Spatial distribution and period of activity of the forest elephant (Loxodonta africana cyclotis) at Taï National Park, south western Côte d'Ivoire

Objective: This study aims at determining the spatial distribution and  period of activities of the forest elephant (Loxodonta africana cyclotis) at Taï National Park (TNP) to contribute to its conservation.Methodology and results: Observations of elephants at different locations and time periods were recorded by using 87 camera traps with date and time-stamped settings. Cameras were installed following a systematic placement approach, and their geographic coordinates were recorded using a GPS. After 120 days of trapping, we observed a high concentration of activities in the southern areas of the park. For the period of activities, we noted that observations of unit individuals were recurrent during the day while those of elephant groups were more important at night.Conclusion and application of the results: The south of the park where  there is a large distribution of elephants would be more favourable to these animals. The small number and remoteness of large cities on the periphery of this area of the park could explain that pattern. The distribution and activity period information is useful for park surveillance by rangers. In addition, further studies are needed for a better explanation on the distribution pattern of elephants at TNP.Key words: Taï National Park, elephant, camera traps, distribution, activity period

The role of human and mosquito behaviour in the efficacy of a house-based intervention : Lethal House Lure for Malaria Mosquitoes

Housing improvement such as blocking eaves and screening windows can help in reducing exposure to indoor biting mosquitoes. The impacts of physical barriers could potentially be boosted by the addition of a mechanism that kills mosquitoes as they attempt to enter the house. One example is to combine household screening with EaveTubes, which are insecticide-treated tubes inserted into closed eaves that attract and kill host-searching mosquitoes. The epidemiological impact of screening + EaveTubes is being evaluated in a large cluster randomized trial in Cote d'Ivoire. The study presented here is designed as a complement to this trial to help better understand the functional roles of screening and EaveTubes. We began by evaluating householder behaviour and household condition in the study villages. This work revealed that doors (and to some extent windows) were left open for large parts of the evening and morning, and that even houses modified to make them more 'mosquito proof' often had possible entry points for mosquitoes. We next built two realistic experimental houses in a village to enable us to explore how these aspects of behaviour and household quality affected the impact of screening and EaveTubes. We found that screening could have a substantial impact on indoor mosquito densities, even with realistic household condition and behaviour. By contrast, EaveTubes had no significant impact on indoor mosquito density, either as a stand-alone intervention or in combination with screening. However, there was evidence that mosquitoes recruited to the EaveTubes, and the resulting mortality could create a community benefit. These complementary modes of action of screening and EaveTubes support the rationale of combining the technologies to create a 'Lethal House Lure'. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'

Biochemical characterization of juices from three wild fruit species consumed in Côte d’Ivoire "Adansonia digitata, Parkia biglobosa and Tamarindus indica"

In the context of the valorization and the development of local products in Côte d’Ivoire, this study is based on juices samples prepared from the pulp of wild fruits of Baobab (Adansonia digitata), Tomi (Tamarindus indica) and Néré (Parkia biglobosa). The physiochemical characteristics such as dry matter (desiccation, 105°C), mineral (spectrophotometer), ash, fat, fiber and protein (AOAC), Energy (coefficients), vitamins A & C (HPLC), organic acids & total polyphenols (HPLC), carbohydrate (by difference), pH and titratable acidity (titrimetry, NaOH) of pasteurized juices (75°C, 5 min) were investigated. Data showed that the juices have been characterized by low protein (0.21-0.28 %), fat (0.26-0.65 %) and ash (0.20-0.47 %) content and high level of total carbohydrates (21-30 %) and energy (85.83-124.43 Kcal/100mL). Baobab and Tomi juices were distinguished by their high acidity (103-159 meq.g / Kg) while Baobab and Néré juices were characterized by their average fiber content (4-5.30 %). The juices of Baobab, Tomi and Néré are very rich in some minerals (K and Mg) but calcium (Ca) and iron (Fe) are not bioavailable (Oxales/Ca and Oxalates/Fe > 2). The juice of baobab is rich in vit A (80 mg/100mL) and vit C (189 mg/100mL) than the others juices. Catechin was the most phenolic content (52.29-110.32 mg/100mL) where tartric acid was the most organic acid (4.02-6.82 mg/100mL) in the juices. The knowledge of the nutritional value of these juices could contribute to a better understanding of the essential role of these three wild fruits in terms of food and trade

Screening and field performance of powder-formulated insecticides on eave tube inserts against pyrethroid resistant Anopheles gambiae s.l.:an investigation into 'actives' prior to a randomized controlled trial in Côte d'Ivoire

BACKGROUND: The widespread emergence of insecticide resistance in African malaria vectors remains one of the main challenges facing control programmes. Electrostatic coating that uses polarity to bind insecticide particles is a new way of delivering insecticides to mosquitoes. Although previous tests demonstrated the resistance breaking potential of this application method, studies screening and investigating the residual efficacy of a broader range of insecticides are necessary. METHODS: Eleven insecticide powder formulations belonging to six insecticide classes (pyrethroid, carbamate, organophosphate, neonicotinoid, entomopathogenic fungus and boric acid) were initially screened for residual activity over 4 weeks against pyrethroid resistant Anopheles gambiae sensu lato (s.l.) from the M'bé valley, central Côte d'Ivoire. Tests were performed using the eave tube assay that simulates the behavioural interaction between mosquitoes and insecticide-treated inserts. With the best performing insecticide, persistence was monitored over 12 months and the actual contact time lethal to mosquitoes was explored, using a range of transient exposure time (5 s, 30 s, 1 min up to 2 min) in the tube assays in laboratory. The mortality data were calibrated against overnight release-recapture data from enclosure around experimental huts incorporating treated inserts at the M'bé site. The natural recruitment rate of mosquitoes to the tube without insecticide treatment was assessed using fluorescent dust particles. RESULTS: Although most insecticides assayed during the initial screening induced significant mortality (45-100%) of pyrethroid resistant An. gambiae during the first 2 weeks, only 10% beta-cyfluthrin retained high residual efficacy, killing 100% of An. gambiae during the first month and > 80% over 8 subsequent months. Transient exposure for 5 s of mosquitoes to 10% beta-cyfluthrin produced 56% mortality, with an increase to 98% when contact time was extended to 2 min (P = 0.001). In the experimental hut enclosures, mortality of An. gambiae with 10% beta-cyfluthrin treated inserts was 55% compared to similar rate (44%) of mosquitoes that contacted the inserts treated with fluorescent dusts. This suggests that all host-seeking female mosquitoes that contacted beta-cyfluthrin treated inserts during host-seeking were killed. CONCLUSION: The eave tube technology is a novel malaria control approach which combines house proofing and targeted control of anopheline mosquitoes using insecticide treated inserts. Beta-cyfluthrin showed great promise for providing prolonged control of pyrethroid resistant An. gambiae and has potential to be deployed year-round in areas where malaria parasites are transmitted by highly pyrethroid resistant An. gambiae across sub-Saharan Africa

Assessing the variability in experimental hut trials evaluating insecticide-treated nets against malaria vectors.

Experimental hut trials (EHTs) are used to evaluate indoor vector control interventions against malaria vectors in a controlled setting. The level of variability present in the assay will influence whether a given study is well powered to answer the research question being considered. We utilised disaggregated data from 15 previous EHTs to gain insight into the behaviour typically observed. Using simulations from generalised linear mixed models to obtain power estimates for EHTs, we show how factors such as the number of mosquitoes entering the huts each night and the magnitude of included random effects can influence study power. A wide variation in behaviour is observed in both the mean number of mosquitoes collected per hut per night (ranging from 1.6 to 32.5) and overdispersion in mosquito mortality. This variability in mortality is substantially greater than would be expected by chance and should be included in all statistical analyses to prevent false precision of results. We utilise both superiority and non-inferiority trials to illustrate our methodology, using mosquito mortality as the outcome of interest. The framework allows the measurement error of the assay to be reliably assessed and enables the identification of outlier results which could warrant further investigation. EHTs are increasingly playing an important role in the evaluation and regulation of indoor vector control interventions so it is important to ensure that these studies are adequately powered. [Abstract copyright: © 2023 The Authors.

The Effect of Climate Fluctuation on Chimpanzee Birth Sex Ratio

Climate and weather conditions, such as the North Atlantic Oscillation, precipitation and temperature influence the birth sex ratio (BSR) of various higher latitude species, including deer, elephant seals or northern human populations. Although, tropical regions show only little variation in temperature, climate and weather conditions can fluctuate with consequences for phenology and food resource availability. Here, we evaluate, whether the BSR of chimpanzees, inhabiting African tropical forests, is affected by climate fluctuations as well. Additionally, we evaluate, if variation in consumption of a key food resource with high nutritional value, Coula edulis nuts, is linked to both climate fluctuations and variation in BSR. We use long-term data from two study groups located in Taï National Park, Côte d'Ivoire to assess the influence of local weather conditions and the global climate driver El Niño Southern Oscillation (ENSO) on offspring sex. Côte d'Ivoire has experienced considerable climate variation over the last decades, with increasing temperature and declining precipitation. For both groups we find very similar time windows around the month of conception, in which offspring sex is well predicted by ENSO, with more males following low ENSO values, corresponding to periods of high rainfall. Furthermore, we find that the time spent cracking and feeding on Coula nuts is strongly influenced by climate conditions. Although, some of our analysis suggest that a higher proportion of males is born after periods with higher nut consumption frequency, we cannot conclude decisively at this point that nut consumption may influence shifts in BSR. All results combined suggest that also chimpanzees may experience climate related shifts in offspring sex ratios as response to climate fluctuation

Aging partially restores the efficacy of malaria vector control in insecticide-resistant populations of Anopheles gambiae s.l. from Burkina Faso

<br>Background: The operational impact of insecticide resistance on the effectiveness of long-lasting insecticide nets (LLINs) and indoor residual spraying (IRS) is poorly understood. One factor which may prolong the effectiveness of these tools in the field is the increase in insecticide susceptibility with mosquito age. In this study, LLINs and IRS were tested against young (three to five days) and old (17-19 days) pyrethroid resistant Anopheles gambiae s.l. from Burkina Faso.</br> <br>Methods: Blood-fed adult Anopheles gambiae s.l. were collected from south-west Burkina Faso and identified to species/form level. Cohorts of the F1 progeny of An. gambiae s.s. S-forms were exposed to deltamethrin (0.05%) at three to five or 17-19 days post-emergence and tested for the frequency of the resistance allele 1014F. Isofemale lines of the M, S- form of An. gambiae s.s. and Anopheles arabiensis were exposed in WHO cone tests to either a) LLINs deployed in households for two years or (b) bendiocarb sprayed walls.</br> <br>Results: Mortality rates in response to deltamethrin (0.05%) increased from levels indicative of strong resistance in three to five day old F1 mosquitoes, to near full susceptibility in the 17-19 day old cohort. On exposure to LLINs sampled from the field, the mortality rate in isofemale lines was higher in older mosquitoes than young (OR = 5.28, CI 95% = 2.81-9.92), although the mortality estimates were affected by the LLIN tested. In general, the LLINs sampled from the field performed poorly in WHO cone bioassays using either laboratory susceptible or field caught mosquito populations. Finally, there was a clear relationship between mortality and age on exposure to bendiocarb-sprayed walls, with older mosquitoes again proving more susceptible (OR = 3.39, CI 95% = 2.35-4.90).</br> <br>Conclusions: Age is a key factor determining the susceptibility of mosquitoes to insecticides, not only in laboratory studies, but in response to field-based vector control interventions. This has important implications for understanding the epidemiological impact of resistance. If mosquitoes old enough to transmit malaria are still being suppressed with available insecticides, is resistance potentially having less of an impact than often assumed? However, the poor performance of LLINs used in this study in Burkina Faso, is a cause for concern and requires urgent investigation.</br&gt

Optimising the deployment of vector control tools against malaria: a data-informed modelling study

Background Concern that insecticide resistant mosquitoes are threatening malaria control has driven the development of new types of insecticide treated nets (ITNs) and indoor residual spraying (IRS) of insecticide. Malaria control programmes have a choice of vector control interventions although it is unclear which controls should be used to combat the disease. The study aimed at producing a framework to easily compare the public health impact and cost-effectiveness of different malaria prevention measures currently in widespread use. Methods We used published data from experimental hut trials conducted across Africa to characterise the entomological effect of pyrethroid-only ITNs versus ITNs combining a pyrethroid insecticide with the synergist piperonyl butoxide (PBO). We use these estimates to parameterise a dynamic mathematical model of Plasmodium falciparum malaria which is validated for two sites by comparing simulated results to empirical data from randomised control trials (RCTs) in Tanzania and Uganda. We extrapolated model simulations for a series of potential scenarios likely across the sub-Saharan African region and include results in an online tool (Malaria INtervention Tool [MINT]) that aims to identify optimum vector control intervention packages for scenarios with varying budget, price, entomological and epidemiological factors. Findings Our model indicates that switching from pyrethroid-only to pyrethroid-PBO ITNs could averted up to twice as many cases, although the additional benefit is highly variable and depends on the setting conditions. We project that annual delivery of long-lasting, non-pyrethroid IRS would prevent substantially more cases over 3-years, while pyrethroid-PBO ITNs tend to be the most cost-effective intervention per case averted. The model was able to predict prevalence and efficacy against prevalence in both RCTs for the intervention types tested. MINT is applicable to regions of sub-Saharan Africa with endemic malaria and provides users with a method of designing intervention packages given their setting and budget. Interpretation The most cost-effective vector control package will vary locally. Models able to recreate results of RCTs can be used to extrapolate outcomes elsewhere to support evidence-based decision making for investment in vector control

P7 Etude descriptive de la réglementation des substituts du lait maternel en Côte d’Ivoire

Introduction : La réglementation des substituts du lait maternel (SLM) relève d’une importance capitale pour la santé du nourrisson avec un impact sur sa santé à l’âge adulte. L’objectif de notre étude était de décrire la réglementation des SLM en Côte d’Ivoire. Méthodologie : Nous avons réalisé une étude transversale à visée descriptive qui a porté sur les textes juridiques communautaires et nationaux applicables aux produits de santé en Côte d’Ivoire. Nous nous sommes particulièrement intéressés à la loi n°2015-533 relative à l’exercice de la pharmacie, aux arrêtés interministériels n° 687, 688 et 689 MSHPCMU/MCI/MFFE du 02 août 2021 portant sur les SLM et la Décision n°4/2022/UEMOA portant sur la même matière. Résultats : La commercialisation des SLM a été incluse dans le monopole pharmaceutique par la loi n°2015-533 rendue applicable en cet aspect par trois arrêtés interministériels de 2021. La Décision n°4/2022/UEMOA s’étend en plus des SLM, aux produits diététiques et de régime. Ces produits sont homologués selon un schéma semblable aux médicaments à usage humain avec une analyse administrative, une analyse technique et la délivrance de l’Autorisation de Commercialisation par l’Autorité de Réglementation Pharmaceutique après avis d’une commission spécialisée. La   délivrance des SLM répond à une prescription des professionnels de santé. Même si la publicité de ces substituts est interdite, le matériel d’information doit porter des renseignements clairs, notamment sur les avantages et la supériorité du lait maternel. De plus, la Décision n°4/2022/UEMOA prend en compte le contrôle de la fabrication, de l’importation et de la qualité ; et met en place d’un système national de surveillance des SLM. Conclusion : La réglementation des SLM applicable en Côte d’Ivoire couvre toutes les étapes de la chaîne d’approvisionnement de ces produits et constitue une formidable opportunité de promotion de l’allaitement maternel dans l’espace UEMO