Serological Data Shows Low Levels of Chikungunya Exposure in Senegalese Nomadic Pastoralists

The chikungunya virus (CHIKV) is spread by Aedes aegypti and Ae. albopictus mosquitos worldwide; infection can lead to disease including joint pain, fever, and rash, with some convalescent persons experiencing chronic symptoms. Historically, CHIKV transmission has occurred in Africa and Asia, but recent outbreaks have taken place in Europe, Indonesia, and the Americas. From September to October 2014, a survey was undertaken with nomadic pastoralists residing in the northeast departments of Senegal. Blood dried on filter paper (dried blood spots; DBS) were collected from 1465 participants of all ages, and assayed for Immunoglobulin G (IgG) antibodies against CHIKV E1 antigen by a bead-based multiplex assay. The overall seroprevalence of all participants to CHIKV E1 was 2.7%, with no persons under 10 years of age found to be antibody positive. Above 10 years of age, clear increases of seroprevalence and IgG levels were observed with increasing age; 7.6% of participants older than 50 years were found to be positive for anti-CHIKV IgG. Reported net ownership, net usage, and gender were all non-significant explanatory variables of seropositivity. These data show a low-level historical exposure of this pastoralist population to CHIKV, with no evidence of recent CHIKV transmission in the past decade

Onychomycosis Caused by Fusarium spp. in Dakar, Senegal: Epidemiological, Clinical, and Mycological Study

Fusarium spp. represent 9 to 44% of onychomycoses caused by fungi other than dermatophytes. This retrospective study describes 17 cases of Fusarium onychomycosis diagnosed at the Laboratory of Parasitology and Mycology of Le Dantec University Hospital in Dakar, Senegal, from 2014 to 2016. It included all patients received in the laboratory for suspicion of onychomycosis between January 1, 2014, and December 31, 2016. Diagnosis was based on mycological examination including direct examination and culture. Mycological analysis was considered positive when direct examination and culture were positive after at least one repeat. Seventeen Fusarium onychomycosis cases representing 12.9% of all onychomycoses reported were diagnosed. There were 5 cases on the fingernails and 12 on the toenails in 6 males and 11 females, and the mean age was 44 years (range: 26–64). Onychomycoses were diagnosed in immunocompetent patients except in a diabetic patient. The mean duration of lesions was 4.9 years (range: 1–15), and distal subungual onychomycosis was predominant. Almost all patients were from suburban areas of Dakar region. The most frequent species isolated belong to Fusarium solani complex. Because of the risk of disseminated infection in immunocompromised patients, realization of susceptibility tests is necessary to ensure better therapeutic management

A Comparative Study on Phenotypic versus ITS-Based Molecular Identification of Dermatophytes Isolated in Dakar, Senegal

International audienc

Evaluation of knowledge and experience of fungal infections (mycoses) among clinical doctors in Senegal

International audienc

Quality control of malaria microscopy reveals misdiagnosed non-falciparum species and other microscopically detectable pathogens in Senegal

Abstract Background In developing countries, malaria diagnosis relies on microscopy and rapid diagnostic tests. In Senegal, national malaria control program (NMCP) regularly conducts supervisory visits in health services where malaria microscopy is performed. In this study, expert microscopists assessed the performance of laboratory technicians in malaria microscopy. Methods The present external quality assessment (EQA) was conducted in three different areas of malaria transmission. Participants were laboratory technicians previously trained by NMCP on malaria microscopy. Stored read slides were randomly collected for blinded re-checking by expert microscopists. At the same time a set of 8 slides (3 positive P. falciparum and 5 negative slides) were submitted to participants for proficiency testing. Microscopists performance were evaluated on the basis of the errors rates on slide reading—high false positive (HFP), high false negative (HFN), low false positive (LFP) and low false negative (LFN)—and the calculation of their sensitivities and specificities relative to expert microscopy. Data were entered and analysed using Microsoft Excel software. Results A total of 450 stored slides were collected from 17 laboratories for re-checking. Eight laboratories scored 100% of correct reading. Only one major error was recorded (HFP). Six laboratories recorded LFN results: Borrelia, P. ovale, and low parasite densities (95 and 155 p/μl) were missed. Two P. falciparum slides were misidentified as P. malariae and one P. ovale slide as P. vivax. The overall sensitivities and specificities for all participants against expert microscopists were 97.8 and 98.2% respectively; Sensitivities and specificities of hospital microscopists (96.7 and 98.9%) were statistically similar to those of health centre microscopists (98.5 and 97.8% respectively) (p = 0.3993 and p = 0.9412 respectively). Overall, a very good agreement was noted with kappa value of 0.96 (CI95% 93.4–98.6%) relative to expert microscopy. Proficiency testing showed that among the 17 participants, 11 laboratories scored 100% of correct reading. Three LFN and four LFP results were recorded respectively. The P. falciparum slide with Maurer dots was misidentified as P. ovale in 1 centre and the same slide was misread as P. vivax in another centre; No major error (HFP or HFN) was noted. Conclusion EQA of malaria microscopy showed an overall good performance especially regarding P. falciparum detection. However, efforts need to be made addressing the ability to detect non-falciparum species and others endemic blood pathogens such as Borrelia. The further NMCP training sessions and evaluations should consider those aspects to expect high quality-assured capacity for malaria microscopy