Assessment of the heat stability of seven rapid HIV assays

Abstract

Human Immunodeficiency Virus Rapid Diagnostic Tests (HIV RDTs) are robust, quick to perform, effective diagnostic tools. The stability of seven commonly used RDTs for detecting antibody to HIV was assessed during exposure to temperatures above 30°C, the usual maximum recommended by manufacturers. The aim of the study was to determine if HIV RDTs retain their testing outcomes after exposure to higher temperatures. At two testing sites, seven RDTs were exposed to a short heat shock (60°C for 72 hours) as might occur during transport. RDTs were exposed to ambient (22 or 30°C), warm (35 or 37°C) or hot (45°C) temperatures for up to 90 days. Testing was performed at five intervals on a panel of seven positive and three negative plasma samples. Results showed no changes consistent with altered testing outcomes over time and/or temperature when test indicators were compared with the control indicators. Only one HIV RDT achieved 100% consensus with reference results at all four storage temperatures (median 97.5%, lowest 74% for RDT5 at 45°C). Testing outcomes in a limited sample panel showed six of seven HIV RDT kits were relatively robust despite exposure to higher than recommended temperatures.