted away from specialized laboratory facilities and give results in not more than 15 minutes [13]. Rapid tests were first developed in the early 1990s for use in developing countries (where specialized laboratory facilities may not be available) [14]. An advantage of this test type is that it is a very rapid test procedure, with results available in as little as 15 minutes [2].
Although RDT kits have the lowest detection ability, they remain the preferred assay for HIV testing in many countries [3]. The performance of HIV RDT kits differ with brand(s), therefore, are used in combination to give accurate diagnosis [4]. More often than not, First Response HIV-1-2 kit is often used as a single test kit in national HIV prevention and control programs [15]. A study by Ly et al., linked the practice of single RDT kit use (for screening test samples) to high HIV infection rates. In that study, single RDT kit detected 85% of infections that were detectable by standard Enzyme Linked Immuno-Sorbent Assay (ELISA). In other words, 15% HIV infected individuals were not detected when a single RDT kit was used to screen the population [16]. It was recorded in Cape Town, South Africa during a study that, 1100 HIV positive cases were initially diagnosed negative due to poor RDT sensitivity [5]. Other conducted studies in sub- Saharan Africa revealed that 3% of individuals undergoing HIV testing are at a risk of receiving false negative results and advised a follow-up post-transfusion HIV testing for blood recipients to monitor sero-conversion [6].
Owusu-ofori et al. proposed that Ghana complement serologic rapid test with Nucleic Acid Test (NAT) in pre-donation screening of blood donors. Nevertheless, NAT comes with a lot of technical and economic limitation [7]. This leaves the country in equipoise since studies on the affordable HIV RDT kits are reporting varying sensitivity and specificity with test specimen types [8].
Several rapid tests have been developed in various countries, and most of them have not been extensively evaluated. A lot of attempts have been made to determine how sensitive the HIV RDTs are to the viruses, however, it is sensitivity to the less common serotype of the virus, that is HIV-2, has received little attention [9].
A number of test kits that are widely used in other countries are First Response HIV-1/2, Oraquick Advance Rapid HIV-1/2, Multisure MP Diagnostics, Determine HIV 1/2 (Alere), Determine HIV 1/2 Ag/Ab Com, INSTI HIV-1/HIV-2 Rapid Antibody Test (Pasante/BioLytical Laboratories) (Alere), Core HIV 1&2 (Core Diagnostics), Immunoflow HIV1-HIV 2 (Core Diagnostics), Vikia HIV 1/2 (bioMerieux), Rapidan anti-HIV1/2 (Turklab).
Various studies have reported on HIV-1 & 2 globally and also pointed out that HIV- 2 is prevalent in West African countries [17] such as Ghana. The need to determine sensitivity in the detection of HIV-1 or 2 is crucial since most clinical settings in Ghana depend only on HIV RDTs in the preliminary diagnosis of HIV prior to initiation of antiretroviral therapy (ART), due to resource constraints. Specifically, in the HIV Support and Care Centres in Ghana, First Response HIV-1/2 and Oraquick Advance Rapid HIV-1/2 are used in the detection of HIV infection prior to the initiation of ART without a higher level of confirmatory testing as provided by the Inno-Lia Test kit [20]. Some patients showing symptoms of immunosuppression could be as a result of HIV-2 or both types; and hence may not be detected by the commonly used RDT kits. This could affect diagnosis of the patient by giving false negative results.
Also, treatments for both HIV-1&2 differ, but since there is the prevalence of HIV-1 as compared to HIV-2, some patients who test positive may be treated as HIV-1 patients though they may be HIV-2, this can also affect the proper treatment of the infection.
Rapid test kits for testing for HIV-1&2 may not be able to accurately determine whether the infecting virus is Type 1 or Type 2 or both. This goes a long way to affect the treatment therapies since it differs with each virus and also gives the likelihood of reporting false negatives. Some patients suffering from HIV-2, unknowingly may find themselves taking drugs from the First Line Art regimen (20) that work for HIV-1, which may lead to suboptimal response from HIV-2 infected persons. This study was designed to determine whether HIV-2 was being accurately diagnosed using the RDTs available in the health sector of Ghana - First Response HIV-1-2, OraQuick Advance (OraSure/Launch), and Multisure MP Diagnostics – in order to address the issue of misclassification of the HIV infection so as to improve diagnosis and treatment of the patients. The study also sought to determine the prevalence of HIV-2 among the study population and to assess the level of sensitivity and specificity of the of the RDTs in use at the study site and other HIV Care and Support Centres in Ghana.