Gastrointestinal protist infections, mainly caused by Giardia duodenalis and Cryptosporidium spp., are major contributors to childhood morbidity in resource-limited settings, yet their epidemiology in Madagascar remains poorly documented.We conducted a microscopy-based prospective cross-sectional study in three deprived areas of southern Madagascar to investigate pathogenic and commensal protists among children and adolescents (n = 318), young women (n = 57), and their children (n = 61).Epidemiological questionnaires were collected, and selected species were characterised using PCR and Sanger sequencing.Risk factors were analysed using binary logistic regression.A total of 436 stool samples and 221 questionnaires were analysed.G. duodenalis was the most prevalent pathogenic species (81.9%), followed by Cryptosporidium spp.(1.2%); Balantioides coli was not detected.Potentially pathogenic species included Blastocystis sp.(70.4%) and Dientamoeba fragilis (0.2%).The most frequent commensals were Entamoeba coli (37.4%),Endolimax nana (15.4%) and Iodamoeba bütschlii (12.6%).Assemblages A, B and A+B were identified for G. duodenalis, and C. hominis, C. felis and C. parvum for Cryptosporidium spp.;Blastocystis subtypes ST1-ST3 were detected.G. duodenalis infection was associated with abdominal pain and loss of appetite, but not diarrhoea.Geographical origin predicted G. duodenalis infection and Blastocystis sp. and E. coli colonisation.Gastrointestinal protist infections by G. duodenalis and, to a lesser extent, by Cryptosporidium spp., are a public health concern in resource-limited settings in Madagascar.Our results are the most important contribution made in the country in terms of molecular epidemiology of intestinal protist.
Tapia-Veloz et al. (Tue,) studied this question.