Introduction: Scalp ringworms or Tinea capitis are ubiquitous superficial fungal infections of the scalp and hair. They represent the most common dermatophytic in the world. They reach almost exclusively pre-pubescent children and mainly school-aged children. The objective of this study was to assess the prevalence of tinea capitis and its associated factors among residents of koranic schools located in the Thiès region of Senegal. Patients and Methods: A cross-sectional study was conducted from February 2019 to March 2020. School children living in Thiès region (Central part of Senegal) were included in this study. Socio-demographic, clinical and biological data were collected standard questionary. Samples collected were examined directly and developed on a medium of Sabouraud-Chloramphenicol and Sabouraud-Chloramphenicol-Actidione. A descriptive analysis was done with the Stata MP. Risk factors were assessed by multivariate survey logistic regression models. Significance level of the different tests was 0.05 two-sided. Results: A total of 110 children were included in this study. The mean age was 9 years and the population was predominantly male (96.4%). The average number of residents in Koranic schools was 112. The prevalence of scalp ringworms was 68.2% [(75/110) (95% CI: 53.6 – 85.5)]. The fungal species found were Trichophyton soudanense (93.4%), Microsporum audouinii (2.7%). Trichophyton mentagrophytes, and Trichophyton violaceum were found with each (1.3%). Parasitism was endothrix-like in 86.7%. Children over 10 years old were more affected (72.9%), OR =2,16, CI (0,48 - 9,69). The rate of positivity was higher in children with small plaques (72.7%). Children with irregular-edged plaques were most affected (76.5%), Prevalence was higher among children who slept at more than 3 per mattress (79.1%), OR=1.82 (95% CI: 1.08 – 3.04). Conclusion: These results showed that Tinea capitis are frequent in children living in community. Trichophyton soudanense is the main fungal specie identified. Better knowledge of the epidemiology of these diseases and improved living conditions for children in Koranic schools could help improve patient management.

Bulinus snails surviving drought play a key role in seasonal transmission of urogenital schistosomiasis although our knowledge of their adaptation to dry season is still limited. We investigated the survival dynamic and infestation by Schistosoma haematobium of Bulinus snails during the dry and rainy seasons in a single pond in an area of seasonal schistosomiasis transmission in Senegal. Additionally, their aestivation capacity was evaluated under semi natural conditions. During the rainy season, of the 104 specimens collected, 98 (94.23%) and 06 (5.76%) were identified as B. senegalensis and B. umbilicatus, respectively. In the dry season, B. umbilicatus outnumbered B. senegalensis, however, all 5 (100%) B. senegalensis collected were viable and alive after interruption of aestivation by immersion in water while only 7 of 24 (29.16%) B. umbilicatus collected emerged from their dormant state. The adaptation of B. senegalensis and B. umbilicatus to the rainy and dry seasons, respectively, was also observed in semi-natural conditions. The rate of infestation with S. haeamatobium during the rainy season was 18.2% (19/104) while all the viable snails collected during the dry season were negative. B. senegalensis and B. umbilicatus have different seasonal dynamics with no evidence of maintaining S. haematobium infestation during the drought. Further studies including more survey sites and taking account both snails biology and ecological conditions are needed to better understand snail adaptation to seasonal changes and their ability to maintain S. haeamatobium infestation during drought.