Associations between Antimicrobial-Resistant Gram-Negative Infections and Climate-Related Exposure in a Tertiary Medical Center in Central Luzon, Philippines

Abstract

Antimicrobial resistance (AMR) can worsen due to climate change. Several studies from China, Europe, and the USA have reported linear associations between weather and AMR. To provide additional evidence, this epidemiological study explored the nonlinear associations of short-term (28-day prior) and long-term (annual anomaly) temperature and rainfall exposure with AMR cases and multidrug resistance (MDR) at a single hospital in Pampanga, Philippines, a province with a tropical climate and high flood risk. Robust Poisson regression was used to estimate the associations between temperature and rainfall with AMR cases and the number of resistant antibiotics across subgroups of bacteria, priority pathogens, specimens, age, sex, and season. Several nonlinear associations exhibited an inverted U-shape, suggesting that the AMR risk peaks at specific temperatures or rainfall levels before declining at extreme values. Another recurring nonlinear association was U- or J-shaped, suggesting increased MDR severity or a greater number of resistant antibiotics with low or high rainfall. These findings underscore the possibility of a more complex link between climate and AMR, warranting further investigation across more locations and settings, whenever individual records are available. Future research should integrate ecological data to elucidate the mechanisms underlying these associations.