Development and proof of concept evaluation of a low-resourcereliant diagnostic platform for arbovirus detection and surveillance

Emerging and re-emerging arboviruses, such as Zika virus (ZIKV) and Chikungunya virus (CHIKV), pose significant global public health threats, particularly in resource-limited settings where effective diagnostic tools are scarce. The rapid spread, increasing vector competence and significant lack of vaccination and specific therapeutics further add to the challenges in arbovirus infection mitigation. This PhD project sought to address these challenges by evaluating current diagnostic methods and developing novel, rapid, non-invasive approaches tailored for low resource environments. The Isothermal ZIKV and CHIKV diagnostic (Iso-ZIKV and CHIKV-Dx) strategies, which utilize urine as a clinical matrix, achieved 100% specificity and delivered results five times faster than the ‘gold standard’, conventional RNA isolation and RT-qPCR. The simplistic implementation strategy, rapid sample processing and real-time end point detection demonstrated considerable advantages for low-resource diagnostics when compared to conventional methods. Notably, the Iso-ZIKV-Dx demonstrated a sensitivity as low as 34.28 RNA copies per reaction within just 30 minutes, while the Iso-CHIKV-Dx detected 570 CHIKV RNA copies per microlitre, significantly expediting the diagnostic process. The innovative strategies also proved effective in vector surveillance, accurately identifying ZIKV- and CHIKV-infected Aedes aegypti mosquitoes with 100% sensitivity (n=10) in 30 minutes. Furthermore, testing pooled mosquito samples with five mosquitoes per pool for both viruses yielded positive accuracy rates exceeding 50% (n=5). With further optimisation, these diagnostic tools hold significant potential for enhancing disease management and surveillance in resource-constrained regions, offering alternative powerful tools to mitigate the global burden of ZIKV and CHIKV infections. The advancement of rapid, field-deployable diagnostics will be crucial in the global fight against arbovirus outbreaks.