Diagnosing Human Immuno-deficiency Virus (HIV) infection at the early stages is instrumental in HIV/AIDS disease surveillance. Technologies that allow the detection of very low levels of HIV nucleic acids (RNA or DNA), viral p24 antigens, and HIV-specific antibodies have been developed [
1]. In spite of these successes, laboratory assays in general are still imperfect, and some recent infections remain undetected [
2]. Viral load test, the gold standard, can identify 96 % of recent infections. The fourth generation Enzyme Immuno Assays (EIAs) identify 93 % and the third generation EIAs [Rapid Diagnostic Test (RDT) kits] (also identify) 63 % of all recent infections [
3]. Although RDT kits have the lowest detection ability, they remain the preferred assay for HIV testing in many countries. This is because they require little expertise to use, run on little sample volumes, cheaper in cost and produce test results in 15 min [
4]. The performance of HIV RDT kits differ with brand(s) [
5], therefore, are used in combination to improve diagnosis [
6]. Ghana has adopted the serial testing algorithm where First Response HIV-1-2 kit (Premier Medical Corporation Ltd., Kachigam, India) is used to screen samples and Oraquick Advance HIV-1-2 kit (OraSure Technologies, Bethlehem, PA, USA) is primarily used to confirm infection. Nonetheless, First Response HIV-1-2 kit is often used as a single test kit in national HIV prevention and control programmes. A study by Laperche et al. [
7], linked the practice of single RDT kit use (for screening test samples) to high HIV infection rates. In that study, single RDT kit use detected 85 % of infections that were detectable by standard Enzyme Linked Immuno-Sorbent Assay (ELISA) [
7]. In other words, 15 % HIV infected individuals were not detected when a single RDT kit was used to screen the population. The results were similar when the test specimen was either whole blood or serum.
Blood specimen (whole blood, plasma or serum) is the sample to apply on First Response HIV-1-2 RDT kit. Field reports indicate that blood specimen contains unequal concentrations of detectable HIV-specific antibodies in whole blood and serum. Sensitivity and specificity of HIV rapid test kits differ with whole blood (95 %) and serum specimens (98 %) [
6,
8]. Better specificity (99.9 %) is achieved with whole blood than using serum specimen (99 %) [
9]. One may argue that it is better to use highly sensitive samples (serum) for testing. Conversely, a field study found serum samples to produce more false negative results compared to whole blood samples [
10]. This loss of sensitivity is important especially in resource limited settings where RDTs are widely used. A study in Cape Town, South Africa, recorded 1100 HIV positive cases that were initially diagnosed negative due to poor RDT sensitivity [
5]. Other studies conducted in sub-Saharan Africa reported that 3 % of people undergoing HIV testing at out-patient departments are at risk of receiving false negative results and recommended a follow-up post-transfusion HIV testing for blood recipients to monitor sero-conversion [
11,
12].
The concern of the authors suggests that the test specimen and/or kit used to screen blood prior to donation might have missed possible positive cases.
In Ghana, depending on the setting where the test is performed, either whole blood or serum sample is used on the First Response HIV-1-2 kit. What is not known is whether the test kit produces consistent results with these specimens and there have not been any independent post-market assessment studies to ascertain the comparability of the kit using the different blood-based specimens. This study assessed the First Response HIV-1-2 kit using whole blood and serum samples to determine its performance characteristics in these specimens.