Efficacy of ICON® Maxx in the laboratory and against insecticide-resistant Anopheles gambiae in central Côte d'Ivoire

ABSTRACT: BACKGROUND: Long-lasting treatment kits, designed to transform untreated nets into long-lasting insecticidal nets (LLINs), may facilitate high coverage with LLINs where non-treated nets are in place. In this study, the efficacy of ICON(R) Maxx (Syngenta) was evaluated under laboratory conditions and in an experimental hut trial in central Cote d'Ivoire, where Anopheles gambiae s.s. are resistant to pyrethroid insecticides. METHODS: In the laboratory, polyester and polyethylene net samples were treated with ICON(R) Maxx, washed up to 20 times and their efficacy determined in World Health Organization (WHO) cone assays against a susceptible laboratory An. gambiae s.s. colony. Over a 12-month period, the polyester nets were evaluated in a hut trial to determine mosquito deterrence, induced exophily, blood-feeding inhibition and mortality. RESULTS: In the laboratory, ICON(R) Maxx-treated polyethylene nets showed higher efficacy against pyrethroid-susceptible mosquitoes than polyester nets. After 20 washings, insecticidal efficacy in bioassays was 59.4% knockdown (KD) and 22.3% mortality for polyethylene, and 55.3% KD and 17.9% mortality for polyester nets. In experimental huts, treated nets showed strong deterrence, induced exophily and an over three-fold reduction in blood-fed mosquitoes. More than half (61.8%) of the mosquitoes entering the huts with treated nets were found dead the next morning despite high levels of KD resistance. After washing the treated nets, KD and mortality rates were close to or exceeded predefined WHO thresholds in cone bioassays. CONCLUSION: In contrast to previous laboratory investigation, ICON(R) Maxx-treated nets showed only moderate KD and mortality rates. However, under semi-field conditions, in an area where mosquitoes are resistant to pyrethroids, ICON(R) Maxx showed high deterrence, induced exophily and provided a significant reduction in blood-feeding rates; features that are likely to have a positive impact in reducing malaria transmission. The WHO cone test may not always be a good proxy for predicting product performance under field condition

Micro-encapsulated pirimiphos-methyl shows high insecticidal efficacy and long residual activity against pyrethroid-resistant malaria vectors in central Côte d'Ivoire

The wide-scale implementation of insecticide-treated nets and indoor residual spraying (IRS) has contributed to a considerable decrease of malaria morbidity and mortality in sub-Saharan Africa over the last decade. Due to increasing resistance in Anopheles gambiae sensu lato mosquitoes to dichlorodiphenyl trichloroethane (DDT) and pyrethroids, alternative insecticide formulations for IRS with long-lasting residual activity are required to sustain the gains obtained in most malaria-endemic countries.; Three experimental capsule suspension (CS) formulations of the organophosphate pirimiphos-methyl were evaluated together with Actellic 50 EC, an emulsifiable concentrate (EC) of pirimiphos-methyl, and the pyrethroid ICON 10 CS, a lambda-cyhalothrin CS formulation, in an experimental hut trial. The formulations were tested on two types of surfaces: mud and cement. The study with a 12-month follow-up was carried out in Bouaké, central Côte d'Ivoire, where An. gambiae mosquitoes show high levels of resistance against pyrethroids, DDT and carbamates. Residual activity was also tested in cone bioassays with the susceptible An. gambiae KISUMU strain.; One of the CS formulations of pirimiphos-methyl, CS BM, outperformed all other formulations tested. On cement surfaces, the odds ratios of overall insecticidal effect on An. gambiae s.l. of pirimiphos-methyl CS BM compared to Actellic 50 EC were 1.4 (95% confidence interval (CI): 1.2-1.7) for the first three months, 5.6 (95% CI: 4.4-7.2) for the second three months, and 3.6 (95% CI: 3.0-4.4) for the last six months of follow-up. On mud surfaces, the respective odds ratios were 2.5 (95% CI: 1.9-3.3), 3.5 (95% CI: 2.7-4.5), and 1.7 (95% CI: 1.4-2.2). On cement, the residual activity of pirimiphos-methyl CS BM measured using cone tests was similar to that of lambda-cyhalothrin and for both treatments, mortality of susceptible Kisumu laboratory strain was not significantly below the World Health Organization pre-set threshold of 80% for 30 weeks after spraying. Residual activity was shorter on mud surfaces, mortality falling below 80% on both pirimiphos-methyl CS BM and lambda-cyhalothrin treated surfaces at 25 weeks post-treatment.; CS formulations of pirimiphos-methyl are promising alternatives for IRS, as they demonstrate prolonged insecticidal effect and residual activity against malaria mosquitoes

Barriers and facilitators to mobility of patients hospitalised on an acute medical ward: a systematic review.

BACKGROUND low patient mobility is common during hospitalisation and is associated with adverse outcomes. To change practice, interventions should address barriers and facilitators to mobility. Our aim was to systematically review the literature to provide a synthesised overview of patient-, health care professional (HCP)- and environment-/system-related barriers and facilitators to mobility of patients hospitalised on an acute care medical ward. METHODS we searched Medline, Embase, PsycInfo, Web of Science Core Collection, Cochrane CENTRAL, CINHAHL and Google Scholar (inception to 18 October 2021) to identify studies reporting barriers and/or facilitators to mobility of adults hospitalised on an acute medical ward. We applied a deductive and inductive thematic analysis to classify barriers and facilitators into themes and subthemes relevant for clinical practice. RESULTS among 26 studies (16 qualitative, 7 quantitative and 3 mixed methods), barriers and facilitators were categorised into 10 themes: patient situation, knowledge, beliefs, experiences, intentions, emotions, social influences, role/identity, implementation/organisation and environment/resources. Barriers included patient characteristics (e.g. impaired cognitive/physical status) and symptoms, HCPs prioritising other tasks over mobility, HCPs labelling patients as 'too sick', fear of injury, lack of time, lack of clarity about responsibility, patient medical devices and non-encouraging environment. Facilitators included knowledge of mobility importance, HCP skills, interdisciplinarity, documentation and unit expectations, encouraging staff, goal individualisation, activity programme, family/visitor/volunteer support and availability of equipment. CONCLUSION this synthesised overview of patient-, HCP- and environment-/system-related barriers and facilitators to mobility of adults hospitalised on an acute medical ward can help researchers and clinicians focus on what can realistically be influenced to improve mobility. SYSTEMATIC REVIEW REGISTRATION PROSPERO, CRD42021285954

Effect of nutritional support in patients with lower respiratory tract infection: Secondary analysis of a randomized clinical trial.

BACKGROUND In polymorbid patients with bronchopulmonary infection, malnutrition is an independent risk factor for mortality. There is a lack of interventional data investigating whether providing nutritional support during the hospital stay in patients at risk for malnutrition presenting with lower respiratory tract infection lowers mortality. METHODS For this secondary analysis of a randomized clinical trial (EFFORT), we analyzed data of a subgroup of patients with confirmed lower respiratory tract infection from an initial cohort of 2028 patients. Patients at nutritional risk (Nutritional Risk Screening [NRS] score ≥3 points) were randomized to receive protocol-guided individualized nutritional support to reach protein and energy goals (intervention group) or standard hospital food (control group). The primary endpoint of this analysis was all-cause 30-day mortality. RESULTS We included 378 of 2028 EFFORT patients (mean age 74.4 years, 24% with COPD) into this analysis. Compared to usual care hospital nutrition, individualized nutritional support to reach caloric and protein goals showed a similar beneficial effect of on the risk of mortality in the subgroup of respiratory tract infection patients as compared to the main EFFORT trial (odds ratio 0.47 [95%CI 0.17 to 1.27, p = 0.136] vs 0.65 [95%CI 0.47 to 0.91, p = 0.011]) with no evidence of a subgroup effect (p for interaction 0.859). Effects were also similar among different subgroups based on etiology and type of respiratory tract infection and for other secondary endpoints. CONCLUSION This subgroup analysis from a large nutrition support trial suggests that patients at nutritional risk as assessed by NRS 2002 presenting with bronchopulmonary infection to the hospital likely have a mortality benefit from individualized inhospital nutritional support. The small sample size and limited statistical power calls for larger nutritional studies focusing on this highly vulnerable patient population. CLINICAL TRIAL REGISTRATION Registered under ClinicalTrials.gov Identifier no. NCT02517476