Adaptation of hypothalamic CRH neuron responses to stress and pup cues during motherhood.

Over the past two decades, interventions targeting malaria vectors have been scaled up, leading to significant declines in global malaria morbidity and mortality []. One of the most widely implemented vector control strategies is the distribution of long-lasting insecticidal nets (LLINs), with approximately 181 million LLINs delivered to malaria endemic regions in 2024 []. Since LLINs are designed to retain their insecticidal properties for at least three years, mass distribution campaigns (MDCs) have been recommended to coincide with this timeframe [, ]. However, LLIN durability is often compromised under real-world conditions due to wear and tear, improper handling, and environmental factors [–]. Moreover, many LLINs are discarded and a significant proportion is given away or relocated between households and communities []. LLINs protect users from mosquito bites by creating a physical barrier and by killing or deterring mosquitoes that land on the net [, –], thus providing a household and community-level effect []. LLIN use is highly associated with individual access [–]. Periodic MDCs are expected to guarantee high LLIN coverage of access and use [], but studies analyzing post-MDC data reveal a significant and rapid decrease in LLIN access [, ]. Some possible reasons for this lack of retention of distributed nets include poor knowledge of the health risks posed by malaria and low perception of the protective benefits of LLINs [–]. Since 2015, vector control on Bioko Island has relied heavily on LLINs and indoor residual spraying (IRS). Two island-wide MDCs took place in 2015 and 2018, respectively, observing the 3-year interval recommendation. These were door-to-door MDCs, meaning that campaign field workers targeted every active household on the island to provide enough LLINs to serve all residents. The LLINs distributed were PermaNet 3.0 (Adiwara) in 2015 and Olyset Plus (Sumitomo Chemical) in 2018. Each campaign successfully reached around 90% of the island population, with 149 thousand and 156 thousand LLINs distributed to 60,810 and 63,149 households in 2015 and 2018, respectively []. Both MDCs were resource intensive, with around 90 field workers deployed for almost 150 workdays. However, between a third to almost half the nets were lost between 3 and 5 months after each distribution and numbers continued to decline in subsequent years []. Thus, Bioko presents an example where the gap between access and use is substantial despite having guaranteed access, suggesting behavioral factors are at play [, ]. These persistent challenges prompted a critical evaluation of distribution strategies, including a shift from door-to-door MDCs toward fixed distribution points [].