Parasitologia

Rhinonyssids are obligate hematophagous mites that parasitize the nasal cavity of domestic and wilds birds worldwide. For the first time, two species of nasal mites of the genus Rhinonyssus from Estonia are described. One species of nasal mite, Rhinonyssus pluvialis Fain et Johnston, 1966, is described and illustrated based on material from Pluvialis apricaria Linnaeus, 1758 (Charadriiformes, Charadriidae). Another species of nasal mite, Rhinonyssus tringae Fain, 1963, is described and illustrated based on material from Tringa glareola Linnaeus, 1758 (Charadriiformes, Scolopacidae). The bird hosts were collected in Estonia, Puhato järv. Full article

Dirofilaria immitis is a mosquito-borne nematode of dogs, other carnivores and, occasionally, humans. Globally, D. immitis infection (which causes heartworm) is typically more prevalent in tropical than temperate regions. In this study, the seroprevalence of D. immitis was determined from a sample of 335 non-stray dogs from four municipalities, two each from the states of Puebla and Guerrero in Mexico, using polyclonal antibodies to detect serum antigens using an enzyme-linked immunosorbent assay (ELISA). The accuracy of the assay was compared with the modified Knott’s test. The polyclonal antibody used in the direct ELISA had a high sensitivity (100%) with variable specificity (98.2–98.8%) in the municipalities of Puebla and Guerrero. The area under the curve for the four municipalities was 1.0, indicating a high accuracy test, with a cut-off value ranging from 0.45 to 0.50. The overall prevalence of D. immitis infection was 17.56% (59 out of 335). The highest prevalence was in Acapulco (24.78%), followed by Chilpancingo (20.93%), Tecamachalco (10.81%) and Quecholac (8.06%). The highest percentage of positive samples was detected in tropical regions (23.12%) and the lowest in temperate regions (9.56%). This study demonstrates that polyclonal anti-D. immitis antibodies can successfully diagnose heartworm-infected dogs and be used to monitor prevalence effectively and develop prevention strategies against Dirofilaria infection. Full article

Hedgehogs, Erinaceus spp., are commonly admitted to rescue centres in European countries. However, there are still few studies on parasitological fauna and treatment possibilities, including for E. roumanicus. This study aimed to evaluate parasitism in 34 hedgehogs directly after their admission to the Budapest Zoo and Botanical Garden Wildlife Rescue Centre, as well as the efficacy of fenbendazole treatment. The Mini-Flotac method was used to quantitatively evaluate and assess the efficacy of treatment with fenbendazole (100 mg/kg PO. BID for 7 days) in five selected individuals. Faecal samples were analysed at D0 and D14 after the beginning of the treatment. Globally, the prevalence of positive animals was 76%. Capillaria spp. were the most prevalent (68%), while coccidia showed a prevalence of 32%. Considering the range of action of this benzimidazole, the treatment provided an efficacy of 100%, eliminating all forms of Capillaria spp. Considering the high number of hedgehogs admitted to rescue centres and the potential effects of parasitism in morbidity and mortality during recovery, it is essential to improve our knowledge with regard to the parasitological fauna of these species and to attain effective treatment protocols. Full article

Cerebral coenurosis affects sheep and goats worldwide and has zoonotic implications. Information on the financial burden and understanding of the disease and control practices may inform control strategies. A cross-sectional study was conducted in Babati and Ngorongoro Districts, Tanzania, to determine economic losses, farmers’ knowledge, and attitudes and practices on the control of coenurosis in small ruminants. A structured questionnaire was administered to 558 households for data collection. The total annual loss was TZS 122.8 M (USD 52.9 K) for Babati and TZS 656.5 M (USD 282.9 K) for Ngorongoro District. The average annual household financial loss was TZS 356.8 K (USD 153.83) for Babati and TZS 3.1 M (USD 1.3 K) for Ngorongoro District. Almost 90% of respondents were aware of coenurosis while less than 1% of the respondents had no knowledge of it at all. The average knowledge score was 5.85 out of 16 (36.6%), which implies a low level of knowledge on coenurosis. About 94% of respondents showed a willingness to participate and pay the control costs. Given the economic loss and favorable attitudes toward control participation, delivery of an educational package on epidemiology and control of coenurosis to livestock keepers may trigger collaborative and sustainable intervention. Full article

The prevalence of endoparasites associated with chaetognath abundance in the coastal waters of the Mexican Central Pacific was studied fortnightly from November 2010 to December 2011. A total of 35 (0.21%) out of 16,407 chaetognaths were found to be parasitized. Five out of twelve chaetognath species (Flaccisagitta enflata, F. hexaptera, Parasagitta euneritica, Serratosagitta pacifica, Zonosagitta bedoti) were found to be parasitized by nine endoparasitic taxa: Protists (two morphotypes), digenean metacercariae [Didymozoidae, Hemiuridae, Parahemiurus sp., Lepocreadiidae, Prosorhynchus sp. (Bucephalidae)], and cestodes (metacestodes) [Tetraphyllidea (two morphotypes)]. Parasagitta. euneritica and Z. bedoti were the most abundant chaetognath species, and Protist sp. 2 and Tetraphyllidea sp. 1 were the most abundant parasites. The highest prevalence for most of the endoparasite species occurred in June, and the values varied according to three hydroclimatic periods: stratified (S), semi-mixed (SM), and mixed (M). Eight non-infected chaetognath species, two parasitized chaetognaths (F. enflata and S. pacifica), and two parasites (Protist sp. 1 and Tetraphyllidea sp. 2) were associated with warm temperatures (S and SM periods); in contrast, P. euneritica, Z. bedoti, parasitized F. hexaptera, and the parasite Tetraphyllidea sp. 1 showed a strong local preference for cooler temperatures, high productivity, and high biomass conditions (M periods). We discovered the occurrence of the digenean Prosorhynchus sp. (Bucephalidae) parasitizing the chaetognath P. euneritica, and this is the first report of Prosorhynchus parasitizing chaetognaths worldwide. We also confirmed the presence of Lepocrediidae (metacercariae larval stage) infecting F. hexaptera, a parasite that had only been recorded infecting other chaetognaths of the Atlantic Ocean. The parasite diversity affecting the chaetognath populations of the Central Mexican Pacific coast likely differs between the offshore, outer slope areas, and the surveyed coastal system. Full article

The aim of this study was to evaluate the isolated and associated use of the nematophagous fungi Pochonia chlamydosporia (isolate VC4) as an ovicide and Duddingtonia flagrans (isolate AC001) as a predator in the control of Taenia saginata eggs. Viable T. saginata eggs were obtained by dissecting mature proglottids from a specimen. For the experimental assay, four groups were formed in microtubes, as follows: (G1—T. saginata eggs/control); (G2—100 T. saginata eggs + VC4); (G3—100 T. saginata eggs + AC001); (G4—100 T. saginata eggs + VC4 + AC001). All the groups were stored in a B.O.D. incubation chamber at a temperature of 27 °C for 15 days and then the contents of the microtubes were analyzed using an optical microscope with a 40x objective. At the end of the assay the treated groups (G2 to G4) showed ovicidal activity (destruction of eggs) compared to the control group (G1). The highest ovicidal percentage was observed in group G2 (eggs + VC4), with 43.3%. In groups G3 and G4 (combination of fungal isolates), the ovicidal percentages were 25.7% and 25.6%, respectively. The results of this study shed light on a new possibility for the combined use of different species of nematophagous fungi, which could be used in the future for environmental biological control of T. saginata eggs. Full article

Endocytosis is a quintessential feature of eukaryotes, and the emergence of endocytosis played a major role in the origin and evolution of eukaryotes. During the early evolution of eukaryotes, phagocytosis and the digestion of prey (i.e., bacteria) combined with the endocytosis of macromolecules opened a new source of nutrients beyond osmotrophy. Pathogenic and commensal protozoa have retained endocytosis as a major mechanism of nutrient acquisition even though, in theory, nutrients could be obtained from the host through osmotrophy. Nearly all pathogenic protozoa exhibit endocytosis and have lysosomal-like compartments that function as digestive vacuoles, and endocytosis appears to play a major role in the acquisition of nutrients. Cryptosporidium is a possible exception that may not exhibit endocytosis. Phagotrophy, however, is only observed in parasites of the intestinal lumen and appears to have been lost in blood and tissue parasites. Overall, the basic features of endocytosis and lysosomes are similar to other eukaryotes. Nonetheless, adaptation to the host has generated some novel features that are specific to certain protozoan lineages. Full article

Background: Neospora caninum is a protozoan parasite and a main cause of abortions in cattle worldwide. However, its role in abortions and decreased fertility in sheep is not completely understood, especially due to the complex, multifactorial etiology of abortions. This study aimed to perform a longitudinal field study to investigate the epidemiology of neosporosis and its effect on fertility in endemic sheep herds. Methods: Serological (IFAT) and clinical (outcome of pregnancy) data from 153 ewe-lambs was collected in four intensive management farms in Israel during three consecutive pregnancies. Results: The seroprevalence in ewe-lambs at different farms varied between 24% and 93%. The overall seroprevalence increased from 50% in ewe-lambs to 96.6% at the end of the third pregnancy. Horizontal infection was observed in all farms, with seroconversion in 59% of seronegative sheep. Abortion rates were lower (p = 0.004) in seropositive ewes in the first pregnancy and not significantly higher in seropositive sheep in consecutive pregnancies. Seropositivity or seroconversion were not associated with abortions or repeated abortions; however, many aborting ewes were removed from the flock. Conclusions: No direct short- or long-term association was found between Neopsora infection and abortions. The variations between flocks and pregnancies suggest a more complex etiology. Full article

Balamuthia mandrillaris is a free-living amoeba (FLA) that causes granulomatous amebic encephalitis (GAE) and skin lesions. Transcriptomic analysis is a powerful tool used to study B. mandrillaris pathogenic infections. However, preliminary tests of RNA extraction showed poor results, so it has become essential to standardize a protocol for high-quality RNA. The present study evaluated 11 RNA extraction protocols based on three commercial kits by making modifications to the temperature and centrifugation times, and by combining kits. Four protocols, namely Q3 (based on QIAGEN RNeasy Mini Kit, with modifications in temperature and centrifugation times), T1 (Invitrogen TRIzol Reagent), T2 (combination of TRIzol and QIAGEN modified protocols) and T3 (combination of TRIzol and PROMEGA SV Total RNA Isolation protocols), presented RNA with good integrity and purity, except for the T1 protocol, which obtained an A260/230 value below the acceptable threshold. High RNA integrity (RIN) values were obtained with the Q3 (9.8), T2 (9.2), and T3 (8.9) protocols, while the T1 protocol obtained a lower RIN value (7.1). The Q3, T2, and T3 protocols obtained high-quality RNA from B. mandrillaris based on the criteria of integrity, purity, and concentration, where the implemented modifications and combinations raised the quality; thus, their use is recommended to obtain accurate results when performing transcriptomic analysis. Full article

During an epidemiological survey following a mortality event of freshwater mussels in 2018 in the Embarrass River, Wisconsin, USA, we identified a novel microsporidian parasite in the ovaries of mucket (Actinonaias ligamentina), plain pocketbook (Lampsilis cardium), and fatmucket (Lampsilis siliquoidea) (Unionidae). Histopathology showed round-to-oval microsporidian spores in the cytoplasm of oocytes in 60% (3/5) of female mucket, 100% (4/4) of female plain pocketbook, and 50% (1/2) of female fatmucket. Using transmission electron microscopy, we found that mature spores were round-to-oval and measured 4.13 ± 0.64 µm (3.14–5.31) long by 2.88 ± 0.37 µm (2.36–3.68) wide. The spores had a thin electron-dense exospore with a spiky “hairy” coat, a thick electron lucent endospore, diplokaryotic nuclei, a polar vacuole, and 27–28 polar filaments arranged in 1–3 rows. Sequencing of the small subunit rRNA produced a 1356 bp sequence most similar to that of Pseudonosema cristatellae (92%), and phylogenetic analysis grouped it within the freshwater Neopereziida. Genetic, morphological, and ultrastructural characteristics did not closely match those of other Pseudonosema spp., and a new genus and species, Hirsutonosema embarrassi n. gen. n. sp., were designated. Additional studies could evaluate host susceptibility, distribution, seasonality, transmission, and lethal or sub-lethal effects of this parasite on freshwater mussels. Full article

Soil-transmitted helminths (STHs) are a group of parasites that are globally distributed and are the most prevalent neglected disease (NTD) in Latin America and the Caribbean (LAC); their presence is associated with health and development problems. In Argentina, their distribution is heterogenous, and there are highly endemic areas in the north of the country. The World Health Organization (WHO) recommends the mass deworming of children as a first-line strategy for the prevention and control of STHs and recently also encourage the development of more sensitive diagnostic tests. The aim of this study was to determine the prevalence of STHs in Tartagal (Salta, Argentina) after four years of deworming interruption with albendazole and ivermectin. A total of 437 fecal samples were analyzed using standard coprological techniques, a subset of which were selected to molecularly typify protozoan parasites; 257 blood samples were analyzed for the presence of specific antibodies to the STH Strongyloides stercoralis. The most prevalent protozoan species were G. intestinalis (19.6–49.2%) and B. hominis (19.1–38.5%). Molecular characterization allowed us to evidence possible zoonotic or human-to-human transmission pathways for Giardia intestinalis or Blastocystis spp., while serology for S. stercoralis proved to be a useful screening tool for monitoring this parasite after treatment. In general, a decrease in the prevalence of STHs was observed in the area, from 60% to 2.9–20% for hookworms and from 51% to 1–9.3% for S. stercoralis four years after treatment, demonstrating the effectiveness and duration of anthelmintic treatment with these two drugs. Full article

Babesiosis, caused by Babesia ovis, is a major seasonal issue in sheep, particularly in countries like Türkiye with high Rhipicephalus bursa tick populations. Previous studies employing various methods such as microscopy, serology, or molecular techniques have reported different epidemiological data concerning ovine babesiosis. Addressing this knowledge gap, our study employed a combined nested PCR (nPCR)/indirect ELISA (iELISA) approach, analyzing blood samples collected from 414 sheep between April and July 2023 using both techniques. nPCR amplified the 18S ribosomal RNA gene of B. ovis and determined a molecular prevalence of 1.9%. Conversely, serological testing using iELISA targeted the BoSA1 antigen and revealed a significantly higher positivity rate of 59.9% for anti-B. ovis antibodies. The temporary presence of Babesia after recovery reduces nPCR sensitivity, resulting in lower molecular prevalence. However, even if Babesia is not present in the host, anti-B. ovis antibodies remain in the serum for a long time and can be detected serologically. Our study underscores the necessity of concurrently employing molecular and serological methods for an accurate assessment of B. ovis prevalence. It highlights the importance of comprehensive epidemiological approaches for effective disease management in sheep populations. Full article

Background: Accurate malaria diagnosis constitutes a challenging task, necessitating the need for the implementation of targeted and effective diagnostic tools. The purpose of the current study was to evaluate the effectiveness of two different molecular methodologies in terms of sensitivity for the detection of External Quality Assessment (EQA) Plasmodium samples. Methods: A total of 104 lyophilized blood samples from 14 different UK-NEQAS (National External Quality Assessment Site) (2016–2021) and eight WHO-NEQAS distributions (2017–2020) were analyzed. An in-house multiplex PCR protocol, followed by single target real-time PCR protocols for all five Plasmodium species, was implemented. Results: The multiplex PCR had a success rate of 10/16 and 20/28 for P. vivax and P. falciparum species, respectively. On the other hand, the respective results for real-time PCR had a success rate of 13/16 (P. vivax), 28/28 (P. falciparum), 5/8 (P. malariae), 8/10 (P. ovale), and 10/14 (P. knowlesi). Plasmodium falciparum samples displayed the highest sensitivity of detection, 0.02 parasites/μL. Plasmodium vivax samples displayed a 0.1 parasites/μL cutoff value, greater than the respective value for whole blood samples, while P. ovale species displayed a respective cutoff value of 0.05 parasites/μL. Due to the limited number of tested samples, data obtained for P. malariae and P. knowlesi species samples were inconclusive. Conclusions: Real-time PCR comprises a credible molecular methodology in terms of sensitivity assessment and detection of low parasitemia levels of Plasmodium sp. in EQA lyophilized blood samples. Full article

The control of parasitic nematode infection in sheep and other animals is threatened by the evolution of drug resistance in parasite populations. One recommendation to delay the onset of drug resistance is to estimate the flock mean faecal egg counts by sampling a subpopulation and to treat sheep only when egg counts are high. However, there is little research on the accuracy and precision of estimates of the flock mean obtained from samples. In silico sampling was used to quantify the influence of flock variation, sample size, flock size and mean egg count on the accuracy and precision of the estimated mean egg count. Commonly used and recommended sampling schemes gave alarmingly imprecise estimates of the true flock means. Simply providing a point estimate of the flock egg count can be seriously misleading. Therefore, quantiles were provided for the proportion of estimates in a plausible scenario that is likely to require treatment. It may be more informative to use these quantiles to predict the probability that the true flock mean is sufficiently high to consider treatment. Full article

Demodex mites are acari, common ectoparasites of humans and other mammalian pilosebaceous units. Demodicosis occurs when mites overpopulate the skin, causing several skin disorders. Our aim was to investigate the prevalence of demodicosis in patients with suspicious clinical features, such as cheek redness, itching, and skin sensitivity, who presented at the outpatient clinic of the Andreas Syggros Dermatology Hospital in Greece. We studied 184 individuals aged between 18 and 97 years and analyzed the content of pilosebaceous units by microscopy to determine the density of Demodex mites. Samples were evaluated as positive when Demodex spp. densities equaled or exceeded 5 mites per square cm. Sixty-six percent of the examined subjects were positive for demodicosis. The age distribution was statistically normal (p = 0.2), and the median age was 51.29 years. Seventy percent of the patients were females, and 30% were males, while 64.46% of the demodicosis-positive individuals were females, and 35.54% were males. We observed a rise in the percentage of males as the age of the patients increased. Demodicosis can be a challenging disease because it presents apart from the typical symptoms, with a variety of nonspecific symptoms mimicking other dermatological skin conditions. Therefore, it is important to investigate Demodex spp. in patients who present with common facial dermatological diseases to improve treatment results. Further studies could contribute to a better understanding of the pathogenic role of Demodex mites and how this role is affected by mite density, host sex and age. Full article

Schistosomiasis, acquired by skin-penetrating cercariae of dioecious digenean schistosomes during freshwater contact, afflicts nearly 260 and 440 million people with active infections and residual morbidity, respectively. About 10 million women at reproductive age contract schistosomiasis during gestation every year. Acute schistosomiasis is characterized by pre-patent pro-inflammatory CD4+ T-helper 1 or CD4+ Th1/T-helper 17 reactivity against immature schistosomulae. Chronic schistosomiasis is dominated by post-patent anti-inflammatory CD4+ T-helper 2 reactivity against ova epitopes. Flukes co-exist in immunocompetent definitive hosts as they are capable of evading their defense mechanisms. Preventive measures should be complemented by vaccination, inducing long-term protection against transmission, infection, and disease recurrence, given the latest advancements in schistosomal vaccines. Vaccines become pivotal when considering constraints of chemotherapy, i.e., lack of protection against re-infection, and evolving resistance or reduced sensitivity. Transmission models for human non-zoonotic schistosomiasis incorporating vaccination available in PubMed, Embase and Web of Science up to 31 December 2023 are presented. Besides conceptual model differences, predictions meant to guide decision- and policymaking reveal continued worm harboring that facilitates transmission besides residual infections. In addition, increased susceptibility to re-infection and rebound morbidity, both shifted to later life stages following the intervention, are forecasted. Consequently, a vaccination schedule is pivotal that considers the optimal age for initial immunization, i.e., pre-schoolchildren or schoolchildren in a cohort-based or population-based manner, while incorporating potential non-adherers promoting ongoing transmission. Longevity over magnitude of vaccine protection to antigenic schistosomal moieties is crucial. Accounting for pre-acquired immunity from natural exposure, in utero priming in addition to herd immunity, and induced by chemotherapy is crucial. Combining, as a multi-component approach, long-term effects of vaccination with short-term effects of chemotherapy as regular repeated vaccine-linked therapy seems most promising to achieve WHO’s endpoints of transmission elimination and morbidity control. Full article

Bovine neosporosis is an infection caused by the protozoan parasite Neospora caninum and has substantial veterinary hazards. Neosporosis cannot be controlled by vaccination or chemotherapy. Thus, accurate diagnosis followed by isolation and culling of infected animals is regarded as the most efficient method of control. In vivo diagnosis often relies on serologic testing of the animals, and milk represents a non-invasive and easy-to-collect sample matrix. However, indirect enzyme-linked immunosorbent assay (ELISA) specifically designed for antibody detection in milk are sometimes not easily available and it is tempting to use ELISA kits that are originally designed for use in serum in milk samples instead. Herein, we evaluated a widely used commercial ELISA (ID Screen^® Neospora caninum competition Multispecies ELISA (ID. Vet, Grabels, France)), developed for detection of N. caninum antibodies in serum samples, for its performance on milk samples. Milk samples from dairy ruminants (cows, buffaloes, sheep, and goats; n = 149) were tested in parallel with the serum ELISA and a commercial milk ELISA as a standard test (Neospora caninum Milk Competitive ELISA, ID. Vet, Grabels, France). The detected prevalence values were 28.2% (42/149), 17.4% (26/149), and 17.4% (26/149) using milk ELISA, serum ELISA, and both ELISAs, respectively. Sensitivity, specificity, positive predictive value, and negative predictive value for the serum ELISA used with milk samples were 61.9%, 100%, 100%, and 87%, respectively. The agreement and kappa value between the two ELISAs were 89.3% and 0.70, respectively, suggesting substantial agreement. High values of Pearson correlation coefficient (0.904, p ≥ 0.0001) and area under the receiver operating characteristic (ROC) curve (0.789, p ≥ 0.0001) demonstrated the high diagnostic performance of the serum ELISA in milk samples. Also, a Bland–Altman Plot and histogram describing the frequency of distribution of ELISA optical densities confirmed the high agreement of both serum and milk ELISAs. The current results revealed the high specificity but moderate sensitivity of the serum ELISA used for milk samples compared with the milk ELISA. However, the excellent positive predictive value of the serum ELISA makes it an alternative option in case of the unavailability of milk ELISAs. With this study, we provided additional evidence that a widely used serum ELISA test kit may also be used for the detection of N. caninum antibodies in milk samples. Full article

The genus Erinaceus is commonly found in rescue centres across the European continent despite the reported decline in some countries. Parasite infections are frequently detected in rescued hedgehogs, leading to increased morbidity and mortality and consequently conditioning their recovery. Some of the most frequent parasites include respiratory nematodes, such as Crenosoma striatum and Capillaria spp., which may lead to important pneumonia. Moreover, some of these agents have zoonotic potential, such as Cryptosporidium spp., Sarcoptes spp., and several species of ticks and fleas, which may transmit different vector-borne pathogens. This review provides a brief guide on hedgehogs’ internal and external parasitology, as well as some suggestions for diagnosis and treatment that are relevant for wildlife veterinarians, biologists and other researchers. Full article