Dosage du plomb et du cadmium dans le sperme des sujets consultant pour infertilité masculine dans la ville de Cotonou

La diminution de la concentration des paramètres d’appréciation du sperme a soulevé le problème de la fertilité des hommes. La pollution de l’environnement est incriminée en grande partie dans cette infertilité. Dans la ville de Cotonou (BENIN), nous avons recherché au cours de la présente étude les effets du plomb et du cadmium sur la fertilité masculine. Ces métaux lourds toxiques n’ont aucune utilité pour l’organisme et perturbent le système de reproduction entrainant une infertilité du couple. Dans le cadre de cette étude, nous avons étudié en deux phases le sperme de 27 sujets qui souffrent d’une infertilité masculine dans la ville de Cotonou. La première phase a consisté à faire le bilan de l’infertilité masculine sur le sperme des 27 sujets qui ont fait l’objet de notre étude. Quant à la seconde phase, nous avons dosé par Spectrophotométrie d’Absorption Atomique le plomb et le cadmium dans 10 échantillons de sperme de volume supérieur à 2 g. Les résultats ont montré que 7 des 10 échantillons de sperme ont accumulé le cadmium à des concentrations différentes. Par contre, les teneurs en plomb des échantillons de sperme étaient inférieures à la limite de détection de l’appareil pour le plomb. Mais aucune relation significative n’a pu être démontrée entre les teneurs en cadmium et les anomalies observées. Toutefois, on peut soupçonner que la présence de cadmium dans le sperme, même à un taux infirme, serait responsable des Anomalies observées.Mots clés: Fertilité, Plomb, Cadmium, Spermatozoïde

Field Durability of <i>Yorkool<sup>®</sup>LN</i> Nets in the Benin Republic

CONTEXT: Recent publications on WHO recommended methods for estimating the survival of LLINs are good guidelines for assessing the performance of long-lasting insecticidal nets (LLINs). Thus, this field trial study was undertaken to evaluate the durability of the Yorkool® LN mosquito net distributed during the 2017 campaign in Benin. METHODS: The monitoring of Yorkool® LN nets was carried out in two districts (Djougou III and Barienou) in Djougou, department of Donga, northern Benin from October 2017 to March 2019. A representative sample of 250 households that had received the Yorkool® LN polyester LLINs during the 2017 campaign was selected in the rural and urban areas of each district and monitored for 6, 12 and 18 months. An evaluation of the survival of Yorkool® LN nets was conducted based on the rate of loss and physical condition of the surviving nets as measured by the proportional hole index (pHI). Finally, the chemical efficacy of these LLINs during each period was determined using the WHO cone tests. RESULTS: Survival of Yorkool® LN nets was similar in both rural and urban areas, although there was a difference in survival between the 6-month (95.3%), 12-month (89.7%), and 18-month follow-up periods (74.4%). A difference in survival was also observed between the NetCalc model (84%) compared to the Yorkool® LN nets of this study (74.4%). The attrition rate was 29.6% for LLINs at 18 months. Surprisingly, the physical integrity of the LLINs was minimally affected in the municipality. Indeed, the proportion of mosquito nets in good condition without a hole was 51.8% compared to 56.8% with a hole after 18 months. Only 7.8% of the LLINs in the two districts were damaged compared to 2.6% which needed to be replaced. The washing frequency, location of the LLINs and the frequency of use are some factors contributing to the appearance of the holes in LLINs. The bio-efficacy results of LLINs based on the cone test were good with mortality rates of 74%, 66%, 72% and 58% respectively after baseline, 6, 12 and 18 months of use. CONCLUSIONS: The observed differences in the survival of Yorkool® LN nets are due to community living conditions and movements and not to the equipment used to manufacture LLINs. However, the estimated median survival has shown that Yorkool® LN nets would have an average lifespan of 2 years 8 months despite their fairly good physical condition. These results may be useful to the National Malaria Control Program (NMCP) during the period of replacement of these nets on the field

Service selection in networks based on proximity confirmation using infrared

There are protocols that can be used by mobile clients to discover service providers in foreign networks to which they get attached, e.g. SDP of Bluetooth and SLP of IETF. These protocols do address service discovery, but do not address the selection of a service provider among a set of candidates according to physical proximity of the client and service provider. The goal of the research described in this paper is to integrate proximity-based selection mechanisms to service discovery protocols. We present in this paper protocols that allow nomadic clients to discover and select service providers according to physical proximity

Indoor Ad Hoc Proximity-Location Sensing for Service Provider Selection

There are protocols that can be used by mobile clients to discover service providers in foreign networks to which they get attached, e.g., SDP of Bluetooth and SLP of IETF. These protocols do address service discovery, but do not address the selection of a service provider among a set of candidates according to a physical proximity of the client and service provider. The goal of the research described in this paper is to integrate proximity-based selection mechanisms to service discovery protocols. We present in this paper protocols that allow nomadic clients to discover and select service providers according to physical proximity

Impact of Insecticide Resistance on the Effectiveness of Pyrethroid-Based Malaria Vectors Control Tools in Benin: Decreased Toxicity and Repellent Effect.

Since the first evidence of pyrethroids resistance in 1999 in Benin, mutations have rapidly increased in mosquitoes and it is now difficult to design a study including a control area where malaria vectors are fully susceptible. Few studies have assessed the after effect of resistance on the success of pyrethroid based prevention methods in mosquito populations. We therefore assessed the impact of resistance on the effectiveness of pyrethroids based indoor residual spraying (IRS) in semi-field conditions and long lasting insecticidal nets (LLINs) in laboratory conditions. The results observed showed low repulsion and low toxicity of pyrethroids compounds in the test populations. The toxicity of pyrethroids used in IRS was significantly low with An. gambiae s.l (< 46%) but high for other predominant species such as Mansonia africana (93% to 97%). There were significant differences in terms of the repellent effect expressed as exophily and deterrence compared to the untreated huts (P<0.001). Furthermore, mortality was 23.71% for OlyseNet® and 39.06% for PermaNet®. However, with laboratory susceptible "Kisumu", mortality was 100% for both nets suggesting a resistance within the wild mosquito populations. Thus treatment with pyrethroids at World Health Organization recommended dose will not be effective at reducing malaria in the coming years. Therefore it is necessary to study how insecticide resistance decreases the efficacy of particular pyrethroids used in pyrethroid-based vector control so that a targeted approach can be adopted

Microdistribution of the resistance of malaria vectors to deltamethrin in the region of Plateau (southeastern Benin) in preparation for an assessment of the impact of resistance on the effectiveness of Long Lasting Insecticidal Nets (LLINs)

Background: This study aims to research two areas, one with a resistant and the other with a susceptible profile of An. gambiae to deltamethrin in the region of Plateau (southern Benin). In each area, eight localities were sought. Both areas were needed for the assessment of the impact of malaria vector resistance to pyrethroids on the effectiveness of Long Lasting Insecticidal Nets (LLINs). The susceptible area of An. gambiae to deltamethrin was used as a control. Methods: In total, 119 localities in the region of Plateau were screened by sampling An. gambiae s.l larvae. Female mosquitoes resulting from these larvae were exposed to 0.05% deltamethrin following WHO standards. PCR was used to identify species and molecular forms of the dead and alive mosquitoes. Finally, we identified kdr mutations (1014 F and 1014S) using the HOLA technique. Results: Fifty-six out of 119 prospected localities tested positive for Anopheles gambae s.l breeding sites. The results showed that An. gambiae was resistant to deltamethrin in 39 localities and susceptible in only 2 localities; resistance to deltamethrin was suspected in 15 localities. The HOLA technique confirmed the presence of kdr 1014 F mutation and the absence of kdr 1014S mutation. The kdr 1014 F mutation was found in both M and S molecular forms at relatively high frequencies therefore confirming the susceptibility tests. Conclusion: We were unable to identify the eight susceptible areas due to the overall resistance of An. gambiae to deltamethrin in the region of Plateau. To implement the study, we kept two areas, one with high resistance (R+++) and the other with low resistance (R+) of An. gambiae to deltamethrin