Evaluating the zoonotic spectrum of sandfly-borne phleboviruses, Africa.

Sandfly-borne phleboviruses (SBPs) are an important cause of febrile diseases and neuroinvasive infections in humans, especially in endemic regions. They have been described in Central Asia, Africa, the Middle East, and the Mediterranean regions. Current investigations suggest that SBPs originated from Africa, albeit with little zoonotic threat information. Particularly pertinent is the recent identification of genetically diverse SBPs associated with human infection circulating in North and East Africa. Spread of these viruses to new regions may pose a significant risk to the local populations with little or no pre-existing immunity. Additionally, the lack of SBP detection methods at the point of care may lead to an incorrect diagnosis of malaria and influenza, inappropriate treatment, and an underestimated disease burden. Despite the availability of a wide range of analytic approaches that include cell culture, electron microscopy, and serological screening, diagnosis remains a challenge. Application of new molecular techniques such as next-generation sequencing (NGS) would enable description of new SBPs; however, correlation with additional field clinical data is needed to evaluate the zoonotic significance of any new SBPs. In this review, we provide a summary of the disease ecology of SBPs in Africa to concatenate the existing knowledge on transmission dynamics. The review also highlights the limited surveillance of SBPs in Africa, thus confirming the need for enhanced virus characterization incorporating advanced approaches such as capture-based target enrichment NGS, allowing for the detection of existing and novel SBPs, in addition to epidemiologic data on their clinical relevance.