Evaluation of the Effectiveness of Malaria Vector Control Measures in Urban Settings of Dakar by a Specific Anopheles Salivary Biomarker

Standard entomological methods for evaluating the impact of vector control lack sensitivity in low-malaria-risk areas. The detection of human IgG specific to Anopheles gSG6-P1 salivary antigen reflects a direct measure of human–vector contact. This study aimed to assess the effectiveness of a range of vector control measures (VCMs) in urban settings by using this biomarker approach. The study was conducted from October to December 2008 on 2,774 residents of 45 districts of urban Dakar. IgG responses to gSG6-P1 and the use of malaria VCMs highly varied between districts. At the district level, specific IgG levels significantly increased with age and decreased with season and with VCM use. The use of insecticide-treated nets, by drastically reducing specific IgG levels, was by far the most efficient VCM regardless of age, season or exposure level to mosquito bites. The use of spray bombs was also associated with a significant reduction of specific IgG levels, whereas the use of mosquito coils or electric fans/air conditioning did not show a significant effect. Human IgG response to gSG6-P1 as biomarker of vector exposure represents a reliable alternative for accurately assessing the effectiveness of malaria VCM in low-malaria-risk areas. This biomarker tool could be especially relevant for malaria control monitoring and surveillance programmes in low-exposure/low-transmission settings.     

Epidemiology and Genetic Characterization of Measles Strains in Senegal, 2004-2013

BackgroundIn Senegal, with the variable routine vaccination coverage, the risk for illness and death from measles still exists as evidenced by the measles epidemic episode in 2009. Since 2002 a laboratory-based surveillance system of measles was established by the Ministry of Health and the Institut Pasteur de Dakar. The present study analysed the data collected over the 10 years inclusive between 2004-2013 in order to define a measles epidemiological profile in Senegal, and we carried out a phylogenetic analysis of measles virus circulating in Senegal over the period 2009-2012.ConclusionImprovements in the measles surveillance in Senegal are required and the introduction of oral fluid and FTA cards as an alternative to transportation of sera should be investigated to improve surveillance. The introduction of a national vaccine database including number of doses of measles-containing vaccine will greatly improve efforts to interrupt and ultimately eliminate measles virus transmission in Senegal.     

High Prevalence of Severe Food Insecurity and Malnutrition among HIV-Infected Adults in Senegal,West Africa

Background

Malnutrition and food insecurity are associated with increased mortality and poor clinical outcomes among people living with HIV/AIDS; however, the prevalence of malnutrition and food insecurity among people living with HIV/AIDS in Senegal, West Africa is unknown. The objective of this study was to determine the prevalence and severity of food insecurity and malnutrition among HIV-infected adults in Senegal, and to identify associations between food insecurity, malnutrition, and HIV outcomes.

Methods

We conducted a cross-sectional study at outpatient clinics in Dakar and Ziguinchor, Senegal. Data were collected using participant interviews, anthropometry, the Household Food Insecurity Access Scale, the Individual Dietary Diversity Scale, and chart review.

Results

One hundred and nine HIV-1 and/or HIV-2 participants were enrolled. The prevalence of food insecurity was 84.6% in Dakar and 89.5% in Ziguinchor. The prevalence of severe food insecurity was 59.6% in Dakar and 75.4% in Ziguinchor. The prevalence of malnutrition (BMI <18.5) was 19.2% in Dakar and 26.3% in Ziguinchor. Severe food insecurity was associated with missing clinic appointments (p = 0.01) and not taking antiretroviral therapy due to hunger (p = 0.02). Malnutrition was associated with lower CD4 cell counts (p = 0.01).

Conclusions

Severe food insecurity and malnutrition are highly prevalent among HIV-infected adults in both Dakar and Ziguinchor, and are associated with poor HIV outcomes. Our findings warrant further studies to determine the root causes of malnutrition and food insecurity in Senegal, and the short- and long-term impacts of malnutrition and food insecurity on HIV care. Urgent interventions are needed to address the unacceptably high rates of malnutrition and food insecurity in this population.     

Lésions des organes génitaux externes par arme a feu: a propos de six observations

Patients and Methods

This is a retrospective study of patients admitted with gunshot injuries to the external genital organs to the urology departments of Aristide Le Dantec Hospital, Grand Yoff General Hospital and Dakar Principal Hospital, between January 1998 and January 2003. The following parameters were studied: patients’ age and gender, interval between accident and admission, clinical features, complementary investigations and treatment, and early and late outcomes.

Results

Only males were observed and the mean age of these patients was 37.7 years (range: 22–52 years). Lesions were accidental in five cases. Two cases of testicular wounds, two cases of corpus cavernosum injuries, two cases of urethral injury, and one case of perineal wound were observed. After excision of the lesions, complementary procedures consisted of: orchidectomy in two cases, corpus cavernosum — albuginea suture in two cases and end-to-end urethral suture in one case. Perineoscrotal wounds were sutured three days after debridement. All patients received antibiotics and antitetanus serum. No death was observed during the immediate follow-up. No case of urethral stricture or erectile dysfunction was observed with a follow-up of 18 months. Semen analysis was normal in the two cases of orchidectomy.     

Genetic variations in influx transporter gene <Emphasis Type="BoldItalic">SLC22A1</Emphasis> are associated with clinical responses to imatinib mesylate among Malaysian chronic myeloid leukaemia patients

Imatinib mesylate (IM), a well-established gold standard drug in the treatment of chronic myeloid leukaemia (CML), is a synthetic tyrosine kinase inhibitor. Despite excellent efficacy, a significant number of patients on IM therapy develop resistance to IM. Currently, great focus has been laid on the effect of interindividual pharmacogenetic variability on IM treatment responses. IM uptake is mediated by the hOCT1 protein encoded by the solute carrier 22 gene (SLC22A1). The current study investigated the impact of few single-nucleotide polymorphisms (SNPs) of SLC22A1 on mediating resistance and/or good response to IM among 278 Malaysian CML patients (146 IM-resistant group and 132 IM good response group) undergoing IM therapy on 400 mg daily. Our results showed that the allelic frequencies of heterozygous (CG) and homozygous variant (GG) genotypes of SLC22A1 C480G were significantly higher in the IM-resistant group compared with the IM good response group (41.8% versus 30.3% and 10.9% versus 4.5% with P values of 0.047 and 0.048, respectively). On evaluating the association of genotypes with risk of IM resistance development, heterozygous (CG) and homozygous (GG) variant genotypes showed significantly higher risk for developing resistance to IM treatment with odds ratio (OR): 1.901 (95% confidence interval (CI): 1.142–3.163, \(P=0.013\)) and 3.324 (95% CI: 1.235–8.947, \(P=0.017\)), respectively. Two SNPs and two insertions/deletions were detected in exon 7 of SLC22A1. For exon 7, 1222AA carriers together with the presence of both the 8-bp insertion and 3-bp deletion, and M420del alleles showed higher possibility of developing resistance towards IM treatment. Our results warrant the need of genotyping this SNP in terms of modulating IM treatment in CML patients.     

Ectomycorrhizal fungi are shared between seedlings and adults in a monodominant Gilbertiodendron dewevrei rain forest in Cameroon

Ectomycorrhizal networks may facilitate the establishment and survival of seedlings regenerating under the canopies of tropical forests and are often invoked as a potential contributor to monodominance. We identified ectomycorrhizal fungi in a monodominant Gilbertiodendron dewevrei (Fabaceae) rain forest in Cameroon, using sporocarps and ectomycorrhizae of three age categories (seedlings, intermediate trees, and large trees) and tentatively revealed nutrient transfer through ectomycorrhizal networks by measuring spontaneous isotopic (¹³C and ¹⁵N) abundances in seedlings. Sporocarp surveys revealed fewer ectomycorrhizal fungal taxa (59 species from 1030 sporocarps) than molecular barcoding of ectomycorrhizal roots (75 operational taxonomic units from 828 ectomycorrhizae). Our observations suggest that ectomycorrhizal fungal diversity is similar to that in other mixed tropical forests and provide the first report of the Tuber‐Helvella lineage in a tropical forest. Despite some differences, all age categories of G. dewevrei had overlapping ectomycorrhizal fungal communities, with families belonging to Thelephoraceae, Russulaceae, Sebacinaceae, Boletaceae, and Clavulinaceae. Of the 49 operational taxonomic units shared by the three age categories (65.3% of the ectomycorrhizal fungal community), 19 were the most abundant on root tips of all categories (38.7% of the shared taxa), supporting the likelihood of ectomycorrhizal networks. However, we obtained no evidence for nutrient transfer from trees to seedlings. We discuss the composition of the ectomycorrhizal fungal community among the G. dewevrei age categories and the possible role of common ectomycorrhizal networks in this rain forest.     

Is there NO help for leptin?

Since the initial identification of leptin as the product of the ob gene in 1994, the signaling pathways by which this hormone alters cell physiology have been the subject of extensive investigations. The fact that leptin can induce nitric oxide (NO) production was first demonstrated in studies of the pituitary gland and pancreatic islets. A large number of additional studies further showed that this adipokine stimulates NO synthesis in multiple tissues. This review article discusses the role of leptin in NO production and its pathophysiological consequences. The role of this gaseous messenger in cell physiology depends on the cell type, the concentration of NO and the duration of exposure. It can be either a potent oxidant or a protector of cell integrity against the formation of reactive oxygen species. Leptin plays two opposing roles on arterial pressure. It exerts a hypertensive effect due to sympathetic activation and a vasorelaxant effect due to NO production. This adipokine acts via NO to produce pro-inflammatory factors in cartilage pathology, potentially contributing to an increased risk for osteoarthritis. Another well-documented role of leptin-induced NO, acting either directly or via the hypothalamus, concerns lipid metabolism in muscle and adipose tissue. In adipocytes, the direct and rapid action of leptin is to activate the nitric oxide synthase III, which favors lipolysis. In contrast, in the long-term, leptin reduces lipolysis. However, both in the short-term and in the long-term, glyceroneogenesis and its key enzyme, the cytosolic phosphoenolpyruvatecarboxykinase (PEPCK-C), are down-regulated by the adipokine, thus favoring fatty acid release. Hence, leptin-induced NO production plays a crucial role in fatty acid metabolism in adipose tissue. The resulting effects are to prevent lipid storage and to improve energy expenditure, with possible improvements of the obese state and its associated diseases.     

Human antibody responses to the Anopheles salivary gSG6-P1 peptide: a novel tool for evaluating the efficacy of ITNs in malaria vector control

To optimize malaria control, WHO has prioritised the need for new indicators to evaluate the efficacy of malaria vector control strategies. The gSG6-P1 peptide from gSG6 protein of Anopheles gambiae salivary glands was previously designed as a specific salivary sequence of malaria vector species. It was shown that the quantification of human antibody (Ab) responses to Anopheles salivary proteins in general and especially to the gSG6-P1 peptide was a pertinent biomarker of human exposure to Anopheles. The present objective was to validate this indicator in the evaluation of the efficacy of Insecticide Treated Nets (ITNs). A longitudinal evaluation, including parasitological, entomological and immunological assessments, was conducted on children and adults from a malaria-endemic area before and after the introduction of ITNs. Significant decrease of anti-gSG6-P1 IgG response was observed just after the efficient ITNs use. Interestingly, specific IgG Ab level was especially pertinent to evaluate a short-time period of ITNs efficacy and at individual level. However, specific IgG rose back up within four months as correct ITN use waned. IgG responses to one salivary peptide could constitute a reliable biomarker for the evaluation of ITN efficacy, at short- and long-term use, and provide a valuable tool in malaria vector control based on a real measurement of human-vector contact.     

Improvement of the antibody-dependent respiratory burst assay for assessing protective immune responses to malaria

The antibody-dependent respiratory burst (ADRB) assay is a sensitive isoluminol-based chemiluminescence (CL) functional assay designed to assess the capacity of opsonizing antibodies against merozoites to induce neutrophil respiratory burst. ADRB was shown to measure protective immunity against malaria in endemic areas, but the assay needed further improvement to ensure better sensitivity and reproducibility. Here, we adjusted parameters such as the freezing–thawing procedure of merozoites, merozoites''s concentration and the buffer solution''s pH, and we used the improved assay to measure ADRB activity of 207 sera from 97 and 110 individuals living, respectively, in Dielmo and Ndiop villages with differing malaria endemicity. The improvement led to increased CL intensity and assay sensitivity, and a higher reproducibility. In both areas, ADRB activity correlated with malaria endemicity and individual''s age discriminated groups with and without clinical malaria episodes, and significantly correlated with in vivo clinical protection from Plasmodium falciparum malaria. Our results demonstrate that the improved ADRB assay can be valuably used to assess acquired immunity during monitoring by control programmes and/or clinical trials.