Homeostatic Disruption in Oceania Malaria: Outdoor Biting Shift, Spatial Repellents, and the Recoherence Imperative

Malaria in Oceania presents a paradox: an increasingly sophisticated global intervention toolkit deployed against a system that has demonstrably shifted beyond that toolkit’s operational envelope. Papua New Guinea (PNG) and the broader Western Pacific Region carry a disproportionate and rising malaria burden, with case incidence and mortality increasing 35% and 33% respectively between 2015 and 2023 — a trajectory four times above WHO Global Technical Strategy targets. This paper applies the Ecological Homeostasis (EH) framework and General Theory of Regulated Stability (GTRS) to malaria transmission in Oceania, arguing that the outdoor biting shift — strongly inferred from converging indirect evidence but pending direct longitudinal confirmation in PNG’s Anopheles punctulatus vectors — constitutes a probable regulatory displacement event: one in which accumulated environmental and anthropogenic pressure has moved transmission beyond the homeostatic basin that indoor-targeted interventions were designed to maintain. Drawing on evidence from 32 graded records across eight domains — epidemiology, climate science, wind modelling, WHO spatial repellent assessment, health economics, Indigenous sovereignty, anthropology, and psychology — we demonstrate that: (1) the PNG malaria resurgence from 2015 is a measurable GTRS threshold event, not a linear programme shortfall; (2) climate change is systematically expanding both the altitude and seasonal envelope of transmission, adding load to an already destabilised system; (3) spatial repellents (volatile pyrethroid emanators) represent the first new class of vector control in decades and carry a conditional WHO recommendation as of August 2025, but critical evidence gaps remain around outdoor use and PNG-specific vector testing; and (4) every prior PNG malaria control programme that achieved burden reduction subsequently collapsed through disengagement failure, not biology — establishing community co-design as a recoherence precondition, not an optional enhancement. We identify two critical structural gaps requiring dedicated research prior to large-scale spatial repellent deployment in PNG: computational fluid dynamics modelling of outdoor tropical repellent dispersal, and PNG-specific community co-design protocols. We recommend alignment with WHO’s AEGIS/Unitaid framework for the former, and the NATNAT project partnership model for the latter. The paper concludes that the outdoor biting shift represents not merely a vector ecology problem but a system-level homeostatic failure requiring recoherence at four simultaneous levels: biological, environmental, economic, and social. Keywords: malaria, Oceania, Papua New Guinea, outdoor biting shift, spatial repellents, ecological homeostasis, GTRS, community co-design, vector control, climate change, Indigenous sovereignty, transfluthrin,WHO conditional recommendation,health economics,NATNAT,CFD dispersal modelling,Plasmodium falciparum,Plasmodium vivax,ENSO,altitude, expansion,insecticide treated nets,LLIN bioefficacy,recoherence,Sovereign Ideas Fund,SIP working paper,HATI²,