Acta Parasitologica最新文献

Purpose: Nothing is known about coccidians (Apicomplexa: Eimeriidae) from the Pacific blue-tailed skink, Emoia caeruleocauda. Here, we report mensural and morphometric data on a new species of Isospora from E. caeruleocauda from Guam, US Territory.

Methods: Feces from four E. caeruleocauda collected by hand in November 2023 were placed in individual vials containing 2.5% potassium dichromate. They were examined for sporulated oocysts after flotation in Sheather's sugar solution, measured, and photographed.

Results: A single (25%) E. caeruleocauda was found to be passing oocysts representing a new species of Isospora. Oocysts of Isospora guamensis n. sp. are ellipsoidal to ovoidal with a bi-layered wall, measure (L × W) 16.5 × 11.8 μm, and have a length/width (L/W) ratio of 1.4; a micropyle and an oocyst residuum were absent but a polar granule was present. Sporocysts are ovoidal and measure 9.4 × 6.5 μm, L/W 1.4; Stieda and sub-Stieda bodies were present but a para-Stieda body was absent. The sporocyst residuum is composed various-sized granules in a compact rounded or irregular mass, sometimes dispersed between the sporozoites. The new species can be differentiated from all other isosporans from skinks by possessing the smallest oocysts known from this host family.

Conclusion: This is the first time an isosporan coccidian has been reported from E. caeruleocauda as well as the first report of a coccidian from a Guam-inhabiting skink.

Purpose: In this study, 143 lutjanid fishes representing four different species from the Northeast coast off Brazil were analyzed for parasites. The aim of the present study is to provide a detailed redescription of R. (I.) vicentei, collected from lutjanid fishes in Brazil, including the first observation of the species using scanning electron microscopy (SEM).

Methods: Nematodes found clarified in a crescent glycerin series, were photographed and measured (in mm), and some specimens destined for SEM. The Illustrations were made using an optical microscope with a drawing tube.

Results: Nematodes found were identified as Raphidascaris (Ichthyascaris) vicentei, infecting 6.29% of the examined fish. Detailed morphological analysis revealed the following characteristics observed for the first time in this species: labial papillae, narrow lateral alae and the detailed structure of male spicules. These contributions help filling the gaps in the literature and expand the knowledge of this parasite morphology.

Conclusions: The presence of R. (I.) vicentei in four lutjanid species may indicates low host specificity, highlighting its adaptability to different hosts. Furthermore, new host records are given. This research provides the most comprehensive morphological description of R. (I.) vicentei to date, generating crucial insights for a better understanding of the parasitic biodiversity off the Brazilian Northeastern coast of Brazil, as well as establishing foundation for future investigations on the ecology and impacts of these parasites in fish populations from this region.

Background: Macracanthorhynchus hirudinaceus (Pallas, 1781) is a zoonotic acanthocephalan that parasitizes the small intestine of wild boars. It is a pathogenic that causes economic losses, and poses a public health threat due to increased emergence.

Purpose: The aims of this study is describes histopathologically the damage caused by M. hirudinaceus in the small intestine of wild boar Sus scrofa Linnaeus, 1758, and molecularly characterize this parasite (sequences, haplotypes, phylogeny) for the first time in Elazig city, Türkiye.

Results: A high prevalence of infection was obtained. Upon separating the worms, it was discovered that there were ulcers resembling craters in the center, of the small intestine mucosa, surrounded by edema. The intestine wall where the parasite attached was damaged, with the villi epithelium and lamina propria in the mucosa being destroyed. The genomic DNA was isolated from all M. hirudinaceus samples, and PCR amplified the 489 bp gene fragments were sequenced and confirmed that all 21 sequences were M. hirudinaceus. The haplotype analysis of the sequences revealed the presence of a central star-shaped haplotype, in addition to four other haplotypes.

Conclusion: After conducting sequence analysis, the genetic differences between the M. hirudinaceus sequences obtained in this study and those reported from Europe and Japan suggest that this parasite is endemic to Türkiye's local wild boar population. Also, four haplotypes were identified, distinguishing it from other haplotypes by 1-5 mutation steps. It is essential to consider the worm's sequences and the formation of haplotypes, since these intrinsic characteristics may impact in the epidemiology and pathology of the worm in the future.

Purpose: This study describes the composition and infection patterns of macro endoparasites associated with the lizard Phyllopezus periosus.

Methods: We collected 115 P. periosus over 12 expeditions on the rocky cliffs of the Missão Velha waterfall canyon in northeastern Brazil. Specimens were collected by hand, during active searches conducted between 18:00 h and 23:30 h. The infection patterns were estimated using prevalence, total abundance, and mean intensity of infection for all parasites found.

Results: A total of 4256 parasites were collected from 104 hosts, resulting in an exceptionally high overall prevalence of 90.4%. No significant ontogenetic difference in the prevalence of infection was detected. Although juveniles exhibited a high parasite prevalence their parasite loads were significantly lower compared to adults. Six species of endoparasites were found; among these, the nematode Spauligodon oxkutzcabiensis was the most common endoparasite in the digestive tract, while the pentastomid Raillietiella mottae was the only species found in the respiratory tract.

Conclusions: Infection rates in Gekkota species appear to correlate with body size, with larger individuals generally exhibiting a higher prevalence. This pattern was also observed across separate populations of P. periosus and other geckos from distinct ecological domains. The dominance of the monoxenous S. oxkutzcabiensis highlights potential transmission mechanisms, suggesting that behaviors such as limb licking after feeding may contribute to its prevalence. The occurrence of Physalopteroides venancioi, Oswaldocruzia sp., Parapharyngodon sp., Physaloptera sp., infecting P. periosus are new records for this host. These findings significantly contribute to the knowledge of host-parasite dynamics in geckos.

Heartworm infection is a chronic disease with clinical signs and effects ranging from an asymptomatic condition to severe disease and death. The prevalence of heartworm disease in the state of Rio de Janeiro has been reported to be high (21.3%). The present study was conducted to evaluate the seroprevalence and risk factors of heartworm infection for the canine population with access to veterinary services in different areas of the state of Rio de Janeiro, Brazil. A total of 1787 canine blood samples were obtained from 135 practices across 8 different areas of Rio de Janeiro state (Rio de Janeiro municipality, São Gonçalo municipality, Niterói municipality, Baixada Fluminense, and the northern, southern, eastern, and mountainous areas) and tested for the presence of Dirofilaria immitis antigens and antibodies against several tick-borne disease pathogens using a commercial immunochromatography technique (Vetscan® Flex 4 Rapid Test; Zoetis; NJ USA). Pet owners reported living conditions, physical characteristics, demographics, and clinical signs for evaluation of risk factors for heartworm infection. Only two evaluated risk factors were shown to enhance the risk for D. immitis infection, including having a short hair coat vs. having a medium or long hair coat (OR 2.62) or positive for antibodies to tick-borne disease parasites (OR 3.83). Clinical signs reported for dogs with heartworm disease were typical for that condition. The overall prevalence of heartworm disease in the state was 8.2%, ranging from 2.4% in the mountainous region to 29.4% in the eastern area. It could not be determined if veterinarians were not diligent about dispensing heartworm preventatives or if poor levels of compliance by dog owners were responsible for higher infection rates in some areas of the state.

Purpose: This study was carried out to determine the presence of Entamoeba histolytica in water sources of Niğde province in Turkey, between June and November 2021.

Methods: A total of 90 water samples were taken from 15 different water sources (drinking water, well water, spring water, wastewater and dam water) every month and the presence of E. histolytica antigens in the samples was examined by ELISA.

Results: The positivity for E. histolytica was determined in 7 (7.7%) of 90 samples. While no antigens were found in any of the samples in June and September, E. histolytica was positive for three samples (20%) in July, one sample (6.6%) in August and October and two samples in November (13.3%). One of 24 dam samples (4.1%), 1 of 12 wastewater samples (8.3%), 1 of 12 well samples (8.3%), and 4 of 24 fountain samples (16.6%) that examined by ELISA were found positive. On the other hand, none of the examined 18 spring samples were positive. In addition, 4 (8.8%) of 45 samples that examined in summer and 3 (6.6%) of 45 samples that examined in autumn were detected positive by using ELISA. Entamoeba histolytica positivity in samples was statistically insignificant in terms of months, water resources and seasons (P > 0.05).

Conclusion: As a result, the presence of E. histolytica, which is an important public health problem in water sources, was determined for the first time in Niğde province of Türkiye with this study.

Purpose: Visceral leishmaniasis (VL) is caused by an intracellular parasite that is transmitted to humans by sandfly bites. It is prevalent throughout Asia, Africa, the Americas, and the Mediterranean area, where 147 million people are at risk of contracting the illness. The manifestation of heterotrophic illness relies on both Leishmania implicated and the host's immunological response, ranging from asymptomatic to severe leishmaniasis with potentially lethal effects.

Method: We reviewed the literature (published till 31st December 2023) on the worldwide situation of leishmaniasis, standard and novel detection techniques, and traditional and modern treatment strategies and endeavors to eliminate VL. Moreover, epidemiological data was collected from the World Health Organization's publicly available databases. GraphPad Prism Version 8 was used to analyze and produce figures based on the epidemiological data.

Results: Diagnosis of parasites in tissues or serology is commonly employed. Diagnosis by identifying parasite DNA using molecular techniques is becoming more popular. Despite recent findings of L. donovani resistance to pentavalent antimoniate medications, it continues to be the cornerstone in the medical management of VL. Amphotericin B and its lipid formulations, injectable paromomycin, and oral miltefosine are among the new therapy options being researched. The number of reported VL cases has reduced remarkably over the last decade due to human interventions made to eliminate VL. Particularly countries from the South East Asian region have experienced momentous progress in reducing VL cases and eliminating this disease from this region. Owing to the robust elimination programs, countries such as Bangladesh has eliminated VL as a public health concern. India and Nepal are on the verge of its elimination.

Conclusion: Rapid diagnosis, effective and inexpensive treatment, simple access to newly discovered medications, appropriate vector control, and a well-designed vaccine are all required for the elimination of this disease burden in impoverished areas of the globe.

Introduction: In Ethiopia, visceral leishmaniasis (VL) is a public health concern that has been spreading to new endemic foci in recent years. An estimated 3.2 million people are at risk of infection, with 3700-7400 new cases yearly. Thus, the study aimed to determine the prevalence of VL and associated risk factors among febrile patients attending Metema Hospital, North West Ethiopia.

Methods: A hospital-based cross-sectional study was conducted on 404 febrile patients attending Metema Hospital from February 2021 to June 2021. The test for VL was done using an immune-chromatographic test (RK39) according to the manufacturer's instructions (InBios International Inc., USA). An interviewer-administered, pretested questionnaire was used to collect data on risk factors associated with VL. Logistic regression and Chi-square assessed the association between VL and the associated risk factors.

Reults: The overall prevalence of visceral leishmaniasis was 18.8% (76/404), with a higher prevalence of VL in males, in the age category between 21 and 30, in study participants who completed elementary school, and in those who earned less than 500 birr monthly compared to their counterparts. Houses with thatched roofs (adjusted odd ratio (AOR) = 17.648, 95CI = 6.549,47.563), houses with mud walls (AOR = 2.538, 95% CI = 1.187-5.411), cattle ownership (AOR = 3.173, 95% CI = 1.286-7.826), dog ownership (AOR = 2,533, 95% CI = 1.256-5.111), presence of Acacia trees near houses (AOR = 1.975, 95% CI:1.004-3.886), presence of Balanites tree (AOR = 3.015, 95% CI = 1.610-5.992), and outdoor sleeping (AOR = 2.259, 95% CI: 1.107-14.607) were the predictors of VL in the present study.

Conclusions: In the study area, VL is still very common. Thus, preventing and controlling infection in the area is largely dependent on raising community awareness of VL prevention and control measures and implementing the necessary interventions on the determinants that have been identified.

Visceral Leishmaniasis is a serious public health problem caused by Leishmania species parasites. Approximately 500 thousand people get Visceral Leishmaniasis (VL) every year. An effective and reliable vaccine against the disease has still not been formulated. Choosing the right adjuvant is important to increase immunogenicity in vaccines prepared with total antigens. In this study, we investigate the ideal adjuvant for use in vaccine formulations against VL. For this purpose, Leishmania antigens (FTLA) obtained from L. infantum parasites by the freeze-thaw method and three different adjuvants (alum-saponin and calcium phosphate) were used. The effectiveness of the formulations was investigated in vitro by cell viability analysis and determination of nitric oxide and cytokine production abilities in J774 macrophage cells. According to the study results, it was determined that formulations prepared with calcium phosphate produced 72% more NO and approximately 7.2 times more IL-12 cytokine. The results obtained showed that calcium phosphate salts can be used as ideal adjuvants in vaccine research against leishmaniasis.

Purpose: Tick-transmitted parasites as Babesia gibsoni, Babesia vogeli, Ehrlichia canis, and Hepatozoon canis are major health concern for dogs. Owing to prevalence and infection severity, there is need of sensitive, specific, and affordable test for their simultaneous detection.

Methods: Prevalence of B. gibsoni, B. vogeli, E. canis, and H. canis infections was assessed on 719 blood samples by microscopy and multiplex PCR assay targeting 18S rRNA (B. gibsoni & H. canis), ITS1 & 5.8S rRNA (B. vogeli) and VirB9 gene (E. canis). An internal control (canine-actin) was also included to increase the accuracy of assay and effect of associated risk factors with disease prevalence was also studied.

Results: Microscopic prevalence of B. gibsoni, B. vogeli, E. canis and H. canis was 5.0%, 0.1%, 1.4% and 1.0%, respectively, whereas with multiplex PCR assay, the corresponding values were 8.9%, 1.1%, 2.6% and 5.1% besides concurrent infections of B. gibsoni & H. canis (0.4%), B. gibsoni & E. canis (0.4%), E. canis & H. canis (0.3%) and B. gibsoni & B. vogeli (0.1%). Analytical sensitivity of developed assay was 0.1pg (B. gibsoni & H. canis), 0.01pg (B. vogeli), and 1.0pg (E. canis). A ″fair″ (B. vogeli & H. canis) to ″substantial″ (B. gibsoni & E. canis) agreement between two tests was observed with data as statistically significant. Breed, sex and location were significantly associated with B. gibsoni infection.

Conclusion: The developed multiplex PCR assay offers a potential solution to detect these pathogens simultaneously, aiding in timely diagnosis and effective disease management in suspected dogs.