Parasitological Survey Research Articles

Unveiling the potential of parasites as proxy bioindicators for water quality assessment in river Jhelum Kashmir, India.

This study aimed to evaluate the effects of deteriorated physicochemical conditions in the river Jhelum on parasitic infestations and to investigate the potential of fish parasites as bioindicators of water quality. All the physicochemical parameters exhibited statistically significant differences based on both site and season (p < 0.01).The interaction term (Site × Season) was also kept in the model since it was statistically significant (p < 0.01). A parasitological survey of 360 schizothoracine fish revealed a 30.3% prevalence (109/360) of endohelminth infection. The study identified four predominant parasitic taxa across two distinct classes: Cestoda, including Adenoscolex oreini and Schyzocotyle acheilognathi, and Acanthocephala, comprising Pomphorhynchus kashmirensis and Neoechinorhynchus manasbalensis. For the assessment of parasitic load, we calculated the prevalence, mean intensity, mean abundance, and index ofinfection for each sampling period. Correspondence analysis identified associations between parasite occurrence and specific water quality parameters. Regression analysis, including R2 and p values, demonstrated a positive correlation between the number of parasites and both the proportion of infected fish and the ratio of infected to examined fish. Given that parasitic load is significantly influenced by a range of water quality parameters, fish parasites can serve as a robust indicator of declining water quality. Fish parasites are highly sensitive to water quality changes such as pollutants, toxins, and fluctuations in pH, temperature, and oxygen levels. Deteriorating water quality can stress fish, compromising their immune systems and increasing their susceptibility to parasitic infections. Additionally, complex life cycles of parasites can be disrupted by poor water conditions, making them indicators of water quality issues.

Molecular phylogeny, including a new species of Anindobothrium (Cestoda, Rhinebothriidea) from the Southern eagle ray Myliobatis goodei, finally solves the taxonomic enigma of Phyllobothrium myliobatidis

During a parasitological survey of tapeworms from Myliobatis goodei Garman, 1885 (Myliobatiformes: Myliobatidae) in coastal waters off Argentina in the Southwestern Atlantic, a new rhinebothriidean cestode species, Anindobothrium danielaesp. nov., is described using morphological and molecular techniques. This species differs from its congeners by a particular combination of features, including the configuration of the bothridia, the number of marginal loculi, and the number and distribution of testes. Additionally, Anindobothrium myliobatidiscomb. nov. is proposed based on several morphological traits, including the presence of stalked bothridia with marginal loculi and an apical sucker, euapolytic strobila, and postvaginal testes. The diagnosis of the genus Anindobothrium Marques, Brooks &amp; Lasso, 2001 is amended to include the features exhibited by these two species; two species subsets are suggested based on the configuration of the bothridia. The presence of A. danielaesp. nov. and A. myliobatidiscomb. nov. in the studied area not only increases the number of cestodes in M. goodei here from eight to ten but also represents the first report of a rhinebothriidean cestode parasitizing stingrays of the family Myliobatidae in the Southwestern Atlantic.

The species composition of the definitive hosts of the trematode &lt;i&gt;Bilharziella polonica&lt;/i&gt; (Schistosomatidae) of Southern Karelia (Northwestern Russia)

We performed a parasitological survey of helminths of 398 waterfowl specimens from an ecologically unique territory of southern Karelia (North-West Russia). This is the first study of species composition and infection of birds that are definitive hosts of Bilharziella polonica have been obtained. The trematoda of Bilharziella polonica has been recorded only in seven species of birds — mallard, teal, garganey, goldeneye, tufted duck, shoveler, and red-necked grebe. The species of B. polonica has been recorded of red-necked grebe for the North-West of Russia for the first time. The role of infected birds of Bilharziella polonica in support of schistosomiasis, a disease that causes morbidity for causing human cercarial dermatitis or swimmer’s itch, were shown. We present data that life cycle of Bilharziella polonica is successfully implemented in the conditions of Karelia.

Urogenital schistosomiasis in schoolchildren in the lake zones of Kankossa and Oued Rawdha, southern Mauritania: The first parasitological and malacological survey.

Urogenital schistosomiasis due to Schistosoma haematobium is a major public health problem in Mauritania, but little is known about its epidemiology in many areas of the country, particularly in the lake zones. The objectives of the present parasitological and malacological study were to assess the prevalence and intensity of urogenital schistosomiasis among school children in Kankossa and Oued Rawdha lakes, southern Mauritania, and determine the species of intermediate host snails and the prevalence of snails with schistosome. A school-based epidemiological survey was conducted in two villages in the lake areas of Kankossa and Oued Rawdha. Urine samples were collected from 450 state primary school children and Koranic school children and examined for the presence of S. haematobium eggs using filtration technique. Water bodies adjacent to human settlement were surveyed for Bulinus and Biomphalaria snails that may potentially be intermediate hosts of S. haematobium. Morphological, molecular, and proteomic (i.e. matrix-assisted laser desorption ionization time-of-flight mass spectrometry [MALDI-TOF MS]) identification of collected snails were conducted, and their infection status was assessed by real-time polymerase chain reaction (RT-PCR) using the highly repetitive DraI gene. The prevalence of urogenital schistosomiasis was 35.6% and 15.8% in Kankossa and Oued Rawdha villages, respectively, corresponding to 'moderate' prevalence (i.e., 10-49% infected schoolchildren). Urogenital schistosomiasis prevalence was higher in boys (30.0%) than in girls (21.2%; P < 0.05), and in Koranic schools pupils (37.1%) than in state schools (20.5%; P < 0.05) pupils. Multiple regression analysis showed that sex (odds ratio [OR]: 1.64; 95% confidence interval [95% CI]: 1.06-2.57; P = 0.03) and Koranic school level (OR: 1.79; 95% CI: 1.06-3.04; P = 0.03) were independently and significantly associated with urogenital schistosomiasis. Based on molecular and proteomic identification, both B. senegalensis and B. umbilicatus colonized the water bodies of Oued Rawdha, whereas both B. forskalii and B. truncatus colonized those of Kankossa. The DraI RT-PCR detected S. haematobium complex DNA in 8 of 66 (12.1%) analysed snails: one B. truncatus and one B. forskalii in Kankossa and five B. senegalensis and one B. umbilicatus in Oued Rawdha. Urogenital schistosomiasis is moderately prevalent in the lake zones of Kankossa and, to a lesser extent, Oued Rawdha, located in southern Mauritania. Mass drug administration campaigns with praziquantel should be conducted to reduce the prevalence of urogenital schistosomiasis among school-aged children in the lake zone of Kankossa and Oued Rawdha village. Further parasitological and malacological studies should be conducted in other villages located in the Mauritanian lakes in the southern Sahelian zones and the northern oasis areas to strengthen our knowledge of the current epidemiological situation and implement appropriate urogenital schistosomiasis control strategies.

Helminths in fish from lake and river systems of the Upper Kolyma Highlands that have medical and veterinary significance

The purpose of the research is to extend information across the distribution of zooanthroponotic helminth infections transmitted through freshwater fish in the Magadan Region.Materials and methods. The study area is located in the Upper Kolyma basin on the Magadan Region and the Republic of Sakha (Yakutia) border. The Omulevsky Park is also located here, one of the clusters of the Chersky National Park named after A. V. Andreev. The existing lake and river systems (Darpir, Momontai, Malyk, Urultun and Ui) are inhabited by 7 fish species: Arctic char (Salvelinus alpinus), east-Siberian grayling (Thymallus arcticus pallasi), round fish (Prosopium cylindraceum), Siberian sucker (Catostomus catostomus rostratus), burbot (Lota lota leptura), common minnow (Phoxinus phoxinus) and sculpin from the Kolyma (Cottus kolymensis). 685 specimens of fish were undergone parasitological survey using established procedures. The found helminths were fixed in 70% ethanol and clarified in glycerol.Results and discussion. In the study of the fish helminth fauna in the lake and river systems of the Upper Kolyma Highlands, three helminth species that posed a danger to humans and animals were identified, Dibothriocephalus dendriticus, D. ditremus (Diphyllobothriidae) and Eustrongylides excisus (Dioctophymatidae). Information was provided on fish infection with these parasites in the lake and river systems, and their distribution in the Magadan Region, and a brief description of these types of helminths was given. In domestic scientific and methodological publications, the problem of eustrongylidiasis as a zooanthroponotic disease is not sufficiently covered, therefore, emphasis is placed on nematodes of the genus Eustrongylides. The research results may attract the attention of sanitary and veterinary service specialists to this issue, especially given the creation of a national park in the Magadan Region. Data on the freshwater fish infection with Diphyllobothriidae in the Upper Kolyma Lake and river systems expand the diphyllobothriasis nosoarea in the Magadan Region and allows the Susumansky District to be included in its boundaries.

Morphological and molecular identification of metacestodes infecting teleost fishes of Moreton Bay, Australia

In a parasitological survey of fishes from Moreton Bay (southeastern Queensland, Australia), 169 teleost fishes, representing 54 species from 28 families, were examined for larval cestodes. Of these 54 species, 36 were found to be infected by metacestodes. Metacestodes were characterised by morphological and molecular data (the D1-D3 region of the 28S rDNA gene); these data were analysed in parallel to inform larval type allocation. Metacestodes collected represented eight morphological types, seven previously reported (Types I, II, IV, V, VI, VII, and X) and one novel type (Type XVI). Phylogenetic analyses were conducted to genetically match larval types to adult cestodes. Six of the eight larval types found were matched to adult forms: Type I metacestodes matched species of Phoreiobothrium Linton, 1889 (Onchobothriidae); Type II metacestodes matched species of Acanthobothrium van Beneden, 1849 (Onchobothriidae); Type IV metacestodes matched species of Scyphophyllidium Woodland, 1927 and Alexandercestus Ruhnke & Workman, 2013 (Phyllobothriidae); Type VI metacestodes matched species of Anthobothrium van Beneden, 1850 (Tetraphyllidea incertae sedis); Type X metacestodes matched species of Ambitalveolus Caira & Jensen, 2022 (Tetraphyllidea incertae sedis); and Type XVI metacestodes matched species of Platybothrium Linton, 1890 (Onchobothriidae). Based on phylogenetic topology, Type V metacestodes are inferred to match Pedibothrium Linton, 1909 (Balanobothriidae) and Type VII metacestodes are inferred to match Spongiobothrium Linton, 1889 (Rhinebothriidae). These findings support and extend the unified morphological type system proposed previously, but suggest that morphological types will ultimately be informative to identify metacestodes to a group of related genera rather than any distinct genus.

Anisakid larvae in the skipjack tuna Katsuwonus pelamis captured in Japanese waters: Two-year monitoring of infection levels after the outbreak of human anisakiasis in 2018

In 2018, human anisakiasis caused by the ingestion of the skipjack tuna Katsuwonus pelamis occurred frequently in Japan. This may be attributable to a heavy infection of A. simplex (s.s.) in the host's muscle tissue. In this study, we investigate infection levels of anisakid L3 larvae in skipjack tuna captured in Japanese waters afterward (2019–2020) to contribute to predict and prevent the outbreak of human anisakiasis. A total of 476 larvae were detected from 78 out of 85 skipjack tuna captured at 14 stations of the Pacific and East China Sea. The present parasitological survey suggests that infection levels in 2019–2020 were low, comparing that in 2018; in total only seven larvae were found from the host's muscle tissue. The collected larvae were identified by molecular methods to Anisakis berlandi, A. pegreffii, A. simplex (s.s.), A. typica and Skrjabinisakis physeteris (s.l.). Not only larvae of A. simplex (s.s.) but also those of A. berlandi were found from the muscle tissue and thus the latter species may also be a causative agent of human anisakiasis. In addition, this study confirmed the geographic distribution pattern that A. simplex (s.s.) is abundant in the Pacific, while A. pegreffii is dominant in the East China Sea. Our results contribute to understanding the risk of food poisoning and stock delimitation of host animals.

Effectiveness of Three Sampling Approaches for Optimizing Mapping and Preventive Chemotherapy against Schistosoma mansoni in the Western Part of Côte d'Ivoire.

The elimination of schistosomiasis as a public health problem by 2030 is one of the main goals put forth in the World Health Organization's roadmap for neglected tropical diseases. This study aimed to compare different sampling approaches to guide mapping and preventive chemotherapy. A cross-sectional parasitological survey was conducted from August to September 2022 in the health districts of Biankouma, Ouaninou, and Touba in the western part of Côte d'Ivoire. The prevalence and intensity of Schistosoma mansoni infection were assessed in children aged 5-14 years using three sampling approaches. The first approach involved a random selection of 50% of the villages in the health districts. The second approach involved a random selection of half of the villages selected in approach 1, thus constituting 25% of the villages in the health district. The third approach consisted of randomly selecting 15 villages from villages selected by approach 2 in each health district. The overall prevalence of S. mansoni was 23.5% (95% confidence interval (CI): 19.9-27.6%), 21.6% (95% CI: 17.1-26.8%), and 18.3% (95% CI: 11.9-27.1%) with the first, second, and third approach, respectively. The respective geometric mean S. mansoni infection intensity was 117.9 eggs per gram of stool (EPG) (95% CI: 109.3-127.3 EPG), 104.6 EPG (95% CI: 93.8-116.6 EPG), and 94.6 EPG (95% CI 79.5-112.7 EPG). We conclude that, although randomly sampling up to 50% of villages in a health district provides more precise population-based prevalence and intensity measures of S. mansoni, randomly selecting only 15 villages in a district characterized by low heterogeneity provides reasonable estimates and is less costly.

Revealing bovine schistosomiasis in Malawi: Connecting human and hybrid schistosomes within cattle

In Malawi, the putative origin of a newly described Schistosoma haematobium-mattheei hybrid human schistosome was assessed upon a seminal molecular parasitological survey of cattle. Using miracidia hatch test (MHT) and carcass inspection at slaughter, mean prevalence of bovine schistosomiasis was 49.1% (95% CI: 43.7–54.6%) and 10.3% (95% CI: 6.0–16.2%) respectively, though significant spatial heterogeneity was noted. Approximately 2.0% of infected cattle, and only those from Mangochi District, shed S. haematobium-mattheei and/or S. haematobium in faeces. To quantify schistosome (re)infection dynamics, where a S. haematobium-mattheei hybrid was present, we undertook a novel pilot GPS-datalogging sub-study within a specific herd of cattle (n = 8) on the Lake Malawi shoreline, alongside a praziquantel (40 mg/kg) treatment efficacy spot check. At sub-study baseline, all GPS-tagged cattle had proven daily water contact with the lake. Each animal was patently infected upon MHT, with older animals shedding less miracidia. At one month review, whilst parasitological cure was 100.0%, from six weeks onwards, (re)infection was first noted in the youngest animal. By three-month review, all animals were patently (re)infected though only miracidia of S. mattheei were recovered, albeit in much lower numbers. To conclude, infection with S. mattheei is particularly common in cattle and demonstrates a previously cryptic burden of bovine schistosomiasis. Within Mangochi District, bovine transmission of both S. haematobium-mattheei hybrids and S. haematobium are now incriminated, with unequivocal evidence of contemporary zoonotic spill-over. Future control of urogenital schistosomiasis here in the southern region needs to develop, then successfully integrate, a One Health approach with appropriate mitigating strategies to reduce and/or contain bovine schistosomiasis transmission.

DESCRIPTION OF FEMALE DENDRITOBILHARZIA PULVERULENTA (BRAUN, 1901) SKRJABIN, 1924 FROM TWO NEW AVIAN HOSTS IN NAMIBIA WITH PHYLOGENETIC ANALYSES AND COMMENTS ON SEVERAL TAXONOMICALLY UNCERTAIN AVIAN SCHISTOSOME SEQUENCES.

During a 2021 parasitological survey of birds in the Nyae Nyae-Khaudum Dispersal Area (Kavango-Zambezi Transfrontier Conservation Area, Namibia), we collected 9 specimens of Dendritobilharzia pulverulenta (Braun, 1901) Skrjabin, 1924 infecting the blood (heart lumen) of a white-backed duck, Thalassornis leuconotus (Eyton, 1838) (Anseriformes: Anatidae), and a fulvous whistling duck, Dendrocygna bicolor (Vieillot, 1816) (Anatidae). These flukes were fixed for morphology and preserved for DNA extraction. We assigned our specimens to DendritobilharziaSkrjabin and Zakharow, 1920 because they were strongly dorso-ventrally flattened in both sexes and had an intestinal cyclocoel with a zig-zag common cecum with lateral dendritic ramifications, numerous testes posterior to the cyclocoel and flanking the dendritic ramifications, and a tightly compacted convoluted ovary as well as lacking an oral sucker, ventral sucker, and gynaecophoric canal. Further, our specimens were morphologically identical to previously published descriptions of D. pulverulenta. Sequences of the 28S from our specimens were nearly identical to those identified as D. pulverulenta from North America (New Mexico), and our 28S phylogenetic analysis recovered D. pulverulenta within a polytomy of other Gigantobilharziinae spp. The CO1 phylogenetic analysis recovered a monophyletic Dendritobilharzia and, with low taxon sampling, a monophyletic Gigantobilharzia. This is the first record of a species of Dendritobilharzia infecting these ducks as well as the first record of an adult Dendritobilharzia from sub-Saharan Africa. The original description of adult D. pulverulenta (type locality: northern Sudan) was based on 2 males only, and hence the present study is the first description of female D. pulverulenta from Africa (the continent of the type locality). We reassign 2 Gigantobilharziinae spp. based on morphology and nucleotide evidence: Gigantobilharzia ensenadense (Lorenti, Brant, Gilardoni, Diaz, and Cremonte, 2022) Dutton and Bullard, n. comb., and Gigantobilharzia patagonense (Lorenti, Brant, Gilardoni, Diaz, and Cremonte, 2022) Dutton and Bullard, n. comb. We also comment on several avian schistosome sequences whose identities need confirmation or that likely have been misidentified.

Prevalence of helmintic infections in Brazilian Maxakali indigenous: a repeated cross-sectional design.

The prevalence of intestinal parasites is known to be high among Amerindian populations; further, there are serious problems in the healthcare of these populations in Brazil. The Maxakali, located in the northeastern region of Minas Gerais, Brazil, is an indigenous group that still preserves many of its cultural aspects. This study aimed to compare the positivity rate of schistosomiasis and soil-transmitted helminths in this ethnic group in epidemiological surveys conducted in 1972 and 2014. Stool parasitological examinations were performed by the Kato-Katz technique during both periods in this population. In 2014, the parasitological diagnosis was also realized with the TF-Test® technique. In 1972, 270 inhabitants were examined. The positivity rates were 67.4% for Schistosoma mansoni, 72.9% for hookworms, 43.7% for Ascaris lumbricoides, and 23.7% for Trichuris trichiura. In 2014, 545 individuals were examined, and the positivity rates obtained were 45.7% for S. mansoni, 22.8% for hookworms, 0.6% for A. lumbricoides, and 2.8% for T. trichiura. The comparison of the parasitological surveys conducted in 1972 and 2014, indicates that the indigenous Maxakali remained neglected by the health and indigenous protection authorities during these four decades. The infection rate observed in 2014 for schistosomiasis and hookworm remains high, considering the current epidemiological view of these diseases in the Brazilian population.

Entamoeba histolytica Infection in the Philippines: A Review

Entamoeba histolytica, an intestinal protozoan parasite, is the primary causative agent of both intestinal and extraintestinal amoebiasis. While six species of Entamoeba have been identified in the human gut, only E. histolytica is well recognized as a pathogenic amoeba associated with intestinal and extraintestinal infections. In many cases of E. histolytica infection, symptoms are either absent or mild, whereas the most frequent clinical manifestations are colitis and liver abscess due to amoebic infection. Diagnosis typically relies on microscopic and serological methods. Metronidazole is the standard therapy for treating children and adults with invasive amoebiasis. However, the absence of an effective vaccine poses a significant challenge to controlling the transmission and progression of the parasite into an active, invasive disease. Notably, in developing tropical countries like the Philippines, significant cases of E. histolytica infections have been documented in communities with inadequate sanitation and hygiene practices. The development of pragmatic and cost-effective diagnostic methods is therefore crucial for the clinical care of amoebiasis patients. Drawing from a limited pool of published articles (2010 to date) on cases of E. histolytica infections and parasitological surveys in the Philippines, the current review underscores the critical knowledge gap on the prevalence of amoebiasis as well as the disease pathology and treatment of this zoonotic parasitic disease.

First microphological and molecular parasitological survey of Benedenia in humpback grouper (Cromileptes altivelis) of Lampung and Situbondo, Indonesia

Abstract. Amiin MK, Subekti S, Masithah ED, Nirmala D, Yunus M, Santanumurti MB, Rivaie AR. 2023. First microphological and molecular parasitological survey of Benedenia in humpback grouper (Cromileptes altivelis) of Lampung and Situbondo, Indonesia. Biodiversitas 24: 6858-6867. Capsalid monogenean infections, such as Benedenia, affect grouper aquaculture production. Benedenia will cause lesions and skin damage which will cause fish prices to drop. Secondary infection from bacteria, viruses, and fungi by Benedenia triggers a slow growth rate and even mortality. Benedenia infection on grouper has been conducted in Indonesia, specifically in this study in Lampung and Situbondo. However, molecular identification of this parasite is still lacking. This study aims to determine the microscopic and molecular characteristics of Benedenia from the Hurun Bay waters of Lampung and the North Coast of the Java Sea, Situbondo. The main parameters observed in this study were DNA base sequence, morphology, and phylogenetic tree. Benedenia from Lampung (637 bp) and Situbondo (741 bp) in this study was confirmed by the morphological and molecular close as Benedenia sargocentron with nucleotides. Interestingly, the similarity was less than 98% with B. sargocentron with accession ID JN797597.1 (similarity of 97.15% from Lampung and 86.33% from Situbondo). It could be indicated as a new species of Benedenia. The prevalence of Benedenia in Lampung was 90%, while Situbondo showed 80% with 3 parasite/fish intensity for each location. The outcome of this study is the characteristics of Benedenia from Lampung and Situbondo were similar to B. sargocentron according to morphological and molecular identification. This is the first report of B. sargocentron from Lampung and Situbondo since no molecular identification has been done in those places to confirm their species. Further research by another molecular target apart from 28S rRNA should be needed to identify this parasite more accurately.

Plasmodium falciparum remains the dominant parasite affecting children despite decades of implementing vector control in two villages of Wolaita Zone, Southwest Ethiopia.

Malaria is still a significant public health concern, and its prevention and control measures have different impacts in different areas. This study assesses the prevalence of malaria and the effectiveness of routine malaria control programmes such as indoor residual spray (IRS) in two Ethiopian villages. The Kebeles (villages) were purposefully selected based on their malaria prevalence rates. A parasitology survey was conducted in Fango-Gelchecha pre- and post-IRS implementation, whereas in Shochora-Abela it was only conducted post-IRS implementation. The IRS was implemented as part of the routine malaria control programme in August 2017. Every fourth house from the village registration list was systematically selected, resulting in a sample of 300 households per village. A total of 3,075 individuals were enrolled for malaria testing using microscopy. After three to four months of application of IRS in August 2017, 59 malaria cases were confirmed, resulting in an overall prevalence of 1.9% (95% CI: 1.5-2.5). Of the positive cases, 18 cases (0.59%: 95% CI: 1.3-1.8) were from Shochora-Abela village, and 41 cases (1.33%: 95% CI: 1.1-1.3) were from Fango-Gelchecha. About age categories, the prevalence of malaria was 10.1% (95% CI: 5.9-15.9) among children under five, 4.7% (95% CI: 3.3-6.4) in children aged 5-14, and only 0.32% (95% CI: 0.13-0.67) in the age group 15 and above. Overall, P. falciparum was the dominant malaria parasite, accounting for 69.5% (95% CI: 56.1-80.8), while P. vivax malaria accounted for 30.5% (95% CI: 19.2-43.8). The malaria prevalence in Fango-Gelchecha village was 3.1% (95% CI: 2.3-4.0) before IRS and 2.6% (95% CI: 1.8-3.5) after IRS application. In the village of Shochora-Abela, the prevalence of malaria post-IRS was 1.2% (95% CI: 0.7-1.9), but the prevalence prior to IRS was not evaluated. Plasmodium falciparum is the predominant parasite in the villages, mainly affecting children under five. Therefore, protecting young children should be the top priority for reducing infection burdens.

Two new Neotetraonchus species (Dactylogyridea, Dactylogyridae) parasitising the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae), including molecular data.

As part of a parasitological survey, several specimens of two new monopisthocotylean species, Neotetraonchus celsomanueli sp. nov. and N.peruvianus sp. nov. (Dactylogyridea, Dactylogyridae), were collected from the gill filaments of the Peruvian sea catfish Galeichthys peruvianus (Siluriformes, Ariidae) off Puerto Pizarro, Tumbes region, Peru. Neotetraonchus celsomanueli sp. nov. is characterised by an MCO with a T-shaped distal end and an accessory piece that is ribbed and expanded proximally with a worm-shaped termination. Neotetraonchus peruvianus sp. nov. is typified by its MCO, which has a sledgehammer-shaped distal end and an accessory piece with a claw-shaped distal end. Additionally, N.peruvianus sp. nov. is characterised by its jellyfish-shaped onchium. A partial 28S rDNA sequence was obtained from N.celsomanueli sp. nov., and a phylogenetic analysis was conducted. This analysis revealed the phylogenetic position of Neotetraonchus celsomanueli sp. nov. within a clade comprising monopisthocotylean parasites of diadromous and marine ariid catfishes, including Hamatopeduncularia spp., Chauhanellus spp., Thysanotohaptor Kritsky, Shameem, Kumari & Krishnaveni, , and Neocalceostomoides spinivaginalis Lim, 1995. This finding brings the number of known Neotetraonchus species to seven and represents the first described Neotetraonchus species infecting marine catfishes from Peru.

Распространенность гельминтозов среди сельского населения Хабаровского края

The large medical and socio-economic burden of helminth infections provides the basis for studying the frequency and type of helminth infections among the population of residents of the Russian Far East and is relevant. The purpose of this study was to study the prevalence and type of parasitosis among different age groups of the rural population of the Lazo District. The study was carried out in the design of a retrospective cohort non-randomized continuous study. On the basis of the District Hospital of the Lazo District, 26,483 medical records were processed and analyzed among the adult and child population for the period 2013–2023, with the study of data on the incidence of parasitosis in the rural population based on the results of a microscopic examination of feces for helminth eggs and protozoan cysts ( by Kato method). Statistical analysis was carried out in the STATISTICA 16.0 program, as well as the use of statistical functions of the EXCEL program, using nonparametric data processing methods. After a parasitological survey carried out in 2013–2023, it was revealed that the largest proportion among the infested were children, predominantly in the age group of 4–7 years. There were no significant differences by gender. Based on the set of indicators that determine the structure and dynamics of epidemiological processes in the Lazo District, clonorchiasis (0.07 %, 19 people), ascariasis (0.90 %, 238 people), enterobiasis (1.90 %, 503 people) were diagnostically significant. people), as well as giardiasis (2.00 %, 530 people). There is a need for improved diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and treatment of helminth infections in the Russian Far East.

Loa loa and Mansonella perstans microfilaremia in the department of Lékoumou, Republic of Congo

BackgroundLoiasis is endemic in the northern and western part of the Republic of Congo. Between 2004 and 2010, surveys were conducted, using the RAPLOA method, in all departments of the Republic of Congo to assess the distribution of loiasis. Prior to 2004, only two parasitological surveys on loiasis had been conducted in Congo and mainly in the Department of Lékoumou, in the southwestern of the country. In 2019, we conducted a parasitological survey in this same department, more than 30 years after the first surveys.MethodsThe study was conducted in 21 villages. Loa loa and Mansonella perstans microfilaremia levels were quantified using 50 µl calibrated blood smears.ResultsA total of 2444 individuals were examined. The median age of the screened individuals was 43 (interquartile range: 30–57, range: 18–91) years old. The overall prevalences of L. loa and M. perstans microfilaremia were 20.0% [95% confidence intervals (CI) 18.0–21.6%] and 1.0% (95% CI 0.6–1.4%) respectively. The proportion of individuals with a microfilarial density of L. loa > 8000 mf/ml and > 30,000 mf/ml were 5.1% (95% CI 4.3–6.1%) and 1.1% (95% CI 0.8–1.7%), respectively. The overall community microfilarial load was 3.4 mf/ml.ConclusionsPrevalences and intensities of L. loa infection remained generally stable between the late 1980s and 2019 in the Lékoumou Department. In contrast, parasitological indicators for M. perstans have declined sharply in the intervening years for an unknown reason.Graphical

Parasitic helminths of alien invasive anurans in Butuan City, Northeastern Mindanao, Philippines.

This study aimed to identify the helminth parasites of invasive anuran species in selected barangays in Butuan City, Philippines. In urbanized areas, invasive species dominate anuran diversity, and one of the primary threats they pose to native wildlife is the transmission of diseases and parasites. Out of the 91 collected individuals of invasive anuran species, Rhinella marina was the most abundant (88 %), followed by Hoplobatrachus rugulosus (12 %) and Kaloula pulchra (3 %). The study identified five species of parasites, with Spirometra sp. being the most prevalent (17.58 %), followed by Echinostoma sp. (16.5 %), Rhabdias bufonis (14.3 %), Cosmocerca sp. (6.6 %), and Strongyloides stercoralis (3.30 %), respectively. Spirometra sp. also had the highest intensity (7.67), followed by Cosmocerca sp. (5), Strongyloides stercoralis (3.33), Rhabdias bufonis (3.30), and Echinostoma sp. (2.73). This parasitological survey revealed that H. rugulosus had the highest prevalence and infection of parasites, and residential areas had the highest parasite prevalence among the habitat types. Adult hosts were found to harbor a higher prevalence and intensity, and male hosts had a higher prevalence. The results highlight the high risk of parasite transmission from anurans to other animals and emphasize the need for the community to control the population of invasive anuran species for the safety of native anurans and to prevent zoonotic transmission to other animals and humans.

Unveiling a novel parasitosis: Trichostrongylus colubriformis infection in captive ring-tailed lemurs (Lemur catta)

Ring-tailed Lemur (Lemur catta) is the only surviving semi-terrestrial diurnal lemur in Madagascar. Despite being the most intensively studied of lemur taxa, only a few helminths have been described in this species. In this study we describe a persistent infection due to Trichostrongylus colubriformis in a captive population of L. catta hosted in a zoological park of northern Italy. In the context of a parasitological survey on zoo animals, we investigated parasites in a captive colony of ring-tailed lemurs within a zoological park. Parasitological analysis included necropsy of a deceased lemur in 2019, subsequent fecal sample collections in 2021–2022, followed by coprological examination and coprocolture. Morphological and molecular analyses were conducted on adult helminths, larvae and eggs, involving microscopy, scanning electron microscopy (SEM), and sequencing of the ITS rDNA region. Trichostrongylidae parasites were primarily found after necropsy in the intestine of the lemur. Morphological and molecular investigations on adults and eggs/larvae recovered from feces collected at different times from lemurs of the same captive population, allowed to properly identify the parasite as T. colubriformis. To the best of our knowledge this is the first description of T. colubriformis in L. catta. Although its presence in wild populations is not necessarily implied by our finding, this parasitosis represent a cause of concern in captive lemurs, considering the possibility of interspecies transmission and the zoonotic implications.

Geographical emergence of sulfadoxine-pyrimethamine drug resistance-associated P. falciparum and P. malariae alleles in co-existing Anopheles mosquito and asymptomatic human populations across Cameroon.

Malaria molecular surveillance remains critical in detecting and tracking emerging parasite resistance to anti-malarial drugs. The current study employed molecular techniques to determine Plasmodium species prevalence and characterize the genetic diversity of Plasmodium falciparum and Plasmodium malariae molecular markers of sulfadoxine-pyrimethamine resistance in humans and wild Anopheles mosquito populations in Cameroon. Anopheles mosquito collections and parasitological survey were conducted in villages to determine Plasmodium species infection, and genomic phenotyping of anti-folate resistance was accomplished by sequencing the dihydrofolate-reductase (dhfr) and dihydropteroate-synthase (dhps) genes of naturally circulating P. falciparum and P. malariae isolates. The malaria prevalence in Elende was 73.5% with the 5-15 years age group harboring significant P. falciparum (27%) and P. falciparum + P. malariae (19%) infections. The polymorphism breadth of the pyrimethamine-associated Pfdhfr marker revealed a near fixation (94%) of the triple-mutant -A16I51R59N108I164. The Pfdhps backbone mediating sulfadoxine resistance reveals a high frequency of the V431A436G437K540A581A613 alleles (20.8%). Similarly, the Pmdhfr N50K55L57R58S59S114F168I170 haplotype (78.4%) was predominantly detected in the asexual blood stage. In contrast, the Pmdhps- S436A437occured at 37.2% frequency. The combined quadruple N50K55L57R58S59S114F168I170_ S436G437K540A581A613 (31.9%) was the major circulating haplotype with similar frequency in humans and mosquitoes. This study highlights the increasing frequency of the P. malariae parasite mostly common in asymptomatic individuals with apparent P. falciparum infection. Interventions directed at reducing malaria transmission such as the scaling-up of SP are favoring the emergence and spread of multiple drug-resistant alleles between the human and mosquito host systems.