Intestinal parasitic infections (IPIs) are a worldwide public health problem, especially in resources limited countries. Globally, about 3.5 billion people are affected by parasitic infections. The annual morbidities and mortalities due to IPIs are estimated to be over 450 million and 200,000, respectively 123. According to World Health Organization (WHO), children living in endemic are most affected with an estimated number of 270 million preschool children and over 600 million school children 4. This endemicity could be explained by a high population density and low environmental and socio-economic conditions such as poor hygiene conditions, low access to improved water sources, lack of standard sanitary facilities and limited economic resources 56. Morbidity and indirect effects of IPIs have a substantial impact on health and quality of life 4. Two groups of parasites can colonize the digestive tract, protozoa, and helminths. Their pathogenicity is variable from asymptomatic carriage to severe morbidity cases depending on the intensity of the infection 7. Symptoms such as diarrhea, dysentery, vomiting, and anorexia are often observed. Diarrhea, including that of parasitic origin, is among the most common illnesses which cause infant and childhood mortality in developing countries 89. IPIs can also be responsible of anemia, stunting, underweight, physical weakness, and low educational performance in schoolchildren 1011.

In Senegal, intestinal parasites are a common cause of outpatient. A study carried out at the Fann University Hospital showed a prevalence of 26.8% with a predominance of protozoa (83%) 12. Other studies carried out in community level have shown a predominance of protozoa over helminths 1314.

According to WHO, 10% of the world's population is infected by Entamoeba parasites. Infection with Entamoeba histolytica is the third leading cause of mortalitý by parasitic diseases in the world after malaria and bilharzia. It affects approximately 50 million people, of whom 40,000 to 110,000 each deaths year15. Giardia intestinalis infection is one of the most digestive flagelloses both in terms of frequency and pathogenicity with an estimated number of 280 million cases mainly located in Asia, Africa, and Latin America 16. Other protozoan infections such as Blastocystis sp. are gaining interest with prevalence becoming increasingly high 17

To control morbidity related to intestinal parasitic infection, several strategies are recommended by WHO, including mass deworming campaign with Mebendazole and/or Albendazole. In Senegal, this strategy has been implemented since 2006 by the Ministry of Health (MoH). This strategy has considerably reduced the frequency of intestinal parasite carriage with a decrease of helminths parasites but a persistence of intestinal protozoa parasites 1318. In this context, it become relevant to generate new data in order to update the epidemiology of intestinal parasites for better orienting control strategies. The objective of this study was to evaluate the prevalence of intestinal protozoan infection diagnosed in Fann University Hospital.

Intestinal parasitic infections are major cause of morbidity and mortality worldwide especially in developing countries. With the implementation of mass deworming campaign with Mebendazole/Albendazole, there is a rarefaction of helminths and a persistence of intestinal protozoa.

The results of our study showed an overall prevalence of 26.4% of intestinal protozoan infection. Sylla et al when studying the epidemiological aspects of intestinal parasitic infection in the same hospital between, have found a prevalence of 26.8% with a predominance of protozoa (83%) 19. Similar trends were previously described by Tine et al and Faye et al who reported 29.6% and 23.7% prevalence of intestinal protozoa parasites respectively1419 . Other studies conducted in worldwide have showed the endemic characters of intestinal protozoa parasites. In Côte d’Ivoire, Ouatara et al when assessing the prevalence and polyparasitism of intestinal protozoa in school aged children have noted a high intestinal protozoa prevalence 98.5% (4398/4466) 20. Afshar et al in Iran reported high prevalence of protozoan parasites 32.3% (95% CI 28.4 to 36.5) compared helminthic parasites 3.2% (95% CI 2.1 to 4.7) 21.

The species most frequently found in our series were Blastocystis sp. (40.8%), E. coli (38.2%), E. nana (8.2%), G. intestinalis (8.1%), E. histolytica (2.3%).These species are therefore mostly non-pathogenic except G. intestinalis. Diongue et al in 2017 have found́ in their series Entamoeba coli (51.5%), E histolytica (17%), G. intestinalis (10.5%) and Blastocystissp (5.6%) 22. The high frequency of intestinal protozoa parasites was described in other countries. In Benin by Nicolas et al have showed 76.03% intestinal parasite prevalence with high proportion of protozoa parasites (87.5%). The main protozoa species were Giardia lamblia (39.42%), E. histolytica (25.96%), E. coli (11.54%), Trichomonas intestinalis (10.58%)23. Dorkenoo et al in Togo when studying the prevalence of Soil-Transmitted Helminths and Intestinal Protozoa among School Children in Lomé have observed high prevalence of intestinal protozoa (52.2%) with the following main species: E. coli (16.5%), E. histolytica (2.3%), G. lamblia (11.5%), Blastocystis sp. (10.9%) 24. Similar species were noted in Marocco by Hafida et al with Blastocystis sp. (30.2%), E. coli (25.6%), G. intestinalis (17.4%) and E. histolytica (10.5%)25. Au Tchad, Emmanuel et al have showed 39.5% prevalence of intestinal parasites. The parasitism was mainly due to protozoa with 97%. The main parasites identified are G. intestinalis (27%), E. histolytica (21%), E. coli (18%) T. intestinalis (15%) 26.

The results from this study showed that intestinal protozoa carriage was more important in patients aged 15 - 30 years with a percentage of 28.3%. The prevalence in subject under 15 years old was 25.9%. The lower frequency observed in the 0-15 years category (25.9%) is probably the result of the action of the Ministry of Health which since 2006 has implemented regular systematic deworming campaigns with Mebendazole/Albendazole in children in all health districts of Senegal.

Our results showed that the frequency of protozoa parasite was higher in males (26.9%) than in females (25.7%). Similar results showing predominance of intestinal protozoan infection in male patients were observed in Yemen and Malaysia 2728. Other studies conducted in Senegal have demonstrated that the prevalence of intestinal protozoa parasites was more important among female participants1423. This is in line with previous study conducted in Kenya where the prevalence of intestinal parasitic infection was higher in female participant (42.5%) compared to male participants (41.6%) 29.

Regarding the season, the results from our study showed that intestinal protozoa carriage was is more frequent during the rainy season (26.9%). This situation could be explained by a degradation of hygiene conditions observed during the period. Similar results were obtained by Sylla et al with a higher frequency in rainy season (27.27%) than in the dry season 26.5% 12.

According to the aspect of stool samples, the results of this study showed that intestinal protozoa parasite carriage was observed in patients with watery stool and watery+mucus stools was 20.8% and 19.8% respectively.Patients with watery stools with blood and mucus had a positivity rate of 21.5% This was previously described in Rwanda by Emilie et al who noted that intestinal parasites were found in patients having watery stool (78.9%), watery+mucus (42.2%). Low parasite carriage (8.3%) was noted in patients with watery+mucus+blood in their stool samples 30. In patients with consistent stool sample, similar results were noted in Rwanda.

Therefore, our results point out that in developing countries intestinal parasitic infection is still endemic despite the implementation of mass deworming campaign in children and other age groups. Intestinal protozoa parasites are frequent with a predominance of non or low pathogenic forms.

The study showed that intestinal protozoan infection is a public health concern in health facilities in Senegal. Adults and male subjects are more infected. In the rainy season which is associated with degradation of socio-environmental factors, the prevalence intestinal protozoan infection is high. Therefore, there is a need to improve access to safe water, quality of sanitary facilities and also to sensitize populations on the respect of hands washing in order to limit the spread of parasites. Additional studies should be conducted with advanced microscopic and molecular techniques that can be helpful for a better diagnosis of intestinal parasites and to update the epidemiology of the disease in order to take appropriate prevention and control measures.

This study was not funded. Funding for data collection was covered by the Laboratory of Parasitology-Mycology, of Fann teaching Hospital.

We would like to acknowledge the entire study participant and the staff of the laboratory of parasitology at Fann Teaching Hospital.

KS conceived and designed the study. KS supervised the data collection. KS analyzed the data and wrote the first draft of the manuscript. All authors read and approved the final manuscript.

The data used for this research article are available from the corresponding author upon request.