Acta Parasitologica最新文献

Background

Neglected Tropical Diseases (NTDs) remain a major public health concern in sub-Saharan Africa, where inadequate sanitation and unsafe water contribute to ongoing transmission.

Objective

This study examined the prevalence and associated risk factors of Schistosoma haematobium among school-aged children in 20 WASH-focused communities across four Local Government Areas in Ogun Central, Nigeria, between March 2021 and March 2023.

Methods

Urine and stool samples were collected from 1,019 pupils and analyzed using standard parasitological techniques, while structured questionnaires captured demographic information, WASH indicators, and attitudes toward anthelmintic treatment.

Results

The overall prevalence of S. haematobium was 2%. Significant associations were observed between infection and water sources (p < 0.05), toilet facilities (p = 0.045), and haematuria (p < 0.001). Age was also identified as a significant demographic factor influencing infection.

Conclusion

These findings highlight the persistent vulnerability of children in WASH-dependent communities to urinary schistosomiasis and emphasize the need for integrated control strategies that combine improved sanitation, safe water supply, health education, and regular mass drug administration.

Purpose

Neospora caninum is a common infectious cause of abortion in cattle globally. This study aimed to investigate the seroprevalence of N. caninum, identify associated risk factors, and assess the diagnostic agreement between serum and milk samples.

Methods

A total of 254 individual serum samples were collected from dairy cattle in two Egyptian governorates. The seroprevalence of N. caninum antibodies was determined using a commercial ELISA kit (ID Vet – France). For assessment of diagnostic agreement between individual serum and milk samples, 92 milk samples from the same animals representing different days in milk (DIM) were tested using the same ELISA kit.

Results

The overall seroprevalence of N. caninum antibodies was 31.9%. The seroprevalence rates for Faiyum and Alexandria governorates were 28% and 40.5%, respectively. For seropositive animals to N. caninum, the odds of suffering from abortion are 5.5 times greater than the odds for seronegative animals (P < 0.001), reaching 12.4 times in multivariable analysis. While the animal’s location was found to have a significant relationship with the seroprevalence of N. caninum (P = 0.048) in univariable analysis, multivariable logistic regression showed no significant effect (P = 0.33). The age, parity, animal productive category, gynecological disorders, and the average milk production had no significant relation with the seroprevalence of N. caninum (P > 0.05). The Kappa coefficients between individual serum and milk samples were 0.59, 0.52, and 0.64 for all samples (n = 92), ≤ 220 DIM (n = 42), and ˃ 220 DIM (n = 50), respectively.

Conclusion

N. caninum is prevalent in Egypt. Abortion history can be used as a key predictor factor for Neospora in the examined herds. The late lactation period is the preferred time for testing milk samples; however, we do not recommend replacing individual serum samples with milk samples.

Background

Toxoplasma gondii (T. gondii) is a zoonotic parasite that causes severe disease, particularly in immunocompromised individuals. Current treatments have significant side effects and are ineffective against the latent stage of the parasite. S-Methylcysteine (SMC), a compound from garlic, has antioxidant and anti-inflammatory properties, but its efficacy against T. gondii is unknown.

Objective

To evaluate the in vivo effects of SMC on T. gondii infection, focusing on hormonal and histopathological changes and its therapeutic potential.

Materials and Methods

Forty-eight adult female albino rats were divided into eight groups of six. Four groups were infected intra-vaginally with 200 T. gondii cysts, while controls received saline. For two months, treatment groups were administered daily doses of SMC (50 mg/kg), Spiramycin (200 mg/kg), or a combination of both via gastric tube. After sacrifice, blood samples were collected for hormonal analysis (estrogen, progesterone, LH, FSH). The ovaries and uterus were excised and histologically examined using hematoxylin and eosin staining for microscopic evaluation.

Results

Toxoplasma gondii infection caused significant hormonal disruption and severe uterine and ovarian inflammation. Treatment with either SP or SMC alone partially mitigated these effects. However, the combined SMC and Spiramycin treatment showed the most significant improvement, significantly mitigated hormonal imbalances and promoted substantial tissue recovery.

Conclusion

S-Methylcysteine shows promising therapeutic potential in ameliorating the hormonal and histopathological damage associated with T. gondii infection, especially when combined with Spiramycin. Future studies, including human clinical trials, are needed to investigate its mechanisms and confirm its safety and effectiveness.

Background

Toxoplasma gondii (T. gondii) causes latent infections in host tissues, including those of the central nervous system. In males, the hypothalamic pituitary gonadal (HPG) axis controls reproductive function through a hormonal cascade. Disruption of this axis can impair spermatogenesis and lead to infertility. This study aimed to investigate the impact of chronic infection by T. gondii on the HPG axis in male rats, especially with respect to FSH, serum, and intratesticular testosterone (ITT) concentrations, via histopathological examination of the testes.

Methods

A total of 36 outbred male Wistar rats were included in this study (24 cases and 12 controls). The ME-49 strain of T. gondii was utilized to infect rats. At days 40, 50, and 60 following infections, the rats were euthanized, and the testes were obtained for histopathological examination. Serum and testicular tissue samples were investigated for FSH and testosterone serum levels, and the ITT concentration was measured.

Results

There was a statistically insignificant decrease in the serum testosterone level and the concentration of ITT at 40 and 50 days between the Toxoplasma-infected group and the control group; the difference was significant on day 60 (P < 0.05). At all specified time points, the Toxoplasma-infected rat group’s mean serum FSH concentration was substantially greater than that of the control group (P <  0.01). The Toxoplasma-infected groups presented abnormal histopathology findings in their testicular tissues.

Conclusion

Toxoplasmosis impacts the male hormones essential for spermatogenesis and disrupts testicular histology, indicating that chronic toxoplasmosis has a negative effect on the HPG axis and impacts male fertility.

Purpose

Raw milk and its products are increasingly popular among consumers recently. Milk already harbors a primary microbial flora during milking but can be further contaminated at any stage with pathogenic microorganisms. Although, the presence of C. burnetii in milk and other dairy products is frequently reported, E. bieneusi has been documented in a few studies, and D. fragilis has not been reported previously. Therefore, this study aimed to evaluate the contamination of raw milk from cattle, sheep, and goats, as well as cheese from cattle, with these pathogens to assess public health risk.

Methods

A total of 150 samples from cattle, sheep, goat and homemade ready-to-eat cattle milk cheese were collected from farms, open-air markets, and delicatessen were examined using PCR analysis. Pathogen positive samples were sequenced for species identification and genotyping.

Results

The overall prevalence of E. bieneusi, C. burnetii, and D. fragilis in the samples was 2.0%, 8.6%, and 6.0%, respectively. In cattle milk cheese samples, the prevalence was 3.3% for E. bieneusi, 10.0% for C. burnetii, and 3.3% for D. fragilis. The potentially zoonotic E. bieneusi BEB6 genotype was found in sheep milk and cattle milk cheese. D. fragilis isolates detected in cattle and sheep milk and cattle milk cheeses showed homology with genotype 1 from human, cattle and budgerigars in various countries including Türkiye.

Conclusion

This is the first report of D. fragilis in milk and cattle milk cheese samples, as well as E. bieneusi in cattle milk cheese samples. These findings provide critical insights into the zoonotic transmission potential of these foods and contribute to a better understanding of epidemiology and public health risk.

Purpose

The excretory-secretory antigen (ESA) of Toxoplasma gondii has been classified as a good diagnostic marker for the acute and chronic phases of toxoplasmosis. The objective of this study was to determine an antigenic pattern that allows distinguishing both acute and chronic phases of toxoplasmosis.

Methods

T. gondii RH ESA cultured in the LLC-MK2 cell line was used and challenged with sera from Swiss mice infected experimentally with T. gondii RH (group I), T. gondii Me49 (group II) tachyzoites and a control group of uninfected mice (group III) by Western blot (WB) test. The success of the proliferation of both strains was confirmed by microscopy and quantified by qPCR, which corroborated the acute and chronic phases with the RH and Me49 strains, respective.

Results

In WB, no bands were detected with ESA against mice from group I. Antigenic bands were obtained in the range of 10–129 kDa in the mice from group II at 60 days post infection (dpi). On the other hand, bands of 28 kDa and 33 kDa were evident in all mouse sera 56–165 dpi.

Conclusion

Although, in this study, the use of ESA did not allow obtaining an antigenic profile to distinguish both the acute and chronic phases of toxoplasmosis, an antigenic profile was found that could be useful to identify the chronic phase and monitor the clinical evolution of patients with toxoplasmosis.

Introduction

Cutaneous leishmaniasis remains a significant public health problem and continues to pose a substantial challenge to the healthcare system. First-line drugs, particularly pentavalent compounds, are used to treat this disease. The increasing drug resistance, the reduced efficacy of current therapies, and the high treatment costs. Have shifted the focus of research toward herbal remedies and natural products. This study sought to examine the possible antileishmanial properties of the ethanolic extract from R. coriaria and compounds of linalool and eugenol, both in vitro and in vivo against skin lesions caused by L. major in BALB/c mice.

Methods

The CC50 toxicity and IC50 anti-leishmanial effect of linalool and eugenol were examined on the macrophage cell line and promastigotes. In the in vivo phase, a total of 54 mice were infected with L. major and treated. Three weeks after the end of treatment, parasitological and molecular examinations were performed using real-time PCR.

Results

An in vitro study showed that linalool and eugenol had favorable lethality and toxicity values and were significantly correlated with the control group. According to the results of this study, the healing rates of lesions in the high-dose eugenol, low-dose linalool, and Glucantime® groups was 90.6%, 89.01%, and 85.58%, respectively. The results of the evaluations showed that the parasite load in the treated groups was significantly reduced. The reduction of specific KDNA gene expression and parasite load in the liver and spleen organs showed the degree of improvement and efficacy of the extract and compounds in real-time PCR.

Conclusion

This study demonstrates that the alcoholic extract of sumac and compounds of linalool and eugenol are effective in the treatment of cutaneous leishmaniasis and offers a promising perspective for the development of herbal medicines with fewer side effects.

Graphical abstract

Evaluation of the effects of linalool, eugenol, and R. coriaria on L. major infection in a murine model: Analysis of parasite burden, wound healing progression, and molecular assessment using Real-Time PCR (BioRender., 2025).

Purpose

Continuous surveillance of Plasmodium falciparum Kelch 13 (pfk13) mutations associated with artemisinin resistance is essential for monitoring the emergence of drug-resistant parasites in malaria-endemic regions. Herein, we have assessed the prevalence of point mutations in the pfk13 gene linked to artemisinin resistance in Iranian P. falciparum isolates, 18 years following the nationwide introduction of artemisinin-based combination therapies (ACTs).

Methods

A total of 60 finger-prick blood samples were obtained from Iranian patients with symptomatic, uncomplicated P. falciparum malaria during the period of 2022 to 2023. A nested polymerase chain reaction (PCR) assay was employed to verify infections by amplifying the 18 S small subunit ribosomal RNA (18 S ssrRNA) gene. Nested PCR was utilized to amplify the pfk13 gene, followed by sequencing of the amplicons to identify both previously reported and novel mutations.

Results

Of the successfully sequenced samples (n = 50), 98% (49/50) carried the wild-type allele. One sample harbored a novel nonsynonymous mutation, R513C, corresponding to a C1537T nucleotide change.

Conclusion

No validated pfk13 mutations indicative of artemisinin resistance were detected in the study population. These findings suggest that artemisinin remains effective for treating P. falciparum malaria in this region. Continued molecular surveillance is warranted to ensure early detection of emerging resistance.

Objective

To document cases of free-living amoebae (FLA) infections in humans diagnosed at a Reference Parasitology Laboratory in Argentina, contributing to the epidemiological understanding of these infections in the country.

Methods

A retrospective analysis was performed on 43 samples from suspected cases of FLA infection collected between October 2022 and June 2025. The samples included 4 ocular specimens, 20 brain biopsies, 12 cerebrospinal fluid samples, 6 skin biopsies, and 1 liver biopsy. FLA culture was carried out only in suspected keratitis cases, using liquid Page’s solution supplemented with fresh Escherichia coli culture. In all cases, multiplex real-time PCR (qPCR) was employed for the simultaneous detection of Acanthamoeba spp., Naegleria fowleri, and Balamuthia mandrillaris. The cases were analyzed together with the information provided in the epidemiological forms that accompanied the samples.

Results

Of the 43 analyzed samples from suspected cases, 5 tested positive (11.6%), including 1 case of keratitis caused by Acanthamoeba spp. and 4 cases of granulomatous amebic encephalitis (GAE) due to B. mandrillaris. The GAE cases involved immunocompetent children and one adult with a functional immunosuppression risk factor (chronic alcoholism). One patient presented with chronic skin lesions prior to the CNS infection, and another case involved co-infection with Toxoplasma gondii. Neuroimaging in all GAE patients showed lesions consistent with mass or infectious processes, and brain biopsy samples were essential for diagnosis. Two of the GAE patients survived following combined therapy.

Conclusions

Infections caused by FLA are rare but highly severe, particularly non-keratitis presentations. Early clinical suspicion, rapid and accurate diagnosis, and aggressive treatment are crucial to improving patient outcomes.

Purpose

Livestock sustainability intersects environmental, economic, and social dimensions, particularly through its influence on animal health. This study aimed to evaluate the diversity of eukaryotic gastrointestinal parasites and microbiota in domestic animals from productive systems located within Colombian conservation areas, where livestock coexist with wild mammals such as primates, pumas, Andean bears, and tapirs. Specifically, we examined how natural vegetation fragmentation relates to parasite diversity, richness, and equitability.

Methods

Fecal samples from cattle, horses, and domestic dogs were analyzed using metabarcoding of the 18S rRNA gene via Nanopore sequencing, focusing on protozoa as key indicators. Microscopy was used to confirm molecular findings. Epidemiological descriptors, including prevalence, mean intensity, and mean abundance, were estimated, and Bayesian Poisson regression models were applied to assess associations between landscape metrics and parasite or fungal diversity.

Results

From 50 collected samples, 27 yielded usable sequences, revealing 11, 12, and 3 parasite taxa in cattle, horses, and dogs, respectively. The diversity of eukaryotic microbiota and parasites in cattle and horses correlated positively with native forest cover and negatively with forest shape irregularity, indicating that larger and more compact forest patches favor greater parasite diversity.

Conclusion

Parasite transmission between livestock and wild mammals in conservation landscapes represents a bidirectional ecological risk. Although extensive forest cover enhances ecosystem integrity, it may also increase parasite diversity, with potential implications for livestock health and disease management strategies.