Consider the following statements regarding Orthobunyaviruses, their transmission characteristics, and the One Health framework for emerging zoonotic diseases:

Statements

1. Orthobunyaviruses of the Simbu group — such as Shamonda, Schmallenberg, and Akabane viruses — are vector-borne arboviruses primarily transmitted by Culicoides biting midges, placing them in the same broad transmission category as dengue and chikungunya, which are also transmitted by blood-feeding arthropods.
2. In the context of zoonotic spillover, the absence of evidence for sustained human-to-human transmission of a newly identified zoonotic virus is sufficient to classify it as posing no public health risk, since epidemic spread requires an established human transmission chain.
3. The One Health approach, as applied to emerging zoonotic infections, recognises that integrated surveillance across human, animal and environmental health domains is essential for early detection of spillover events — because animal reservoirs may harbour pathogens for extended periods before human cases are detected.