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Concept: Protozoan infection


The authors report the results of parasitological analyses of stool samples in N'Djamena (Chad) since 1963 and in Garoua (North Cameroon) since 1990. The number of positive stool examinations has fallen, with a significant decline in helminthiases, although the level of protozoan infections has remained essentially the same.

Concepts: Bacteria, Intestinal parasite, Protozoa, Chad, Cameroon, Protozoan infection


BACKGROUND The first scientific case related to Urbanorum spp protozoan infection was identified in Peru in 1994. Considering there are few cases catalogued, the aim of this study was to register the first case of Urbanorum spp infection in Brazil. CASE REPORT A thin 41-year-old female patient with dark skin, weighing 55 to 60 kg attended the Buriti Municipal Central Laboratory, in Maranhão, Brazil to undergo routine exams. Among the exams requested was a parasitological exam of feces, which was processed according to the protocol of Hoffman, Pons, and Janer (HPJ) or Lutz, an easy, simple, and low-cost parasitological technique. This method consists in spontaneous sedimentation of a filtered homogenate of feces sample and water. The sample was stained with Lugol and examined under light microscopy at 10× and 40×. We detected a light-yellow structure with rounded shape and several filaments similar to pseudopods. The microscopic analysis raised doubts about the identity and pathogenicity of this microorganism. CONCLUSIONS This study reports the first case of Urbanorum spp infection in Brazil, where the current environmental conditions have contributed to new parasitological cases. Therefore, further studies are recommended to identify unknown cases of Urbanorum spp infection in other regions of the country to create a national registry related to this new protozoan.

Concepts: Eukaryote, Microscope, Case, Microscopy, Kilogram, Windows Registry, Subroutine, Protozoan infection


Enteric protozoan infections are associated with morbidity and mortality worldwide. We evaluated effects of individual and combined water, sanitation, handwashing (WSH), and nutritional interventions on protozoan infections in children.

Concepts: Mortality rate, Protozoa, Child, Protozoan infection


Intestinal protozoa are parasites transmitted by consumption of contaminated water and food and mainly affect children and elder people and cause considerable health problems. They are the leading causes of outpatient morbidity due to diarrhea in the developing countries. So, assessing water and food source of diarrheal patients and identifying the main associated factors for transmission of protozoan parasitic infections help for effective control measures of protozoan infections. Hence, the current study was aimed at determining the prevalence of foodborne intestinal protozoa infections and associated factors among diarrheic patients in North Ethiopia.

Concepts: Immune system, Bacteria, Protozoa, Diarrhea, Protozoan infection


As part of lymphatic filariasis (LF) transmission assessment surveys (TAS) on Fiji, an island-wide assessment of gastrointestinal protozoan infection was performed through concomitant stool sample collections to investigate the distribution of the protozoan infection. All grade 1 and 2 students of 69 schools in the two main islands were targeted in two phases (one in the Western Division and the other in the Central and Northern, except Taveuni sub-Division of Northern), where fecal samples of 1,800 students were available for coproscopy using the formalin-ether-acetate concentration. The overall prevalence of Giardia infections was 1.6%, having 2.2% in Western and 0.8% in Central/Northern Divisions (P = 0.094). The school-level prevalence of giardiasis ranged from 0% to 15.4%, and hotspot analysis using the Getis-Ord Gi* method detected the special heterogeneity of giardiasis prevalence in schools around Lautoka (Z-score = 3.36, P value < 0.05), an area affected by Cyclone Kofi in February 2014. Any protozoan infection prevalence was 4.9% in Western and 4.4% in Central/Northern Divisions (P = 0.8254). Real-time polymerase chain reaction analysis to confirm the findings from a parasitological examination of a 10% stool archive in 95% ethanol from Western revealed an elevated prevalence of giardiasis up to 22.4%, the presence of Entamoeba histolytica, and the absence of Cryptosporidium parvum. Obtaining stool samples alongside LF TAS is a convenient access platform for cosurveillance of gastrointestinal protozoan infections and has pinpointed hitherto unknown hotspots of Giardia infections in urban city centers of Fiji. This calls for greater attention to apply tailored water, sanitation, and hygiene measures for the control of these parasites.

Concepts: Infectious disease, Giardia lamblia, Protozoa, Parasitic diseases, Entamoeba histolytica, Cryptosporidium parvum, Coccidia, Protozoan infection


The lack of an effective chemotherapy for treatment of protozoan disease urges a wide investigation for active compounds, and plant-derived compounds continue to provide key leads for therapeutic agents. The current study reports the in vitro antiprotozoal evaluation of the Algerian medicinal plant Pulicaria inuloides against Leishmania amazonensis, Trypanosoma cruzi, and Acanthamoeba castellanii str. Neff. All the extracts from the aerial part showed to be present a higher leishmanicidal activity than anti-Acanthamoeba or Trypanosoma. Therefore, bioguided fractionation of the active CHCl3 extract led to the isolation and characterization of the flavonol, quercetagetin-3,5,7,3'-tetramethyl ether (1) as the main component. The structure of compound 1 was established by extensive 1D and 2D NMR spectroscopic analysis (COSY, HSQC, HMBC, and ROESY experiments), chemical transformation (derivatives 2 and 3), and comparison with data in the literature. Compound 1 and derivatives 2 and 3 were further evaluated against the promastigote and amastigote stage of L. amazonensis. Compounds 1-3 exhibited moderate leishmanicidal activity with IC50 values ranging from 0.234 to 0.484 mM and from 0.006 to 0.017 mM for the promastigote and amastigote forms, respectively, as well as low toxicity levels on macrophages (CC50 ranging from 0.365 to 0.664 mM). This study represents the first report of the antiprotozoal evaluation of Pulicaria inuloides, and the results highlight this species as a promising source of leishmanicidal agents.

Concepts: Immune system, Spectroscopy, Chagas disease, Chemical compound, Leishmania, Trypanosome, Trypanosoma cruzi, Protozoan infection


Ichthyophthirius multifiliis is a widespread, ciliated protozoan ectoparasite of fish. In the present study, we investigated the effects of metal nanoparticles on the reproduction and infectivity of free-living stages of I. multifiliis. We determined that ~50% of theronts could be killed within 30 min of exposure to either 20 ng mL-1 gold, 10 ng mL-1 silver or 5 ng mL-1 zinc oxide nanoparticles. Silver and zinc oxide nanoparticles at concentration of 10 and 5 ng mL-1 killed 100 and 97% of theronts, respectively and inhibited reproduction of tomonts after 2 h exposure. Gold nanoparticles at 20 ng mL killed 80 and 78% of tomonts and theronts 2 h post exposure, respectively. In vivo exposure studies using rainbow trout (Oncoryhnchus mykiss) demonstrated that theronts, which survived zinc oxide nanoparticles exposure, showed reduced infectivity compared with control theronts. No mortalities were recorded in the fish groups cohabited with theronts exposed to either nanoparticles compared with 100% mortality in the control group. On the basis of the results obtained from this study, metal nanoparticles particularly silver nanoparticles hold the best promise for the development of effective antiprotozoal agents useful in the management of ichthyophthiriosis in aquaculture.

Concepts: Nanoparticle, Aluminium, Zinc, Copper, Gold, Silver, Ciliate, Protozoan infection


Bolivia is one of the countries with a high intestinal helminth and protozoan infection rate. Despite the high prevalence of the parasitic infection, nationwide preventive measures for Bolivian children have not yet been implemented. We evaluated the effect of mass stool examination and treatment as a strategy for decreasing the infection rate. This study was conducted between 2013 and 2015 in children aged 2-18 years. A total of 2,033 stool samples (575 in 2013, 815 in 2014 and 642 in 2015) were collected and examined using the formalin-ether medical sedimentation method. As an anthelminthic medicine, nitazoxanide was given to all infected children within 2 months post-examination, each year. The effect of mass stool examination and treatment was evaluated based on the changes in the overall or individual parasitic infection rates during the study period. The overall parasitic infection rate decreased significantly from 65.2% in 2013 to 43.0% in 2015; a 22.2 percentage point decrease (P<0.001). Protozoan infection accounted for a large portion of the parasitic infections, in the following rates: 62.4% in 2013, 49.3% in 2014, and 41.0% in 2015. The rate of the most common helminth infection, Hymenolepis nana, decreased significantly from 9.0% in 2013 to 6.4% in 2014 to 3.4% in 2015 (P<0.001). Prevalence of the most common pathogenic protozoan infection, Entamoeba histolytica, decreased significantly from 19.0% in 2013 to 3.0% in 2015 (P<0.001). Conversely, the rate of Giardia intestinalis increased significantly from 16.5% in 2013 to 21.2% in 2015 (P<0.01). Mass stool examination and treatment for intestinal helminth and protozoan infections was effective for decreasing the overall parasitic infection rate in the study population, excluding Giardia intestinalis. Further studies on the long-term effect of mass stool examination and treatment for decreasing all intestinal parasitic infection rates in Bolivian children are needed.

Concepts: Bacteria, Infection, Intestinal parasite, Giardia lamblia, Protozoa, Transmission and infection of H5N1, Entamoeba histolytica, Protozoan infection


Parasitic infections are still a significant health problem in rural areas in developing countries including Iran. There is no recent population-based data about the prevalence of human intestinal parasites in most rural areas of Iran. The current study aimed to determine the prevalence of intestinal protozoan infection in inhabitants of rural areas of Boyer-Ahmad district, Southwestern Iran.

Concepts: Immune system, Epidemiology, Disease, Bacteria, Intestinal parasite, Protozoan infection


Visceral leishmaniasis (VL) is a protozoan disease that is invariably fatal if left untreated. The disease is found in 70 countries with incidence of 0.2 - 0.4 million cases. The mainstay of treatment in resource limited countries like Ethiopia is antimonials, while use of liposomal amphotericin B is reserved for treatment of complicated VL cases. The aim of this study was to assess the safety and efficacy of liposomal amphotericin B in HIV negative VL patients diagnosed with complications.

Concepts: Infectious disease, Medical terms, Amphotericin B, Leishmaniasis, Visceral leishmaniasis, Leishmania, Protozoan infection, Oral candidiasis