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Background: After almost 70 years of using indoor residual spraying (IRS) as the primary intervention for malaria vector control, the Republic of Panama wanted to evaluate the operational feasibility and acceptability of distributing long-lasting insecticidal hammock nets (LLIHNs) and long-lasting insecticidal nets (LLINs) in the country., Methods: A pilot study conducted in 2019 distributed LLINs and LLIHNs to cover all sleeping spaces in 15 high burden localities of the indigenous Comarca of Guna Yala and measured retention, coverage, use and physical deterioration, washing and drying practices, as well as people's satisfaction with product characteristics post-distribution., Results: Overall, 89.9% of enumerated sleeping spaces were covered during the campaign. Monitoring post-distribution showed that 82.7% of the population received messages about the campaign before it happened and 92.4% claimed to know the purpose of the net and how to care for and repair it. Mild adverse reactions, specifically skin irritation associated with the insecticide in LLINs and LLIHNs, were reported by 38.4% of households. Two years after distribution, 86.3% of the LLIHN/LLINs were retained. Use was very high right after distribution (85%) but decreased to 57% six months after distribution and to 38% two years after distribution. The main reason for not using the LLIHN/LLINs was the reported absence of mosquitoes. Two years post-distribution, LLIHN/LLINs were preserved in good physical condition (4% torn), very few were washed with insecticide-damaging products (chlorine or detergent) (9%) or dried under the sun (15%), and LLIHN/LLINs were washed on average less than once every two months. The average number of people per sleeping space was 1.34., Conclusion: Although the distribution of LLIHN/LLINs was operationally feasible and LLIHN/LLINs were initially well-accepted and cared for by these communities, use decreased drastically over the two years of follow up after distribution. Hence, should there be future LLIHN/LLIN distributions in this area, sufficient resources and efforts need to be allocated to promoting LLIHN/LLIN use. Further investigation into the reasons for low LLIHN/LLIN use are needed to guide such efforts., Competing Interests: Declarations. Ethics approval and consent to participants: This pilot introduction of LLIHN/LLIN was led by the vector-borne disease department of the Ministry of Health and implemented as programmatic data collection and program evaluation. Participants’ verbal consent was obtained before the household surveys. The data collected during this pilot introduction of LLIHN/LLIN is safely stored in the Ministry of Health official malaria data repository and is only accessible to the Ministry of Health staff and certain staff from the Clinton Health Access Initiative that supported this project. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Background: Although most of Panamá is free from malaria, localized foci of transmission persist, including in the Guna Yala region. Government-led entomological surveillance using an Entomological Surveillance Planning Tool (ESPT) sought to answer programmatically relevant questions on local entomological drivers of transmission and gaps in protection to guide local vector control decision-making., Methods: The ESPT was used to design a sampling plan to answer priority programmatic questions about the appropriateness of Long Lasting Insecticidal Nets (LLINs) and spaces and times where humans remain exposed to Anopheles bites (gaps in protection) in the communities of Permé and Puerto Obaldía, Guna Yala. Adult Anopheles were sampled at three time points via human landing catches (HLCs) during the rainy and dry seasons (2018/2019). Human behaviour observations (HBOs) were conducted alongside HLCs to examine intervention use, indoor versus outdoor activity, and sleeping patterns. HLC and HBO data were integrated to evaluate HBO-adjusted human biting rate (HBR)., Results: A total of 7,431 adult Anopheles were collected across both sites. Of the 450 specimens molecularly confirmed to species-level, 75.5% (n = 340) were confirmed as Anopheles Nyssorhynchus albimanus, followed by Anopheles (Ny.) aquasalis. Anopheles host seeking activity was demonstrated to be primarily exophagic throughout all sampling periods and in both communities. When adjusted with HBOs, exposure to mosquito bites was predominantly indoors and overnight in Permé (Nov, Mar), compared to predominantly outdoors in Puerto Obaldía (Nov, Mar, Jul). Differences in site-specific human-vector exposure profiles were due to contrasting cultural and lifestyle practices between Permé and Puerto Obaldía (possibly partly influenced by the absence of electricity in Permé), and lower LLIN use in Permé. This evidence supported a previously planned LLIN campaign alongside a social behaviour change communication (SBCC) strategy in the Guna Yala Comarca (Jul 2019), which increased LLIN use. In turn, this led to a reduction of indoor exposure to mosquito bites, and a shift to predominant outdoor exposure to mosquito bites., Conclusion: ESPT-based question-driven planning and the integration of HBOs, intervention, and HLC data generated evidence towards answering the programmatic questions. This evidence enabled the characterization of site-specific human-vector exposure profiles, and the quantification of remaining gaps in protection. These data also provide important insights into remaining gaps in protection that must be addressed to further reduce human exposure to mosquito bites at these sites., (© 2023. The Author(s).)

Background: Though most of Panamá is free from malaria, localized foci of transmission persist, including in the Guna Yala region. Government-led entomological surveillance using an entomological surveillance planning tool (ESPT) sought to answer programmatically-relevant questions that would enhance the understanding of both local entomological drivers of transmission and gaps in protection that result in persisting malaria transmission to guide local vector control decision-making., Methods: The ESPT was used to design a sampling plan centered around the collection of minimum essential indicators to investigate the relevance of LLINs and IRS in the communities of Permé and Puerto Obaldía, Guna Yala, as well as to pinpoint any remaining spaces and times where humans are exposed to Anopheles bites (gaps in protection). Adult Anopheles were collected at three time points via human landing catches (HLCs), CDC Light Traps (LT), and pyrethrum spray catches (PSCs) during the rainy and dry seasons. Mosquitoes were identified to species via molecular methods. Insecticide susceptibility testing of the main vector species to fenitrothion was conducted., Results: In total, 7537 adult Anopheles were collected from both sites. Of the 493 specimens molecularly confirmed to species, two thirds (n = 340) were identified as Nyssorhynchus albimanus, followed by Anopheles aquasalis. Overall Anopheles human biting rates (HBRs) were higher outdoors than indoors, and were higher in Permé than in Puerto Obaldía: nightly outdoor HBR ranged from 2.71 bites per person per night (bpn) (Puerto Obaldía), to 221.00 bpn (Permé), whereas indoor nightly HBR ranged from 0.70 bpn (Puerto Obaldía) to 81.90 bpn (Permé). Generally, peak biting occurred during the early evening. The CDC LT trap yields were significantly lower than that of HLCs and this collection method was dropped after the first collection. Pyrethrum spray catches resulted in only three indoor resting Anopheles collected. Insecticide resistance (IR) of Ny. albimanus to fenitrothion was confirmed, with only 65.5% mortality at the diagnostic time., Conclusion: The early evening exophagic behaviour of Anopheles vectors, the absence of indoor resting behaviours, and the presence of resistance to the primary intervention insecticide demonstrate limitations of the current malaria strategy, including indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs), and point to both gaps in protection and to the drivers of persisting malaria transmission in Guna Yala. These findings highlight the need for continued and directed entomological surveillance, based on programmatic questions, that generates entomological evidence to inform an adaptive malaria elimination strategy., (© 2021. The Author(s).)