Review 3: "Climate Warming and Urbanization May Expand Dengue Transmission Risk in California"

Couper et al address an increasingly important public health challenge: estimating dengue transmission risk in non-endemic regions that are becoming vulnerable to outbreaks.This work fills a meaningful gap in the literature, as most existing dengue transmission models focus on endemic regions where local transmission is self-sustaining, whereas relatively few studies have examined the dynamics of outbreak risk in non-endemic areas.The authors conclude that approximately 18.2 million California residents currently live in areas exceeding risk thresholds observed during recent local transmission, with an additional 4.1 million potentially at risk by mid-century under climate warming scenarios.The approach of separately estimating transmission components to identify region-specific bottlenecks is particularly valuable for guiding targeted surveillance and intervention strategies.Some methodological and conceptual issues require attention, particularly regarding the interpretability of risk metrics, the treatment of urbanization, and the scope of importation pathways considered.Reliable.The main study claims are generally justified by its methods and data.The results and conclusions are likely to be similar to the hypothetical ideal study.There are some minor caveats or limitations, but they would/do not change the major claims of the study.The study provides sufficient strength of evidence on its own that its main claims should be considered actionable, with some room for future revision.