Parasitologia, Volume 5, Issue 3 (September 2025) – 13 articles

Objectives: Anisakidosis is an emerging, cosmopolitan, and underdiagnosed parasitic disease caused by the accidental ingestion of third-stage anisakid larvae when consuming raw or improperly prepared seafood. Within hours to days of consuming infected raw seafood, patients may develop acute gastrointestinal symptoms including pain, nausea, vomiting, diarrhea and/or constipation, as live anisakid larvae attach to the gastric, or more rarely, the intestinal mucosa. Cases have been reported in which the nematodes succeed at migrating from the stomach upwards to the esophagus and then the oral cavity. Therefore, the purpose of the present literature review is to collect, analyze, summarize and present the relevant epidemiological, clinical, diagnostic, parasitological, therapeutic, and prognostic data concerning anisakidosis localized inside the oral cavity. Methods: An electronic search of the PubMed, Scopus, and Ovid databases was performed with them being accessed for the last time on 29 March 2025. Results: The present literature review identified 13 individual case reports of oral mucosa anisakidosis, which were published in the period 1971–2022. Conclusions: Our review aims to summarize the relevant epidemiological, clinical, diagnostic, parasitological, therapeutic, and prognostic data regarding the oral localization of anisakidosis, a helminthic infection caused by the accidental ingestion of live anisakid larvae and which manifests mainly with gastrointestinal symptoms. Its localization in the oral mucosa appears to be exceptionally rare and, in most cases, occurs with a characteristic clinical picture, defined by the onset of acute mouth or throat pain immediately after the consumption of raw seafood and by the observation of one or more larvae, either lying on or penetrating the oral mucosa. Despite its rarity, dental health professionals and other clinicians should be aware of this disease and the possibility of its intraoral localization, since environmental factors on the one hand, and the adoption of foreign dietary habits on the other, will likely make anisakidosis a much more common disease worldwide in the near future. Full article

Cystic echinococcosis is a zoonosis caused by the cestode Echinococcus granulosus sensu stricto. Population genetic studies and phylogeographic patterns are essential to understanding the transmission dynamics of this parasite under varying environmental conditions. In this study, the genetic diversity of E. granulosus s.s. was evaluated using 46 hydatid cyst samples obtained from sheep, goats, cattle, and humans across three regions of Chile: Coquimbo, La Araucanía, and Magallanes. Mitochondrial cox1 gene sequences were analyzed and compared with reference sequences reported from South America, Europe, Africa, Asia, and Oceania. In Chile, the EG01 haplotype was the predominant haplotype. A total of four haplotypes were identified, with low haplotype diversity (Hd = 0.461 ± 0.00637) and low nucleotide diversity (π = 0.00181 ± 0.00036). The haplotype network displayed a star-like configuration, with the EG01 genotype at the center, suggesting a potentially ancestral or widely distributed lineage. In Coquimbo (Tajima’s D = −0.93302, p = 0.061; Fu’s Fs = −0.003, p = 0.502) and Magallanes (Tajima’s D = −0.17406, p = 0.386; Fu’s Fs = −0.121, p = 0.414), both neutrality tests were non-significant, indicating no strong evidence for recent population expansion or selection. Star-like haplotype network patterns were also observed in populations from Europe, the Middle East, Asia, Africa, and Oceania, with the EG01 genotype occupying the central position. The population genetic structure of Echinococcus granulosus s.s. in Chile demonstrates considerable complexity, with EG01 as the predominant haplotype. Further comprehensive studies are required to assess the intraspecific genetic variability of E. granulosus s.s. throughout Chile and to determine whether this variability influences the key biological traits of the parasite. This structure may prove even more complex when longer fragments are analyzed, which could allow for the detection of finer-scale microdiversity among isolates from different hosts. We recommended that future cystic echinococcosis control programs take into account the genetic variability of E. granulosus s.s. strains circulating in each endemic region, to better understand their epidemiological, immunological, and possibly pathological differences. Full article

Background: Anaemia in adolescents can be influenced by parasitic infections, systemic inflammation, and nutritional status. Objective: To determine whether C-reactive protein (CRP), nutritional status, and infection with Ascaris lumbricoides, Giardia lamblia, or Trichuris trichiura are associated with anaemia in adolescent athletes from Tacna compared to non-athletes. Methods: A cross-sectional study was conducted involving 250 male football players aged 13–18 years and 150 age-matched non-athletes. Haemoglobin, haematocrit, ferritin, serum iron, CRP, and parasitic status were measured; mean comparisons and logistic regression were applied. Results: Anaemia was more prevalent among athletes than non-athletes (30% vs. 18%; p < 0.001). Infected athletes showed lower haemoglobin (11.9 ± 1.1 g/dL) and higher CRP (5.0 ± 1.9 mg/L) levels compared to non-infected athletes (13.8 ± 1.0 g/dL and 2.2 ± 1.1 mg/L; p < 0.001). Logistic regression identified CRP as an independent predictor of anaemia (adjusted OR = 1.20; 95% CI: 1.08–1.38; p < 0.001), while parasitic infections showed no direct association after adjustment. Underweight status was associated with a higher prevalence of anaemia (36%). Conclusions: Systemic inflammation emerged as the main factor associated with anaemia in this population, with parasitic infections contributing indirectly by increasing inflammation. Periodic deworming, iron supplementation, and CRP monitoring are recommended to reduce the burden of anaemia in adolescent athletes from endemic regions. Full article

Equine piroplasmosis (EP) is a tick-borne disease caused by Theileria equi, Theileria haneyi and Babesia caballi. It affects equids, representing significant health and economic concerns for the equine industry. EP is endemic in Portugal, so developing and implementing preventive strategies is essential. Accessing veterinarians’ knowledge, attitudes and practices (KAP) through a survey is a suitable approach, and no such studies have been conducted in Portugal until now. A KAP survey was applied to 41 Portuguese equine vets, representing mainly the Alentejo region. The average knowledge score went from medium to high, correctly identifying the causative agents, transmission routes and clinical signs. Knowledge gaps mostly concerned the identification of T. haneyi as an agent, transplacental transmission, duration of infection and diagnostic methods. Reported practices were appropriate overall, including enhancing breeders’ awareness of the disease and its prevention. Diagnostic and treatment protocols were generally consistent with current recommendations; however, these protocols are not yet fully standardized. Our findings highlight key areas where increasing expertise is needed and could serve as a foundation for future evidence-based guidelines to improve EP control in Portugal. Full article

The Atlantic chub mackerel, Scomber colias, is sold in Spain, as well as another species of the genus, like the Atlantic mackerel, S. scombrus, often mistaken to be the same fish. This study aims to analyse the risk of human anisakiosis through the consumption of S. colias, and to clarify if these two species differ regarding this risk. A total of 250 S. colias (125 originating from the Atlantic and 125 from the Mediterranean) were helminthologically analysed using conventional parasitological techniques. Concerning Ascaridoid nematodes, the prevalence of Anisakis type I was higher in the Atlantic than in the Mediterranean. The presence of three other helminth parasites stands out, two other Ascaridoid nematodes, the larvae of Contracaecum spp. and Hysterothylacium spp., the latter a food-spoiling and non-pathogenic parasite. The other helminth found was the intestinal adult of the acanthocephalan Rhadinorhynchus pristis, also non-pathogenic. The comparison of the current results with previously published ones by our research group on S. scombrus show that Anisakis type I prevalence was higher in S. scombrus than in S. colias, making the correct differentiation between them necessary, given their varying risk of human anisakiosis. Furthermore, fish label information is important to prevent the risk of anisakiosis for consumers. Full article

Plasmodium vivax malaria continues to pose a significant and enduring public health challenge across the Americas. Transmission-blocking vaccines (TBVs), which target gametocyte surface antigens such as Pvs47 and Pvs48/45, are being investigated as promising tools to interrupt transmission and advance toward disease elimination. To investigate the genetic diversity and phylogeographic structure of the pvs47 and pvs48/45 genes in P. vivax, we conducted molecular analyses on samples collected from seven malaria-endemic regions of Honduras using PCR-based sequencing, population genetics, and phylogenetic approaches. This study presents the first complete characterization of the pvs47 gene and expands the available data on pvs48/45 in P. vivax from Honduras. We observed a low level of genetic diversity with no evidence of geographic structuring within the country. At a global scale, Honduran sequences shared variants with other Latin American strains and exhibited region-specific amino acid signatures. These findings suggest that local selective pressures, possibly driven by mosquito vector compatibility, are shaping the evolution of these TBV candidate genes. Our results underscore the importance of regional surveillance to inform the development and deployment of effective transmission-blocking strategies. Full article

Intestinal microbial eukaryotic parasites represent a significant public and veterinary health burden, especially in low- and middle-income countries, yet their transmission dynamics at the human–animal–environment interface remain poorly characterized in certain countries. This study investigated the prevalence and genetic diversity of key microbial eukaryotes, including Cryptosporidium spp., Giardia duodenalis, Blastocystis spp., Entamoeba histolytica, and Enterocytozoon bieneusi, in a rural village in Iraq. Samples collected from humans (n = 50), livestock (sheep and goats, n = 50), water (n = 20), and soil (n = 20) were analysed using microscopy and molecular methods (qPCR and nested PCR). Blastocystis spp. (78% animals, 16% humans, 45% soil, 5% water) and Cryptosporidium spp. (26% animals, 12% humans, 5% soil, 15% water) were the most frequently found microeukaryotes using either microscopy and/or molecular detection. Molecular methods identified Cryptosporidium parvum in humans and sheep, hinting at zoonotic transmission potential. Enterocytozoon bieneusi and Giardia were also found. Cryptosporidium ubiquitum and E. bieneusi genotypes BEB6 and COS-I, respectively, were detected exclusively in sheep, suggesting roles as potential reservoirs. Blastocystis ST1 was detected in humans, while ST4 and ST10 occurred in sheep. Notably, molecular detection rates of Blastocystis were much lower than those of microscopy. Entamoeba histolytica was not detected. The detection of the same organisms in humans, animals and the environment suggest zoonotic and environmental transmission pathways, which warrant further investigation using the One Health approach. Full article

Fascioliasis, a parasitic disease caused by liver flukes of the genus Fasciola, remains a significant threat to livestock productivity globally. Despite its economic and zoonotic importance, the knowledge levels of dairy farm personnel regarding this disease remain insufficiently explored in South Africa. This study assessed knowledge and awareness of bovine fasciolosis, including its etiology, risk factors, clinical signs, zoonotic implications, and control measures, among dairy farm personnel in the Eastern Cape Province. A structured questionnaire was randomly administered to 152 dairy farm workers. Descriptive statistics and Chi-square tests were used to examine associations between respondents’ demographic characteristics and their knowledge of fasciolosis. Most respondents were males (65.8%), aged 31–40 years (45.4%), with tertiary education (64%), over six years of experience (65%), and residing in inland regions (65.4%). A high proportion reported implementing pasture management practices such as irrigation (90.8%), pasture resting (69.8%), and rotation (94.7). Significant associations were found between geographic location and knowledge of Fasciola spp. as the causative agent, as well as awareness of swampy areas and water snails as key risk factors (p < 0.01). Educational level was significantly associated with awareness of the zoonotic potential of fasciolosis (p < 0.01), and regional location influenced knowledge on control practices (p < 0.01). These findings highlight persistent gaps in the understanding of bovine fasciolosis among dairy farm personnel, particularly in relation to causative agents, clinical signs, and zoonotic risk. Strengthening extension services, enhancing community awareness, and implementing targeted training programs are essential to address these knowledge gaps and improve disease control strategies in the Eastern Cape Province. Full article

Seabirds of the families Fregatidae, Phalacrocoracidae and Sulidae, common on the southeastern coast of Brazil, form colonies and play a bioindicator role in coastal ecosystems due to their ecological habits. This study aimed to identify the prevalence of parasitic helminths in Suliformes birds, of the species Fregata magnificens Mathews, 1914, Sula leucogaster Boddaert, 1783 and Nannopterum um Gmelin, 1789, from the Instituto de Pesquisas Cananeia (IPeC) on the southern coast of the State of São Paulo, and to record the diversity and parasitic indices, since reports of helminth prevalence in pelagic birds are scarce in Brazil. From 2018 to 2020, a total of 270 nematode specimens and 271 acanthocephalan parasites were collected from 51 Suliformes birds (20 F. magnificens, 10 N. brasilianum and 21 S. leucogaster). The host species F. magnificens was parasitized by Contracaecum plagiaticium and Contracaecum pelagicum. The host S. leucogaster was parasitized by C. plagiaticium. In the host N. brasilianum, specimens of Contracaecum australe, Contracaecum rudolphii, Contracaecum multipapillatum, Syncuaria squamata and Andracantha tandemtesticulata were found. This is the first report of C. plagiaticium and C. pelagicum in F. magnificens in Brazilian territory, and of A. tandemtesticulata in N. brasilianum in the southeast region of Brazil. Full article

Microsporidia MB (MB), a promising biological control agent, suppresses Plasmodium falciparum transmission in Anopheles mosquitoes. This study examined the spatial distribution of MB infection in natural populations of An. gambiae s.l. mosquitoes collected in Nigeria and Niger Republic, and its association with insecticide susceptibility in the mosquitoes. Microsporidia MB has wide geographic distribution across Nigeria and Niger Republic. The overall prevalence of MB in F₀ mosquitoes was 12.25% (95% CI: 7.76–16.75%); 25 mosquitoes out of 204 were positive. Geographic variation was observed, with a higher prevalence (5/15 mosquitoes) in Ebonyi State (33.33%, CI: 9.48–57.19%, Fisher’s exact test, p = 0.008). Infection rates were higher in An. coluzzii mosquitoes (21/133 mosquitoes), estimated at 15.79% (CI: 9.59–21.99%) compared to An. gambiae s.s. mosquitoes (4/71), with approximately 5.63% (CI: 0.27–11.00%, χ² = 4.44; df = 1, p = 0.035). Resistant mosquitoes had a significantly higher prevalence of MB infection than susceptible mosquitos at 28.57% (CI: 16.74–40.40%) with an odds ratio of 3.33 (CI: 1.23–9.03, p = 0.017). These findings suggests that MB can be exploited as an alternative for vector control in Nigeria and Niger, but its possible association with pyrethroid resistance suggests that it should be taken into account as a potential confounder when designing insecticide resistance management strategies. Full article

Estimating the human impact on parasites in wildlife is essential to create efficient strategies to control diseases and improve public health. This study assessed the human influence on the parasite burden of the two commonest canine mesocarnivores, the red fox (N = 194) and the golden jackal (N = 151), in Europe. We compared the infracommunity crowding index, parasite diversity, prevalence, and abundance of different parasite taxa, and the presence of Echinococcus multilocularis between groups of hosts, such as jackals and foxes hunted at different distances from human settlements. The analysis of hosts’ distribution ascertained that 61.2% of the investigated wild canids were hunted in a 500–1750 m ring around the human settlements. Ancylostomatidae proved the most prevalent taxon (>60%), while Echinococcus multilocularis and Dipylidium caninum occurred least frequently. The two taxa that mostly contributed to the crowding of infracommunities were Ancylostomatidae and Toxocaridae, with a negative correlation between their abundances (Spearman’s ρ = −0.445, p < 0.001). Parasite infracommunities were more crowded in Echinococcus multilocularis infected foxes (p = 0.02) and jackals (p = 0.001). Our study highlighted that human modification of landscapes worsened the parasite burden of wild mesocarnivores, which could increase the public health risk of zoonotic parasites. Full article

Vector-borne parasitic diseases represent a critical public health challenge in Africa, disproportionately impacting vulnerable populations and linking human, animal, and environmental health through the One Health framework. In this review, we explore the existing burden of these diseases, particularly those that are underreported. Climate change, urbanization, the introduction of alien species, and deforestation exacerbate the emergence and reemergence of arthropod-borne zoonotic parasitic diseases like malaria, leishmaniasis, and trypanosomiasis, complicating control and disease elimination efforts. Despite progress in managing certain diseases, gaps in surveillance and funding hinder effective responses, allowing many arthropod zoonotic parasitic infections to persist unnoticed. The increased interactions between humans and wildlife, driven by environmental changes, heighten the risk of spillover events. Leveraging comprehensive data on disease existence and distribution coupled with a One Health approach is essential for developing adaptive surveillance systems and sustainable control strategies. This review emphasizes the urgent need for interdisciplinary collaboration among medical professionals, veterinarians, ecologists, and policymakers to effectively address the challenges posed by vector-borne zoonotic parasitic diseases in Africa, ensuring improved health outcomes for both humans and animals. Full article