Acta Parasitologica最新文献

Toxocara canis larvae are one of the most overlooked agents of nervous system infection in paratenic hosts. Previous studies in mouse models have shown that infection with various (mainly high) numbers of larvae leads to neurobehavioral disturbances and pathological changes. Our study investigated whether the infection with low and moderate numbers of larvae could affect the physical condition, motor skills, and pathogenesis in the brains of experimentally infected mice.Two groups of BALB/c mice were orally infected with 10 and 100 T. canis larvae per animal and examined regularly until the 97th week after infection. General appearance, specific antibody responses, and motor/balance skills were assessed. The number and viability of larvae in the liver, spleen, lungs, and brain were assessed by quantitative compressed biopsy technique, while the pathological changes of the brain infection were studied histologically.As a result, changes were observed in overall appearance, activity, as well as motor and balance ability. The infections were associated with an increased IgG antibody response to the specific anti-T. canis excretory/secretory antigen and tissue damage in the brain characterized by necrosis, cell infiltrations, including foamy cells, and hemorrhages.The study demonstrated the effects of low and moderate T. canis infection in a paratenic host during the chronic phase of infection, which lasted up to 97 weeks for the first time.

Objective: Bartonellosis is a global vector-borne zoonosis caused by Bartonella, a genus of intracellular Gram-negative bacteria. It is one of 14 emerging infectious diseases that have recently been identified in China, and the prevalence varies by region. A more in-depth understanding is needed regarding the role and influencing factors of ticks in the transmission of Bartonella, including the infection rate of ticks with Bartonella in different regions. This study explored the prevalence of Bartonella in ticks and the factors that influence it.

Methods: Databases (PubMed, Embase, Elsevier ScienceDirect, Cochrane Library, Web of Science, CNKI, VIP, CBM, and WanFang) were searched to review the preliminary research on Bartonella-carrying ticks in China.

Results: We identified and included 22 articles. Bartonella infection rates in ticks varied from 0 to 22.79% examined by the included studies. Our meta-analysis revealed that the prevalence of Bartonella in ticks was 3.15% (95% CI: 1.22 - 5.82%); the prevalence was higher in parasitic ticks (4.90%; 95% CI: 1.39 -10.14%) than ticks seeking hosts (1.42%; 95% CI: 0.62 - 2.50%) (P = 0.047).

Conclusion: The prevalence of Bartonella in the southern region of China (6.45%) was higher than that in the northern region (1.28%) (P = 0.030). Knowledge of ticks' vectors and reservoir competence is crucial to reduce the disease burden.

Background: Colonic schistosomiasis is a significant health issue in endemic areas, presenting diagnostic challenges due to its nonspecific clinical symptoms and radiographic features. This case report highlights a patient with concomitant colorectal cancer and chronic Schistosoma japonicum infection, emphasizing the need for a comprehensive diagnostic approach.

Case presentation: A 67-year-old male from an endemic region presented with a six-month history of intermittent hematochezia. Initial colonoscopy revealed multiple mucosal elevations in the sigmoid colon and rectum. Subsequent investigations, including CT scans and endoscopic ultrasonography, indicated high echogenic changes and multiple lesions. The patient underwent endoscopic submucosal dissection (ESD), revealing adenocarcinoma of the rectal mucosa and tubular adenoma in the sigmoid colon, both with extensive deposition of Schistosoma japonicum eggs. Postoperative pathology confirmed the diagnosis of moderately differentiated adenocarcinoma with chronic schistosomiasis.

Conclusion: This case underscores the diagnostic complexity of colonic schistosomiasis, particularly when coexisting with malignancy. The integration of colonoscopy, histopathology, and auxiliary tests is crucial for accurate diagnosis. Clinicians should maintain a high index of suspicion for schistosomiasis in patients from endemic areas presenting with gastrointestinal symptoms. Regular screening and detailed medical histories are essential for early detection and treatment, improving patient outcomes and reducing the risk of misdiagnosis.

Purpose: Fascioliasis is a zoonotic parasitic disease spread by genus Fasciola that causes considerable health and economic losses to both humans and livestock. Pakistan is an endemic region for fascioliasis and only a few molecular studies have been conducted to describe the etiology of disease in the country.

Methods: Current study involved the molecular characterization of adult fluke specimens (n = 31) through ITS-1 region of rDNA collected from four host species (sheep, goats, cattle and buffaloes) of district Sargodha. Moreover, coprology based epidemiology (n = 28620) and association of different risk factors with disease prevalence was also determined. Additionally, an overview of prevalence of fascioliasis in Pakistan, including molecular studies in the four provinces and livestock species, was also carried out.

Results: The phylogenetic analysis revealed that Fasciola gigantica was the main etiological agent infecting the livestock species of this region. The coprological survey revealed an overall prevalence of 30.18% among the livestock species (sheep = 32.31%, goats = 30.67%, cattle = 31.01%, buffaloes = 25.23%). It was inferred that females were slightly more susceptible to infection (32.59%) and that the older age group had higher infection rate (34.01%) in all the host species.

Conclusion: The current study suggests that fascioliasis is a disease of primary concern indicating its status as one of the prevalent diseases affecting livestock in this region. It was also concluded that both Fasciola gigantica and Fasciola hepatica existed among the infected animals in addition to presence of hybrid/intermediate form in Pakistan with F. gigantica as dominant species in Punjab province.

Introduction: Soil-transmitted helminth (STH) is a group of helminths that are considered to be neglected tropical diseases (NTDs) and, globally, affect more than 1.5 to 2.6 million people yearly. Depending on the species, they can be acquired by ingesting embryonated eggs from contaminated matter or by skin penetration. Most species of STH are found in the tropics, such as the Philippines. Despite the Mass Drug Administration (MDA), the cases of STH infection continue to rise in the country. Surveys from the Research Institute of Tropical Medicine (RITM) indicate that a high prevalence of STH (Ascaris lumbricoides, Trichuris trichiura, and Necator americanus) was primarily observed in the provinces of the country, such as in Camarines Sur.

Objectives: To correlate remote sensing covariates such as Normalized Difference Vegetation Index (NDVI) and Normalized Difference Built-up Index (NDBI) - to STH-infected cases of the 37 municipalities of Camarines Sur.

Methodology: The available public health record of STH cases from 2015 to 2019 were calculated using the Quantum Geographic Information System (QGIS)and correlated using Pearson Correlation Coefficient.

Results: The results showed that infection was higher in children than adults, and A. lumbricoides caused 60% of infection. No correlation of indices with infection cases during 2015 and 2017 was observed; however, 2019 showed a moderate strength (p = 0.037) in correlation.

Conclusion: This indicates that infection relied not mainly on vegetation and urbanization but on additional environmental factors and non-environmental variables.

Purpose: At least thirty species of wild carnivores have been recorded harboring Bartonella, and one of the most common pathogenic species infecting them is Bartonella rochalimae, which can cause endocarditis in humans and dogs. This bacterium can infect various mammals including wild carnivores, as well as ectoparasitic vectors such as fleas and ticks. Here we report the presence of B. rochalimae, in a Pulex simulans flea collected from a Mephitis macroura skunk in the municipality of Santa Cruz in Sonora, Mexico.

Methods: Fleas were collected from a M. macroura in Sonora, Mexico, in October 2019. They were identified to species level and subsequently tested for the presence of Bartonella using molecular tools including conventional PCR, sequencing, and phylogenetic analysis.

Results: A total of 10 P. simulans fleas (one male, nine females) were collected from the M. macroura skunk. The PCR and phylogenetic analysis indicated a prevalence of 10% (1/10) and a sequence clustered with the clade of B. rochalimae.

Conclusions: We confirmed the presence of B. rochalimae in a P. simulans flea collected from a M. macroura skunk in the area of Santa Cruz, Sonora, Mexico. Based on our results and previous studies in northern Mexico, which are consistent, it is necessary to continue monitoring Bartonella in M. macroura skunks and their fleas, since they could be important reservoirs of this bacterium in northern Mexico.

Purpose: Coccidiosis caused by eimerian parasites results in lethal watery or bloody diarrhea in hosts, and markedly impairs the growth of and feed utilization by host animals. We previously investigated detailed the life cycle of Eimeria krijgsmanni as a mouse eimerian parasite. Only second-generation meronts, as an asexual stage, were morphologically detected in the epithelium of the host cecum for at least 8 weeks after infection, even though oocyst shedding finished approximately 3 weeks after infection. The presence of zoites was of interest because infection by eimerian parasites is considered to be self-limited after their patent period.

Methods: To clarify the significance of residual second-generation meronts in E. krijgsmanni infection, we performed infection experiments using immunocompetent mice under artificial immunosuppression and congenital immunodeficient mice.

Results: The number of oocysts discharged and the duration of oocyst discharge both increased in immunosuppressed mice. In immunodeficient mice, numerous oocysts were shed over a markedly longer period, and oocyst discharge did not finish until 56 days after inoculation.

Conclusions: The present results suggest that the second-generation meronts survived in the epithelial cells of the cecum after the patent period, thereby contributing to extended infection as an asexual stage. The results obtained on E. krijgsmanni indicate that infections by Eimeria spp. are not self-limited and potentially continue for a long period of time.

Purpose: The aim of the present study is to assess the molluscicidal, larvicidal and genotoxicological activities of papain and how it can affect the host-parasite interactions.

Methods: Toxicity of papain on snails by making series of concentrations to calculate LC₅₀, and then study its larvicide effect on the free larval stages of S. mansoni and infection rate of snails.

Results: Papain has a molluscicidal activity on adult snails of Biomphalaria alexandrina with a lethal concentration LC₅₀ equals to 43.1 mg/L. In addition, it has activity on miracidia with half Lethal time (LT₅₀) of 16.11 min., and on cercariae with 12.1 min. compared to control ones. The sub lethal concentration LC₁₀ and LC₂₅ (6.9 or 24.1 mg/L, respectively) decreased the survival rate of snails at the first cercarial shedding, the rate of infection, the average total number of cercariae per snail, the shedding period and the life span of snails, while the prepatent period was significantly increased than the control ones. The morphological alterations in cercariae after exposure to papain were occurred where the cercariae lacked motility and some had a dark tail with complete detachment of head and tail. Compared to the control group, the levels of cytochrome oxidase subunit I (COI) and (ND1) genes significantly decreased in snails after exposure to papain.

Conclusions: Papain could be used as a potential molluscicide for elimination of schistosomiasis and decrease its transmission and deterioration of host-parasite interaction.