Species Of Helminth Parasites Research Articles

Gregariousness is associated with parasite species richness in a community of wild chimpanzees.

Increased risk of pathogen transmission through proximity and contact is a well-documented cost of sociality. Affiliative social contact, however, is an integral part of primate group life and can benefit health. Despite its importance to the evolution and maintenance of sociality, the tradeoff between costs and benefits of social contact for group-living primate species remains poorly understood. To improve our understanding of this interplay, we used social network analysis to investigate whether contact via association in the same space and/or physical contact measured through grooming were associated with helminth parasite species richness in a community of wild chimpanzees (Pan troglodytes schweinfurthii). We identified parasite taxa in 381 fecal samples from 36 individuals from the Kasekela community of chimpanzees in Gombe National Park, Tanzania, from November 1, 2006 - October 31, 2012. Over the study period, eight environmentally transmitted helminth taxa were identified. We quantified three network metrics for association and grooming contact, including degree strength, betweenness, and closeness. Our findings suggest that more gregarious individuals - those who spent more time with more individuals in the same space - had higher parasite richness, while the connections in the grooming network were not related to parasite richness. The expected parasite richness in individuals increased by 1.13 taxa (CI: 1.04, 1.22; p = 0.02) per one standard deviation increase in degree strength of association contact. The results of this study add to the understanding of the role that different types of social contact plays in the parasite richness of group-living social primates.

Helminths of the Black-Legged Kittiwake (Rissa tridactyla Linnaeus, 1758) and the Brünnich’s Guillemot (Uria lomvia Linnaeus, 1758) in Russkaya Gavan Bay, Severny Island, Novaya Zemlya Archipelago

This article provides results of a helminthological study of two seabird species, the Black-Legged Kittiwake (Rissa tridactyla Linnaeus, 1758) and the Brunnich’s Guillemot (Uria lomvia Linnaeus, 1758), from Russkaya Gavan Bay, Severny Island, Novaya Zemlya Archipelago. A total of five species of helminth parasites were identified in kittiwakes and six species in guillemots. The cestode Tetrabothrius erostris and the nematode Stegophorus stellaepolaris proved to be common helminth parasites for both seabird species. Two species, T. erostris and the acanthocephalan Corynosoma strumosum, were found for the first time in seabirds from Novaya Zemlya. Brunnich’s guillemot was recorded as a new definitive host for C. strumosum in the Barents Sea region. The main characteristic feature of the helminth infestation in birds from northern Novaya Zemlya is the absence of trematodes, endemic and highly specific parasite species, as well as helminths with freshwater life cycles. The prevalence of helminth parasites in kittiwakes and guillemots from different parts of the Barents Sea is analyzed. It has been established that the nematode S. stellaepolaris exerts the most pronounced negative impact on the physiological condition of Brunnich’s guillemots.

Zoonotic Helminthiases in Rodents (Bandicota indica, Bandicota savilei, and Leopoldamys edwardsi) from Vientiane Capital, Lao PDR.

Zoonotic helminths of three rodent species, Bandicota indiaca, Bandicota savilei, and Leopoldamys edwardsi, were investigated in Vientiane capital, Lao PDR. A total of 310 rodents were infected with 11 species of helminth parasites. There were 168 (54.2%) of 310 rodents infected with zoonotic helminths. From our results, there are six recorded zoonotic helminth species, and the highest prevalence was exhibited by Raillietina sp. (30.7%), followed by Hymenolepis diminuta (17.7%), Hymenolepis nana (2.6%), Echinostoma ilocanum (1.9%), Echinostoma malayanum (1.3%), and Angiostrongylus cantonensis (1%). This is the first study of zoonotic helminths in L. edwardsi and the first report of H. diminuta, H. nana, E. ilocanum, and E. malayanum in Bandicota indica and B. savilei, and the first demonstration of A. cantonenensis in B. indica in Lao PDR. From our results, these three rodents are potentially important reservoir hosts of zoonotic helminths. Thus, effective control programs should be considered for implementation to prevent the transmission of these zoonoses in this area.

Hydrolytic bacteria associated with natural helminth infection in the midgut of Red Sea marbled spinefoot rabbit fish Siganus rivulatus

Fish infected with intestinal helminths or pathogenic bacteria can pose a serious risk of foodborne disease, threatening human and animal health, and require high attention. The current study investigates the diversity and composition of the microbiota in the midgut of rabbit fish Siganus rivulatus naturally infected with helminths. Six species of helminth parasites, including the digeneans Hexangium sigani and Gyliauchen volubilis, the acanthocephalans Sclerocollum rubrimaris and Neorhadinorhynchus macrospinosus, and the nematodes Procammalanus elatensis, and Ascaridoid larvae were recorded in the fish intestine. P. elatensis had the highest prevalence, occurring in 65% of infected fish; 72.2% of infected fish had concurrent infection with two or more helminth species. The total count of aerobic bacteria ranged from 1 to 305 colony-forming units (CFU)/g midgut contents. Four hydrolytic bacteria were recovered from the infected samples: Escherichia coli (ASU 31), Bacillus cereus (ASU 36) MN955553, Bacillus thuringiensis (ASU 34) MN955550, and Novosphingobium aromaticivorans (ASU 35) MN955552, which were identified using 16S rRNA genes. Bacterial richness was significantly correlated with concurrent parasitic infection and high content of extracellular hydrolytic amylases, proteases, cellulases, and lipases. The present results showed that the composition of the microbiota was affected by natural helminth infections in Siganus rivulatus, and the significant interaction between parasitic load and intestinal pathogenic bacteria, which may be primary in fish diseases etiology.

The topology and drivers of ant-symbiont networks across Europe.

Intimate associations between different species drive community composition across ecosystems. Understanding the ecological and evolutionary drivers of these symbiotic associations is challenging because their structure eventually determines stability and resilience of the entire species network. Here, we compiled a detailed database on naturally occurring ant-symbiont networks in Europe to identify factors that affect symbiont network topology. These networks host an unrivalled diversity of macrosymbiotic associations, spanning the entire mutualism-antagonism continuum, including: (i) myrmecophiles - commensalistic and parasitic arthropods; (ii) trophobionts - mutualistic aphids, scale insects, planthoppers and caterpillars; (iii) social parasites - parasitic ant species; (iv) parasitic helminths; and (v) parasitic fungi. We dissected network topology to investigate what determines host specificity, symbiont species richness, and the capacity of different symbiont types to switch hosts. We found 722 macrosymbionts (multicellular symbionts) associated with European ants. Symbiont type explained host specificity and the average relatedness of the host species. Social parasites were associated with few hosts that were phylogenetically highly related, whereas the other symbiont types interacted with a larger number of hosts across a wider taxonomic distribution. The hosts of trophobionts were the least phylogenetically related across all symbiont types. Colony size, host range and habitat type predicted total symbiont richness: ant hosts with larger colony size, a larger distribution range or with a wider habitat range contained more symbiont species. However, we found that different sets of host factors affected diversity in the different types of symbionts. Ecological factors, such as colony size, host range and niche width predominantly determined myrmecophile species richness, whereas host phylogeny was the most important predictor of mutualistic trophobiont, social parasite and parasitic helminth species richness. Lastly, we found that hosts with a common biogeographic history support a more similar community of symbionts. Phylogenetically related hosts also shared more trophobionts, social parasites and helminths, but not myrmecophiles. Taken together, these results suggest that ecological and evolutionary processes structure host specificity and symbiont richness in large-scale ant-symbiont networks, but these drivers may shift in importance depending on the type of symbiosis. Our findings highlight the potential of well-characterized bipartite networks composed of different types of symbioses to identify candidate processes driving community composition.

Intestinal Helminth Infections, Compliance and Effectiveness of Albendazole Treatment among CDC Workers (18-45 Years) in Tiko, South-West Region, Cameroon

Intestinal helminthes infections are among the most prevalent of chronic human infections worldwide. These infections are common among people who work under very poor conditions most of the time without protective hand gloves, shoes and uniforms in the field. A cross-sectional study was done to determine the prevalence of intestinal helminthes among Cameroon Development Cooperation (CDC) workers and their compliance to anti-helminthic treatement form November 2017 to April 2018. It involved 102 workers aged18-45 years attending CDC cottage Hospital in Tiko. A cross-sectional study was done in which demographic data and data related to predisposing factors and preventive measures was collected using a simplified questionnaire, stool samples were collected pre and post treatement. Macroscopic and microscopic examination of stool samples was carried out in the hospital laboratory. Out of 102 people, a total of 81 (79.4%) people were infected with one or more species of intestitinal helminthes and there was significant difference in the infection with respect to various helminthes species (0.004). Among the 81 infected cases, 58(71.6%) were infected with single helminth species and 23 (28.4%) were infected with more than one species (coinfection). Intestinal helminths varied significantly among the participants with prevalences of 24.5% for T. trichuris, 6,9% for Hookworm, 0.9% for S. japanicum, 24.5% for S. haematobium, 34.3% for A. lumbricoides and 7.8% for S. mansoni (P<0.004). Out of the 40 participants who took the drug (albendazole), 32 (80%) came for retesting and disappointedly, 8 (20.00%) of the treated participants did not come. A majority of the 32 people retested were negative (28, 87.5%) for all species of intestinal helminth parasites, 4 (12.5%) still tested positive for the parasite presence in their stool among which 2 had schistosoma haematobium, one had schistosoma mansoni and one had Ascaris lumbricoides. Workers were recommended to wear protective hand gloves, and proper working shoes in line with their work description.

Parasitism in Gambusia affinis: Fitness Effects in an Incipient Matrotroph.

Gambusia affinis (western mosquitofish) serves as a host for a variety of larval and adult parasites. Gambusia affinis is also an incipient matrotroph, exhibiting adjustments in post-fertilization provisioning to some offspring within a brood using recently acquired resources. Nutrient transfer to embryos is expected to limit the loss of embryo mass during development resulting in larger offspring. Since larger offspring are more likely to survive, maternal contributions are expected to increase fitness. The presence of parasites, particularly intestinal helminths, potentially reduces body condition and resources available for developing offspring, thereby reducing host fitness. The effects of parasitism on the fitness of G. affinis were investigated in the present study. Fish were collected from 3 sites monthly from June 2015 through August 2016. All helminth parasites were collected during necropsy and identified. Brood size and embryo developmental stage were recorded for each female fish. Additionally, 10 ova/embryos of each developmental stage from each female fish collected from May through August 2016 were haphazardly selected and individually weighed. From 429 female mosquitofish, 5,072 helminths were collected. Brood size varied among collection sites and was positively influenced by maternal body condition, the number of daylight hours, water temperature, and the intensity of both plerocercoid and adult Schyzocotyle acheilognathi. However, brood size was negatively related to the intensity of Neoechinorhynchus cylindratus cystacanth and an increasing number of days between collection and dissection. Embryo weight increased with the presence of either Camallanidae or Contracaecum multipapulatum, embryo developmental stage, and relative host density. These results indicate that some parasitic helminth species negatively affect the fitness of G. affinis, while some positively affect fitness, and that effect can vary with intensity.

Prevalence and Intensity of Gastrointestinal Parasites in Donkeys in Selected Abattoirs in Kenya

The aim of this study was to determine the prevalence and intensity of gastrointestinal parasites in donkeys slaughtered in Kinamba, Mogotio, and Lodwar slaughterhouses and their association with several host factors. A survey was done between July and September 2017 in three slaughterhouses. Faecal samples were collected per rectum from all the study donkeys for faecal egg counts (EPG) and morphological identification of the eggs. At slaughter, the gastrointestinal tracts were opened and examined visually, and all helminth parasites collected were subjected to morphological identification. Prevalence and intensity were calculated based on the helminth identified and EPG. A total of 282 donkeys were sampled. A majority of the donkeys (89%) were in poor body condition. Ten helminth parasite species were identified in 85.5% donkeys. They were Strongylus vulgaris (52.8%), Parascaris equorum (20.2%), Strongylus edentatus (12.1%), Anaplocephala perfoliata (10.3%), Setaria equina (3.5%) Anaplocephala magna (2.5%), Cylicocyclus auriculatus (2.1%), Cyathostomum species (1.8%), Strongylus equinus (0.4%), and Triodontophorus serratus (0.4%). A significant percentage (55.3%) had no eggs in their feces, 39% had low infection, 5% had medium, and only 0.7% were heavily infected. Prevalence rates via use of the EPG showed Strongyles (44.7%), Parascaris equorum (5.3%), Oxyuris equi (11%), Triodontophorus tenuicolis (0.7%), Habronema species (0.7%), and cestodes eggs (0.4%). No significant differences were observed between fecal Strongylus egg count and age, sex, and pregnancy status. However, donkeys with poor body condition shed more Strongylus eggs in feces. Helminth infections are prevalent in donkeys in Kenya; however, this is not reflected in coprological analyses. These helminth parasites may contribute to poor body condition, ill health, and poor productivity of donkeys.

The hidden faces of a biological invasion: parasite dynamics of invaders and natives

One of the primary drivers of emerging infectious diseases (EIDs) is human intervention via host or parasite translocations. A unique opportunity to study host and parasite dispersal during a bio-invasion currently exists in Ireland due to the introduction of the bank vole (Myodes glareolus) in the 1920s. The continuing range expansion of M. glareolus within Ireland presents a natural large-scale perturbation experiment. This study used the Irish M. glareolus model to conduct a spatiotemporal study analysing the parasite dynamics of native and invasive species throughout their range. Myodes glareolus and native Apodemus sylvaticus were trapped in woodlands across Ireland and surveyed for their helminth parasites. Myodes glareolus in Ireland were found to have lower parasite diversity in comparison to records of M. glareolus from across Europe and A. sylvaticus in Ireland. Increased density of M. glareolus resulted in a dilution effect, with significantly lower levels of parasitism overall in native hosts, where M. glareolus has been established longest. However, three helminth parasite species of A. sylvaticus increased in abundance in the presence of M. glareolus. Furthermore, M. glareolus at the expansion front were less parasitised (lower abundance and prevalence of certain parasites and lower parasite diversity) than M. glareolus from the core population. This “enemy release” is believed to be mediating the continued successful spread of the invader across Ireland. Our results identify two important variables, seasonality and the stage of the invasion, which should not be overlooked when investigating or managing the changing distribution of hosts and their parasites. Studies of bio-invasions and parasite transmission have primarily focused on the invasive host species or the native host species in cases where virulent pathogen spillover is observed. Our results demonstrate how the concurrent study of invasive and native hosts, and the careful identification of their parasite communities, allows the dynamic processes influencing the parasite component and intracommunity to be identified.

Gastrointestinal Parasites of Sheep in Jember District (East Java – Indonesia)

Sheep is a ruminant livestock that has the most population in Indonesia and the highest distribution of maintenance in rural areas. Increasing livestock production, controlling factors and preventing diseases including parasites need attention, especially from the gastrointestinal parasite group. This study aims to identify the diversity of gastrointestinal parasites in sheep in Jember district. This research was conducted by randomly collecting 175 sheep faecal samples from various regions in Jember district. Identification of gastrointestinal parasite diversity by examining worm eggs in sheep faecal samples using sedimentation methods carried out at BBVet Wates (Veterinary Center). Based on the results of sheep feces examination in Jember, 84 samples (48,0%) were examined were infected with one or more gastrointestinal helminth parasites and (52,0%) obtained negative results. Gastrointestinal helminth parasites were found from the Trematode class: Paramphistomum sp., Cestode class: Moniezia sp., and nematode class consisting of Ostertagia sp., Trichostrongylus sp., Cooperia sp., Capillaria sp., Bunostomum sp., Strongyloides sp., Oesophagostomum sp., Trichuris sp., and Toxocara sp. with 56 samples were infected with at least one species and 28 samples were infected with two or more species of gastrointestinal helminth parasites which is useful information for future medication.

First study on the helminth community structure of the neotropical marsupial Metachirus myosuros (Didelphimorphia, Didelphidae).

Metachirus myosuros is a marsupial species widely distributed in South America. Despite this, there is a lack of knowledge about its helminth parasites and helminth community structure. The aims of this study were to describe the species composition and determine the parasitological parameters of helminth communities of M. myosuros in preserved areas of the Atlantic Forest, Igrapiúna, Bahia state, northeastern Brazil. Parasites were searched from 19 specimens of this marsupial (18 were infected with at least one species), counted and identified. Ten species of helminth parasites were obtained: 7 nematodes, 2 platyhelminths and 1 acanthocephalan. The most abundant species were Aspidodera raillieti, Cruzia tentaculata, Physaloptera mirandai and Viannaia conspicua (Nematoda). These species were also the only dominant ones in the component community. Male hosts had higher prevalence of P. mirandai and greater abundance of V. conspicua. We observed a relationship between host body size and helminth abundance in both male and female hosts, and between host body size and helminth species richness in female hosts. This was the first study to analyze the helminth fauna and helminth community structure of M. myosuros. This was the first report of occurrences of A. raillieti and Didelphonema longispiculata in M. myosuros.

A multiyear survey of helminths from wild saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarins.

The establishment of baseline data on parasites from wild primates is essential to understand how changes in habitat or climatic disturbances will impact parasite-host relationships. In nature, multiparasitic infections of primates usually fluctuate temporally and seasonally, implying that the acquisition of reliable data must occur over time. Individual parasite infection data from two wild populations of New World primates, the saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarin, were collected over 3 years to establish baseline levels of helminth prevalence and parasite species richness (PSR). Secondarily, we explored variation in parasite prevalence across age and sex classes, test nonrandom associations of parasite co-occurrence, and assess the relationship between group size and PSR. From 288 fecal samples across 105 individuals (71 saddleback and 34 emperor tamarins), 10 parasite taxa were identified by light microscopy following centrifugation and ethyl-acetate sedimentation. Of these taxa, none were host-specific, Dicrocoeliidae and Cestoda prevalences differed between host species, Prosthenorchis and Strongylida were the most prevalent. Host age was positively associated with Prosthenorchis ova and filariform larva, but negatively with cestode and the Rhabditoidea ova. We detected no differences between expected and observed levels of co-infection, nor between group size and parasite species richness over 30 group-years. Logistic models of individual infection status did not identify a sex bias; however, age and species predicted the presence of four and three parasite taxa, respectively, with saddleback tamarins exhibiting higher PSR. Now that we have reliable baseline data for future monitoring of these populations, next steps involve the molecular characterization of these parasites, and exploration of linkages with health parameters.

Helminth parasites occurrence in wild proboscis monkeys (Nasalis larvatus), endemic primates to Borneo Island.

Nasalis larvatus are well-known attraction for tourists in the mangrove forest of Bako National Park (BNP). Little is known regarding the infestation of helminth parasites in proboscis monkeys. Therefore, the objectives of this study are to determine the prevalence species of major helminth parasites of public health importance in proboscis monkeys in BNP. A total of 65 faecal samples screened for helminth parasites via sodium nitrate floatation and faecal sedimentation techniques. A total of 14 helminth parasite species comprising of eight genera of nematodes, two species of cestodes and two trematodes were identified. Eggs of Trichuris trichiura were the most frequently encountered in proboscis monkeys. This is the first survey on the fauna of helminth parasites of proboscis monkeys living in mangrove forests, and therefore, it implies the important baseline information that increases our current knowledge for future research regarding parasite-host ecology in primates.

Intestinal parasites in six Islamic medieval period latrines from 10th–11th century Córdoba (Spain) and 12th–13th century Mértola (Portugal)

ObjectiveTo investigate the types of intestinal parasites that infected people living in Islamic period southern Iberia (al-Andalus), and compare with other regions of Europe. MaterialsFour cesspits from 10th–11th century CE Córdoba (Spain), and two from 12th–13th century Mértola (Portugal). MethodsSediment from each cesspit was analyzed using digital light microscopy and enzyme-linked immunosorbent assay (ELISA). ResultsAnalysis revealed eggs of roundworm (Ascaris lumbricoides) in every cesspit analyzed, but no evidence of other species of helminth or protozoal parasites. ConclusionDifferences were noted between parasite species found in Mediterranean Europe and northern Europe, where a range of zoonotic parasites were endemic alongside sanitation-related parasites. We suggest that the scarcity of zoonotic parasites in southern Europe in the medieval period may reflect contrasts in climate between northern and southern Europe. SignificanceThe repeated identification of roundworm eggs suggests that al-Andalus was less hygienic than historically depicted. We did not note a difference between parasites found in Muslim and Christian regions of Iberia, and the predominance of parasites spread by fecal contamination of food is consistent with past research. LimitationsThe eggs of some species of parasite are fragile, so may theoretically have been present in the population but did not survive for us to identify them. Suggestions for further researchTo further investigate the role of climate upon the parasites that affected past human populations.

Tình hình nhiễm giun sán ở Cá Thia đầu sọc (Dascyllus reticulatus Richardson, 1846) và Cá Thia ba đốm trắng (Dascyllus trimaculatus Ruppell, 1829) khu vực vịnh Nha Trang, tỉnh Khánh Hòa

The survey was carried in Nha Trang bay, Khanh Hoa province from June to November 2018, a total of 275 samples of Dascyllus (155 individuals of D. reticulatus and 120 individuals of D. trimaculatus) were examined for parasites. The results identified 5 species of parasitic helminth: Haliotrema sp., Hysterolecitha nahaensis, Bivesicula sp., Hysterothylacium sp. and Contracaecum sp.. Of these, one species was found in the gills (Haliotrema sp.), two species (Hysterolecitha nahaensis, Bivesicula sp.) in the stomach and two species (Hysterothylacium sp., Contracaecum sp.) in the gut. Infested prevalence of Haliotrema sp. on D. trimaculatus was highest (70%) and prevalence of Bivesicula sp. on D. reticulatus. was the lowest (0.6%).

Helminth endoparasites of black drongo, Dicrurus macrocercus (Passeriformes: Dicruridae) from Chattogram, Bangladesh

The common passerine bird species of Bangladesh, the Black Drongo (Dicrurus macrocercus), was collected between November 2013 and March 2014 from paddy fields around the Chittagong University campus to study endohelminth parasites. In total, four helminth adult parasite species, one trematoda (Eumegacetes triangularis), one cestoda (Notopentorchis sp.), two nematoda (Viguiera dicrurusi and Diplotriaena bargusinica) and single unidentified pleurocercoid larva were evident from the body cavity and digestive tracts of the sampled birds. With prevalence, mean intensity and abundance of 52.94%, 3.33 ± 3.04 and 1.76, respectively. It was apparent that the nematodes were the most prevalent (41.18%) species and the male (60%) hosts were found to be more susceptible to infection with the helminths. The mean intensity and the abundance of male also followed the same trend. However, the maximum (100%) prevalence was in February 2014. Parasitic abundance was found to be dependent with total length (t = 40.19, p = 0.000), body length (t = 31.97, p = 0.000) and body weight (t = 39.88, p = 0.000) of the host. Among the identified helminths E. triangularis, Notopentorchis sp. and Diplotriaena bargusinica are the new records for Bangladesh and from the present host. Stomach contents showed that the bird is affirmed as insectivorous, predominant abundance of insect (97-100%) having an abundance gradient of lepidopteran > odonates > dipteran > coleopterans > hemipterans > hymenopterans. The present study coincided with the winter and spring season of an isolated study area, i.e. Chittagong University campus only. Therefore, a detailed study is expected to have a complete helminth profile and epidemiological aspects of the present host at different ecological areas of the country.
 Bangladesh J. Zool. 47(1): 159-171, 2019

The effect of water sources, nutritional qualities and management systems on the prevalence of gastrointestinal helminth infections in ruminants in Benue State, Nigeria

Parasitic helminth infections are a frequent burden to livestock farmers. In this study, some domestic ruminants were examined for gastrointestinal helminth infections at some locations in Benue State Nigeria. Six hundred faecal samples were collected per rectum from cattle, goat and sheep in Makurdi, Guma and Gboko. The faeces were analysed using Concentration Method, and direct microscopic examination of helminth parasites. Data were also obtained on the source of drinking water, feeding, and the management system used to keep the ruminants. The results showed that 43.7% of all animals were infected. The species of helminth parasites identified were Strongyloides spp. 74.8% Haemonchus spp., 11.8% while Monieza spp., Trichuris spp., Taenia spp., Fasciola spp., Ascaris spp., and Toxocara spp., constituted 13.4%. Helminths infection was associated with the type of animal (p = 0.01), the source of drinking water (p < 0.001), food, and the management system (p<0.001), but not the sampled locations (p = 0.98). It was concluded that improved management practices, provision of good quality food and clean drinking water significantly reduced the prevalence of gastrointestinal helminths infection in ruminants in Benue State, Nigeria. Keywords: gastrointestinal helminths, parasites, ruminants, livestock

Helminthic infection in three native rodent species from a semiarid Mediterranean ecosystem.

Helminth parasites are still not a well-known component of animal biodiversity. In this study, we describe and compare the endoparasite assemblages of three native rodent species from a semiarid Mediterranean ecosystem. A total of eight species of gastrointestinal helminth parasites were detected. The endoparasitic communities of the rodents Phyllotis darwini (5 species), Octodon degus (4 species), and Abrothrix olivaceus (3 species) were described in terms of their prevalence and mean abundance. In addition, endoparasite records by rodent species were submitted to rarefaction analyses to verify sampling robustness and used to compare richness and similarity among rodent species. O. degus presented the highest prevalence and parasitic load, but was of low diversity, while P. darwini presented the highest diversity, but had a low prevalence rate. Conversely, A. olivaceus presented the lowest prevalence and diversity. This study contributes to the existing knowledge of the endoparasitic fauna of rodent species from semiarid Mediterranean zones.

Gastrointestinal Helminth Parasites of Chicken under Different Management System in Mekelle Town, Tigray Region, Ethiopia.

The poultry industry is an infant but fast growing sector in Ethiopia. However, it is largely dependent on local chicken managed under backyard production system. The sector is facing different challenges, mainly emanated from prevalence of infectious diseases such as helminth parasite species. Hence, this study came up with an aim to determine the infection rate and identify helminth parasite species in chickens managed under different production systems, in Mekelle, Ethiopia. A cross-sectional study design was employed, from November 2015 to March 2016. Postmortem (N=138) and fecal (N=410) samples of chicken were considered for necropsy and coproscopic examination to see both adult and eggs of helminth parasites, respectively. Similar gastrointestinal helminth parasites infection rate of chicken was obtained from both examination approaches (necropsy, 90.60%; and coproscopy, 90.97%). The study attested high prevalence (87.7%) of mixed infection with helminth parasites of chicken. Heterakis gallinarum (72.5%) and Ascaridia galli (68.8%) were found as the most dominant species (necropsy). During coproscopic examination cestode (89%) infections showed a relatively higher prevalence than nematodes (84.4%), although no difference was observed during that of necropsy examination results. Chickens of local breed from backyard production system had shown more likelihood of getting helminth infection when compared with their corresponding relatives (coproscopy). However, the variation was not statistically significant during that of necropsy finding. Therefore, the higher prevalence of parasitism and mixed infection observed in the study area would warrant for an urgent intervention with regular deworming scheme, and strict attention should be given towards hygienic measures and other health related management activities.

Contrasting latitudinal gradients of body size in helminth parasites and their hosts

AbstractAimWe examined body size scaling relationships for two developmental life stages of parasitic helminths (egg and adult) separately in relationship to latitude (i.e. Bergmann's rule), temperature and temperature seasonality. Given that helminth eggs experience environmental conditions more directly, whereas adults live inside infected host individuals, we predict stronger environmentally driven gradients of body size for eggs than for adults.LocationGlobal.Time periodPresent day.Major taxa studiedParasitic helminths.MethodsWe compiled egg size and adult body size data (both minimum and maximum) for 265 parasitic helminth species from the literature, along with species latitudinal distribution information using an extensive global helminth occurrence database. We then examined how the average helminth egg and adult body size of all helminth species present (minimum and maximum separately) scaled with latitude, temperature and temperature variability, using generalized linear models.ResultsBoth the egg size and the adult body size of helminths tended to decrease towards higher latitudes, although we found the opposite body size scaling pattern for their host species. Helminth sizes were also positively correlated with temperature and negatively, but more weakly, with temperature seasonality.Main conclusionsInstead of following the body size patterns of their hosts, helminth parasites are more similar to other ectotherms in that they follow the converse Bergmann's rule. This pattern did not differ between helminth developmental stages, suggesting that mean annual temperature and seasonality are unlikely to be related mechanistically to body size variation in this case.