Preliminary evaluation of inactivated antigens as diagnostic controls in molecular detection of vector-borne diseases in low-resource settings

Background & objectives: Molecular tests play crucial role in diagnosis, however, acquiring appropriate controls is challenging owing to strict biosafety and biosecurity regulations. Herein, we suggest an alternative to live virus for inclusion as positive controls in molecular testing. Methods: We used inactivated antigens provided with ELISA kits, both as they are and after spiking the vector samples. The extracted RNA/DNA was used as a positive control in RT- PCR/PCR reactions. Results: The PCR product of expected size and sequencing results confirmed that the inactivated antigens can be used as positive controls for Dengue, Chikungunya, Japanese Encephalitis and Lymphatic Filariasis in molecular tests. Interpretation & conclusion: We demonstrate that the inactivated antigens supplied with ELISA kits or obtained from microscopic slide can be used as positive controls in molecular tests while testing human and vector samples. This will be a useful technique for laboratories in resource constrained settings or during emergency situations.