Acta Parasitologica最新文献

Rationale

Soil-transmitted helminths (STH) remain endemic in the Philippines. Despite efforts through information campaigns and deworming initiatives aimed at reducing worm burdens, these programs predominantly target preschool and school-aged children, along with pregnant and lactating women, leaving much of the population susceptible and at risk of infection.

Objective

The study aimed to provide baseline data for adult farmers, which are another group of vulnerable stakeholders in terms of STH infection in rural areas of the Philippines.

Methodology

The study assessed the health, knowledge, attitudes, and practices of adult farmers, one of the determined at-risk populations by the Department of Health—Philippines, via a validated Likert health, knowledge, attitudes, and practices questionnaire, which was analyzed concerning parasite infection risk or soil-transmitted helminth prevalence with stool samples examined with direct fecal smear and duplicate Kato-Katz thick smear methods.

Results

As determined in the occupationally exposed population, there is an STH prevalence of 15.26%; among the seventeen single-organism infections, Trichuris trichiura had the highest positivity rate (5.93%), followed by Ascaris lumbricoides (4.24%), and Hookworm spp. (4.24%), With only one coinfection between T. trichiura and Hookworm spp. (0.85%). As for factors associated with infection risk, Fisher’s exact test of independence identifies the main contributing factors for STH infection risk as the practices of (1) using an unclean source of water, (2) using an unclean toilet, and (3) handling and transportation of animal fecal matter and plant remains.

Conclusion

This study confirms that adult farmers from Panay have a positive prevalence of STH infection, hence a more proactive public health strategy is recommended to be implemented on targeted local health areas of the Philippins.

Background

Schistosomiasis is a neglected tropical disease that affects over 250 million people globally, with Ethiopia being an endemic region. The Shabelle River in the Somali Regional State provides an ideal habitat for transmission. Although earlier studies confirmed the presence of schistosomiasis in parts of the Mustahil and Kalafo districts, recent and comprehensive epidemiological data for the wider area remain limited. Therefore, this study aimed to assess the epidemiology of schistosomiasis in villages along the Shabelle River in the Kalefo, Mustahil, and Fer-fer Districts of the Somali Regional State of Ethiopia.

Methods

A community-based cross-sectional study was conducted from August to December 2023 among 1200 participants aged ≥ 5 years. Sociodemographic data, water-contact behaviors, and sanitation practices were collected through questionnaires and observations. Urine and stool samples were analyzed to diagnose Schistosoma infection. Multivariate logistic regression was used to identify the risk factors.

Results

The overall prevalence of schistosomiasis was 29% (95% CI: 25.99%–31.21%), with S. haematobium (22.17%; 95% CI: 19.76%–24.74%) being more prevalent than S. mansoni (6.42%; 95% CI: 5.09%–7.97%). Significant risk factors included receiving health information from professionals (AOR = 3.73), female-dominant bathing practices (AOR = 0.27), adult fishing (AOR = 0.25), and longer residence duration (AOR = 0.17–0.20). Limited sanitation access (10.25%) and a high reliance on river water (69.83%) were the major contributors to transmission.

Conclusions

This study found a high prevalence of schistosomiasis (29%) along the Shabelle River, with S. haematobium (22.16%) being more prevalent than S. mansoni (6.41%). Key risk factors included limited sanitation access (10.25%), high reliance on river water (69.83%), and low awareness of transmission (18.42%). Adult fishermen had lower infection odds, whereas those receiving health information from professionals had higher odds, likely due to reverse causality. These findings highlight the need for targeted interventions that combine health education, improved WASH infrastructure, and MDA to reduce transmission in endemic areas.

Objectives

In this restrospective and cross-sectional study, it was aimed to analyze the time-dependent change in mortality due to liver hydatid cysts in a multicenter and multivariate manner over 25 years.

Methods

In the study, 213 files of patients with liver Hydatid cysts underwent surgery in multicenter between 1993 and 2018 were retrospectively included. The mortality rate in patients was reported as 11.7%. Gender, age, cyst stage, number of cysts, localization, maximum cyst diameter, latex and albendazole use, comorbidity, early and late complications, mortality, hospitalization and follow-up periods of the patients were analyzed.

Results

Age mean, right localization and cardiovascular disease (CVD) frequency parameters were significantly higher in mortality group (p < 0.05). Follow up duration was significantly higher in living group (p < 0.05). Mortality was significantly correlated with age (r = 0.375; p < 0.01), localization (r = − 0.153; p < 0.05), CVD (r = 0.264; p < 0.01) and follow up duration (r = − 0.262; p < 0.01). According to year controlled partial correlation analysis, mortality was only significantly correlated with age (r = 0.301; p < 0.05). Cox regression analysis results showed that effects of age (B = 0.093; p < 0.01), right localization (B = 2.215; p < 0.05) and left localization (B = 2.704; p < 0.05) on mortality were significant. Survival function for mortality showed that about first 100 days after surgery were important for mortality. After 200 day, cumulative survival trend was more stable than before. In left localized cyst, about first 500 days after surgery is important for mortality. In right and segment localized patients, first 1000 days after surgery is important for mortality.

Conclusion

According to the results of multicenter and 25-year experience in patients with hydatid cysts, the causes of mortality did not change significantly over time, and only age and localization were found to be important factors. Although there have been improvements in environmental hygiene and risk factors over time, their effects on disease-related mortality were found to be insignificant.

Purpose

Blastocystis spp. is the most commonly identified protozoan in humans, yet its clinical significance and pathogenicity remain controversial. While often asymptomatic, it has been associated with gastrointestinal symptoms and urticaria. Metronidazole is the most frequently used first-line treatment; however, increasing reports of resistance and treatment failure have led to growing interest in alternative therapeutic options.

Methods

In this systematic review, we searched the Web of Science, Scopus, and PubMed databases using relevant keywords in article titles to identify studies related to the treatment of Blastocystis spp.

Results

A total of 195 records were retrieved. After removing duplicates and applying inclusion and exclusion criteria, 39 studies were deemed eligible. Data extracted included author, publication year, country, number of participants or samples, diagnostic method, subtype, treatment agent, dosage, intervention details, and clinical and parasitological outcomes. Of the included studies, 17 were human studies (14 clinical trials and 3 case reports), and 22 were in vitro or animal studies.

Conclusion

Our findings suggest that metronidazole may be inappropriate as a first-line treatment, as it can increase the number of viable parasites and promote their transformation into apoptosis-resistant granular or more pathogenic amoeboid forms. Alternative agents—such as ronidazole, satranidazole, and C17 (2-position 5-nitroimidazoles), as well as ornidazole, secnidazole, and tinidazole (1-position 5-nitroimidazoles with different side chains compared with metronidazole)—show potential efficacy. Trimethoprim-sulfamethoxazole and nitazoxanide have also demonstrated promising results. Further studies, particularly subtype-specific and human clinical trials, are needed to assess the safety and efficacy of these alternative agents against Blastocystis spp.

Toxoplasma gondii is a widespread zoonotic parasite with significant public health and veterinary importance. This cross-sectional study was conducted between November 2023 and October 2024 to determine the seroprevalence of Toxoplasma gondii infection and associated risk factors in sheep from Nineveh Governorate, northern Iraq. A total of 507 serum samples from 30 herds were tested using a commercial indirect enzyme-linked immunosorbent assay (ELISA) kit. The overall seroprevalence was 38.1% (95% CI: 34.0–42.4), with 83.3% of herds having at least one seropositive animal. Statistical analysis revealed significant associations between seropositivity and flock size, grazing system, water source, cat presence, and season. Larger flocks, open grazing, untreated water, presence of cats, and spring season were all strongly linked to higher prevalence. In contrast, host age and sex were not significant predictors. These findings highlight the importance of flock-level and environmental factors in disease transmission. Practical control measures such as improved water management, limiting cat access, and farmer education are essential to reduce infection risk.

Purpose

Cryptosporidium and Giardia are significant causes of gastrointestinal diseases in humans and animals worldwide, especially in pigs. This study investigated the molecular occurrence, genetic diversity, and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis in domestic pigs in the Chattogram Hill Tracts (CHT), Bangladesh.

Methods

A total of 408 fecal samples were collected from Rangamati, Khagrachari, and Bandarban districts and examined using nested PCR, targeting the SSU rRNA gene for Cryptosporidium and the β-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) genes for G. duodenalis. Nucleotide sequencing and phylogenetic analysis were conducted for molecular characterization.

Results

The prevalence of Cryptosporidium was 3.43%, and G. duodenalis was 23.52%. The prevalence varied by several factors, although the variations were not significant for Cryptosporidium. Age, anthelmintic administration, and diarrheal status of the pigs had a significant influence on the occurrence of Giardia. Among the 14 Cryptosporidium and 96 Giardia isolates, two Cryptosporidium species (C. suis and C. scrofarum) and three G. duodenalis assemblages (A, B, and E) were found, among which assemblage A (56.25%) was the most prevalent. Additionally, 13 novel genotypic variations were identified at the bg, gdh, and tpi genes of G. duodenalis.

Conclusion

Pigs in the CHT region harbor Cryptosporidium and Giardia with notable genotypic diversity and zoonotic potential. Addressing this issue requires further research within a One Health framework, focusing on integrated surveillance and the development of evidence-based policies for pig farming to reduce transmission and safeguard animal and public health.

Graphical Abstract

DNA methylation is a key epigenetic mechanism regulating gene expression during spermatogenesis. This study investigated the effects of experimental amebiasis induced by Entamoeba histolytica and its treatment with metronidazole (MTZ) on the methylation status of the Spermatogenesis Associated 6 (SPATA6) gene and male reproductive function. Twenty-four adult male rats were assigned to control, infected, and MTZ-treated groups. Following treatment, testicular tissues were analyzed for SPATA6 promoter methylation via bisulfite sequencing, infection confirmation by PCR, histopathological changes by hematoxylin and eosin (H&E) staining, Inhibin B and Androgen-Binding Protein (ABP) expression by immunohistochemistry, and sperm quality indices. The infected group exhibited distinct non-CpG methylation at a SPATA6 locus, confirmed reproductive tract infection, severe testicular damage, increased expression of Inhibin B and ABP, and significantly impaired sperm parameters. MTZ treatment successfully cleared the parasite and partially restored testicular architecture and sperm count; however, residual abnormalities in sperm motility, histology, and SPATA6 methylation persisted. While these findings suggest that parasitic infection and its treatment may induce epigenetic dysregulation in the testis, the direct functional link between the observed methylation change and reproductive outcomes remains inconclusive due to the limited scope of analysis. These results underscore the need for genome-wide methylation and transcriptomic profiling to better characterize the molecular basis of infection- and treatment-related reproductive effects. The study provides initial insights into infection-associated epigenetic modulation in male reproduction, with potential implications for fertility and reproductive health.

Babesiosis is endemic in Pakistan and significantly impacts bovine health, leading to economic losses and high mortality rates among young animals. This study aimed to determine the prevalence of Babesia bigemina and identify associated risk factors in Pakistani bovines. A total of 663 blood samples were collected systematically from 430 cattle and 233 buffaloes in the Lahore district of Punjab province. The samples were analyzed using microscopy and by PCR targeting the amplification of the apical membrane antigen (AMA-1) gene followed by gene sequencing. The overall prevalence of B. bigemina was 19%, with higher rates in cattle (21.86%) compared to buffaloes (13.73%). (Odds Ratio: 181.18, 95% Confidence Interval: 34.30–957.05). Male animals were more prone to infection than female animals, with an Odds Ratio of 1.65 (95% CI 1.08–2.53). Phylogenetic analysis revealed that local B. bigemina strains closely resemble a previously reported Pakistani strain, differing from global isolates. Age, sex, species, season, and tick control practices were identified as significant risk factors (Adjusted Odds Ratio > 1). Age, sex, species, season, and tick control practices were identified as significant risk factors (Adjusted Odds Ratio > 1). The study underscores the need for public awareness strategies to reduce B. bigemina prevalence, improving livestock health and productivity.

Purpose

Entomopathogenic nematodes are promising biocontrol agents offering environmentally sustainable alternatives to chemical insecticides. The present study aimed to isolate, identify, and evaluate the bioefficacy of a new Steinernema sp. DA-1 isolate from a forest ecosystem in Bihar, India, with potential application in the management of major lepidopteran pests.

Methods

A new isolate of S. abbasi was recovered through Galleria baiting from soil samples. Morphological and morphometric analyses were conducted to confirm its identity, followed by molecular characterization using the Internal Transcribed Spacer region marker. Phylogenetic relationships were analyzed to determine genetic divergence from other known S. abbasi isolates. Laboratory bioefficacy assays were conducted against different larval instars (3rd, 4th, and 5th) of Mythimna separata and Spodoptera litura. Average time taken to kill and LD₅₀ (lethal dose for 50% mortality) values were calculated.

Results

Morphological, morphometric, and molecular analyses confirmed the identity of the isolate as S. abbasi. Phylogenetic analysis placed it within the S. abbasi clade, showing subtle genetic divergence, indicating local adaptation, except for certain isolates (accession no. KR029837, KR029836, KR029837), which exhibited high divergence. Bioefficacy assays demonstrated significant dose- and age-dependent mortality in both M. separata and S. litura. LD₅₀ values at 48 h post-infection was 30, 35 and 42 infective juveniles (IJs) and 30, 36 and 41 IJs per larva for third, fourth, and fifth instars of M. separata and S. litura respectively. The highest concentration (T5) caused mortality within 28.8 h in third-instar larvae, significantly faster compared to lower concentrations.

Conclusion

This study provides the first validated report of S. abbasi from Bihar, India, revealing its strong virulence against major lepidopteran pests under laboratory conditions. These findings highlight its potential as a biological control agent, warranting further pot and field evaluations before its possible inclusion in regional sustainable pest management programs.

Introduction

Anisakiasis is a zoonotic parasitic disease transmitted through consumption of fish, with increasing global cases. While thorough cooking kills Anisakis larvae, thermo-stable allergens can still cause allergic reactions. Traditional Mediterranean seafood methods such as marinating, salting, and brining, which lack heat treatment, pose a high risk of anisakiasis.

Materials and methods

This study investigated the antilarval effects of nanoemulsions made from thyme, garlic, and grape seed essential oils combined with brines on Anisakis L3 larvae in vitro.

Results

Larvae were collected from mackerel, chub mackerel, anchovy, horse mackerel, and sardine, with 1746 larvae examined, mostly Anisakis type I and molecularly identified as A. pegreffii. Thyme oil’s main components, carvacrol and thymol, showed strong antimicrobial and antioxidant effects and superior larvicidal activity at lower doses compared to garlic and grape seed oils. Garlic oil, rich in organosulfur compounds, was more effective in Lakerda samples. High salt brine alone inactivated larvae within 24 h. The thyme oil nanoemulsion had droplet sizes below 90 nm, enhancing stability, whereas garlic and grape seed oils had larger droplets.

Conclusion

These results indicate that nanoemulsified essential oils, especially thyme oil, are promising natural agents to control Anisakis larvae in traditional sea-food products.