Frontiers in parasitology最新文献

Nematode parasitic infections continue to be a major health problem for humans and animals. Drug resistance to currently available treatments only worsen the problem. Drug discovery is expensive and time-consuming, making drug repurposing an enticing option. Emodepside, a broad-spectrum anthelmintic, has shown efficacy in the treatment of nematode parasitic infections in cats and dogs. It is now being considered and trialed for the treatment of onchocerciasis, trichuriasis (whipworm), and hookworm infections in humans. Its unique mechanism of action distinguishes it from traditional anthelmintics, positioning it as a promising candidate for combating resistance to other current drugs. Here, we provide a brief review of the available information on emodepside's pharmacokinetics, safety, and tolerability. We highlight the potential benefits and risks associated with its use, examining key toxicity effects. By exploring the literature, we aim to provide insights into the risks associated with emodepside that may impact its application in veterinary and human medicine. Although emodepside demonstrates a favorable safety profile, continued monitoring of its toxicity is crucial, particularly in vulnerable populations. This mini-review serves as a concise resource for researchers and clinicians interested in anthelmintic therapy.

Background: Schistosomiasis is caused by infection with parasitic Schistosoma worms and affects more than 250 million people globally. The detection of schistosome derived circulating cathodic and anodic antigens (CCA and CAA) has proven highly valuable for detecting active Schistosoma infections, causing both intestinal and urinary schistosomiasis.

Aim: The combined detection of CCA and CAA was explored to improve accuracy in detecting Schistosoma infections.

Methods: Parallel detection of CCA and CAA was performed on two banked sample sets with matching serum and urine samples from Schistosoma mansoni (Sm) and S. haematobium (Sh) infected individuals using the non-concentration based lateral flow (LF) test comprising the sensitive luminescent up-converting reporter particle (UCP) technology.

Results: Parallel detection of CCA and CAA increased the positivity rate for detecting both Sm and Sh infections compared to the detection of either antigen separately, demonstrating the added value of detecting both antigens in a single sample to confirm diagnosis, independent from the Schistosoma species. Significantly higher CCA concentrations in urine were observed in Sm infected individuals compared to Sh infected individuals, while serum CCA-concentrations were similar between species. CAA concentrations were higher in serum compared to those in urine, irrespective of species. When exploring the relationship of CCA and CAA in urine, the CCA/CAA ratio in Sm infected individuals was significantly higher than in Sh infected individuals, while no differences were observed in serum.

Discussion and conclusion: Parallel detection of CCA and CAA via the UCP-LF platform showed added diagnostic value through an increased positivity rate for the detection of Sm and Sh infections, compared to only detecting either of the antigens. The combined and quantitative detection of CCA and CAA is indicative for identifying the infecting species, but needs further exploration.

Schistosomiasis is a group of both acute and chronic parasitic trematode infections of the genus Schistosoma. Research into schistosomiasis has been minimal, leading to its classification as a neglected tropical disease, yet more than 140 million people are infected with schistosomes globally. There are no treatments available for early-stage infections, schistosomal dermatitis, or Katayama syndrome, other than symptomatic control with steroids and antihistamines, as the maturing organisms seem to be mostly resistant to typical antiparasitics. However, praziquantel (PZQ) has been the drug of choice for schistosomiasis for decades in the latter stages of the disease. Though it is effective against all three clinically relevant species, heavy reliance on PZQ has led to concerns of schistosome resistance, especially in areas that have implemented this drug in mass drug administration (MDA) programs. This article summarizes the available literature concerning the available evidence for and against a warranted concern for PZQ resistance, genomic studies in schistosomes, proposed mechanisms of resistance, and future research in alternative methods of schistosomiasis treatment.

Artemisinin-based treatments (ACTs) are the first therapy currently used to treat malaria produced by Plasmodium falciparum. However, in recent years, increasing evidence shows that some strains of P. falciparum are less susceptible to ACT in the Southeast Asian region. A data reanalysis of several omics approaches currently available about parasites of P. falciparum that have some degree of resistance to ACT was carried out. The data used were from transcriptomics and metabolomics studies. One mitochondrial carrier of the parasite possibly involved in the mechanisms of tolerance to oxidative stress was modeled and subjected to molecular dockings with citrate and oxoglutarate. An increase in glutathione production was detected, changing the direction of the flux of metabolites in the tricarboxylic acid cycle and boosting the glucose consumed. The models of the mitochondrial carrier, called PfCOCP, show that it may be important in transporting citrate and oxoglutarate from the mitochondrial matrix to the cytosol. If so, it may allow the parasite to tolerate the oxidative stress produced by artemisinin. This in-silico analysis shows that P. falciparum may tolerate artemisinin's oxidative stress through metabolic changes not reported before, showing the need for further experimental research on the many metabolic aspects linked to this phenotype.

Introduction: Schistosomiasis, a tropical parasitic disease, affects 779 million people globally, with 85% of cases in Africa. The interplay between schistosomiasis and other sexually transmitted infections (STIs) can exacerbate health burdens, but most attention has focused on interactions with HIV, neglecting coinfections with other STIs. This systematic review and meta-analysis aims to understand the role Schistosoma infections play in STIs within schistosomiasis-endemic populations.

Methods: The study is a systematic review and meta-analysis investigating the link between Schistosoma infections and STIs in endemic regions. It uses PRISMA guidelines, electronic databases, and Google Scholar to assess prevalence, associations, and heterogeneity, reducing bias using a Meta-Mar statistical tool.

Results: A quantitative synthesis of 33 articles from 1975-2024 involved 22,587 participants from 13 countries, including regions in Africa, France, and China, examining coinfections of schistosomiasis and STIs, including HIV. The pooled estimates showed a significant risk association between schistosomiasis and STIs [RR (95% CI) = 1.18, (1.13-1.24); z/t = 7.55, p<0.0001] using a fixed effect model. Cochran's Q test (Tau² = 0.5061, Chi² = 476.65, df = 32, p<0.01) indicated significant heterogeneity. The Higgins I² statistic of 93.0% (91.5%-94.7%), H = 3.86 (3.43-4.33), highlighted substantial variance between studies. Subgroup analysis showed West Africa [Weight IV = 1.7%, RR (95% CI) = 1.78 (1.28-2.47), I² = 59%], East Africa [Weight IV = 10.5%, RR (95% CI) = 0.99 (0.86-1.13), I² = 54%], and Southern Africa [Weight IV = 82.0%, RR (95% CI) = 1.16 (1.10-1.21), I² = 97%] contributed significantly to the high heterogeneity in the pooled analysis. Females had a notably higher risk of STIs in the context of schistosomiasis (k = 17, RR: 1.30, 95% CI: 1.23-1.37, Q = 316.78, I² = 94.9%), compared to males (k = 6, RR: 0.94, 95% CI: 0.77-1.15, Q = 53.44, I² = 90.6%) and the combined group of females and males (k = 9, RR: 0.95, 95% CI: 0.88-1.02, Q = 16.38, I² = 50.2%).

Conclusion: The study found a high risk of coinfections between schistosomiasis and STIs, particularly in West and Southern Africa, confirming female genital schistosomiasis as a major risk for STIs.

Dirofilariasis, caused by the nematode Dirofilaria spp., poses significant challenges in diagnosis due to its diverse clinical manifestations and complex life cycle. This comprehensive literature review focuses on the evolution of diagnostic methodologies, spanning from traditional morphological analyses to modern emerging techniques in the context of dirofilariasis diagnosis. The review traces the historical progression of diagnostic modalities, encompassing traditional approaches such as microscopic examination, serological tests (including ELISA and IFA), radiographic imaging, ultrasonography, and necropsy, which laid the foundation for subsequent advancements. The integration of molecular diagnostics marks a significant turning point in dirofilariasis diagnosis with the adoption of polymerase chain reaction (PCR) assays and real-time PCR (qPCR) facilitating enhanced sensitivity and specificity. Furthermore, recent strides in next-generation sequencing (NGS) technologies, including whole-genome sequencing (WGS), targeted sequencing (TS), metagenomic sequencing (MS), and RNA sequencing (transcriptome sequencing), have revolutionized the landscape of dirofilariasis diagnostics. Emerging techniques such as loop-mediated isothermal amplification (LAMP), digital PCR (dPCR), and digital microfluidics are also explored for their potential to augment diagnostic accuracy. The review addresses challenges associated with standardizing molecular protocols, tackling false positives/negatives, and discusses the advantages and limitations of each technique. By providing a comprehensive overview of dirofilariasis diagnostic strategies, from traditional to cutting-edge methods, this review aims to enhance understanding of the disease's diagnostic landscape. The insights gained have implications for improved disease management and guide future research endeavors toward refining diagnostic protocols and advancing therapeutic interventions.

Cryptosporidium species are parasitic organisms of vertebrates with a worldwide distribution. They have an important impact globally upon human and animal health, and livestock productivity. The life cycle of these species is complex and difficult to disrupt to improve human health, animal health, food security and economic growth. This may contribute to the fact that no new treatment strategy has been widely accepted or applied in livestock for years. Here we consider the natural history of these parasites, their biochemistry and economic impact. Using recent developments in understanding these parasites we then consider viable and affordable approaches to enhancing control of their effects on livestock. These are based on advances in drug discovery, omics research and artificial intelligence applications to human and veterinary medicine that indicate putative new therapeutic approaches.

Background: Malaria continues to be an important threat to public health and infects millions of children under 5 years of age each year. Although Ethiopia has set targets for at-risk group interventions to eradicate and manage malaria, the illness is still a serious public health problem in areas where it is endemic, especially in the unique lowlands in the Borena zone.

Objective: This study aimed to determine the prevalence of malaria and associated factors among children in Borena's pastoral communities, Oromia Regional State, southern Ethiopia, in 2022.

Methods: A community-based cross-sectional study was conducted from 1 March to 30 April 2022 among 437 randomly selected households with children under 5 years of age in pastoral communities in the Borena zone. Data were collected through face-to-face interviews with structured and pretested questionnaires and blood sample examination using microscopy. Thick and thin blood smears were prepared and examined under a microscope at a health center to confirm malaria cases. The data were analyzed using SPSS version 25. Bivariate and multivariable logistic regression analyses were used to identify factors associated with malaria, and a p-value <0.05 was used to declare statistical significance.

Result: The prevalence of malaria among children under 5 years of age was 27.8% (95% CI = 23.5-32.1), and the prevalence rates of Plasmodium falciparum, Plasmodium vivax, and mixed malaria were 68.4%, 25.6%, and 6%, respectively. Regarding the proportion of malaria among age groups, 81% of children under 5 years of age between 48 and 59 months were malaria-positive. In this study, fever within the last week (AOR = 13.34, 95% CI = 6.37-27.95) and not sleeping under insecticide-treated nets (ITNs) (AOR = 3.10, 95% CI =1.95-4.92) were significantly associated with malaria. The age of the children was negatively associated with malaria prevalence.

Conclusion: The prevalence of malaria among children under 5 years old was high during the rainy season in this pastoral region of Ethiopia. Factors such as fever within the last week and not sleeping in insecticide-treated nets were significantly associated with malaria. Therefore, to reduce malaria-related infections and deaths among children under 5 years of age, the government ought to enhance the availability and utilization of insecticide-treated nets (ITNs).

Nuttalliella namaqua Bedford, 1931 is the sole extant tick species that belongs to the genus and family Nuttalliella and Nuttalliellidae respectively. With the characteristics that are respectively distinctive to hard and soft ticks, it is regarded as the species closest to the ancestral lineage of ticks as well as the missing link between the Argasidae and Ixodidae families. In this review, literature search of the articles reporting on N. namaqua was done in Google Scholar and PubMed databases. After relevance and eligibility screening, 12 articles were deemed eligible and appraised. The results showed that N. namaqua was respectively distinct to limited regions of Africa such as Botswana, Namibia, Mozambique, South Africa and Tanzania. The review also indicated that N. namaqua was collected from murid rodents, African Savanna hare, scrub hare, elephant shrews, rock hyraxes, black backed jackal, lizards and off-host in locations that include under a stone, rock crevices, on a rock wall and respectively in the nests of an eagle and a lesser striped swallow. Irrespective of all the reports, natural hosts of the nymphs are still not clearly defined. Numerous phylogeny studies have reported Nuttalliellidae as the sister-lineage to Argasidae and Ixodidae tick families. Moreover, a recent report indicated that the similarities between Nuttalliellidae and the fossil families Deinocrotonidae and Legionaris award them to be merged into one family, preferably Nuttalliellidae Thus, further research on this family, will perhaps provide more knowledge about its unclear distribution, life cycle as well as the evolution of ticks in general.