Drug repurposing for parasitic protozoan diseases.

Protozoan parasites are major hazards to human health, society, and the economy, especially in equatorial regions of the globe. Parasitic diseases, including leishmaniasis, malaria, and others, contribute towards majority of morbidity and mortality. Around 1.1 million people die from these diseases annually. The lack of licensed vaccinations worsens the worldwide impact of these diseases, highlighting the importance of safe and effective medications for their prevention and treatment. However, the appearance of drug resistance in parasites continuously affects the availability of medications. The demand for novel drugs motivates global antiparasitic drug discovery research, necessitating the implementation of many innovative ways to maintain a continuous supply of promising molecules. Drug repurposing has come out as a compelling tool for drug development, offering a cost-effective and efficient alternative to standard de novo approaches. A thorough examination of drug repositioning candidates revealed that certain drugs may not benefit significantly from their original indications. Still, they may exhibit more pronounced effects in other disorders. Furthermore, certain medications can produce a synergistic effect, resulting in enhanced therapeutic effectiveness when given together. In this chapter, we outline the approaches employed in drug repurposing (sometimes referred to as drug repositioning), propose novel strategies to overcome these hurdles and fully exploit the promise of drug repurposing. We highlight a few major human protozoan diseases and a range of exemplary drugs repurposed for various protozoan infections, providing excellent outcomes for each disease.

Intestinal Parasitic Infections in People Referring to the Central Laboratory of Meshkin Shahr County, Ardabil Province, Iran.

Background: Intestinal parasitic infections are still a considerable global public health problem. We aimed to determine the frequency of intestinal parasitic infections among people referring to the central laboratory of Meshkin Shahr City, Ardabil Province, Iran. Methods: In this cross-sectional survey, 460 fecal samples were collected randomly from persons referred to the central laboratory of Meshkin Shahr City, from January to June 2022. The samples were examined by direct wet-mount, Trichrome and modified Ziehl-Neelsen staining, formalin ethyl acetate sedimentation, and agar plate culture. Results: The frequency of intestinal parasites was 15.7% (72 out of 460 cases), with some people with numerous intestinal parasites. The frequency of protozoan infections (13.9%) was higher than the helminthic infections (2.6%). Blastocystis spp. (8.1%) was the most prevalent detected intestinal protozoan. Entamoeba coli (5.7%), Dicrocoelium dendriticum (2.2%), Giardia lamblia (1.5%), Fasciola spp. (0.2%), and Hymenolepis nana (0.2%) were other detected parasites. Conclusion: In- spite of betterment of the health condition in Iran and reduction of parasitic infection, intestinal parasitic infections are still a considerable public health issue in some parts of Iran.

An introduction to scanning transmission electron microscopy for the study of protozoans.

Since its inception in the 1930s, transmission electron microscopy (TEM) has been a powerful method to explore the cellular structure of parasites. TEM usually requires samples of <100 nm thick and with protozoans being larger than 1 µm, their study requires resin embedding and ultrathin sectioning. During the past decade, several new methods have been developed to improve, facilitate, and speed up the structural characterisation of biological samples, offering new imaging modalities for the study of protozoans. In particular, scanning transmission electron microscopy (STEM) can be used to observe sample sections as thick as 1 µm thus becoming an alternative to conventional TEM. STEM can also be performed under cryogenic conditions in combination with cryo-electron tomography providing access to the study of thicker samples in their native hydrated states in 3D. This method, called cryo-scanning transmission electron tomography (cryo-STET), was first developed in 2014. This review presents the basic concepts and benefits of STEM methods and provides examples to illustrate the potential for new insights into the structure and ultrastructure of protozoans.

Detection and genotyping of Dientamoeba fragilis from symptomatic patients: New insights from Italy into a little-known gastrointestinal protozoan.

Dientamoeba fragilis (D. fragilis) represents a common protozoan in both high and low income countries. Despite this, epidemiological data on dientamoebiasis are still limited, and it is possible that the actual prevalence rates of D. fragilis have been underestimated due to the challenges in its detection and identification. In the present study, symptomatic patients from Rome (Central Italy) were surveyed for two years to determine D. fragilis percentage of infection and genotypes. Stool samples collection was performed over 864 patients, DNA extracted, and RT-PCR performed by the SeeGene Allplex™ Gastrointestinal Parasite Panel Assays. Seventy-nine resulted positive for D. fragilis (9.1%). Co-infections were detected in 22 isolates: 21 displayed Blastocystis sp. + D. fragilis (27.8%). Based on the sequence of a central fragment of the SSU rRNA gene, only genotype 1 was identified. These findings are among the few available data regarding genetic diversity of D. fragilis in Italy. Large-scale human and animal research are required to enhance our knowledge of prevalence, host range, genetic variability and zoonotic transmission of this little-known intestinal protozoan.

Comparative prevalence of oral bacteria and protozoa in patients with periodontitis in Taiwan.

OBJECTIVES: Periodontitis is an inflammatory disease caused by bacteria present in the dental biofilm. However, the presence of two oral protozoans, Entamoeba gingivalis and Trichomonas tenax, in patients with the periodontal disease remains largely unknown in Taiwan. Therefore, we investigated the prevalence of oral microbial infections between the sites with mild gingivitis and chronic periodontitis in patients. MATERIALS AND METHODS: We collected 60 dental biofilm samples from sites with mild gingivitis (probing depth <5 mm) and chronic periodontitis (probing depth ≥5 mm) from 30 patients at the National Cheng Kung University Hospital. The samples were analyzed via polymerase chain reaction and gel electrophoresis. RESULTS: Among oral protozoans, E. gingivalis and T. tenax were detected in 44 (74.07%) and 14 (23.33%) of all samples, respectively. Among oral bacteria, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia were detected in 50 (83.33%), 47 (78.33%), and 48 (80.0%) samples, respectively. CONCLUSIONS: This study, which is the first to analyze E. gingivalis and T. tenax presence among patients with periodontitis in Taiwan, revealed an association between periodontitis and oral microbes.

Employing "Red Flags" to Fight the Most Neglected Diseases: Nitroaromatic as Still Suitable Tools to Treat Human and Veterinary Parasitosis.

Nitroaromatic compounds have been used for treating parasitic diseases since the 1960s. Pharmacological alternatives to treat them are under observation. However, for the most neglected diseases, such as those caused by worms and less known protozoans, nitro compounds are still among the drugs of choice, despite their well-known collateral effects. In this review, we describe the chemistry and the uses of the still most employed nitroaromatic compounds for treating parasitosis caused by worms or lesser-known protozoans. We also describe their application as veterinary drugs. The most accepted mechanism of action seems to be the same, leading to collateral effects. For this reason, a special session was dedicated to discussing toxicity, carcinogenicity, and mutagenesis, as well as the most acceptable aspects of the known structure-activity/toxicity relationships involving nitroaromatic compounds. It employed the SciFindern search tool from the American Chemical Society in the search for the most relevant bibliography within the field, exploring keyword expressions such as "NITRO COMPOUNDS" and "BIOLOGICAL ACTIVITY" (within Abstracts or Keywords) and concepts related to parasites, pharmacology and toxicology. The results were classified according to the chemical classes of nitro compounds, being the most relevant studies regarding journal impact and interest of the described results chosen to be discussed. From the found literature, it is easy to notice that nitro compounds, especially the nitroaromatic ones, are still widely used in antiparasitic therapy, despite their toxicity. They also are the best starting point in the search for new active compounds.

Antibiotic nitrofurazone drives the functional dynamics of periphytic protozoan fauna in marine environments.

The use of functional traits of a community as a method to measure its functional dynamics in response to environmental change has gained attention because trait-based approaches offer systematic opportunities to understand the interactions between species diversity and ecosystem function. However, the relationship between functional traits of periphytic protozoa and contamination of aquatic habitats with antibiotics is poorly understood. In this study, we investigated the influence of the antibiotic nitrofurazone on functional traits of marine periphytic protozoan fauna. For this purpose, the protozoan assemblages were collected from coastal waters of the Yellow Sea at Qingdao, northern China, during four seasons of a one-year cycle using glass microscope slides as artificial substrates. The test protozoan communities were then exposed to various treatments of nitrofurazone in laboratory bioassay experiments. Our results demonstrated that the modalities of the functional traits of protozoan communities were generally driven by nitrofurazone toxicity. Briefly, R-mode linked to Q-mode (RLQ) and fourth-corner analyses revealed strong positive correlations between functional traits and nitrofurazone treatments. Trait syndromes in terms of body length, width, weight, height, and size to volume ratios were significantly influenced by nitrofurazone exposure. In particular, small and medium body size species of different feeding types, i.e., algivores, bacterivores, raptors or non-selectives, were more sensitive than other protozoan species to higher concentrations of nitrofurazone. Our findings demonstrate that antibiotic toxicity is likely to affect periphytic protozoan community function, shape the functional processes, and induce toxic responses in the community. The findings of this study suggest that periphytic protozoan communities and their functional traits are suitable bioindicators for evaluating the ecotoxicity of nitrofurazone in marine environments.

Prevalence of intestinal parasites in animal hosts and potential implications to animal and human health in Edo, Nigeria.

BACKGROUND: Intestinal parasites in livestock cause huge economic setbacks. Moreover, these parasites can threaten human health when also present in companion animals. OBJECTIVES: The study examined the prevalence and burden of intestinal parasites among roaming/migrating animals (goats, sheep, cattle, and dogs) to provide insights into the risk of potential human parasitic infections. METHODS: A total of 1,741 fecal samples from goats (n = 920), sheep (n = 335), cattle (n = 230) and dogs (n = 256) were obtained randomly across 18 local government areas in Edo State, Nigeria. The parasite samples were recovered and identified under a microscope. Molecular tools were used to identify Toxocara spp. RESULTS: Eighteen different parasites were isolated. Among the different groups of parasites observed, nematodes occurred the most, followed by protozoans. Among nematodes, Haemonchus was most prevalent in goats (28.04%) and sheep (29.85%), while Strongyloides (10.86%) and Bunostomum (8.69%) were relatively high in cattle. Strongyloides (3.9%), hookworm (3.9%), and Toxocara (3.12%) were the predominant parasites in dogs. For protozoan parasites, Eimeria was most common in all 4 animal hosts. Several goats (2.39%) and sheep (2.38%) tested positive for Fasciola spp. Molecular analysis confirmed Toxocara canis in dogs for the first time in Nigeria. CONCLUSIONS: The major parasites recovered from these roaming/migrating animals have zoonotic potentials that can threaten human health.

Emerging parasites and vectors in a rapidly changing world: from ecology to management.

Global changes have influenced our societies in several ways with both positive (e.g., technology, transportation, and food security), and negative impacts (e.g., mental health problems, spread of diseases, and pandemics). Overall, these changes have affected the distribution patterns of parasites and arthropod vectors with the introduction and spreading of alien species in new geographical areas, eventually posing new challenges in public health. In this framework, the Acta Tropica Special Issue "Emerging parasites and vectors in a rapidly changing world: from ecology to management" provides a focus on the biology, ecology and management of emerging parasites and vectors of human and veterinary importance. Herein we review and discuss novel studies dealing with interactions of parasites and vectors with animals in changing environmental settings. In our opinion, a special focus on the implementation of management strategies of parasitic diseases to face anthropogenic environmental changes still represent a priority for public health. In the final section, key research challenges in this rapidly changing scenario are outlined.

A single exon-encoded Theileria parva strain Muguga cysteine protease (ThpCP): Molecular modelling and characterisation.

The tick-transmitted apicomplexan Theileria parva causes East Coast fever, a bovine disease of great economic and veterinary importance in Africa. Papain-like cysteine proteases play important roles in protozoan parasite host cell entry and egress, nutrition and host immune evasion. This study reports the identification and characterisation of a T. parva strain Muguga cathepsin L-like (C1A subfamily) cysteine protease (ThpCP). Molecular modelling confirmed the papain-like fold of ThpCP, hydrophobic character of the S2 substrate binding pocket and non-covalent interaction between the pro- and catalytic domains preceding low pH autoactivation. ThpCP was recombinantly expressed in a protease deficient E. coli (Rosetta (DE3)pLysS strain) expression host as a 46 kDa proenzyme. Following Ni-chelate affinity chromatography and acidification, the 27 kDa mature ThpCP was purified by cation-exchange chromatography. Purified ThpCP hydrolysed typical cathepsin L substrates N-α-benzyloxycarbonyl (Z)-Phe-Arg-7-amino-4-methyl-coumarin (AMC) (kcat/Km = 4.49 × 105 s-1M-1) and Z-Leu-Arg-AMC (kcat/Km = 4.20 × 105 s-1M-1), but showed no activity against the cathepsin B-selective substrate Z-Arg-Arg-AMC. Recombinant ThpCP was active over a broad pH range from pH 4.5 to 7.5, thereby showing potential activity in the acidic parasite food vacuole and close to neutral pH of the host lymphocyte cytoplasm. Recombinant ThpCP was inhibited by the cysteine protease inhibitors E64, iodoacetate, leupeptin, chymostatin, Z-Phe-Ala-diazomethylketone (DMK) and Z-Phe-Phe-DMK and hydrolysed bovine proteins: haemoglobin, immunoglobulin G, serum albumin and fibrinogen as well as goat IgG at pH 6 and 7. Functional expression and characterisation of Theileria cysteine proteases should enable high throughput screening of cysteine protease inhibitor libraries against these proteases.

Occurrence and Genetic Diversity of the Zoonotic Enteric Protozoans and Enterocytozoon bieneusi in Père David's Deer (Elaphurus davidianus) from Beijing, China.

Cryptosporidium spp., Blastocystis, Giardia duodenalis, Balantioides coli, Pentatrichomonas hominis, and Enterocytozoon bieneusi are enteric protozoan parasites and fungal species in humans and animals. Père David's deer is an endangered species in China, but the prevalence of enteric protozoans in this species still needs to be further studied. Thus, we investigated the prevalence and genetic diversity of zoonotic parasites in Père David's deer during the period of 2018-2021. Among the 286 fecal samples collected from Père David's deer in the Nanhaizi Nature Reserve, 83 (29.0%) were positive for Blastocystis, 70 (24.5%) were positive for E. bieneusi, while other protozoan parasites were negative. Based on a phylogenetic analysis, three Blastocystis subtypes (ST10, ST14, and ST21) and ten E. bieneusi genotypes (Genotype D, MWC_d1, HLJD-V, Peru6, BEB6, BJED-I to BJED-I V) were identified. In addition, the Blastocystis subtype ST14 and the E. bieneusi genotype D and Peru6 were first detected in Père David's deer. Our study first reports the presence of two enteric protozoans in Père David's deer during a 4-year active surveillance and provides more information about zoonotic subtypes/genotypes of Blastocystis and E. bieneusi in deer.

Endoparasites of Wild Boars (Sus Scrofa) in Primorsky Krai, Russia.

This study identified helminthic species among wild boars (Sus scrofa) in Primorsky Krai, Russia. In total, 66 fecal samples were taken from wild boars and examined using the floatation-sedimentation method to identify helminths eggs and protozoan cysts. Age and sex were estimated for each host animal investigated. The helminthic fauna of the wild boars examined involved six parasite genera, but 4 are helminths and 2 are protozoans: the nematodes Metastrongylus spp., Trichuris suis, Capillaria sp. and Ascaris suum; and the protozoan parasites Eimeria sp. and Cystoisospora suis. The most prevalent parasite was Metastrongylus spp. (13.6 %) followed by Trichuris suis (7.6 %). The other parasites found were Eimeria sp. (3 %), Ascaris suum (3 %), Capillaria sp. (1.5 %) and Cystoisospora suis (1.5 %). Not found positive correlation between the host's age and sex and the parasite prevalence. This was the first detailed study on helminths infections among wild boars in Primorsky Krai.

Assessment of intestinal and blood protozoan infections among pregnant women visiting ante-natal care at Tafo Hospital, Ghana.

Introduction: Intestinal and blood protozoans cause morbidity and mortality in both pregnant women and developing foetuses worldwide. It constitutes a major health problem in many tropical areas in Africa. This study assessed the prevalence of intestinal and blood protozoans' parasitic load and their risk factors among pregnant women visiting antenatal care at Tafo Hospital, Ghana from November 2016 to January 2017. Method: A pilot cross-sectional study was conducted among consented pregnant women who visited antenatal care at Tafo Government Hospital, Kumasi Ghana. Structured questionnaires were administered to obtain socio-demographic data, knowledge on protozoan infections, and their risk factors among study participants. A stool sample was obtained from each participant for the microscopic examination of the intestinal protozoa. Venous blood was taken from participants for the detection of Plasmodium and Toxoplasma gondii infections. Wet mount and the faecal protozoan concentrated method were done for the identification of intestinal parasites. Blood films and serological examination for malaria rapid diagnostic tests (RDT) were done for identification of Plasmodium parasites while an Enzyme-linked immunosorbent assay (ELISA) was used for detecting the antibodies of T. gondii among participants. Data were analyzed using statistical packages for the social sciences (SPSS). Results: The mean age of the study participants was 27.83, and ranges from 18 to 40 years. The majority of the participants (82.2%) had never experienced stillbirth nor spontaneous abortion. Intestinal parasites were found in 36.7% of participants. Giardia lamblia (28.1%), Cryptosporidium parvum (5.3%), and Entamoeba histolytica/dispar (3.3%) were among the intestinal protozoans detected. T. gondii antibodies were detected by high levels of immunoglobulins, resulting in IgG (48.0%) and IgM (11.3%) being found among participants, with 7.3% testing positive for both IgM and IgG. The prevalence of malaria infection among the study participants was 2.7%. The consumption of raw or cooked vegetables had significant influence on their intestinal and blood protozoan infections status (p = 0.004) (OR = 0.32, CI = 0.12-0.86). There was a significant association between Hb levels and malaria (p = 0.014) and that of intestinal protozoans (p = 0.035). Conclusion: The prevalence of intestinal protozoans and blood protozoans such as T. gondii were high and therefore effective measures should be put in place to reduce the infectivity. Environmental hygiene should be improved and education by relevant agencies should be intensified on the possible transmission of intestinal and blood parasite infections given the possible role of these infections in adverse pregnancy outcomes.

Eating Animal Products, a Common Cause of Human Diseases.

The human population is plagued by hundreds of infectious agents that cause diseases, and many of these agents can infect a range of wild and domesticated animals as well. In fact, a large proportion of current pathological conditions in humans is caused by our close association with nonhuman animals, some of which we keep as pets, but most of which we raise, prepare as food sources, and ingest. It is well established that most of these diseases are caused by a variety of infectious agents, the most important being bacteria, viruses, prions, and protozoans. In this article, we shall consider these agents and discuss their transmission from various animals and animal products to humans. It is noted that virtually none of these agents are obtained by eating plant-derived products unless the plants are grown and prepared with contaminated water. Consequently, we suggest that Homo sapiens could avoid a significant fraction of the diseases that plague us by shifting to a more vegetarian diet.

Distribution of Gastrointestinal Parasitic Infection in Domestic Pigs in the Republic of Korea: Nationwide Survey from 2020-2021.

This study aimed to examine the distribution of gastrointestinal parasitic infections in domestic pigs in the Republic of Korea. From May 2020 to October 2021, 364 pig fecal samples were collected from 75 farms in 7 Provinces and microscopically examined. A total of 170 (46.7%) pigs were infected with at least one of the following parasites: Balantioides coli, strongyles, Ascaris suum, Trichuris suis, and coccidia. By parasite species, B. coli, strongyles, A. suum, T. suis, and coccidia oocysts or eggs were detected in 144 (39.6%), 24 (6.6%), 14 (3.8%), 4 (1.1%), and 1 (0.3%) samples, respectively. One hundred fifty-four, 15, and 1 cases showed single, double, and triple infections, respectively. Of the swine fecal samples from 75 farms, 69 specimens (92.0%) were infected with 1 or more parasites. All surveyed farms across the country exhibited a positive rate of over 30%, among which the highest positive rate was 65.0% in Chungcheongnam-do, and Jeollabuk-do was followed by 61.9%. Winter showed a statistically lower prevalence than other seasons. This study showed that gastrointestinal parasites are prevalent in pigs in Korea, although the diversity of parasites is low.

Intestinal parasites in stool testing among refugees at a primary care clinic in Toronto, Canada.

BACKGROUND: Enteric parasites are endemic in many of the countries from which refugees originate. Clinical guidelines vary in approaches to screening for and treating intestinal parasites in refugee receiving countries. This study aims to investigate the prevalence and species of intestinal parasites identified in stool ova and parasite (O&P) specimens in a sample of newly arrived refugees in Toronto, Canada. METHODS: We conducted a retrospective chart review of 1042 refugee patients rostered at a specialized primary care clinic in Toronto from December 2011 to September 2016. Patients who completed recommended stool O&P analyses were included. Basic sociodemographic and clinical variables and results of stool O&P were examined. RESULTS: 419 patients (40.2%) had a stool O&P positive for any protozoan or helminth species. Sixty-nine patients (6.6%) had clinically significant parasite species (excluding B hominis, D fragilis, and E dispar, given their lower risk for causing symptoms/complications): 2.3% had clinically significant protozoans and 4.2% had helminths on stool analysis. CONCLUSION: Given the relatively low prevalence of clinically significant parasites identified, our findings do not support universal screening for enteric parasites with stool O&P among refugee claimants/asylum seekers. However, stool analysis should be considered in certain clinical situations, as part of a more tailored approach.

Endoparasites of pet reptiles and amphibians from exotic pet shows in Texas, United States.

Reptiles and amphibians are becoming increasingly more common in the exotic pet trade and as such veterinary care is also rising. Parasitic infections can pose a serious threat to pet reptiles and amphibians and are a common finding in these exotic pets. The purpose of the present study was to determine the species composition of parasites among reptiles and amphibians entering the pet industry. Excreta were collected from 283 reptiles and amphibians (181 geckos, 23 chameleons, 21 frogs, 16 tortoises, 11 snakes, 1 caiman, and 31 other lizard species), representing 58 different species. Samples were collected from animals being sold at exotic pet shows in Texas, USA, where breeders from throughout the United States gathered to showcase their exotic pets. Excreta samples were tested using double centrifugation flotation with Sheather's sucrose solution. Endoparasites were identified in 51.9% of samples. The most prevalent helminth parasite among reptiles and amphibians were Pharyngodonidae (44.5%) nematodes. Oocysts of coccidians such as Isospora, Eimeria, and Choleoeimeria, and cysts of the ciliate Nyctotherus were also identified. The prevalence rates of endoparasites among animal groups ranged from 0 to 87.5%. The highest prevalence of infection was found in Testudines (87.5%), followed by Chamaeleonidae (87%), other lizards (76.7%), Amphibia (71.4%), Serpentes (63.6%), and then Gekkonidae (55.2%). No endoparasites were detected in the one Crocodylia sampled. Our results show that parasitic infections, many of which can cause clinical disease and mortality, are common in exotic reptiles and amphibians being sold or traded as pets in the United States, underlining the need for veterinary care and routine diagnostic screening for parasitic infections.

Concept about the Virulence Factor of Legionella.

Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires' disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity. Conventionally, the proteins involved in initiating replication processes and human macrophage infections have been regarded as virulence factors and linked to pathogenicity. However, because some of the virulence factors are associated with the infection of protozoa and macrophages, it would be more accurate to classify them as survival factors rather than virulence factors. Given that the molecular basis of virulence variations among non-pathogenic, pathogenic, and highly pathogenic Legionella has not yet been elaborated from the perspective of virulence factors, a comprehensive explanation of how Legionella infects its natural hosts, protozoans, and accidental hosts, humans is essential to show a novel concept regarding the virulence factor of Legionella. In this review, we overviewed the pathogenic development of Legionella from protozoa, the function of conventional virulence factors in the infections of protozoa and macrophages, the host's innate immune system, and factors involved in regulating the host immune response, before discussing a probably new definition for the virulence factors of Legionella.

Gastrointestinal parasites of Leontopithecus chrysomelas in the Atlantic Forest, Brazil / Parasitas gastrintestinais de Leontopithecus chrysomelas na Floresta Atlântica, Brasil

Abstract We performed coproparasitological testing of free-living golden-headed lion tamarins, Leontopithecus chrysomelas, using the Hoffmann-Pons-Janner method. In total, we collected 118 samples from ten groups: four living in Federal Protected Area and six living in Non-Protected Areas of cocoa farms. Eggs from parasites of the Acanthocephala phylum and Spiruridae, Ancylostomatidae, Ascarididae and Oxyuridae families were identified, as well as the genus Strongyloides (Nematode: Strongyloididae) and phylum Apicomplexa. This is the first description of infection with coccidian, Trichuridae family and Strongyloides spp. in L. chrysomelas. A total of 48% (n= 57) of the animals were infected and the highest prevalence (37.2±SD 8.72, n = 44) was for Acanthocephalidae, followed by Spiruridae (8.5±SD 5.03, n = 10). There was no difference in parasite prevalence by age classes or sex. However, we found higher diversity and prevalence of parasites in animals living in the Federal Protected Area. These results suggest that intestinal parasites may be influenced by environmental factors, such as the management of the areas where the animals live, in addition to the feeding behavior of L. chrysomelas and distinct transmission strategies of parasites. The combination of ecological and demographic data combined with parasitological studies may contribute to conservation programs for this species.

Resumo Foram realizados testes coproparasitológicos de micos-leões-dourados de vida livre, Leontopithecus chrysomelas, usando-se o método de Hoffmann-Pons-Janner. No total, foram coletadas 118 amostras de dez grupos: quatro grupos residentes em Área de Conservação Federal e seis grupos em Área não protegida de fazendas de cacau. Ovos de parasitas do filo Acantocephala e das famílias Spiruridae, Ancylostomatidae, Ascarididae, Oxyuridae foram identificados, bem como o gênero Strongyloides (Nematoda: Strongyloididae) e o filo Apicomplexa. Esta é a primeira descrição de infecção de coccídeos, família Trichuridae e Strongyloides spp. em L. chrysomelas. Um total de 48% (n = 57) dos animais estavam parasitados e a maior prevalência (37,2 ±DP 8,72, n = 44) foi para Acanthocephalan, seguido por Spiruridae (8,5±DP 5,03, n = 10). Não houve diferença na prevalência do táxon de parasita por idade ou sexo. No entanto, foi encontrada maior diversidade e prevalência de parasitas em animais que vivem na Unidade de Conservação Federal. Esses resultados sugerem que os parasitas intestinais podem ser influenciados por fatores ambientais, como o manejo das áreas, além do comportamento alimentar de L. chrysomelas e distintas estratégias de transmissão dos parasitas. A combinação de dados ecológicos e demográficos com estudos parasitológicos podem contribuir para programas de conservação dessa espécie.

Geographic differences in the distribution of parasitic infections in children of Bolivia.

BACKGROUND: A high percentage of the population in Latin America lives with intestinal parasitic infections, a neglected tropical disease frequently not treated. Intestinal parasitism is associated with other disorders, but information about the epidemiological situation in countries like Bolivia is scarce. Environmental conditions play a role in the prevalence of certain parasites. The main objective was to know the current situation of parasitic infections among children under 12 years old from different geographical areas of Cochabamba - Bolivia. METHODS: We analysed the laboratory reports of four second-line hospitals in different areas and the Tertiary Care Hospital. Results of stool examinations performed between 2011 and 2015 in children under 12 years of age were collected. RESULTS: We gathered the results of 23,221 examinations. The 89% of children were less than five years old. Pathogenic parasites were found in 31%. Entamoeba histolytica and Giardia lamblia were the two most prevalent parasites in all areas. Helminths were 19% of positive samples and Ascaris lumbricoides was the most prevalent. Parasitic infections are more frequent in tropical areas where helminths are highly concentrated. Pre-school age children (OR: 5.296; 95% CI: 4.81-5.83) and semi-tropical area (OR: 3.26; 95% CI: 2.90-3.66) were strongly associated to the presence of pathogenic parasites. CONCLUSIONS: Parasitic infections in children are still very prevalent in Bolivia. Protozoan infections are a major problem, while the prevalence of helminths seems to be decreasing. The most vulnerable population is still concentrated in semi-tropical and tropical areas, where the risk of parasitic infection is probably increased due to poor environmental conditions. Our results could allow reconsideration of more effective parasitic disease control policies, taking into account regional characteristics.