Search Results (4,403)

Background: Strongyle-type gastrointestinal nematodes are among the most important parasitic infections affecting sheep production because of the health and economic losses they cause. Aim: The aim of this study was to determine the positivity, parasite burden, and factors associated with positivity to strongyle-type gastrointestinal nematode eggs in sheep from Guanujo parish, Ecuador. Methods: A quantitative, descriptive, cross-sectional study was conducted between November 2025 and March 2026. Seventy fecal samples were collected individually via rectal sampling from sheep randomly selected within 14 participating farms. The samples were analyzed using coproparasitological techniques with the modified McMaster method to quantify eggs per gram of feces (EPG). Subsequently, univariate analysis and multivariable logistic regression were performed to identify factors associated with positivity for strongyle-type gastrointestinal nematode eggs. Results: The overall positivity was 54.3% (38/70), with a mean parasite burden of 1150 EPG. Mild and moderate infections predominated, although severe infections were also detected. After multivariable adjustment, younger age was consistently associated with positivity. High stocking density was associated with positivity in the primary model, although this association was less stable in the mixed-effects sensitivity analysis. Sheep younger than 12 months showed higher odds of positivity than adults (adjusted OR = 8.75; 95% CI: 3.42–22.38; p < 0.001), while animals from farms with high stocking density also showed higher odds of positivity (adjusted OR = 2.69; 95% CI: 1.21–5.97; p = 0.015). Conclusions: Younger age was the most consistent factor associated with strongyle-type gastrointestinal nematode egg positivity. High stocking density showed higher odds of positivity in the primary analysis, but this association was not statistically significant in the mixed-effects sensitivity analysis and should therefore be interpreted cautiously. Full article

Blood parasites are widespread pathogens of wild birds, yet their reproductive consequences remain poorly understood. We investigated associations between blood parasite infections and reproductive performance in three passerine species breeding sympatrically on Gotland, Sweden: the resident great tit (Parus major) and blue tit (Cyanistes caeruleus) and the migratory collared flycatcher (Ficedula albicollis). The study was based on data from 181 nests and 1201 nestling observations. Adult birds were screened for Plasmodium, Haemoproteus, and Trypanosoma infections using next-generation sequencing, and infection intensity of malaria parasites (Plasmodium/Haemoproteus) and Trypanosoma was quantified using quantitative PCR. We tested whether parental infection status and parasite intensity were associated with reproductive traits measured at the nest level (hatching date, clutch size, and brood size) and nestling level (body mass, growth, and condition). Associations between infections and reproduction differed among parasite groups, parental sexes, and host species, with some of the strongest and most consistent patterns involving Haemoproteus infections. Most significant relationships were detected for nestling traits rather than breeding parameters, and a substantial proportion of associations remained significant after false discovery rate (FDR) correction. Both positive and negative associations were observed, and significant interactions between female and male infection status indicated that offspring performance depended on both parents’ infection status. Moreover, analyses based on infection status and parasite intensity revealed partly different patterns of association with reproductive traits. Overall, these results demonstrate that the reproductive consequences of blood parasite infections are parasite-specific and context-dependent. Full article

C1A cysteine peptidases (CPs) are major contributors to host–parasite crosstalk and have been proposed as anti-trypanosomal chemotherapeutic targets. Trypanosoma evansi is the most widespread animal trypanosome of African origin causing the trypanosomosis known as “Surra” or “derrengadera”. Gelatin zymography combined with peptidase class-specific inhibitors identified four CPs in T. evansi lysates with relative masses of 28, 31, 36 and 40 kDa (p28, p31, p36 and p40). The CPs present in the T. evansi lysate preferentially hydrolyzed the Z-Phe-Arg-AMC fluorogenic substrate over Z-Gly-Arg-AMC and Z-Ala-Arg-AMC, and the hydrolysis of Z-Phe-Arg-AMC was inhibited by the K11777 (also known as SLV213) vinyl sulfone inhibitor with an apparent IC₅₀ of 3.06 nM. Active-site labeling using the ¹²⁵I-LHVS-PhOH vinyl sulfone inhibitor confirmed the identity of p28, p31, p36 and p40 as cathepsin-like peptidases. Partial purification of the T. evansi p40, analysis of its N-terminal peptide sequence and cross-reactivity with an anti-T. brucei (Tbr)CATL antiserum revealed its orthology to the C1A CPs present in T. b. brucei, T. cruzi, T. dionisii and T. rangeli. Treatment of infected mice with the pan-cathepsin irreversible inhibitor, K11777 (10 mg/day), for 14 (n = 5) or 17 (n = 3) consecutive days was trypanocidal and significantly increased mice survival. These results validate TevCATL as a potential therapeutic target for the treatment of animal trypanosomosis caused by T. evansi. Full article

Polyparasitism is frequently documented in cetaceans; however, the pathological consequences of concurrent multispecies helminth infections and their associated tissue responses remain incompletely understood. This study characterized multispecies helminth infections in two live-stranded dolphins from the Andaman coast of Thailand, a spinner dolphin (Stenella longirostris) and a pantropical spotted dolphin (Stenella attenuata), using integrated postmortem, parasitological, molecular, histopathological, and immunohistochemical approaches. Both dolphins harbored helminths involving multiple organ systems. Pulmonary nematodes were identified as Halocercus delphini, while larval and intestinal cestodes were identified as Clistobothrium sp. and Tetrabothrius sp., respectively. The most prominent pathological alterations occurred in the respiratory tract and included chronic pyogranulomatous bronchopneumonia, airway epithelial injury, fibrosis, and pulmonary congestion associated with Halocercus infection. Additional parasite-associated lesions included chronic enteritis, cholangitis with biliary epithelial injury and ductular reaction, pancreatic inflammation, and localized inflammatory responses surrounding larval cestode cysts in the blubber and testis. Immunohistochemistry demonstrated extensive interleukin-4 (IL-4) immunoreactivity in affected pulmonary and intestinal tissues, whereas interleukin-10 (IL-10) was undetectable. Nitrotyrosine and heat shock protein 70 (HSP70) immunoreactivity were widely distributed across parasite-associated tissues, while caspase-3 immunoreactivity showed tissue-dependent patterns. Collectively, these findings demonstrate that multispecies helminth infections in stranded dolphins were associated with multisystem pathological alterations accompanied by inflammatory, oxidative/nitrosative stress, cellular stress, and apoptotic responses. These findings highlight the potential pathological significance of polyparasitism in stranded dolphins and support consideration of parasite burden and associated tissue responses during cetacean postmortem investigations. Full article

(1) Background: Brazil features one of the largest recycling workforces worldwide, with around 800,000 informal waste pickers, mostly living in urban areas of major cities and dealing with low income and precarious working conditions. This context of vulnerability may lead to a high risk of food insecurity, which may be associated with infectious diseases, particularly toxocariasis, a cosmopolitan neglected parasitic zoonosis with high seroprevalence in tropical countries. (2) Methods: Accordingly, this study assessed Toxocara spp. seropositivity and associated risk factors (including food insecurity) in recycling workers of Curitiba, a major Brazilian (fully urban) city currently ranked 8th in population with 1.83 million habitants, 7th in Gross Domestic Product (GDP), and 10th in Human Development Index (HDI) with 0.823 (very high), out of 5569 Brazilian cities. Recycling and non-recycling (used as population control) workers living in the same neighborhood were invited, voluntarily signed consent forms, and had blood serum samples collected and tested by ELISA for detecting anti-Toxocara spp. (IgG) antibodies; in addition, an epidemiological questionnaire (socioeconomic characteristics, owning dog/cat, food and hygiene habits) was applied. (3) Results: Overall, 95/177 (53.7%) recycling and 38/100 (38.0%) non-recycling workers tested positive by ELISA, with recycling workers more likely seropositive than non-recycling population (53.7% vs. 38.0%; OR: 1.89; 95% CI: 1.15–3.12%). Food insecurity (OR = 2.01, 95% CI: 1.04–3.91) and low (<1 minimum wage) monthly household income (OR = 3.03, 95% CI: 1.01–9.71) were associated with Toxocara spp. seropositivity by multivariate analysis. As expected, cohabitation with both dogs and cats was also significantly associated with seropositivity (OR = 3.75, 95% CI: 1.48–9.75). However, other assessed variables (gender, age, ethnicity, hygienic habits, contact with soil, raw meat ingestion) were not associated with seropositivity. (4) Conclusions: The study herein has filled a gap regarding toxocariasis in vulnerable populations and suggests food insecurity as a socioeconomic indicator for Toxocara spp. seropositivity in recycling workers. Furthermore, recycling workers are at higher risk of infection and, as such, need to be prioritized in healthcare programs. Full article

Theileria orientalis and Babesia bigemina are hemoprotozoan parasites that adversely affect domestic cattle (Bos taurus) productivity and health worldwide. Rapid climatic changes in different geo-climatic zones observed over the past few years may have altered the distribution and transmission of tick-borne pathogens and vectors. Though these parasites are reported in Sri Lanka in surveillance records, there is a limited understanding of their current distribution pattern. The present study aimed to determine the prevalence and genetic characterization of B. bigemina and T. orientalis in cattle from three geo-climatic zones of Sri Lanka during the period from January 2025 to March 2026. Out of 384 samples collected from animals (wet, n = 124; dry, n = 208; and intermediate, n = 52 zones) in Sri Lanka, the overall prevalence of 60.2% for T. orientalis and 7.6% for B. bigemina was revealed using PCR-based detection methods. The highest prevalence of T. orientalis was observed in the wet zone (86.3%), while the highest prevalence of B. bigemina was 17.3% in the intermediate zone. Co-infections were detected in 5.7% of cattle across all three zones. These results indicate the dominance of T. orientalis compared with B. bigemina in cattle in Sri Lanka. The observation of co-infections highlights the importance of vector control against vector-borne diseases in Sri Lanka. Full article

Tick-borne parasitic diseases pose important threats to veterinary and public health, particularly in countries with livestock-dependent economies such as Kyrgyzstan. However, molecular epidemiological data on tick-borne pathogens in Kyrgyzstan is limited. This study investigated the prevalence, genetic diversity, and host–tick–pathogen associations in Chuy Province, Kyrgyzstan. A total of 494 ticks belonging to 6 genera and 10 species were collected from various animal hosts in eight survey areas in central-northern Chuy Province and analyzed using polymerase chain reaction, Sanger sequencing, and phylogenetic analysis. Of the 494 ticks, 35 (7.1%) were infected, including 15 (3.0%) with Babesia species and 20 (4.0%) with Theileria species. The highest positive rates were observed in Rhipicephalus annulatus (13.8%) and Haemaphysalis punctata (12.4%). Molecular analysis identified 4 Babesia species (B. caballi, B. major, B. bigemina, B. occultans) and 2 Theileria species (T. orientalis, T. ovis). Ticks collected from horses had the highest infection rates and greatest diversity of pathogens. T. orientalis was the most common pathogen. T. ovis was exclusively found in ticks collected from sheep. Phylogenetic analysis confirmed that the isolates were closely related to strains circulating in neighboring Central Asian and Eurasian countries. The findings provide foundational data for developing region-specific vector control measures. Full article

Theileria annulata (T. annulata) is a parasite that causes tropical theileriosis, affecting around 250 million cattle in regions such as Turkey, Southern Europe, Northern Africa, and Asia. Anemia, a primary symptom of T. annulata infection, is critical to understanding the disease’s pathogenesis. Adipokines secreted from adipose tissue serve as signaling molecules influencing various systems, including energy metabolism and coagulation. This study aims to investigate the role of adipose tissue secretions (adiponectin, leptin, resistin, omentin-1) in the pathogenesis of the disease by evaluating the symptoms of anemia and inflammation associated with tropical theileriosis. The study involved 40 cattle, including 32 infected with T. annulata and eight healthy cattle. Hematological tests and measurements of serum adiponectin, leptin, resistin, and omentin-1 levels were conducted using ELISA kits. Adiponectin (p = 0.002) and omentin-1 (p = 0.001) levels were significantly higher in the infected groups compared to the control group. However, no significant differences were found in leptin and resistin levels between the infected and control groups. Adiponectin exhibited a moderate negative correlation with HCT (p = 0.011, r = −0.397) and RBC (p = 0.033, r = −0.338). A moderate negative correlation was found between HCT concentration and omentin-1 (p = 0.039, r = −0.328). The findings of this study suggest that the levels of adiponectin and omentin-1 are associated with T. annulata infection in cattle and that these adipokines may play a potential role in the pathogenesis of tropical theileriosis. These biomarkers may also have potential diagnostic value in the diagnosis of T. annulata infection. Full article

Cutaneous leishmaniasis (CL) is a chronic infectious disease characterized by extensive tissue destruction and profound extracellular matrix (ECM) remodeling. This study provides the first evidence of O-glycosylated oncofetal fibronectin (onf-FN) expression in human CL lesions. Immunohistochemical analysis revealed increased onf-FN expression throughout the inflammatory lesions, displaying a distribution pattern closely resembling that observed in human tumors and overlapping with total fibronectin expression. The detection of onf-FN in an infectious disease caused by protozoan parasites broadens the current understanding of ECM remodeling beyond cancer and developmental processes, suggesting that onf-FN may also participate in the host tissue response to chronic infection. Given the well-established biological functions of onf-FN in regulating cell adhesion, tissue remodeling, and repair, its expression in CL lesions raises important questions regarding its potential role in disease pathogenesis and parasite persistence. These findings identify onf-FN as a previously unrecognized component of the CL microenvironment, providing a foundation for future studies investigating its biological and clinical significance in parasitic diseases. Full article

Rapid and accurate diagnosis is crucial for the early detection of malaria caused by Plasmodium parasites. This study primarily focuses on identifying a suitable deep learning model for classifying malaria parasites. In an ablation process, we started with single-branch Convolutional Neural Network (SB-CNN) and dual-branch CNN (DB-CNN) architectures enhanced with attention mechanisms to improve feature representation. Specifically, we incorporate the Convolutional Block Attention Module (CBAM) to focus on both channel-wise and spatially important features. We also use the Efficient Channel Attention (ECA) module to capture local inter-channel relationships, while the Squeeze-and-Excitation (SE) block emphasizes globally significant feature maps, further improving the model’s ability to distinguish between classes. To identify the most effective model, we experimented with EfficientNet-B0 and EfficientNet-B3 as backbone networks and conducted an ablation study by integrating various attention modules, resulting in three DB-CNN variants. We applied t-Distributed Stochastic Neighbor Embedding (t-SNE) to visualize the high-dimensional feature space between infected and uninfected samples. Utilizing the 5-fold cross-validation method on the Thick dataset, the best-performing models included architectures such as SB EfficientNet-B3, SB EfficientNet-B3 combined with CBAM, and DB EfficientNet-B3 across both branches, with CBAM in the first and SE in the second. Full article

Intestinal parasitic infections, particularly soil-transmitted helminths (STHs), remain a major public health concern in low- and middle-income countries. As control programs reduce infection intensity, accurate diagnosis becomes increasingly challenging. The McMaster technique has been proposed as an alternative diagnostic method for detecting human intestinal parasites; however, its diagnostic performance in human populations remains unclear. This study aimed to evaluate the diagnostic sensitivity of the McMaster technique for detecting intestinal parasites, particularly STHs. A systematic review and meta-analysis were conducted in accordance with the PRISMA guidelines and registered in PROSPERO (CRD420261298952). Electronic databases (PubMed, Scopus, Web of Science, Ovid, Nursing & Allied Health Premium, and Google Scholar) were searched up to January 2026. Studies assessing the McMaster technique in human populations and reporting sufficient data to calculate sensitivity were included. A random-effects model was used to estimate pooled sensitivity, with subgroup analyses by parasite species, geographic region, and population characteristics. Risk of bias was assessed using the the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Among the 1514 records identified through database searching, 10 studies were included in the final analysis. The pooled sensitivity of the McMaster technique was 73% (95% confidence interval [CI]: 67–78%; I² = 91.0%) for detecting any intestinal parasites and 72% (95% CI: 65–78%; I² = 93.5%) for STHs. Species-specific sensitivities were 67% (95% CI: 61–72%; I² = 80.7%) for Ascaris lumbricoides, 79% (95% CI: 57–91%; I² = 96.9%) for Trichuris trichiura, and 71% (95% CI: 61–80%; I² = 89.9%) for hookworms. The McMaster technique demonstrates moderate sensitivity for detecting intestinal parasites in humans. While it offers practical advantages for field applications, its reduced sensitivity in low-intensity infections limits its utility as a standalone diagnostic tool in control and elimination settings. Further research should focus on methodological standardization and integration with more sensitive diagnostic approaches. Full article

Toxoplasma gondii is a widespread intracellular parasite posing serious risks to immunocompromised individuals and pregnant women, and causing significant economic losses to the livestock industry. Current clinical drugs mainly target acute-stage tachyzoites but are ineffective against chronic cysts, necessitating new interventions. The parasite’s sexual stage in the feline intestine remains poorly understood but is critical for transmission. Here, based on our unpublished weighted gene co-expression network analysis of single-cell transcriptomic data of cat intestine after infection with T. gondii, we selected five previously uncharacterized genes, including three CCCH-type zinc finger proteins (TGME49_257130, TGME49_500318, TGME49_313740) and two subtilisin-like proteases (TGME49_248760/sub7, TGME49_235950/sub8). Using the CRISPR-Cas9 system, individual knockout strains were generated from the type II Pru strain. And, we performed phenotypic assessments at this stage as an essential validation to confirm neutrality before feline infection experiments. Phenotypic analyses revealed that none of the knockout strains showed significant differences in vitro growth, replication, egress, in vivo virulence, or cyst formation from the wild-type strain, corroborating the transcriptional prediction. Publicly available ToxoDB transcriptomic data confirmed that four of these genes were highly expressed at the oocyst or feline enteroepithelial stages, but barely expressed in tachyzoites and bradyzoites, consistent with our phenotypic observations. Collectively, these findings indicate that these genes are dispensable for asexual development, while their expression pattern suggests potential involvement in sexual reproduction, a hypothesis that warrants direct experimental validation. This study provides validated knockout strains and candidate genes, establishing an experimental foundation for future functional studies on Toxoplasma sexual development and transmission-blocking strategies. Full article

We previously demonstrated the therapeutic potential of a 0.5% miltefosine carbopol-based gel (G-MTF) in experimental cutaneous leishmaniasis (CL). To support formulation optimisation before clinical evaluation, this study assessed whether G-MTF retained antileishmanial activity after storage at different temperatures and durations and evaluated its dose–response following topical application to CL lesions in BALB/c mice infected with Leishmania amazonensis. Storage effects on some physicochemical and morphological properties, sterility, and MTF detection were also assessed. In vitro antileishmanial activity was largely maintained, although prolonged storage at 35–45 °C moderately reduced potency. During 60 days of follow-up, CL lesions reactivated in 17% of the 118 treated mice, with most reactivations occurring after treatment with G-MTF formulations stored for 3–6 months at 35–45 °C. Dose–response analysis showed concentration-dependent effects on lesion reduction and parasite burden, with estimated ED₅₀ values of 3.64 and 4.02 mg/kg, respectively. All carbopol-based gel formulations remained sterile and retained physicochemical characteristics at 8–28 °C, with pH values within the normal skin range. Storage at 8 °C increased viscosity and reduced spreadability, whereas higher temperatures increased swelling. MALDI-TOF MS demonstrated that MTF remained detectable after prolonged storage, while SEM showed preserved morphology at 8–28 °C. Overall, carbopol-based G-MTF maintained therapeutic activity and acceptable physicochemical characteristics for up to six months at 8–28 °C. Validated quantitative stability-indicating and drug-release methods are needed to confirm MTF chemical stability and drug availability in the carbopol-based gel. Full article

The objective of this study was to compare fecal egg count (FEC) and serum malondialdehyde (MDA) concentration in naturally parasite-infected goats following administration of an anthelmintic drug and Mitragyna speciosa Korth. as the control and treatment groups, respectively. A total of 34 female goats were randomly allocated into two groups. The control group received albendazole at a dose of 15 mg/kg on the first day of the experiment. Then followed by a daily placebo until day 21. The treatment group was orally administered 5 g/head of dried Mitragyna speciosa Korth. daily for 21 days. Hematological parameters were evaluated on days 0 and 21, while blood biochemical parameters, including blood urea nitrogen (BUN), creatinine, aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT), were measured on day 0 and at 7-day intervals until day 35. Fecal egg count and serum MDA concentration were determined on day 0 and every 7 days until day 42. The results showed that plasma protein levels were significantly affected by time (p < 0.05) and group (p < 0.05), while red blood cell count was significantly influenced by time (p < 0.05). No significant group effects were observed for BUN, creatinine, AST, and GGT. However, AST showed a significant effect over time (p < 0.05). Hematological and blood biochemical parameters remained within physiological ranges in both groups, with no evidence of kratom-associated toxicity. Log₂-transformed fecal egg counts per gram of feces (Log₂-EPG) showed significant time and time × group interaction effects (p < 0.001 and p = 0.008, respectively). Fecal egg count reduction test (FECRT) showed significant time and time × group interaction effects (p = 0.009 and p = 0.013, respectively). Serum MDA was significantly lower in the kratom group only at day 7 (p < 0.05). In conclusion, Mitragyna speciosa Korth. supplementation did not significantly reduce fecal egg count compared to conventional anthelmintic treatment but demonstrated a transient effect on oxidative stress, as indicated by changes in serum MDA concentration. Full article

Background: Intestinal parasitic infections caused by Giardia lamblia and Ascaris lumbricoides remain a public-health problem in resource-limited settings, where conventional microscopy depends on expert personnel and shows variable sensitivity. Artificial intelligence (AI) could standardize and decentralize diagnosis. This study aimed to design and validate FenoParasite, an AI object-detection software (Azure Custom Vision) for the microscopic identification of G. lamblia cysts and trophozoites and A. lumbricoides eggs in stool samples. Methods: Diagnostic-accuracy study. The reference standard was consensus microscopy by two expert readers, with a third reader for discordant cases. An internal validation set (n = 159) and a prospective pilot validation set (n = 31) were analyzed. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy (95% Clopper–Pearson CI), AUC-ROC (bootstrap), and Cohen’s kappa were computed; the confidence threshold was 90%. Results: The model achieved a mAP@0.30 of 98.3% (precision 98.2%; recall 96.4%). In internal validation, G. lamblia showed 100% sensitivity, 98.9% specificity, 99.4% accuracy, and AUC 0.98; A. lumbricoides reached 100% across all indices (AUC 1.00). In the prospective pilot validation, sensitivity and specificity were 100% for both taxa; however, the confidence intervals were very wide (lower sensitivity bounds of 39.8% and 75.3%, based on only 4 and 13 reference-positive specimens, respectively), and these estimates are correspondingly imprecise. Conclusions: FenoParasite showed high agreement with consensus expert microscopy for both a protozoan and a helminth. Because the reference standard was expert microscopy rather than a molecular assay, the reported performance estimates quantify agreement with microscopic reading rather than absolute diagnostic accuracy. These findings remain preliminary. Multicenter validation against molecular reference standards is required before clinical implementation can be considered. Full article