Human intestinal parasites in Mahajanga, Madagascar: The kingdom of the protozoa

Valentin Greigert (1, 2) , Ahmed Abou-Bacar (2, 3) , Julie Brunet (2, 3) , Céline Nourrisson (4, 5) , Alexander Pfaff (2, 3) , Leila Benarbia (3) , Bruno Pereira (6) , Milijaona Randrianarivelojosia (7, 8) , Jean-Louis Razafindrakoto (8) , Rivo Solotiana Rakotomalala (8) , Eugène Morel (9) , Ermanno Candolfi (2, 3) , Philippe Poirier (10, 5)

1 Hôpital pasteur [Colmar]
2 IPPTS - Institut de Parasitologie et de Pathologie Tropicale
3 Laboratoire de Parasitologie et de Mycologie Médicale [Strasbourg]
4 LMGE - Laboratoire Microorganismes : Génome et Environnement
5 Laboratoire de Parasitologie et Mycologie [CHU Clermont-Ferrand]
6 DRCI - Direction de la recherche clinique et de l’innovation [CHU Clermont-Ferrand]
7 Unité de Recherche sur le Paludisme [Antananarivo, Madagascar]
8 CHU PZaga [Mahajanga, Madagascar]
9 CHU Mahavoky Atsimo [Mahajanga, Madagascar]
10 LMGE - Laboratoire Microorganismes : Génome et Environnement

INTRODUCTION: Intestinal parasitic infections are a major public health problem in inter-tropical areas. The aim of our study was to describe the situation in Mahajanga, Madagascar with a particular focus on two protozoa, Dientamoeba fragilis and Blastocystis sp. METHODS: This was a prospective study from February to June 2015. Stool samples from symptomatic hospitalized patients and asymptomatic volunteers were submitted to microscopy and molecular assays in order to detect parasites. RESULTS: A wide panel of intestinal parasites were identified among the 265 included subjects, protozoa being the most prevalent with 72.8% whereas the prevalence of helminths and microsporidia was of 7.9% and 4.5%, respectively. Blastocystis sp. was the most prevalent protozoa (64.5% of the entire cohort) followed by various amoebas (35.5%) and flagellates (27,5%). We only detected subtypes 1, 2 and 3 of Blastocystis sp. Among the patients positive for D. fragilis (9.4%), 23 carried genotype 1 and 1 genotype 2. For the first time, we detected in 4 human stools the DNA of a recently described protozoon, Simplicimonas similis. Interestingly, subjects living in urban areas harbored significantly more different parasitic species than subjects living in rural areas with a correlation between sanitary level of neighborhood and protozoan infection. However, there was no difference in prevalence of digestive symptoms between parasite-free and parasite-infected subjects, except for Giardia intestinalis which had more symptomatic carriers. DISCUSSION: Our study reveals a high overall parasite prevalence, similar to what had been found in 2003 in the same city and to other prevalence studies conducted in Africa. The poor access of the population to sanitary infrastructures may explain this result. Data from our study provide valuable key for sanitation programs and prevention of fecal-related infectious diseases.

Domaines: Maladies infectieuses; Parasitologie

Valentin Greigert, Ahmed Abou-Bacar, Julie Brunet, Céline Nourrisson, Alexander Pfaff, et al.. Human intestinal parasites in Mahajanga, Madagascar: The kingdom of the protozoa. PLoS ONE, 2018, 13 (10), pp.e0204576. ⟨10.1371/journal.pone.0204576⟩. ⟨hal-02150619⟩