Prevalence Of Parasite Species Research Articles

Ratos e camundongos de laboratório do Brasil: décadas se passam, mas as infecções parasitárias permanecem

ABSTRACT: Rats and mice are the most used experimental models in research. Globally, animal houses are subjected to parasite outbreaks. In Brazil, the parasitological profile is used to reflect the sanitary condition of laboratory animals and must be monitored frequently. The present study developed an integrative review of scientific studies on the parasitological profile of rats and mice in animal facilities in Brazil. It identified the most prevalent parasite species reported in animal facilities from different geographic regions of the country, as well as factors contributing to the perpetuation of these parasites, and proposed measures to help prevent such infections. Based on the guiding question “which endoparasites and ectoparasites have already been identified in rat and mouse colonies in animal facilities in Brazil?” and considering inclusion and exclusion criteria, 28 studies published between 1974 and 2021 were selected in four scientific bases. These studies covered facilities in 12 Brazilian States, describing 16 genera of parasites in mice and 18 in rats. Most of the facilities in the selected studies were of the conventional type and with few sanitary barriers, and these conditions may favor the recurrence of parasites. Efforts are, therefore, necessary for institutions to have animal facilities in accordance with the legislation and practice optimal methodologies. The measures proposed in this article can contribute to change the panorama of parasites in the national animal facilities, aiming to safeguard the quality of scientific data and animal welfare.

Detection of Soil-transmitted Helminths and their Risk Factors in Some Local Government Primary Schools Sokoto, Nigeria

Background: Soil-transmitted helminths are among the neglected tropical disease parasites of humans and one of the major public health burdens in developing countries, particularly Sub-Saharan Africa. It is estimated that about 1.5 billion people are affected worldwide.
 Aims: The study was aimed to determine the prevalence and risk factors of Soil-transmitted helminths infection among primary school children.
 Study Design: This was a cross sectional, descriptive study.
 Place and Duration of Study: The study was conducted among primary school children within the age of 4-15 years old in Sokoto South, Wamakko, Yabo and Dange Shuni local government areas of Sokoto State from February 2021 to July 2021.
 Methodology: Faecal samples of 252 children were collected and analyzed using formol-ether concentration technique.
 Results: An overall prevalence of 6.0% was recorded. Differential prevalence of parasite species showed 6.7% Ascaris lumbricoide, and 93.3% hookworm infection. There was high prevalence among Males (7.2%) than Females (4.0%). The age group 10-12 has the high prevalence of 9.8%. The high prevalence of 9.5% was obtained in Yabo and Sokoto South respectively. Tap water and water closet users have the lowest prevalence of 5.3%. High prevalence of 33.3% was recorded among borehole users contaminated with soil.
 Conclusion: The total low prevalence of soil-transmitted helminths may be as a result of improved awareness of the Soil-transmitted helminths in the study area. The government, non-government agencies should help in the provision of social amenities to ensure the total eradication of these diseases. The teaching of health education in both private and public schools should be encouraged by the government.

First record of monogenean fish parasites in the Upper Lufira River Basin (Democratic Republic of Congo): dactylogyrids and gyrodactylids infesting Oreochromis mweruensis, Coptodon rendalli and Serranochromis macrocephalus (Teleostei: Cichlidae)

BackgroundMonogenean parasites have never been formally reported on fishes from the Lufira River Basin. In this context, we decided to record the monogenean parasite fauna of three cichlid species found in the Upper Lufira River Basin for the first time by inventorizing their diversity (species composition) and analysing their infection parameters (prevalence, mean intensity and abundance).MethodsThe African cichlid fishes Oreochromis mweruensis, Coptodon rendalli and Serranochromis macrocephalus were selected for the study, given their economic value and their abundance in the Upper Lufira River Basin. Monogeneans were isolated from the gills and stomach, mounted on glass slides with either Hoyer’s medium or ammonium picrate-glycerin for identification under a stereomicroscope, based on morphological analysis of genital and haptoral hard parts. Indices of diversity and infections parameters were calculated.ResultsA total of 13 gill monogenean parasite species (Cichlidogyrus dossoui, C. halli, C. karibae, C. mbirizei, C. papernastrema, C. quaestio, C. sclerosus, C. tiberianus, C. tilapiae, C. zambezensis, Scutogyrus gravivaginus, S. cf. bailloni and Gyrodactylus nyanzae) and one stomach monogenean (Enterogyrus malmbergi) were identified. A species richness (S) of 10 for O. mweruensis, S = 6 for C. rendalli and S = 2 for S. macrocephalus was recorded. Five parasite species were reported to be common amongst O. mweruensis and C. rendalli. According to cichlid species, the most prevalent parasite species was C. halli (prevalence [P] = 80.9%) on O. mweruensis, C. dossoui (P = 92.9%) on C. rendalli and C. karibae and C. zambezensis (both P = 9.1%) on S. macrocephalus. The parasite species with the highest mean intensity (MI) were G. nyanzae (MI = 8.7) on O. mweruensis, C. papernastrema (MI = 17.1) on C. rendalli and C. karibae (MI = 15) on S. macrocephalus. The findings indicate new host ranges for five parasites species (C. quaestio, S. cf. bailloni, E. malmbergi on O. mweruensis, C. halli on C. rendalli and C. karibae on S. macrocephalus) as well as new geographical records for all of them as they are recorded for the first time in the Lufira River Basin.ConclusionsThis study highlighted the richness of monogenean communities in the Upper Lufira River Basin and is a starting point for future helminthological studies, such as on the use of fish parasites as indicators of anthropogenic impacts.Graphical

A systematic review and meta-analysis of human and zoonotic dog soil-transmitted helminth infections in Australian Indigenous communities.

Soil-transmitted helminths (STH) infect 1.5 billion people and countless animals worldwide. In Australian Indigenous communities, STH infections have largely remained endemic despite control efforts, suggesting reservoirs of infection may exist. Dogs fulfil various important cultural, social and occupational roles in Australian Indigenous communities and are populous in these settings. Dogs may also harbour zoonotic STHs capable of producing morbidity and mortality in dogs and humans. This review provides an overview of human and zoonotic STH infections, identifies the Australian Indigenous locations affected and the parasite species and hosts involved. The meta-analysis provides estimates of individual study and pooled true prevalence of STH infections in Australian Indigenous communities and identifies knowledge gaps for further research on zoonotic or anthroponotic potential. A systematic literature search identified 45 eligible studies documenting the presence of Strongyloides stercoralis, Trichuris trichiura, Ancylostoma caninum, Ancylostoma duodenale, Ancylostoma ceylanicum, undifferentiated hookworm, and Ascaris lumbricoides. Of these studies, 26 were also eligible for inclusion in meta-analysis to establish true prevalence in the light of imperfect diagnostic test sensitivity and specificity by Rogan-Gladen and Bayesian methods. These studies revealed pooled true prevalence estimates of 18.9% (95% CI 15.8-22.1) for human and canine S. stercoralis infections and 77.3% (95% CI 63.7-91.0) for canine A. caninum infections indicating continued endemicity, but considerably more heterogenous pooled estimates for canine A. ceylanicum infections, and A. duodenale, undifferentiated hookworm and T. trichiura in humans. This review suggests that the prevalence of STHs in Australian Indigenous communities has likely been underestimated, principally based on imperfect diagnostic tests. Potential misclassification of hookworm species in humans and dogs due to outdated methodology, also obscures this picture. High-quality contemporary studies are required to establish current true prevalence of parasite species in all relevant hosts to guide future policy development and control decisions under a culturally sound One Health framework.

Some epidemiology aspects of Myxosporean infections in Oreochromis niloticus (Linnaeus, 1758) and Hemichromis fasciatus (Peters, 1857), two cultured Cichlid fishes in the West - Cameroon

In order to assess epidemiology aspects of myxosporean infection in cultured Oreochromis niloticus and Hemichromis fasciatus fishes in Cameroon to develop efficient prevention and control program, a total of 320 Cichlid fishes (189 Oreochromis niloticus and 131 Hemichromis fasciatus) were collected from June 2019 to April 2020 in the ponds located at the Ngoundoup Village, Koutaba Subdivision, Noun Division, Region of West-Cameroon. They were examined both macroscopically and microscopically for myxosporean infections. The prevalence of infection was determined as a function of fish species, sex, size, target organs, and seasons. Results showed that kidneys and ovaries were the only infected organs and harbored nine and three myxosporean species of the genus Myxobolus respectively. A total of 154 fish were infected (54.38%). Irrespective of the parasite species, Oreochromis niloticus (75.13%) was significantly more infected than Hemichromis fasciatus (24.27%). The prevalence of parasites was very low (<25%) whatever the fish species. The sex and fish size did not significantly influence the prevalence of parasite species. The prevalence of Myxobolus tilapiae was negatively and significantly correlated (r= -0.20; p= 0.02) with Oreochromis niloticus size. The overall prevalence was significantly higher during the dry season (88.76%) than during the rainy (75.31%) and the transitional (20.29%) seasons. Oreochromis niloticus was not infected during the transitional season while Hemichromis fasciatus was more infected (p<0.001) during the dry season (26.84%) followed by the rainy (15.80%) and the transitional (10.32%) seasons. The high prevalence of myxosporeans infection may decrease the fish farming yield. The epidemiological data recorded help develop prevention and control strategies to boost the production of Oreochromis niloticus and Hemichromis fasciatus in Cameroon.

Combined effects of heavy metals and parasite infections on the haematological and biochemical profiles of wild rats from Awotan Municipal Dumpsite in Ibadan City

The combined effects of heavy metals and parasitic infections on wild rats from Awotan municipal dumpsite in Ibadan city southwest Nigeria were determined. A total of thirty rats were captured from the dumpsite and five rats from a control site using live traps. Rats were identified, weighed and body length measured to determine body condition index. Blood samples were collected from the rats using the cardiac puncture method. Rats were euthanized and dissected to extract various organs (kidney, liver and intestine). Intestinal helminths were extracted, identified and preserved. Blood parasites were identified using Giemsa staining technique of thick and thin films while intestinal helminths recovered were preserved and identified to species level. Organs, intestinal helminths and blood samples were digested and concentrated for heavy metals (Fe, Cu, Cr, Cd, and Pb) using Atomic Absorption Spectrophotometry (AAS). Cortisol level was determined using ELISA technique. All statistical significance was at probability value p < 0.05. Three species of rats were captured, Rattus rattus, Rattus novergicus and Cricetomys gambianus. The mean ± sd of the body condition index of the rats from dumpsite and control groups were 1.82±0.17 and 1.59± 0.38 respectively. There were significant differences in the mean values of eosinophils, platelets and white blood cell counts of rats from the two study sites. Overall parasite prevalence in dumpsite and control were 76.6% and 20% respectively. The overall prevalence of parasite species from dumpsite was in the order Hymenolepis diminuta (26.6%) >Monoliformis monoliformis (20%) >Plasmodium spp (20%) >Trypanosoma spp (10%). The mean concentration (mg/kg) of heavy metals in kidney, liver, intestine and blood of wild rats from both dumpsite and control decreased in the order Fe> Cr> Cu> Cd> Pb. Cortisol level was higher in infected rats from dumpsite (351±58.83ng/ml) than in uninfected rats from dumpsite (237.22± 44.46ng/ml), indicating exposure to immune stressors. A higher prevalence of parasitic infection, heavy metal pollution and the elevated cortisol concentrations in infected rats showed that the animals’ health and well-being are compromised.

Epidemiological and entomological studies of malaria transmission in Tibati, Adamawa region of Cameroon 6\xa0years following the introduction of long-lasting insecticide nets

BackgroundMalaria remains a serious public health problem in Cameroon. Implementation of control interventions requires prior knowledge of the local epidemiological situation. Here we report the results of epidemiological and entomological surveys carried out in Tibati, Adamawa Region, Cameroon, an area where malaria transmission is seasonal, 6 years after the introduction of long-lasting insecticidal bed nets.MethodsCross-sectional studies were carried out in July 2015 and 2017 in Tibati. Thick blood smears and dried blood spots were collected from asymptomatic and symptomatic individuals in the community and at health centers, respectively, and used for the molecular diagnosis of Plasmodium species. Adult mosquitoes were collected by indoor residual spraying and identified morphologically and molecularly. The infection status of Plasmodium spp. was determined by quantitative PCR, and positivity of PCR-positive samples was confirmed by Sanger sequencing.ResultsOverall malaria prevalence in our study population was 55.0% (752/1367) and Plasmodium falciparum was the most prevalent parasite species (94.3%), followed by P. malariae (17.7%) and P. ovale (0.8%); 92 (12.7%) infections were mixed infections. Infection parameters varied according to clinical status (symptomatic/asymptomatic) and age of the sampled population and the collection sites. Infection prevalence was higher in asymptomatic carriers (60.8%), but asexual and sexual parasite densities were lower. Prevalence and intensity of infection decreased with age in both the symptomatic and asymptomatic groups. Heterogeneity in infections was observed at the neighborhood level, revealing hotspots of transmission. Among the 592 Anopheles mosquitoes collected, 212 (35.8%) were An. gambiae, 172 (29.1%) were An. coluzzii and 208 (35.1%) were An. funestus (s.s.). A total of 26 (4.39%) mosquito specimens were infected by Plasmodium sp. and the three Anopheles mosquitoes transmitted Plasmodium at equal efficiency. Surprisingly, we found an An. coluzzii specimen infected by Plasmodium vivax, which confirms circulation of this species in Cameroon. The positivity of all 26 PCR-positive Plasmodium-infected mosquitoes was successively confirmed by sequencing analysis.ConclusionOur study presents the baseline malaria parasite burden in Tibati, Adamawa Region, Cameroon. Our results highlight the high malaria endemicity in the area, and hotspots of disease transmission are identified. Parasitological indices suggest low bednet usage and that implementation of control interventions in the area is needed to reduce malaria burden. We also report for the first time a mosquito vector with naturally acquired P. vivax infection in Cameroon.Graphical

Factors determining parasite abundance in European perch, Perca fluviatilis, European whitefish, Coregonus lavaretus, and Arctic charr, Salvelinus alpinus, in an oligotrophic lake, southern Norway

Time and spatial variations in macroparasite status were investigated in European perch, Perca fluviatilis, European whitefish, Coregonus lavaretus, and Arctic charr, Salvelinus alpinus in Lake Norsjø (Southern Norway), based on gillnet fishing in three locations in the spring, summer, and fall 2018. In addition, length, weigth, age, sex, δ13C, and δ15N were determined. Parasite abundance was modelled using negative binomial generalized linear models in relation to fish metrics, season, and sampling location. The most prevalent parasite species were determined by the diet and habitat of the host. European perch was mainly infected by acanthocephalans, European whitefish mainly infected by acanthocephalans and cestodes, and Arctic charr mainly infected by cestodes. The most prevalent parasites in European perch are transmitted by benthic animals. Parasites in European whitefish are transmitted by both benthic animals and copepods, while the most prevalent parasites in Arctic charr are copepod transmitted. This corresponds well with the δ13C signatures in the three species, indicating that European perch primarily fed in the littoral zone (δ13C: -24.9 ± 2.5 ‰), Arctic charr in the pelagic and profundal zone (δ13C: -29.4 ± 1.1 ‰), while European whitefish both fed in the littoral and pelagic zone (δ13C: -28.3 ± 2.3 ‰) of Lake Norsjø. Individual abundances of parasites depended on host age, length, sex, δ15N, and season. Positive correlations between parasite abundance and host age, length, or trophic level measured as δ15N were most common, and occurred in all three host species. Many parasites accumulate with age, and larger hosts provide more diverse habitats for parasites.

Compilation of 29 years of postmortem examinations identifies major shifts in equine parasite prevalence from 2000 onwards

Horses are infected by a wide range of parasite species that form complex communities. Parasite control imposes significant constraints on parasite communities whose monitoring remains, however, difficult to track through time. Postmortem examination is a reliable method to quantify parasite communities. Here, we compiled 1,673 necropsy reports accumulated over 29 years, in the reference necropsy centre from Normandy (France). The burden of non-strongylid species was quantified and the presence of strongylid species was noted. Details of horse deworming history and the cause of death were registered. Building on these data, we investigated the temporal trend in non-strongylid epidemiology and we determined the contribution of parasites to the deaths of horses throughout the study period. Data analyses revealed the seasonal variations of non-strongylid parasite abundance and reduced worm burden in race horses. Beyond these observations, we found a shift in the species responsible for fatal parasitic infection from the year 2000 onward, whereby fatal cyathostominosis and Parascaris spp. infection have replaced cases of death caused by Strongylus vulgaris and tapeworms. A concomitant break in the temporal trend of parasite species prevalence was also found within a 10 year window (1998–2007) that has seen the rise of Parascaris spp. and the decline of both Gasterophilus spp. and tapeworms. A few cases of parasite persistence following deworming were identified, which all occurred after 2000. Altogether, these findings provide insights into major shifts in non-strongylid parasite prevalence and abundance over the last 29 years. They also underscore the critical importance of Parascaris spp. in young equids.

Study on the Prevalence of Ectoparasitic Arthropods on Free Range Gallus domesticus in Two Communities in Awka

A survey was carried out to determine the prevalence of ectoparasitic arthropods in free range domestic fowl (Gallus domesticus) in Amansea and Ifite communities, in Awka Capital Territory, Anambra state. A total of 112 G. domesticus comprising of 42 Adult males, 30 adult females and 40 juveniles were examined during a house to house survey for ectoparasitic arthropods. The study was carried out between June and September, 2014. The domestic fowl were caught in their roosting places at night and were examined for ectoparasitic arthropod infestation. 73.21% prevalence of ectoparasitic arthropods on the chicken was recorded. Male adult chicken had higher prevalence of ectoparasitic arthropods than adult females and juvenile chicken. Six species of ectoparasitic arthropods namely; Argas persicus (29.46%), Menopon gallinae (23.21%), Dermanysus gallinae (16.07%), Lipeurus caponis (12.5%), Echidnophaga gallinacea (10.71%) Goniocotes gallinae (5.36%) were recovered from infested chicken. Argas persicus with the prevalence (29.46%) was the most prevalent parasite species. Amansea community had a higher prevalence of ectoparasitic arthropods than Ifite community. The difference was statistically significant (P<0.05). In conclusion, the present study has provided information on the various ectoparasitic arthropods of domestic chicken in Amansea and Ifite communities. There was no significant difference in the prevalence of ectoparasitic arthropods between the two communities. Therefore, further study is needed to determine the impact of infestation on the health and productivity of these birds, and evaluation of cost benefit of various control strategies need to be investigated.

Epidemiological Trends of Malaria in Eastern Shan State, Myanmar 2000-2016

Malaria is a priority communicable disease in Eastern Shan State (ESS) of Myanmar. This study aimed to describe the malaria situation, epidemiology and treatment services in ESS during 2000-2016. Data from township malaria monthly reports in ESS during 2000-2016 were analyzed by time, place, person, species and treatment services. Malaria morbidity, mortality and case-fatality rate decreased from 25.0 to 3.7 per 1,000 population, 15.0 to 0.2 per 100,000 population and 4.6% to 1.3%, respectively, during 2000-2016. The male to female ratio was 3:2 and those over 15 years old constituted 60% of all cases. The number of cases declined by 88% and 99% among those younger than 5 years of age and pregnant women, respectively. During 2011-2016, the case detection rate increased from 2% to 12%, and 94% of blood examinations used a rapid diagnostic test. Plasmodium vivax (63%) was the most prevalent parasite species, followed by Plasmodium falciparum (33%) while mixed parasites accounted for 4% of all infections. Non-government-controlled areas contributed more than 80% of cases between 2013 and 2016. Remarkable reductions in malaria morbidity and mortality in ESS followed improvements in early detection, appropriate treatment and effective vector control. However, the overwhelming contribution on caseload in non-government-controlled areas remain a challenge for the elimination of malaria in Myanmar.

Gastrointestinal parasite infestation in the alpine mountain hare (Lepus timidus varronis): Are abiotic environmental factors such as elevation, temperature and precipitation affecting prevalence of parasite species?

Information concerning factors regulating Alpine mountain hare (Lepus timidus varronis) populations such as host-parasite interactions is missing as only a few parasitological surveys exist of this subspecies. Parasites are not only dependent on their host but also on suitable environmental conditions for infestation. Abiotic environmental factors have an important regulating role on parasites in mammals. It is estimated that the elevation range of parasites is likely to shift in response to alternate host movement and changes in climate. Here we assess the parasitic infestation in the Alpine mountain hare by analysing the parasites in faeces and comparing the parasite infestation at different elevation ranges and at varied weather conditions for two years in the Austrian Alps. Almost half of the faecal samples were free of parasites (46.2%, n = 52). Most frequent was the infection by Coccidia (46.2%), whereas stomach intestine strongylids, Trichuris spp, and Cestoda were only found in 9.6% of all faeces. Hence, only Coccidia may be prevalent enough to regulate Alpine mountain hare populations in the Austrian Alps. Elevation had a significant positive effect on the infection of animals by Trichuris spp, whereas temperature had a significant negative effect on the infection by any parasite traceable in faeces and, when looking at the parasite groups individually, on Coccidia.

Helminth fauna of the screaming hairy armadillo Chaetophractus vellerosus from Argentina: the consequence of host isolation on parasite diversity

Chaetophractus vellerosus in Argentina has a north-west and central distribution. An isolated population is located in the east of the Buenos Aires province, separated from the population of central Argentina by about 500 km. We compared the component community of C. vellerosus between the main population in central Argentina and the isolated population, evaluating the impact of the host isolation on parasite diversity. Sixteen species of helminths were found, namely Ancylostoma caninum, Aspidodera fasciata, Aspidodera scoleciformis, Mazzia bialata, Pterygodermatites chaetophracti, Pterygodermatites argentinensis, Strongyloides sp., Trichohelix tuberculata, Cruzia tentaculata, Cyclobulura superinae, Delicata ransomi, Macielia jorgei, Moennigia celinae, Orihelia anticlava (Nematoda), Mathevotaenia sp. (Cestoda) and Travassosia sp. (Acanthocephala). Only the first 8 species, however, were present in both populations. Prevalences and intensities of the shared species were similar. The parasite community of the isolated population, however, was less rich and diverse than that of the main population. The poor parasite community in the isolated population could have several causes: the founding population was composed of few specimens that were only infected with the most prevalent parasite species and intermediate hosts for parasites with indirect cycles were absent. In addition, coexistence with another Chlamyphoridae would have contributed to maintaining a group of species that are usual in armadillos along their distribution.

Gill parasites of fish and their relation to host and environmental factors in two estuaries in northeastern Brazil

Fish parasites can be good indicators of the quality of water bodies, and their presence or absence can be interpreted as a sign of habitat changes, helping us to diagnose environmental problems. This study was conducted in two estuaries located in the Paraiba state, northeastern Brazil: Mamanguape, an environmental protection area, and Paraiba do Norte, a river with riverside communities along its length. The objective of the study was to determine whether host and abiotic characteristics predict the richness of fish gill parasites and/or the abundance of the most abundant and prevalent parasite species, the copepod Acusicola brasiliensis, testing the species as a possible bioindicator. The fish host species were Anchoa januaria, Atherinella brasiliensis, Mugil curema, and Rhinosardinia bahiensis. Generalized linear models were constructed to test the influence of predictor variables on parasite richness and A. brasiliensis abundance. The predictor variables used in the models were the host relative condition factor (Kn), host length, collection season (rainy or dry), estuary, host species, total phosphorus, and chlorophyll a. Both parasite species richness and A. brasiliensis mean abundance showed a significant relation to water quality parameters, suggesting their possible use as environmental quality indicators.

A Survey of Gopherus polyphemus Intestinal Parasites in South Florida.

Gopherus polyphemus populations are diminishing throughout their range due to urbanization, fragmentation, and poor habitat management. Increased population densities, poor habitat quality, and lack of fire may influence disease transmission. Parasite roles within wild tortoise populations are largely unknown; despite evidence these pathogens may pose significant health risks. This study provides a baseline of gopher tortoise intestinal parasites across South Florida and reports on how varying environmental and tortoise characteristics may affect intestinal parasite species prevalence and approximate loads. Tortoise fecal samples were taken from six tortoise populations across five South Florida sites. Seven species of intestinal parasites were discovered from 123 tortoises. Identified parasites include endohelminths such as cyathostomes, pinworms, ascarids, flukes, and protozoans including Eimeria, Cryptosporidium, and Amoeba species. Significant differences in parasite prevalence and loads were seen between sites, while parasitism among sex, size class, and habitat type remained relatively ubiquitous.

Human infection with Plasmodium knowlesi on the Laos-Vietnam border

BackgroundBorder malaria in the Greater Mekong region of Southeast Asia poses a serious threat to the health of the ethnic minority populations of the region. Traditionally thought to be caused primarily by the malaria parasites Plasmodium falciparum and Plasmodium vivax, recently a zoonotic parasite, Plasmodium knowlesi, has been identified in some countries of the region. The presence of this parasite poses a challenge to malaria control programmes, as it is maintained in a zoonotic reservoir of forest-dwelling macaque monkeys.MethodsA cross-sectional malaria parasite species prevalence survey was conducted along the Laos-Vietnam border in the central part of the two countries. Human blood samples were collected from Savannakhet in Laos and Quang Tri in Vietnam between August and October 2010 and assayed for the presence of human malaria parasite species and P. knowlesi. A PCR targeting the 18S small subunit ribosomal RNA gene and circumsporozoite protein gene was used for Plasmodium species identification.ResultsNine cases of P. knowlesi were detected by PCR in blood samples from the Laos side and three from the Vietnam side. All P. knowlesi infections were found in co-infection with P. vivax, with some triple infections of P. knowlesi, P. vivax and P. falciparum detected in Laos. Phylogenetic analysis of these parasites suggests that P. knowlesi is circulating in the Laos-Vietnam border region.ConclusionThis report shows that P. knowlesi is transmited on both sides of the Vietnam-Laos border. Continued monitoring of the range and prevalence of P. knowlesi on both the sides of Laos-Vietnam border is of importance to the National Malaria Control Programmes of both countries.

Exploring the diversity of Diplostomum (Digenea: Diplostomidae) in fishes from the River Danube using mitochondrial DNA barcodes

BackgroundMetacercariae of Diplostomum are important fish pathogens, but reliable data on their diversity in natural fish populations are virtually lacking. This study was conducted to explore the species diversity and host-parasite association patterns of Diplostomum spp. in a large riverine system in Europe, using molecular and morphological data.MethodsTwenty-eight species of fish of nine families were sampled in the River Danube at Nyergesújfalu in Hungary in 2012 and Štúrovo in Slovakia in 2015. Isolates of Diplostomum spp. were characterised morphologically and molecularly. Partial sequences of the ‘barcode’ region of the cytochrome c oxidase subunit 1 (cox1) and complete sequences of the nicotinamide adenine dinucleotide dehydrogenase subunit 3 (nad3) mitochondrial genes were amplified for 76 and 30 isolates, respectively. The partial cox1 sequences were used for molecular identification of the isolates and an assessment of haplotype diversity and possible host-associated structuring of the most prevalent parasite species. New primers were designed for amplification of the mitochondrial nad3 gene.ResultsOnly lens-infecting Diplostomum spp. were recovered in 16 fish species of five families. Barcoding of representative isolates provided molecular identification for three species/species-level genetic lineages, D. spathaceum, D. pseudospathaceum and ‘D. mergi Lineage 2’, and three single isolates potentially representing distinct species. Molecular data helped to elucidate partially the life-cycle of ‘D. mergi Lineage 2’. Many of the haplotypes of D. spathaceum (16 in total), D. pseudospathaceum (15 in total) and ‘D. mergi Lineage 2’ (7 in total) were shared by a number of fish hosts and there was no indication of genetic structuring associated with the second intermediate host. The most frequent Diplostomum spp. exhibited a low host-specificity, predominantly infecting a wide range of cyprinid fishes, but also species of distant fish families such as the Acipenseridae, Lotidae, Percidae and Siluridae. The nad3 gene exhibited distinctly higher levels of interspecific divergence in comparison with the cox1 gene.ConclusionsThis first exploration of the species diversity and host ranges of Diplostomum spp., in natural fish populations in the River Danube, provided novel molecular, morphological and host-use data which will advance further ecological studies on the distribution and host ranges of these important fish parasites in Europe. Our results also indicate that the nad3 gene is a good candidate marker for multi-gene approaches to systematic estimates within the genus.

Association of Anthropogenic Disturbances and Intestinal Parasitism in Ecuadorian Mantled Howler Monkeys, Alouatta palliata aequatorialis

Forest disturbance and human encroachment have the potential to influence intestinal parasite communities in animal hosts by modifying nutritional health, physiological stress, host densities, contact rates, and ranging patterns. Anthropogenic disturbances also have the ability to affect the ecological landscape of parasitic disease, potentially impacting the health of both wildlife and people. Our research investigated the association of forest disturbance and human encroachment on intestinal parasite communities in mantled howler monkeys, Alouatta palliata aequatorialis. We found that individual parasite species prevalence was associated with group size and forest disturbance. Proximity to people was not a direct factor influencing intestinal parasitism; rather, several human proximity indices were related to group size, which was in turn related to overall species richness and the presence of specific parasite species. These results, coupled with previous findings, suggest that anthropogenic disturbances are likely influencing intestinal parasite communities. Though no single study has definitively explained all relationships between anthropogenic disturbances and intestinal parasitism, we propose that our models are appropriate for meta-analysis testing across other species and environments.

DARC extracellular domain remodeling in maturating reticulocytes explains Plasmodium vivax tropism

AbstractPlasmodium vivax is the most prevalent parasite species that causes malaria in humans and exclusively infects reticulocytes. Reticulocyte infection is facilitated by P vivax Duffy binding protein (DBP), which utilizes DARC (Duffy antigen receptor for chemokines) as an entry point. However, the selective tropism of P vivax for transferrin receptor (CD71)-positive reticulocytes remained unexplained, given the constitutive expression of DARC during reticulocyte maturation. CD71/RNA double staining of reticulocytes enriched from adult peripheral blood reveals 4 distinct reticulocyte populations: CD71high/RNAhigh (∼0.016%), CD71low/RNAhigh (∼0.059%), CD71neg/RNAhigh (∼0.37%), CD71neg/RNAlow (∼0.55%), and erythrocytes CD71neg/RNAneg (∼99%). We hypothesized that selective association of DBP with a small population of immature reticulocytes could explain the preference of P vivax for reticulocytes. Binding of specific monoclonal anti-DARC antibodies and recombinant DBP to CD71high/RNAhigh reticulocytes was significantly higher compared with other reticulocyte populations and erythrocytes. Interestingly, the total DARC protein throughout reticulocyte maturation was constant. The data suggest that selective exposure of the DBP binding site within DARC is key to the preferential binding of DBP to immature reticulocytes, which is the potential mechanism underlying the preferential infection of a reticulocyte subset by P vivax.

English

The aim of this paper is to determine the prevalence of anti-HIV, anti-rubella antibodies, syphilis reagins and enteroparasitosis in pregnant women during their pre-natal monitoring at the Basic Health Units in the city of Umuarama (PR) and checking possible social-economic and behavioral associations. A cross-section study was performed in 690 pregnant women who went to have pre-natal checkup in the period from June 2012 to April 2014. From the 690 pregnant women analyzed, 78 presented enteroparasites, and from these, 69 were monoparasited and nine were polyparasited, nine presented antibodies against syphilis and two against HIV. None was reagent for IgM regarding rubella. The most prevalent parasite species was Endolimax nana 43/78 followed by Entamoeba coli 33/78 and Giardia duodenalis 05/78. Regarding the variables analyzed, the ones associated to enteroparasitary infections were water treated from public suppliers, fundamental level of schooling, sewage destination and public collection of garbage. For syphilis, the variables associated to infection were per capita income and age group. For HIV and rubella, no association among the variables was observed. The number of pregnant women infected in the present study was not considered high when compared to other studies. Key words: Pregnant women, prevalence, prevention, public health.