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Background Intestinal parasitic infections, especially intestinal protozoan parasites remain significant public health problem in Senegal. Several studies have demonstrated the endemicity of the diseases. The study was carried out with the objective of assessing the epidemiolocal profile of intestinal protozoan infection diagnosed among patients attending to Fann University Hospital in Dakar, Senegal. Materials and Method A retrospective study was conducted from 2016 to 2020. Samples were collected from patients attending to the laboratory for parasitological confirmation. Fresh stool samples were observed using direct examination, formal-ether concentration method and modified Zeilh Nielsen staining method. Descriptive analysis was performed using Stata MP 16 software. The significance level was set at 5%. Results Among 3825 patients selected in the study, 1009 were found with at least one intestinal protozoan parasite representing an overall prevalence of 26.4% (CI 95% (24.7– 28)). Mono-parasitic and di-parasitic infection represent 81.6% and 18.2% respectively while polyparasitism was observed in 26 patients representing 2,6%. Among positive samples, 16 (8.7%) were associated with helminths. Blastocystis sp. (40.8%), Entamoeba Coli (38.2%), Endolimax nana (8.2%) and Giardia intestinalis (8.1%) were mainly observed. Trophozoites Entamoeba histolytica was observed with 2.3%. Frequency of intestinal protozoa was higher in the 15 – 30 age group (28.3%) and in male group (26.9%). The parasite carriage was most important during the wet season comparing the dry season (p = 0.65). Asymptomatic patients (29.5%) were more infected than symptomatic patients (23.5%) (p

The emergence of artemisinin-resistant Plasmodium falciparum parasites in Southeast Asia threatens malaria control and elimination. The interconnectedness of parasite populations may be essential to monitor the spread of resistance. Combining a published barcoding system of geographically restricted single-nucleotide polymorphisms (SNPs), mainly mitochondria of P. falciparum with SNPs in the K13 artemisinin resistance marker, could elucidate the parasite population structure and provide insight regarding the spread of drug resistance. We explored the diversity of mitochondrial SNPs (bp position 611-2825) and identified K13 SNPs from malaria patients in the districts of India (Ranchi), Tanzania (Korogwe), and Senegal (Podor, Richard Toll, Kaolack, and Ndoffane). DNA was amplified using a nested PCR and Sanger-sequenced. Overall, 199 K13 sequences (India: N = 92; Tanzania: N = 48; Senegal: N = 59) and 237 mitochondrial sequences (India: N = 93; Tanzania: N = 48; Senegal: N = 96) were generated. SNPs were identified by comparisons with reference genomes. We detected previously reported geographically restricted mitochondrial SNPs (T2175C and G1367A) as markers for parasites originating from the Indian subcontinent and several geographically unrestricted mitochondrial SNPs. Combining haplotypes with published P. falciparum mitochondrial genome data suggested possible regional differences within India. All three countries had G1692A, but Tanzanian and Senegalese SNPs were well-differentiated. Some mitochondrial SNPs are reported here for the first time. Four nonsynonymous K13 SNPs were detected: K189T (India, Tanzania, Senegal); A175T (Tanzania); and A174V and R255K (Senegal). This study supports the use of mitochondrial SNPs to determine the origin of the parasite and suggests that the P. falciparum populations studied were susceptible to artemisinin during sampling because all K13 SNPs observed were outside the propeller domain for artemisinin resistance.

S6.5 Efforts of improving the management of mycetoma: working towards the 2030 goals, September 22, 2022, 4:45 PM - 6:15 PM Background Mycetoma is a chronic granulomatous inflammatory disease that is caused either by bacteria or fungi. The diagnosis of species is important to guide the therapeutic management of patients particularly for white and yellow grains. However, the identification of the causative agents using mycological and histological techniques is a real problem in our countries. This study aims to identify etiologic agents using molecular techniques in Senegal. Methods A prospective study was carried out to compare mycological and histological techniques with molecular methods in patients attending hospital settings. Biopsy specimens and/or grains obtained from these patients were examined by PCR targeting the ITS (fungal agents) and 16S (actinomycosis agents) genes. Sequencing with the SANGER method allowed us to identify the species. Results Preliminary results were obtained from 30 patients. The grains collected were black (38%), red (4.7%), white (47.6%), and yellow (9.5%). Discriminative PCR ITS vs 16S identified 5 actinomycosis agents including white and yellow grains and 1 fungal agent. The fungal agent was identified after sequencing as Microsporum langeronii. Conclusion The preliminary results of this study show the importance of discriminative PCR to guide the therapeutic choice of clinicians. Its widespread use could improve the detection and management of mycetoma cases in Senegal.

Malaria is a serious public health burden in Senegal. Accurate diagnosis is essential to avoided unnecessary presumptive treatment. Malaria diagnosis currently relies on identifying malaria parasite using microscopy and detecting soluble parasite antigens by Rapid Diagnostic Tests (RDT). These techniques do not detect low-level, sub-patent malaria infections and are inherently hazardous and invasive. To overcome these obstacles, alternatives diagnostics method were explored. In contrast to blood, saliva presents a reduced biohazard and can be painlessly collected in relatively large quantities by individuals with moderate training. The objective of this study was to use saliva collected in OmnIGEN Kits as an alternative sample for malaria detection. Methods: A total of 77 febril patients tested malaria positive by mRDT were enrolled in this study. From each patient, blood sample was collected for dried blood spot and blood smear; and saliva sample on OMNIGEN kit. Parasite density was determined from smear and Plasmodium falciparum DNA was extracted from both dried blood spot and saliva samples collected from the same patients. Extracted DNA was amplied by qPCR machine. Results: Malaria prevalence using qPCR was 98,7% and 60% respectively with blood and saliva. Compared to blood, saliva showed a sensitivity; specicity; positive predictive value of 60%; 100 %; and 100 %. The concordance between parasites detection from saliva and blood was (p = 0.45). In addition, no difference was found between these two methods and the microscopy counting. Conclusions:Saliva could be a non-invasive alternative method for P. falciparum detection and epidemiological surveillance in country with limited ressources.

Background: In Senegal, malaria morbidity has shapely felt down over these past years. However, malaria epidemiology remains heterogeneous with persisting transmission in the southeastern part of the country and more important number of cases arising among older children and adolescents. Little is known about factors associated with clinical malaria among this group. A better understanding of malaria transmission among this new vulnerable group will guide future interventions targeting these key populations. This study aimed to identify factors associated with clinical malaria among adolescents in Senegal. Methods: A case control study was conducted from November to December 2020 in four health posts located in Saraya district. Cases were defined as adolescents (10-19 years) with uncomplicated malaria episode with fever (Temperature>37.5°) or history of fever and a positive malaria RDT. Controls were from the same age group, living in the neighborhood of the case, presenting a negative RDT. A standardized, pre-tested questionnaire was administered to each participant followed by home visit to assess participant’s living conditions. Factors associated with clinical malaria was assessed using a Stepwise Logistic regression analysis.Results: In total, 492 individuals were recruited (246 cases and 246 controls). In a multivariate analysis, factors associated with clinical malaria included non-use of bed net (aOR=2.65; 95% CI =1.58 - 4.45), non-use of other preventive measures (aOR=2.51; 95% CI=1.53 - 4.11) and indoor sleeping (aOR=3.22; 95%CI =1.66- 6.23). Protective factors included age of 15-19 years (aOR=0.38; 95% CI 0.23 - 0.62), absence of stagnant water around the house (aOR=0.27; 95% CI=0.16 - 0.44), having a female as head of household (aOR=0.47; 95% CI=0.25 - 0.90), occupation such as apprentice (OR=0.24; 95%CI=0.11 - 0.52).Conclusions: The study revealed that environmental factors and non-use of malaria preventive measures are the main determinant of malaria transmission among adolescents living in areas with persisting malaria transmission in Senegal. Strategies aiming at improving disease awareness and access to health care interventions such as LLIN are thus needed to improve malaria control and prevention among these vulnerable groups.

Background In Senegal, malaria morbidity has sharply decreased over these past years. However, malaria epidemiology remains heterogeneous with persistent transmission in the southeastern part of the country and many cases among older children and adolescents. Little is known about factors associated with clinical malaria among this group. A better understanding of malaria transmission among this newly emerging vulnerable group will guide future interventions targeting this population group. This study aimed to identify factors associated with clinical malaria among adolescents in Senegal. Methods A case–control study was conducted from November to December 2020 in four health posts located in the Saraya district. Cases were defined as adolescents (10–19 years) with an uncomplicated malaria episode with fever (temperature > 37.5°) or a history of fever and positive malaria rapid diagnostic test (RDT). Controls were from the same age group, living in the neighbourhood of the case, presenting a negative RDT. A standardized, pre-tested questionnaire was administered to each study participant followed by a home visit to assess the participant's living conditions. Factors associated with clinical malaria were assessed using stepwise logistic regression analysis. Results In total, 492 individuals were recruited (246 cases and 246 controls). In a multivariate analysis, factors associated with clinical malaria included non-use of long-lasting insecticidal net (LLIN) (aOR = 2.65; 95% CI 1.58–4.45), non-use of other preventive measures (aOR = 2.51; 95% CI 1.53–4.11) and indoor sleeping (aOR = 3.22; 95% CI 1.66–6.23). Protective factors included 15–19 years of age (aOR = 0.38; 95% CI 0.23–0.62), absence of stagnant water around the house (aOR = 0.27; 95% CI 0.16–0.44), having a female as head of household (aOR = 0.47; 95% CI 0.25–0.90), occupation such as apprentice (OR = 0.24; 95% CI 0.11–0.52). Conclusions The study revealed that environmental factors and non-use of malaria preventive measures are the main determinants of malaria transmission among adolescents living in areas with persistent malaria transmission in Senegal. Strategies aimed at improving disease awareness and access to healthcare interventions, such as LLINs, are needed to improve malaria control and prevention among these vulnerable groups.

BackgroundWe aimed to assess the specificity of SARS-CoV-2 antibody detection assays among people with known tissue-borne parasitic infections.MethodsWe tested three SARS-CoV-2 antibody-detection assays (cPass SARS-CoV-2 Neutralization Antibody Detection Kit, Abbott SARS-CoV-2 IgG assay, and STANDARD Q COVID-19 IgM/IgG Combo Rapid Test) among 559 pre-COVID-19 sera.ResultsThe specificity of assays was 95-98% overall. However, lower specificity was observed among sera from patients with protozoan infections of the reticuloendothelial system, such as human African trypanosomiasis (Abbott Architect; 88% [95%CI 75-95]), visceral leishmaniasis (SD RDT IgG; 80% [95%CI 30-99]), and from patients with recent malaria from a holoendemic area of Senegal (ranging from 91% for Abbott Architect and SD RDT IgM to 98-99% for cPass and SD RDT IgG). For specimens from patients with evidence of past or present helminth infection overall, test specificity estimates were all ≥ 96%. Sera collected from patients clinically suspected of parasitic infections that tested negative for these infections yielded a specificity of 98-100%. The majority (>85%) of false-positive results were positive by only one assay.ConclusionsThe specificity of SARS-CoV-2 serological assays among sera from patients with tissue-borne parasitic infections was below the threshold required for decisions about individual patient care. Specificity is markedly increased by the use of confirmatory testing with a second assay. Finally, the SD RDT IgG proved similarly specific to laboratory-based assays and provides an option in low-resource settings when detection of anti-SARS-CoV-2 IgG is indicated.

Background: Seasonal malaria chemoprevention (SMC) with sulfadoxine-pyrimethamine plus amodiaquine (SPAQ) is a malaria prevention strategy recommended since 2012 by the World Health Organization (WHO) for children under 5 years. In Senegal, the scaling up of SMC started in 2013 in the south-eastern regions of the country with an extension of the target to 10 years old children. The scaling up of SMC requires regular evaluation of the strategy as recommended by the WHO. This study was conducted to evaluate the effectiveness of SMC. Methods: A case-control study was conducted in some villages of the health districts of Saraya and Kedougou in the Kedougou region from July to December 2016. A case was a sick child, aged 3 months to 10 years, seen in consultation and with a positive malaria rapid diagnostic test (RDT). The control was a child of the same age group with a negative RDT and living in the same compound as the case or in a neighbouring compound. Each case was matched with two controls. Exposure to SMC was assessed by interviewing the mothers/caretakers and by checking the SMC administration card. Results: Overall, 492 children, including 164 cases and 328 controls, were recruited in our study. Their mean ages were 5.32 (+/- 2.15) and 4.44 (+/-2.25) years for cases and controls, respectively. The number of boys was higher in both cases (55.49%; CI 95%=47.54-63.24%) and controls (51,22%; CI 95%=45.83-56.58%). Net ownership was 85.80% among cases and 90.85% among controls (p=0,053). The proportion of controls who received SMC was higher than that of cases (98.17% vs 85.98% and p=1.10-7). The protective effectiveness of SMC was 89% (OR= 0.12 (CI 95%=0.04-0.28)). Conclusions: SMC is an effective strategy in the control of malaria in children. Case-control studies are a good approach for monitoring the efficacy of drugs administered during SMC.

Vitamin A supplementation (VAS) in 6-59-month-old children is recommended but its sustainability is currently questioned. In Senegal, available data suggest that VAS should be maintained, but geographic and age-related specificities need to be addressed to better implement and target VAS programming. The objective of this comparative cross-sectional study, conducted in urban settings of Dakar, was to compare the vitamin A liver stores (VALS) assessed using the modified-relative dose response (MRDR) test between supplemented and non-supplemented 9–23 month-old children and to study their relationship with VAS. The supplemented group (n = 119) received VAS (either 100 000 UI or 200 000 UI) 2 to 6 months before evaluation while the non-supplemented group (n = 110) had not received VAS during the past 6 months. In addition to MRDR, serum retinol concentrations (SR), and biomarkers of subclinical inflammation were measured. Children’s health-related data and feeding patterns were collected. Mean MRDR values (VAS: 0.030 ± 0.017, non-VAS: 0.028 ± 0.016, P = 0.389) and inflammation-adjusted SR (VAS: 1.34 ± 0.37, non-VAS: 1.3 ± 0.35, P = 0.515) of children were adequate. Low prevalence of VALS (VAS: 5.2%, non-VAS: 5.4%) and inflammation-adjusted VAD (VAS: 2.6%, non-VAS: 0.9%) were detected despite high presence of infections and inflammation. Children were mostly still being breastfed (VAS: 85.7%, non-VAS: 77.3%) and complementary feeding indicators were similar in both groups. Only breastfeeding was associated with VALS and was found to reduce by 76% at least, the odds of VAD (adjusted OR = 0.24, 95% CI: 0.07–0.8, P = 0.020). Based on MRDR values, VAS was not related to improved VALS and SR as well as VAD reduction among these children with adequate VALS. Reinforcing breastfeeding advocacy and morbidity prevention/control are essential in this setting. Scaling-back VAS in this subpopulation should be examined regarding the risk of hypervitaminosis A after an evaluation of dietary vitamin A intake sufficiency and a more quantitative assessment of VALS.

Summary Adding low-dose primaquine to malaria treatment reduced gametocyte carriage by 73%. Patients who received primaquine had more frequent hemoglobinuria and there was a greater reduction in haemoglobin concentration in G6PD-deficient patients. One patient who received primaquine developed moderately severe anemia., Introduction More information is needed about the safety of low-dose primaquine in populations where G6PD deficiency is common. Methods Adults with Plasmodium falciparum malaria were randomized to receive 1 of 3 artemisinin combination therapies (ACTs) with or without primaquine (0.25 mg/kg). Glucose-6-phosphate dehydrogenase (G6PD) status was determined using a rapid test. Patients were followed for 28 days to record hemoglobin concentration, adverse events, and gametocyte carriage. The primary end point was the change in Hb at day 7. Results In sum, 274 patients were randomized, 139 received an ACT alone, and 135 received an ACT + primaquine. The mean reduction in Hb at day 7 was similar in each group, a difference in the ACT + PQ versus the ACT alone group of −0.04 g/dL (95% confidence interval [CI] −0.23, 0.31), but the effect of primaquine differed according to G6PD status. In G6PD-deficient patients the drop in Hb was 0.63 g/dL (95% CI 0.03, 1.24) greater in those who received primaquine than in those who received an ACT alone. In G6PD-normal patients, the reduction in Hb was 0.22 g/dL (95% CI −0.08, 0.52) less in those who received primaquine (interaction P = .01). One G6PD normal patient who received primaquine developed moderately severe anaemia (Hb < 8 g/dL). Dark urine was more frequent in patients who received primaquine. Primaquine was associated with a 73% (95% CI 24–90) reduction in gametocyte carriage (P = .013). Conclusion Primaquine substantially reduced gametocyte carriage. However, the fall in Hb concentration at day 7 was greater in G6PD-deficient patients who received primaquine than in those who did not and one patient who received primaquine developed moderately severe anemia. Clinical Trial registration PACTR201411000937373 (www.pactr.org)

In the context of controlling intestinal parasites, accurate diagnosis is essential. Our objective was to evaluate the performance of new diagnostic kits compared to conventional microscopic methods in identifying intestinal parasites. Faeces collected in rural area in Senegal were subjected to several detection techniques. Thus, the sensitivity, specificity, positive and negative predictive values of new diagnostic techniques were compared to conventional merthiolate-iodine-formalin, conventional Bailenger and modified Ritchie. Furthermore, the kappa coefficient was calculated to evaluate the correlation between the new kit and those of modified Ritchie. Out of the 117 patients examined, 102 presented with a parasite, or prevalence of 87.1%. The Fumouze techniques proved to be as effective as the conventional methods in detecting flagellates and helminths with sensitivities ranging from 97 to 100%. However, conventional techniques were slightly more sensitive in identifying Endolimax nana and Blastocystis hominis. The correlation was nearly perfect (k = 0.83 and 1), respectively between Bailenger Fumouze, Iodesine Fumouze and modified Ritchie in identifying helminths while it was just acceptable (k = 0.27 and 0.28) in identifying B. hominis. The modified Ritchie technique routinely used in our laboratory remains a good diagnostic tool. However, the use of kit techniques was interesting when reading the pellet after concentration and the Colour KOP staining was a considerable contribution to the diagnosis of the vegetative forms. Therefore, it would be interesting to determine the cost of a stool test using Fumouze kit techniques to provide the most cost effective way.

Background Scaling-up of effective anti-malarial control strategies in Central-West region of Senegal has resulted in the sharp decline in malaria prevalence in this area. However, despite these strategies, residual malaria transmission has been observed in some villages (hot spots). The objective of this study was to assess the impact of indoor residual spraying (IRS) with pirimiphos-methyl on malaria transmission in hot spot areas. Methods The malaria vector population dynamics were monitored in each of the six selected villages (4 of which used IRS, 2 were unsprayed control areas) using overnight human landing catches (HLC) and pyrethrum spray catches (PSC). The host source of blood meals from freshly fed females collected using PSC was identified using the direct ELISA method. Females caught through HLC were tested by ELISA for the detection of Plasmodium falciparum circumsporozoite protein and Anopheles gambiae complex was identified using PCR. Results Preliminary data shown that the densities of Anopheles populations were significantly lower in the sprayed areas (179/702) compared to the control. Overall, malaria transmission risk was 14 times lower in the intervention zone (0.94) compared to the control zone (12.7). In the control areas, three Anopheles species belonging to the Gambiae complex (Anopheles arabiensis, Anopheles coluzzii and Anopheles melas) maintained the transmission, while only An. coluzzii was infective in the sprayed areas. Conclusion The preliminary data from this pilot study showed that IRS with the CS formulation of pirimiphos-methyl is likely very effective in reducing malaria transmission risk. However, additional studies including further longitudinal entomological surveys as well as ecological and ethological and genetical characterization of vectors species and their populations are needed to better characterize the entomological impact of indoor residual spraying with pirimiphos-methyl in the residual transmission areas of Senegal.

Introduction: Intestinal parasitic infection (IPI) remains major public health problem in worldwide, being most prevalent in developing countries. Mass drug administration with Mebendazole is an effective strategy for the control of these diseases in pre-school and schoolchildren. The aim of this study was to assess the prevalence of intestinal parasitic infections and established associated risk factors among pre-school and schoolchildren living in rural area in Senegal. Materials and method: A cross sectional survey was carried out between Novembers to December 2014. Children less than 10 years were randomly selected using a systematic random sampling method. Stool samples were examined by light microscopy for the detection of parasite using direct examination, Modified Ritchie Method and the modified Ziehl Neelsen staining method. Results: Among 392 children selected in the study, 137 were found with at least one intestinal parasite representing an overall prevalence of 34.95% [CI 95% (29.3–41.3)]. Protozoan infection was more frequent than helminthic infection (93.4% versus 2.2% respectively). Association between helminths and protozoa was 4.4%. Intestinal parasites identified were Giardia intestinales (72.48%), Entamoeba coli (13.76%), Blastocystis hominis (3.67%) and Hymenolepis nana (1.83%). Prevalence was higher among children aged over 5 years old (48.4%) (aOR= 5.39; 95% IC (2.06–13.9); p=0.001). Children living in family with more than 10 individuals and those drinking unsafe water were found most infected respectively 37.5%) (aOR= 1.24; 95% CI (0.65–2.38); p=0.51) and (42.3%) (aOR=1.45; 95% CI (0.83–2.52); p=0.18). Prevalence was higher in children with underweight 36.3% [aOR= 1.53; 95% IC (0.88–2.67); p=0.13). No correlation was found between sex and intestinal parasitic infection. Conclusion: This study showed that intestinal parasites remain prevalent in pre-school and schoolchildren with a changing of the epidemiological profile. Protozoan infection was more frequent than helminthic infection. Preventive measures including mass drug administration with Albendazole and water supply could reduce the prevalence of these diseases.

In Senegal, antimalarial drugs used in treatment and prevention of malaria are one of the main reasons for the current success in controlling malaria. However, the successful control of malaria is highly dependent on continued effectiveness of these drugs which may be compromised by the spread of drug resistance. Therefore, surveillance of drug resistance in the malaria parasites is essential. The objective of this pilot study was to test the feasibility of routinely sampled malaria rapid diagnostic tests (RDTs) at a national scale to assess the temporal changes in the molecular profiles of antimalarial drug resistance markers of Plasmodium falciparum parasites. Overall, 9,549 positive malaria RDTs were collected from 14 health facilities across the country. A limited random set of RDTs were analyzed regarding Pfcrt gene polymorphisms at codon 72–76. Overall, a high but varied prevalence (> 50%) of the wild-type CVMNK haplotype was observed including a higher CVMNK prevalence in the northern part (75%) compared with the southern part of the country (59%). With caution, the study provides a proof of concept that reuse of discarded P. falciparum positive RDTs can be applied in large-scale surveillance of antimalarial drug resistance.

International audience; Gastrointestinal parasite infections represent one of the biggest public health problems in the world. Therefore, appropriate innovative tools are needed for assessing interventions to control these infections. This study aims to compare the performance of real-time polymerase chain reaction (PCR) assays to microscopic examination for detection of intestinal parasites. A direct microscopic examination and stool concentration was performed on 98 stool samples from patients attending Senegalese hospitals. Negative microscopic control samples were also collected in Nice and Marseille (France). Species-specific primers/probes were used to detect 20commongastrointestinal protozoans and helminths. Positive frequency and the sensitivity of each real-time PCR assay were compared with conventional microscopic examination. Real-time PCR was positive in 72 of 98 samples (73.5%), whereas microscopic examination was positive in 37 (37.7%) samples (P < 0.001). The real-time PCR assays were more sensitive than microscopy, with 57.4% (31/54) versus 18.5% (10/54), respectively, in the detection of parasites in asymptomatic patients (P < 0.05). In terms of polyparasitism, there were more coinfections detected by real-time PCR assays compared with microscopic methods (25.5% versus 3.06%). In comparison to parasite prevalence on individual samples, the results showed a perfect agreement (100%) between the two techniques for seven species, whereas discrepancies were observed for the others (agreement percentage varying from 64.2% to 98.9%). Real-time PCR appeared to be superior to microscopic examination for the detection of parasites in stool samples. This assay will be useful in diagnostic laboratories and in the field for evaluating the efficacy of mass drug administration programs.

Background: Polymorphism and antigenic variation of malaria parasites determine malaria episode and its outcome. The aim of this study was to determine Plasmodium falciparum genetic diversity over time in population with uncomplicated malaria under ACT exposure in Senegal. Method: P. falciparum isolates collected from 300 individuals with uncomplicated malaria infection living in a rural area of Senegal from 2004 to 2008 were analyzed by a nested PCR amplification of msp1 and msp2 genes to compare P. falciparum allelic families’ diversity. Results: Allelic variation in both msp1 and msp2 genes were identified in the samples analyzed. For msp1 gene, 10 different alleles were found (3 msp1_K1, 4 msp1_Mad20 and 3 msp1_Ro33). Among them msp1_k1 allelic family was predominant (>70%) over year. Regarding msp2 gene, 7.0 different alleles were found (3 msp2_3D7, 4 msp2_FC27). However msp2_FC27 strain was predominant, especially in 2006 and 2007. Monoclonal infections were more frequent for msp1 gene, in 2004 (48.78%) and 2005 (45.05%) and for msp2 gene than polyclonal ones. Conclusion: This study demonstrated some differences in the P. falciparum diversity between symptomatic subjects over years living in rural area in Senegal and this should be taken into account when designing msp1 or msp2 malaria vaccine.

Background Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine (SP) plus amodiaquine (AQ), given each month during the transmission season, is recommended for children living in areas of the Sahel where malaria transmission is highly seasonal. The recommendation for SMC is currently limited to children under five years of age, but, in many areas of seasonal transmission, the burden in older children may justify extending this age limit. This study was done to determine the effectiveness of SMC in Senegalese children up to ten years of age. Methods and Findings SMC was introduced into three districts over three years in central Senegal using a stepped-wedge cluster-randomised design. A census of the population was undertaken and a surveillance system was established to record all deaths and to record all cases of malaria seen at health facilities. A pharmacovigilance system was put in place to detect adverse drug reactions. Fifty-four health posts were randomised. Nine started implementation of SMC in 2008, 18 in 2009, and a further 18 in 2010, with 9 remaining as controls. In the first year of implementation, SMC was delivered to children aged 3–59 months; the age range was then extended for the latter two years of the study to include children up to 10 years of age. Cluster sample surveys at the end of each transmission season were done to measure coverage of SMC and the prevalence of parasitaemia and anaemia, to monitor molecular markers of drug resistance, and to measure insecticide-treated net (ITN) use. Entomological monitoring and assessment of costs of delivery in each health post and of community attitudes to SMC were also undertaken. About 780,000 treatments were administered over three years. Coverage exceeded 80% each month. Mortality, the primary endpoint, was similar in SMC and control areas (4.6 and 4.5 per 1000 respectively in children under 5 years and 1.3 and 1.2 per 1000 in children 5-9 years of age; the overall mortality rate ratio [SMC: no SMC] was 0.90, 95% CI 0.68–1.2, p = 0.496). A reduction of 60% (95% CI 54%–64%, p < 0.001) in the incidence of malaria cases confirmed by a rapid diagnostic test (RDT) and a reduction of 69% (95% CI 65%–72%, p < 0.001) in the number of treatments for malaria (confirmed and unconfirmed) was observed in children. In areas where SMC was implemented, incidence of confirmed malaria in adults and in children too old to receive SMC was reduced by 26% (95% CI 18%–33%, p < 0.001) and the total number of treatments for malaria (confirmed and unconfirmed) in these older age groups was reduced by 29% (95% CI 21%–35%, p < 0.001). One hundred and twenty-three children were admitted to hospital with a diagnosis of severe malaria, with 64 in control areas and 59 in SMC areas, showing a reduction in the incidence rate of severe disease of 45% (95% CI 5%–68%, p = 0.031). Estimates of the reduction in the prevalence of parasitaemia at the end of the transmission season in SMC areas were 68% (95% CI 35%–85%) p = 0.002 in 2008, 84% (95% CI 58%–94%, p < 0.001) in 2009, and 30% (95% CI -130%–79%, p = 0.56) in 2010. SMC was well tolerated with no serious adverse reactions attributable to SMC drugs. Vomiting was the most commonly reported mild adverse event but was reported in less than 1% of treatments. The average cost of delivery was US$0.50 per child per month, but varied widely depending on the size of the health post. Limitations included the low rate of mortality, which limited our ability to detect an effect on this endpoint. Conclusions SMC substantially reduced the incidence of outpatient cases of malaria and of severe malaria in children, but no difference in all-cause mortality was observed. Introduction of SMC was associated with an overall reduction in malaria incidence in untreated age groups. In many areas of Africa with seasonal malaria, there is a substantial burden in older children that could be prevented by SMC. SMC in older children is well tolerated and effective and can contribute to reducing malaria transmission. Trial Registration ClinicalTrials.gov NCT00712374, In a stepped-wedge cluster-randomized trial, Paul J. Milligan and colleagues determine the effectiveness of SMC in Senegalese children up to ten years of age., Author Summary Why was this study done? SMC was originally intended for children under five years of age. In many areas of the sub-Sahel, there is a substantial burden of malaria in older children; this may justify extending the age range of SMC. This study was done in central Senegal to evaluate the effectiveness of SMC when given to children up to ten years of age. What did the researchers do and find? SMC was introduced into the area served by 54 health posts by district health teams over three years using a randomised stepped-wedge design. Malaria cases were detected at outpatient clinics and in hospitals, and deaths were recorded through a demographic surveillance system. SMC reduced the incidence of malaria in children up to ten years of age by 60%. No reduction in all-cause child deaths was observed, but the incidence of severe malaria was reduced by 45%. SMC administered to children up to ten years of age led to a reduction in malaria incidence in older age groups by 26%. What do these findings mean? SMC given to children up to ten years of age is highly effective in preventing malaria in children and can contribute to reducing overall malaria transmission. SMC programmes have started in 11 countries. In many of these countries, there is a substantial burden of malaria in older children. The findings of this study indicate that a much greater impact could be achieved by extending the age range of SMC.

Intestinal parasitic infections causes significant morbidity in worldwide. In Senegal, since 2005 mass deworming campaign has been introduced as a preventive strategy. The main objective of this study was to evaluate the prevalence of intestinal parasitic infection among children living in Koranic teaching Schools in Senegal. A cross-sectional study was conducted from January to May 2018. Koranic schools were selected using simple random sampling and data on socio-demographic characteristicsand prevalence were collected. Stool samples were collected and treated accordingly. Descriptive analysis was performed using Stata software. Significance level was set at 5%. A total of 463 children were recruited in this study. The mean age of study population was 10.93 ± 2.4. The overall prevalence of intestinal parasites was 22.68%. Poly-parasitism was detected in 20% of students. Students infected with single, double and triple parasites were 80%, 19.05% and 0.95%, respectively. The most common parasites were Entomoba coli cyst (33.33%), followed by Ascaris lumbricoides (32.38%), Giardia cyst (9.52%), Trichirus Trichiura (3.81%) and Schistosoma mansoni 0.95%. Intestinal parasites were more common in peri-urban areas (66.31%). Intestinal parasitic infection has been found to be very common in Koranic school children. Therefore, health education, improvement of learning and living conditions, and student deworming are essential.

As a result of widespread antimalarial drug resistance, all African countries with endemic malaria have, in recent years, changed their malaria treatment policy. In Senegal, the health authorities changed from chloroquine (CQ) to a combination of sulfadoxine-pyrimethamine (SP) plus amodiaquine (AQ) in 2003. Since 2006, the artemisinin combination therapies (ACTs) artemether-lumefantrine (AL) and artesunate plus amodiaquine (AS/AQ) were adopted for uncomplicated malaria treatment. After several years of CQ withdrawal, the current study wished to determine the level of CQ resistance at the molecular level in selected sites in Senegal, because the scientific community is interested in using CQ again. Finger prick blood samples were collected from Plasmodium falciparum-positive children below the age of 10 years (N = 474) during cross-sectional surveys conducted in two study sites in Senegal with different malaria transmission levels. One site is in central Senegal, and the other site is in the southern part of the country. All samples were analyzed for single nucleotide polymorphisms (SNPs) in the P. falciparum CQ resistance transporter gene (Pfcrt; codons 72-76) using polymerase chain reaction (PCR) sequence-specific oligonucleotide probe (SSOP) enzyme-linked immunosorbent assay (ELISA) and real-time PCR methods. In total, the 72- to 76-codon region of Pfcrt was amplified in 449 blood samples (94.7%; 285 and 164 samples from the central and southern sites of Senegal, respectively). In both study areas, the prevalence of the Pfcrt wild-type single CVMNK haplotype was very high; in central Senegal, the prevalence was 70.5% in 2009 and 74.8% in 2010, and in southern Senegal, the prevalence was 65.4% in 2010 and 71.0% in 2011. Comparing data with older studies in Senegal, a sharp decline in the mutant type Pfcrt prevalence is evident: from 65%, 64%, and 59.5% in samples collected from various sites in 2000, 2001, and 2004 to approximately 30% in our study. A similar decrease in mutant type prevalence is noted in other neighboring countries. With the continued development of increased CQ susceptibility in many African countries, it may be possible to reintroduce CQ in the near future in a drug combination; it could possibly be given to non-vulnerable groups, but it demands close monitoring of possible reemergence of CQ resistance development.

Resume But Evaluer l’efficacite de l’injection intratarsale de triamcinolone acetonide (TA), en comparaison a l’application de dexamethasone pommade, dans le traitement des formes graves de la limboconjonctivite chronique endemique des tropiques (LCET). Patients et methodes Cette etude prospective sur un an a inclus 20 patients presentant une forme grave de LCET. Une injection intratarsale d’1 mL de TA a 40 mg a ete realisee sur l’œil le plus atteint et de la dexamethasone pommade, appliquee sur l’œil controlateral. Les criteres d’efficacite etaient cliniques, recenses sur une echelle d’evaluation concue a dessein. L’analyse statistique a ete realisee par les tests chi2 de Fisher et t de Student avec une comparaison des moyennes sur series appariees. Resultats Dans les deux cas, une amelioration des signes fonctionnels a ete constatee chez tous les patients, des le lendemain ou la premiere semaine, et une amelioration des signes physiques des la deuxieme semaine, jusqu’au terme du premier mois, avec une dose efficace d’1 mL de TA et un protocole de trois semaines de dexamethasone, sans recidive a trois mois. L’efficacite de la pommade etait moindre (33,3 a 75 %) que celle obtenue avec l’injection de TA (90,9 a 100 %) et n’etait maintenue au-dela du premier mois que par repetition des applications. Conclusion L’injection intratarsale de TA, relativement aisee et bien toleree par les patients, serait une meilleure alternative a l’application de dexamethasone pommade dans le traitement des formes graves de la LCET.

BACKGROUND: Home-based management of malaria (HMM) may improve access to diagnostic testing and treatment with artemisinin combination therapy (ACT). In the Sahel region, seasonal malaria chemoprevention (SMC) is now recommended for the prevention of malaria in children. It is likely that combinations of antimalarial interventions can reduce the malaria burden. This study assessed the feasibility, effectiveness and safety of combining SMC and HMM delivered by community health workers (CHWs). METHODS: A cluster-randomised trial was carried out during two transmission seasons in eight villages located in the south-eastern part of Senegal. Intervention communities received HMM+SMC while control communities received HMM. Primary end point was the incidence of malaria attacks during the follow up period. Secondary end points included: malaria diagnostic accuracy; access to ACT treatment; SMC coverage; safety and drug tolerability. RESULTS: The adjusted rate ratio for incidence of malaria attacks in intervention and control communities was 0.15, indicating a protective effect of HMM+SMC of 85% (95% CI: 39.9-96.3%, p=0.01). Access to ACT treatment was 96.4% while SMC coverage represented 97.3% (95% CI: 91.3-100%) in 2010, and 88.8% (95% CI: 84.2-93.6%) in 2011. No serious adverse events were recorded. CONCLUSION: It seems feasible and safe to combine SMC with HMM intervention, while achieving high coverage and effectiveness of both SMC and HMM. TRIAL REGISTRATION: (www.pactr.org) PACTR201305000551876.

The malaria vaccine candidate antigens erythrocyte binding antigen 175 (EBA-175), merozoite surface protein 3 (MSP-3), and apical membrane antigen (AMA-1) from Plasmodium falciparum isolates from countries in central and west Africa were assessed for allelic diversity. Samples were collected on filter paper from 600 P. falciparum-infected symptomatic patients in Cameroon, Republic of Congo, Burkina Faso, Ghana, and Senegal and screened for class-specific amplification fragments. Genetic diversity, assessed by mean heterozygosity, was comparable among countries. We detected a clinical increase in eba 175 F-allele frequency from west to east across the study region. No statistical difference in msp-3 allele distribution between countries was observed. The ama-1 3D7 alleles were present at a lower frequency in central Africa than in West Africa. We also detected little to no genetic differentiation among sampling locations. This finding indicates that, at least at the level of resolution offered by restriction fragment length polymorphism analysis, these antigens showed remarkable genetic homogeneity throughout the region sampled, perhaps caused by balancing selection to maintain a diverse array of antigen haplotyes.

Dans la communaute rurale de Ngohe, le niveau d’hygiene est precaire en raison de la mauvaise qualite de l’eau et de l’absence de latrines dans les habitats. A partir de 2003, un projet de trois ans pour la construction de latrines y a ete initie, dans le cadre d’un programme d’appui a la region medicale de Diourbel. Apres trois annees d’activite, les faibles resultats enregistres ont justi?e l’analyse de la participation communautaire. L’etude, transversale, descriptive et analytique, a ete menee du 14 au 17 decembre 2005. Deux enqueteurs formes ont recueilli les donnees a l’aide de guides d’entretiens individuels et de groupes. La participation communautaire au projet de latrines a ete etroite dans la determination des activites ; limitee dans l’appreciation des besoins, la mobilisation des ressources, la gestion des ressources et le suivi evaluation ;moyenne dans la mise en œuvre des activites. Le faible taux de latrines (1,7 %), correle a la proportion importante de la diarrhee parmi les motifs de consultation en 2004 (33,4 %) et en 2005 (29,4 %), exprimait la non atteinte des objectifs du projet qui devait prendre fin en 2006. Beaucoup de projets pechent dans leur strategie participative a toutes les etapes, surtout celle de mise en œuvre. L’animation qui doit les accompagner, souvent reduite a la recherche d’adherents, merite d’etre adaptee au contexte des pauvres a majorite analphabetes et souvent peu sensibilisees au bien-fonde de la promotion de l’hygiene. Il est du ressort des techniciens d’encadrer les representants de la communaute et de renforcer leur niveau de connaissances dans le domaine de l’hygiene pour l’appropriation de tels projets.

Introduction : Les maladies evitables sont responsables de plus de deux millions de deces par an dans le monde. En Afrique subsaharienne, un enfant sur deux recoit chaque annee une serie de vaccinations incomplete. Au Senegal, ou le Programme elargi de vaccination (PEV) a ete initie en 1979 et generalise en 1985, l’objectif de couverture de 80 % par vaccination est entrave par les abandons. Cette etude a ete menee pour determiner les facteurs d’abandons de la vaccination de routine a Ndoulo, dans le district sanitaire de Diourbel. Methode : Une enquete epidemiologique exhaustive transversale, descriptive et analytique a ete menee du 16 au 25 avril 2005 aupres des meres de 562 enfants âges de 10 a 23 mois a Ndoulo. Resultats : Parmi les enfants qui ont recu leur BCG, 68,0 % ont obtenu leur vaccin antirougeoleux ; 67,1 % etaient vaccines completement (tous les antigenes recus) dont 19,4 % correctement (respectant le calendrier vaccinal du PEV). Le non-respect du calendrier vaccinal etait lie au manque de temps des parents (40,3 %), a l’oubli du rendez-vous (33,2 %), a la perte de la fiche de vaccination (10,3 %), aux voyages (7,7 %) et au manque d’argent (1,1 %). La proportion d’enfants completement vaccines avait un lien statistiquement significatif avec cinq facteurs : le sexe, la disponibilite du carnet de vaccination, la connaissance des reactions et du calendrier vaccinal, et la prise en charge de la vaccination. Elle a ete plus elevee quand l’enfant etait un garcon, le carnet disponible, les reactions vaccinales et le calendrier vaccinal connus par les parents, et la vaccination payee par le pere. Discussion : A Ndoulo, dans le district sanitaire de Diourbel, la couverture vaccinale complete reste faible, a cause du fort taux d’abandon associe a un faible respect du calendrier vaccinal. Les facteurs predominants, surtout lies aux populations, restent domines par la negligence. Conclusion : Il importe de prendre des mesures telles que la sensibilisation des parents, le systeme de parrainage des enfants ou l’exigence du carnet de vaccination a l’ecole, pour ameliorer la couverture vaccinale des enfants, au niveau du district sanitaire de Diourbel.

In Senegal, a significant decrease of malaria transmission intensity has been noted the last years. Parasitaemia has become lower and, therefore, more difficult to detect by microscopy. In the context of submicroscopic parasitaemia, it has become relevant to rely on relevant malaria surveillance tools to better document malaria epidemiology in such settings. Serological markers have been proposed as an essential tool for malaria surveillance. This study aimed to evaluate the sero-epidemiological situation of Plasmodium falciparum malaria in two sentinel sites in Senegal. Cross-sectional surveys were carried out in Velingara (south Senegal) and Keur Soce (central Senegal) between September and October 2010. Children under 10 years old, living in these areas, were enrolled using two-level, random sampling methods. P. falciparum infection was diagnosed using microscopy. P. falciparum antibodies against circumsporozoite protein (CSP), apical membrane protein (AMA1) and merozoite surface protein 1_42 (MSP1_42) were measured by ELISA method. A stepwise logistic regression analysis was done to assess factors associated with P. falciparum antibodies carriage. A total of 1,865 children under 10 years old were enrolled. The overall falciparum malaria prevalence was 4.99% with high prevalence in Velingara of 10.03% compared to Keur Soce of 0.3%. Symptomatic malaria cases (fever associated with parasitaemia) represented 17.37%. Seroprevalence of anti-AMA1, anti-MSP1_42 and anti-CSP antibody was 38.12, 41.55 and 40.38%, respectively. The seroprevalence was more important in Velingara and increased with age, active malaria infection and area of residence. The use of serological markers can contribute to improved malaria surveillance in areas with declining malaria transmission. This study provided useful baseline information about the sero-epidemiological situation of malaria in Senegal and can contribute to the identification of malaria hot spots in order to concentrate intervention efforts. Trial registration number: PACTR201305000551876 ( http://www.pactr.org ).

Identification of fungal clinical isolates is essential for therapeutic management. In resource-limited settings, identification mostly relies on biochemical tests whose sensitivity and specificity are known to be insufficient for identification of closely related or newly described species. MALDI-TOF has been shown in favored countries to be a reliable and powerful tool for microorganism identification, including yeasts. The aim of this study was to compare MALDI-TOF with routine identification procedures in a resource-poor context. A total of 734 clinical specimens (502 vaginal swabs, 147 oral swabs, 61 bronchoalveolar lavage fluids and 24 stool samples) have been tested in the mycology unit of Fann Hospital, Dakar, Senegal. Strains isolated from culture were identified by both conventional phenotypic methods (germ tube formation and biochemical panels) and MALDI-TOF Saramis/VITEK MS, bioMerieux, France. In addition to comparing the final identification, we determined the time of obtaining the results and the cost for both approaches. Overall, 218 (29.7 %) samples were positive for Candida. MALDI-TOF MS enabled the identification of 214 of the 218 strains isolated (98.1 %) at species level. Phenotypic approach yielded identification for 208 strains (95.4 %). Congruence between the tests was observed for 203 isolates. A discrepancy was observed for one isolate identified as Candida krusei with the phenotypic approach and Candida tropicalis with the MALDI-TOF. In addition, ten isolates identified at genus level by phenotypic methods were identified as C. glabrata (n = 8), C. tropicalis (n = 1) and C. parapsilosis (n = 1) by MALDI-TOF. The turnaround time for identification was

Seasonal malaria chemoprevention (SMC) is defined as the intermittent administration of full treatment courses of an antimalarial drug to children during the peak of malaria transmission season with the aim of preventing malaria-associated mortality and morbidity. SMC using sulfadoxine-pyrimethamine (SP) combined with amodiaquine (AQ) is a promising strategy to control malaria morbidity in areas of highly seasonal malaria transmission. However, a concern is whether SMC can delay the natural acquisition of immunity toward malaria parasites in areas with intense SMC delivery. To investigate this, total IgG antibody (Ab) responses to Plasmodium falciparum antigens glutamate-rich protein R0 (GLURP-R0) and apical membrane antigen 1 (AMA-1) were measured by enzyme-linked immunosorbent assay in Senegalese children under the age of 10 years in 2010 living in Saraya and Velingara districts (with SMC using SP + AQ [SMC+] since 2007) and Tambacounda district (without SMC (SMC-)). For both P. falciparum antigens, total IgG response were significantly higher in the SMC- compared with the SMC+ group (for GLURP-R0, P < 0.001 and for AMA-1, P = 0.001). There was as well a nonsignificant tendency for higher percentage of positive responders in the SMC- compared with the SMC+ group (for GLURP-R0: 22.2% versus 14.4%, respectively [P = 0.06]; for AMA-1: 45.6% versus 40.0%, respectively [P = 0.24]). Results suggest that long-term malaria chemoprevention by SMC/SP + AQ have limited impact on the development of acquired immunity, as tested using the P. falciparum antigens GLURP-R0 and AMA-1. However, other factors, not measured in this study, may interfere as well.

Background: Several of the intended P. falciparum vaccine candidate antigens are highly polymorphic and could render a vaccine ineffective if their antigenic sites were not represented in the vaccine. This study aimed to characterize genetic diversity of vaccine candidate antigens merozoite surface protein-3 (MSP-3), apical membrane antigen-1 (AMA-1) and erythrocyte binding antigen (EBA-175) in P. falciparum isolates from Senegal. Methods: DNA analysis was completed on 170 isolates of P. falciparum collected from Keur Soce in Senegal between 2006 and 2008. Genetic diversity was determined in the three P. falciparum genes by, PCR followed by restriction fragment length polymorphism (RFLP). Results: From 170 samples collected, successful, PCR products were obtained from 135 (79%), 140 (82%) and 128 (75%) for AMA-1, MSP-3 and EBA-175, respectively. The results showed that the EBA-175 gene presented 4 different alleles [EBA-175F_loop (62.3%), EBA-175C_loop (46.1%), EBA-175~400bp (17.6%), EBA-175~360bp (8.4%)]. Regarding the MSP-3 patterns, the analysis revealed the presence of three alleles MSP-3_K1 (49.2%), MSP-3_3D7 (54.2%) and MSP-3~350bp (15%). For AMA-1, the results showed three different alleles AMA-1_K1 (39%), AMA-1_HB3 (33%), AMA-1_3D7 (32%). Conclusion: Characterization of the genetic diversity in Plasmodium isolates from Keur Soce in Senegal in the three genes investigated showed a high degree of polymorphism. These findings are helpful in the formulation of a vaccine considering restricted repertoire populations.

Background Community case management of malaria (CCMm) and seasonal malaria chemoprevention (SMC) are anti-malarial interventions that can lead to substantial reduction in malaria burden acting in synergy. However, little is known about the social acceptability of these interventions. A study was undertaken to assess whether combining the interventions would be an acceptable approach to malaria control for community health workers (CHWs). Methods Sixty-one interviews and six focus group discussions were conducted nested in a cluster-randomized trial assessing the impact of combining CCMm and SMC in a rural area of Senegal. Participants consisted of: (i) members of village associations, (ii) members of families who had access to the interventions as well as members of families who did not access the interventions, (iii) CHWs, and (iv) community leaders, e g, religious guides and village chiefs. Results The interventions were acceptable to the local population and perceived as good strategy to make health care services available to community members and thus, to reduce the delays in access to anti-malarial treatment as well as expenses related to patients’ transfer to the health post. The use of malaria rapid diagnostic test (RDT) contributed to improving CHWs diagnostic capacity as well as malaria treatment practices. Study participants notified RDT and drugs stock-out as the major risk for sustainability of the intervention at community level. Conclusion Combining CCMm and SMC is a well accepted, community-based approach that can contribute to control malaria in areas where malaria transmission is seasonal.

Rapid diagnosis tests (RDTs) allow for the confirmation of malaria diagnosis. In Senegal, RDTs detecting HRP2 have been adopted in 2008 for malaria diagnosis. However, the sustainability of this strategy requires adequate and regular quality control. PCR on DNA extracted in nitrocellulose band of RDTs enable quality control. A RDT (Malaria Antigen P.f®) and a thick smear were performed on patients with suspected malaria. DNA was extracted from the nitrocellulose band of RDTs to which a non-specific PCR and a specific PCR were applied. The results of the RDT were compared with those obtained from the thick smear and the PCR to measure sensitivity, specificity as well as positive and negative predictive values. For 81.6% of the 273 patients involved, the thick smear was positive. Rapid diagnosis tests were positive for 85.7% of the patients. Non-specific PCR was positive on 87.9% of RDTs. Plasmodium falciparum was found in 99.5% of patients and Plasmodium ovale appeared in only 0.4% of patients. Sensitivity of the Malaria Antigen Pf® RDT in relation to thick smear and to PCR was 98.2% and 97.1% respectively. Quality control with PCR on the nitrocellulose band performed several months after it was used confirms its adequate level of sensitivity. The collection and screening of DNA present in already used RDT is a good means of quality control for this tool. It is also a relevant alternative to the molecular approach in the context of a reduction in the transmission of malaria.

Senegal has since 2003 used sulphadoxine-pyrimethamine (SP) for Intermittent Preventive Treatment (IPT) of malaria in risk groups. However, the large-scale IPT strategy may result in increasing drug resistance. Our study investigated the possible impact of SP-IPT given to infants and children on the prevalence of SP-resistant haplotypes in the Plasmodium falciparum genes Pfdhfr and Pfdhps, comparing sites with and without IPTi/c. P. falciparum positives samples (n=352) were collected from children under 5years of age during two cross-sectional surveys in 2010 and 2011 in three health districts (two on IPTi/c and one without IPTi/c intervention) located in the southern part of Senegal. The prevalence of SP-resistance-related haplotypes in Pfdhfr and Pfdhps was determined by nested PCR followed by sequence-specific oligonucleotide probe (SSOP)-ELISA. The prevalence of the Pfdhfr double mutant haplotypes (CNRN and CICN) was stable between years at10% in the control group (P=0.69), while it rose significantly in the IPTi/c group from 2% in 2010 to 20% in 2011 (P=0.008). The prevalence of the Pfdhfr triple mutant haplotype (CIRN) increased in both groups, but only significantly in the IPTi/c group from 41% to 65% in 2011 (P=0.005). Conversely, the Pfdhps 437G mutation decreased in both groups from 44.6% to 28.6% (P=0.07) and from 66.7% to 47.5% (P=0.02) between 2010 and 2011 in the control and the IPTi/c groups, respectively. Combined with Pfdhfr, there was a weak trend for decreasing prevalence of quadruple mutants (triple Pfdhfr+Pfdhps 437G) in both groups (P=0.15 and P=0.34). During the two cross-sectional surveys, some significant changes were observed in the SP-resistance-related genes. However, since these changes were observed in the two groups, the IPTi/c strategy does only seem to have limited impact on resistance development and other factors as well. However, continuous monitoring will be needed, due to the up-scaling of the IPTi/c strategy in Senegal according to WHO recommendations.

BACKGROUND: In sub-Saharan Africa, malaria is the leading cause of morbidity and mortality especially in children. In Senegal, seasonal malaria chemoprevention (SMC) previously referred to as intermittent preventive treatment in children (IPTc) is a new strategy for malaria control in areas of high seasonal transmission. An effectiveness study of SMC, using sulphadoxine-pyrimethamine (SP) plus amodiaquine (AQ), was conducted in central Senegal from 2008 to 2010 to obtain information about safety, feasibility of delivery, and cost effectiveness of SMC. Here are report the effect of SMC delivery on the prevalence of markers of resistance to SP and AQ. METHODS: This study was conducted in three health districts in Senegal with 54 health posts with a gradual introduction of SMC. Three administrations of the combination AQ + SP were made during the months of September, October and November of each year in children aged less than 10 years living in the area. Children were surveyed in December of each year and samples (filter paper and thick films) were made in 2008, 2009 and 2010. The prevalence of mutations in the pfdhfr, pfdhps, pfmdr1 and pfcrt genes was investigated by sequencing and RTPCR in samples positive by microscopy for Plasmodium falciparum. RESULTS: Mutations at codon 540 of pfdhps and codon 164 of pfdhfr were not detected in the study. Among children with parasitaemia at the end of the transmission seasons, the CVIET haplotypes of pfcrt and the 86Y polymorphism of pfmdr1 were more common among those that had received SMC, but the number of infections detected was very low and confidence intervals were wide. The overall prevalence of these mutations was lower in SMC areas than in control areas, reflecting the lower prevalence of parasitaemia in areas where SMC was delivered. CONCLUSION: The sensitivity of P. falciparum to SMC drugs should be regularly monitored in areas deploying this intervention. Overall the prevalence of genotypes associated with resistance to either SP or AQ was lower in SMC areas due to the reduced number of parasitaemia individuals.