A 0.85% saline as alternative detection buffer for SD-bioline HIV rapid test in resource limited setting

Accuracy in the diagnosis is a key step to identify HIV infected individuals for appropriate management. Insufficient supply of manufacturer´s buffers in relation to the number of strips per kit has negative impact on patient´s results hence improper patient´s management. In resource limited settings, some laboratory staff use different substitute buffers which has never been validated on their reliability. This study aimed at comparing the performance of 0.85% saline and SD-Bioline manufacturer´s buffer in detection of HIV antibodies. A total of 220 whole blood specimens: 110 HIV positive specimens from patients attending care and treatment center (CTC) and 110 HIV negative specimens from blood donors were re-tested for HIV status using SD-Bioline HIV rapid test using manufacturer´s buffer and 0.85% saline separately. Data and laboratory results were recorded in Microsoft excel sheet followed by analysis using STATA version 13. For all tested samples, the level of agreement between 0.85% saline and manufacturer´s buffer was 98.64% (kappa=0.9727). The value of kappa indicates very good agreement between 0.85% saline and manufacturer´s buffer. In incidents where manufacturer´s buffer is not sufficient, 0.85% saline can give reliable results. Further studies to evaluate the suitable buffer for other rapid tests for HIV and other diseases are recommended especially in resource limited settings.