Prevalence of Mammomonogamus laryngeus(Strongylida:Syngamidae) nematodes in a bovine slaughterhouse

Introduction. Mammomonogamus laryngeus is a nematode parasite that is usually found in the larynx of mammals in the tropics, especially in cattle, sheep and cats. Objective. The prevalence of M. laryngeus was determined in cattle brought to an abattoir as an indicator of its prevalence in the general population. Materials and methods. The present study was undertaken in the municipality of La Tebaida, Quindio, Colombia, to determine the presence of M. laryngeus infection in cattle brought to a local abattoir between December and February 2009. The tracheae and lungs of 500 slaughtered cattle were examined. Results. Parasite prevalence was 14.8% (n=74). The majority of worms were located on aryteno-epiglottic folds, but never in the tracheae or bronchi. The infection rate was highest (47%) in 2 to 2.5 year old animals. In infected animals, an average of 6.4 parasite pairs was found, with higher numbers in older animals. The prevalence of infection in cattle was greater than seen in the provinces of Valle del Cauca (10.0%), Quindío(3,0%) pr Caquetá (1.2%). Conclusions. Reports of this parasite in cattle indicate its circulation throughout Colombia and recommend surveillance studies where cattle are raised and prepared for human consumption.     

Patterns of parasite abundance and distribution in island populations of Galápagos endemic birds

Parasite life-history characteristics, the environment, and host defenses determine variation in parasite population parameters across space and time. Parasite abundance and distribution have received little attention despite their pervasive effects on host populations and community dynamics. We used analyses of variance to estimate the variability of intensity, prevalence, and abundance of 4 species of lice (Insecta: Phthiraptera) infecting Galápagos doves and Galápagos hawks and 1 haemosporidian parasite (Haemosporida: Haemoproteidae) infecting the doves across island populations throughout their entire geographic ranges. Population parameters of parasites with direct life cycles varied less within than among parasite species, and intensity and abundance did not differ significantly across islands. Prevalence explained a proportion of the variance (34%), similar to infection intensity (33%) and parasite abundance (37%). We detected a strong parasite species-by-island interaction, suggesting that parasite population dynamics is independent among islands. Prevalence (up to 100%) and infection intensity (parasitemias up to 12.7%) of Haemoproteus sp. parasites varied little across island populations.     

Intensity of nematode infections in cyclic and non-cyclic rock partridge (Alectoris graeca saxatilis) populations

Populations of rock partridge (Alectoris graeca saxatilis), in the Trentino province of Italy, exhibit cyclic fluctuations in abundance associated with relatively dry habitat. One of the hypothesis to explain these cycles is that survival of some free living parasitic stages and rates of infection are greater in these areas leading to higher parasite burden. This hypothesis was examined by investigating the intensity of parasite infection in cyclic and non cyclic rock partridge populations. Analyses of 87 intestine samples collected from shot rock partridges during 1994 and 1995 identified 8 species of helminths parasites: Ascaridia compar (P = 33.33%; I = 9.28 +/- 1.78), Heterakis tenuicauda (P = 19.54%; I = 10.29 +/- 4.58), Heterakis gallinarum (P = 1.15%; I = 1.0 +/- 0.0), Heterakis altaica (P = 1.15%; I = 17 +/- 0.0), Aonchoteca caudinflata (P = 6.89; I = 2.17 +/- 0.65), Postharmostomum commutatum (P = 5.75; I = 7.0 +/- 3.48), Brachylaema fuscata (P = 1.15; I = 7.0 +/- 0.0), Platynosomum alectoris (P = 2.29; I = 5.5 +/- 1.5). Cestoda, recorded with a prevalence of 5.75, were not identified to species level. A. compar and H. tenuicauda were prevalent in the rock partridge populations and there was no positive association between these species. Intensity of infection in both species was not influenced by host age, sex or year of study but levels of infection with A. compar burdens were significantly greater in cyclic populations than in non cyclic populations and there was a tendency for H. tenuicauda to be greater in cyclic populations. There was no negative relationship between intensity of infection with A. compar or H. tenuicauda and host body mass. These data provide some support for the hypothesis that these parasites may play a role in generating rock partridge population cycles.     

Populations of Lamproglena pulchella von Nordmann 1832 (Copepoda: Eudactylinidae) in cyprinid fish in rivers with different pollution levels

A total of 512 chub ( Leuciscus cephalus L.) individuals sampled from four rivers with different pollution levels were examined for Lamproglena pulchella (von Nordmann 1832) prevalence and mean intensity. As a result of the L. pulchella mode of reproduction, the parasite populations showed a significant degree of aggregation. The results, excluding the effect of fish health conditions on the parasite infection, provide evidence of the influence of water quality on parasite prevalence. Parasite density increase in relation to fish length and age suggests a dependence of infection intensity to the exposure time on the fish.     

Field and laboratory studies of Ophryoglena sp. (Ciliata: Ophryoglenidae) infection in zebra mussels,Dreissena polymorpha (Bivalvia: Dreissenidae)

This study, conducted in the Dnieper-Bug Canal in Belarus, is the first to monitor the seasonal (June-November) dynamics of infection with the parasitic ciliate Ophryoglena sp. in a zebra mussel (Dreissena polymorpha) population. Mean population prevalence and intensity of infection varied, respectively, from 11 to 62% and from 0.9 to 24.1 ciliates/mussel. Mean prevalence was highly correlated with mussel length in mussels <20 mm (R(2)=0.97) and was lower in larger mussels. Mean infection intensity in mussels 1-25 mm long was similarly correlated with their size (R=0.98), reached a maximum in the 20-25 mm size-class, and then sharply decreased, thus providing evidence, albeit limited, that high intensity of infection might be lethal. Transinfection of zebra mussels by Ophryoglena sp. was achieved in the laboratory-a first for a protozoan parasite of D. polymorpha; from an initial complete lack of infection, mean prevalence and intensity rose, respectively, to 86.7% and 8.3 ciliates/mussel.     

Temporal changes in the prevalence of parasites in two Oregon estuary-dwelling fishes

The parasite faunas of juvenile English sole (Parophrys vetulus) in 1971-1972 and staghorn sculpin (Leptocottus armatus) in 1971 from Yaquina Bay, Oregon, were compared with faunas found in the same estuary in 1997-2000 (English sole) and 1999-2000 (staghorn sculpin). The 7 most commonly occurring parasites in 1971 were compared with the same species observed during the same month and sampling sites in 1997-2000. Multivariate community analysis of juvenile English sole parasites supported the suggestion that the 1971 parasite data were representative of the early-1970s time period. Four of the parasite species infecting English sole and 6 of those infecting staghorn sculpins had significantly lower prevalences in 1997-2000. Parasite species with significantly lower prevalences also had reduced intensity levels. One parasite (Glugea stephani) of English sole increased in prevalence in the 1997-2000 samples in association with the warm estuarine temperatures during the 1997 El Ni?o year. Although the causes for the changes in occurrence of other parasites were not determined, ecological changes in Yaquina Bay that may have influenced parasite ecology include apparent changes in the estuary ichthyofauna that occurred between the sampling periods. Such changes could be associated with increases in the number of California sea lions (Zalophus californianus) subsequent to establishment of the Marine Mammal Protection Act in 1972.     

Aspects of the ecology and natural history of Paraergasilus rylovi (Copepoda, Ergasilidae) parasitic in unionids of Finland

The distribution of Paraergasilus rylovi in 17 populations of unionids was investigated. In 1 unionid population, the parasite was studied regarding host age, size, sex, and the reproductive period (occurrence of egg sacs). Results from pooled material from the years 1987--1989 and 1996 (southern Finland, 11 populations) indicated that Anodonta piscinalis (n = 1,359) is the main host (total mean prevalence 71% and intensity +/-SE of infection 16.4+/-0.6). Pseudanodonta complanata (n = 106) was infected occasionally (3% and 1.3+/-0.3), whereas Unio pictorum (n = 108) and U. tumidus (n = 17) were not infected. Results from 17 A. piscinalis populations showed that P. rylovi occurs in southern Finland but not in northern Finland. In A. piscinalis, the mean intensity of infection was higher in lake populations than in river populations. Both host age and length had a negative relationship with the intensity of P. rylovi infection. Host sex did not affect the intensity of infection. Egg sacs of P. rylovi were found from June to August. There was a tendency for higher intensities of infection in autumn. Infection by the digenean Rhipidocotyle fennica had no effect on the intensity of P. rylovi infection.     

Relationship between bronchopulmonary nematode larvae and relative abundances of Spanish ibex (Capra pyrenaica hispanica) from Castilla-La Mancha, Spain

The excretion of bronchopulmonary nematode infective larvae was evaluated in 160 faecal samples of Spanish ibex (Capra pyrenaica hispanica) collected from 13 populations in Castilla-La Mancha, south-central Spain in September 2003. Intensities and prevalences were compared with pasture availability, abundances of wild and domestic ungulates at both levels, i.e. for populations and for faeces in a two-step procedure. Protostrongylid larvae showed similar infection rates (mean intensity: 1.56+/-0.12, n=94; mean prevalence: 25.62+/-6.86%, n=160) to Dictyocaulus spp. (mean intensity: 1.03+/-0.11, n=48; mean prevalence: 30.00+/-7.11%, n=160). At the population level, positive correlations were found between the prevalences of both bronchopulmonary taxa. The prevalence in both groups, but not intensity, also correlated positively with Spanish ibex abundance indexes both for the populations and individual faeces. These findings suggest that: (i) parasite spreading across Spanish ibex populations in Castilla-La Mancha could respond to host density-dependent processes; and (ii) these populations may have similar exposition and/or susceptibility to both bronchopulmonary taxa resulting in similar host-parasite patterns, despite their different life cycles. Bronchopulmonary outputs in the Spanish ibex from Castilla-La Mancha seems not to represent a health risk for this endemic wild ungulate but may be useful in any health surveillance scheme for the increasing populations of Spanish ibex.     

Soboliphyme baturini infection does not affect the nutritional condition of American marten (Martes americana) in Alaska

Soboliphyme baturini, a stomach-dwelling nematode of American martens (Martes Americana), reaches high levels of infection; however, its effects on the nutritional condition of the host are unknown. To understand the effects of this parasite on American martens, we collected S. baturini and measured abdominal fat deposits from 155 marten carcasses on Prince of Wales Island, southeastern Alaska, in the winter 2006-2007. We analyzed how the dried mass of abdominal fat varied as a function of S. baturini intensity. Parasite intensity and nutritional condition were not correlated; these results suggest that American martens were able to withstand even very high levels of S. baturini infection (up to 178 parasites per host).     

Seasonal and biogeographical patterns of gastrointestinal parasites in large carnivores: wolves in a coastal archipelago

Parasites are increasingly recognized for their profound influences on individual, population and ecosystem health. We provide the first report of gastrointestinal parasites in gray wolves from the central and north coasts of British Columbia, Canada. Across 60 000 km(2), wolf feces were collected from 34 packs in 2005-2008. At a smaller spatial scale (3300 km(2)), 8 packs were sampled in spring and autumn. Parasite eggs, larvae, and cysts were identified using standard flotation techniques and morphology. A subset of samples was analysed by PCR and sequencing to identify tapeworm eggs (n=9) and Giardia cysts (n=14). We detected ≥14 parasite taxa in 1558 fecal samples. Sarcocystis sporocysts occurred most frequently in feces (43·7%), followed by taeniid eggs (23·9%), Diphyllobothrium eggs (9·1%), Giardia cysts (6·8%), Toxocara canis eggs (2·1%), and Cryptosporidium oocysts (1·7%). Other parasites occurred in ≤1% of feces. Genetic analyses revealed Echinococcus canadensis strains G8 and G10, Taenia ovis krabbei, Diphyllobothrium nehonkaiense, and Giardia duodenalis assemblages A and B. Parasite prevalence differed between seasons and island/mainland sites. Patterns in parasite prevalence reflect seasonal and spatial resource use by wolves and wolf-salmon associations. These data provide a unique, extensive and solid baseline for monitoring parasite community structure in relation to environmental change.     

Mixed infection by tick-borne encephalitis virus and Borrelia in ticks

To investigate the relationships between tick-borne encephalitis (TBE) virus and the bacterial spirochaete Borrelia burgdorferi sensu lato in vectors with mixed infections, unfed adult Ixodes persulcatus ticks were collected by flagging from vegetation in southern-taiga forests of the Pre-Urals region of Russia where both infections circulate sympatrically. Prevalences of TBE and Borrelia infections in a total of 4234 ticks were compared over 5 years. No significant differences were revealed between the prevalence of Borrelia infection in ticks with and without TBE virus (29.4+/-7.8% vs 23+/-3.6%), or between the prevalence of TBE virus infection in ticks with and without Borrelia (24.0+/-6.6% vs 18.4+/-3.4%). In ticks with mixed infection (40/689 = 5.8%), concentrations of TBE virus and Borrelia were not significantly correlated with one another. Field observations showed parallel trends in the prevalence of these pathogens in tick populations from year to year (1993-1997) indicating that, in I. persulcatus with mixed infection, Borrelia and TBE virus do not seem to interfere with each other and are apparently not involved in any antagonistic relationships.     

Parasite Prevalence Corresponds to Host Life History in a Diverse Assemblage of Afrotropical Birds and Haemosporidian Parasites

Avian host life history traits have been hypothesized to predict rates of infection by haemosporidian parasites. Using molecular techniques, we tested this hypothesis for parasites from three haemosporidian genera (Plasmodium, Haemoproteus, and Leucocytozoon) collected from a diverse sampling of birds in northern Malawi. We found that host life history traits were significantly associated with parasitism rates by all three parasite genera. Nest type and nest location predicted infection probability for all three parasite genera, whereas flocking behavior is an important predictor of Plasmodium and Haemoproteus infection and habitat is an important predictor of Leucocytozoon infection. Parasite prevalence was 79.1% across all individuals sampled, higher than that reported for comparable studies from any other region of the world. Parasite diversity was also exceptionally high, with 248 parasite cytochrome b lineages identified from 152 host species. A large proportion of Plasmodium, Haemoproteus, and Leucocytozoon parasite DNA sequences identified in this study represent new, previously undocumented lineages (n = 201; 81% of total identified) based on BLAST queries against the avian malaria database, MalAvi.     

Seasonal occurrence of Opechona pyriforme metacercariae (Digenea: Lepocreadiidae) in Eirene tenuis medusae (Hydrozoa: Leptothecata) from a hypersaline lagoon in western Gulf of Mexico

Seasonal occurrence of Opechona pyriforme metacercariae in the Eirene tenuis population from Laguna Madre, Mexico was analyzed in zooplankton samples collected in October 1997 and January, May, and July 1998. Eirene tenuis medusae were present in May, July, and October, although parasites were found only in October and July samples. Host population density was positively correlated with both surface water temperature and salinity. Total sample prevalence was 3.74%, mean abundance of the parasite was 0.06, and intensity of infection ranged between 1 and 59 metacercariae/host. Prevalence differed significantly among seasons, while intensity of infection did not. Parasite distribution was found to be highly aggregated. Although O. pyriforme infected hydromedusae of all sizes, prevalence was higher in sizes above 2.11 mm umbrella diameter. Additionally, a tendency towards increasing intensity of infection values with increasing umbrella diameter of medusae was observed. This is the first record of E. tenuis as a second intermediate host of O. pyriforme, as well as the first record of this helminth in the Gulf of Mexico.     

Observations on myiasis by the calliphorid,Bufolucilia silvarum,in the eastern American toad (Bufo americanus americanus) from southeastern Wisconsin

Larvae of certain species of blowflies (Calliphoridae) cause myiasis in amphibians which may result in significant mortality, yet there are few reports from North America. In this study, we observed primary myiasis in a population of juvenile eastern American toads (Bufo americanus americanus) collected during May-July 1998 from southeastern Wisconsin (USA). Nine (6%) of 140 toads were infected by the green blow fly (Bufolucilia silvarum) with a mean intensity of 10.5 +/- 7.2 (range = 1-24). Weekly parasite prevalence and mean intensity remained low, ranging from 0-20% and 2 +/- 1.4 to 14 +/- 6, respectively. We found: 1) flies lay eggs on healthy toads, 2) eggs hatch with first instar maggots penetrating under the skin, 3) maggots develop to mature third instars within 5-7 days, 4) maggots leave the host and form pupa within 8-11 days of hatching, and 5) maggots pupate within 7-9 days at room temperature. All infected toads died within 1-2 wk as a result of the infection. The low prevalence observed in this study and other reports of this species from mammalian and bird carcasses indicated that B. silvarum is probably a facultative parasite of toads and other amphibians in the United States. This is the first report of B. silvarum causing myiasis in Wisconsin amphibians and the first report in eastern American toads in the United States.     

Effects of social status and stress on patterns of gastrointestinal parasitism in wild white‐handed gibbons (Hylobates lar)

Although gibbons (family Hylobatidae) are typically monogamous, polyandrous groups occur regularly. Stress associated with elevated intragroup competition among males in polyandrous groups may increase susceptibility to infectious disease. To better understand this interplay, as well as to provide the first comprehensive assessment of parasitism in free‐ranging gibbons, we characterized the richness of gastrointestinal parasites and examined their prevalence in males from 14 groups (10 pair‐living, 4 multi‐male) of white‐handed gibbons (Hylobates lar) at Khao Yai National Park, Thailand. From September 2008 to May 2009, 324 fecal samples were collected from 23 individually recognizable male gibbons and screened for gastrointestinal helminths and protozoa after isolation via fecal floatation, sedimentation, and immunofluorescent antibody detection. A total of 10 parasite species recovered, including seven nematodes, two protozoans, and one trematode. Parasite richness and species‐specific prevalence were examined relative to social organization (pair‐living vs. multi‐male), male status (primary vs. secondary), age (subadult, adult, senior), fecal glucocorticoid levels, and time of the year. No relationship was found between parasite richness and sociodemographic or physiological factors. Similarly, prevalence of infection with parasite species was not associated with the majority of sociodemographic factors; however, Ternidens sp. and Balantidium coli varied seasonally and Trichuris sp. decreased with increasing age. Moreover, observational data suggest that competition is low in this gibbon population, and our findings are consistent with those observations in that cooperative defense may offset stress and reduce susceptibility to infection. Am J Phys Anthropol 150:602–608, 2013. © 2013 Wiley Periodicals, Inc.     

Cystidicola farionis as a swimbladder parasite of the whitefish in the Bothnian Bay

Material comprising 3167 specimens of the parasite Cystidicola farionis was assembled from 1741 individuals of the sea-spawning whitefish, Coregonus nasus in the shallow northeastern and deeper central areas of the Bothnian Bay. Occasional parasites were found in the immature fish (≦ 175 mm), but infection increased in the two larger classes as the fish aged, reaching 27% in the northeastern area, and as much as 67% in the southern area. This difference is explained partly by the more frequent feeding on Pontoporeia affinis , the intermediate host for the parasite, the deeper waters extending nearer the coast in the majority of the central and southern Bothnian Bay. The increased intensity of infection with age does not vary significantly between the areas studied. No clear seasonal fluctuations in the prevalence or intensity of infection could be found.     

Effects of fishing on parasitism in a sparid fish: contrasts between two areas of the Western Mediterranean

This study addressed the impacts of fishing on the rates of parasitism using the sparid Boops boops as a model fish species. Using a large suite of parasite species in B. boops, with different life histories, transmission pathways and host specificity, we compared parasite diversity, prevalence, abundance and community structure at two Mediterranean localities in the Balearic Sea, Santa Pola Bay and the Gulf of Oran, that are characterised by a contrasting pattern of fishing of B. boops. A total of 360 fish were examined comprising nine distinct samples collected during the warm and the cold weather months. A total of 29 parasite species were identified, with eight species in common for the two localities. Parasite component communities at Santa Pola Bay were more species rich and abundant than those at the Gulf of Oran and exhibited a different community structure. Of the eight common taxa used in the quantitative comparisons, five exhibited significant difference for prevalence between the two localities, four having substantially higher prevalence at Santa Pola and only one being more prevalent at the Gulf of Oran. Two specialist trematodes and the sparid generalist monogenean exhibited consistently higher prevalence and abundance at Santa Pola Bay than at the Gulf of Oran; the two specialists were also identified as key species for assigning individual fish to their locality of origin. The consistent differences in the richness, abundance and structure of parasite communities in B. boops from Santa Pola Bay and the Gulf of Oran may reflect the contrasting patterns of exploitation of the populations of this fish host at the two localities.     

Spatial variability in digenean metacercariae infection of 0-group common sole Solea solea among nurseries along the French Atlantic coast

We sampled 0-group sole juveniles (N = 174) in September and October 2003 in 9 major nurseries located along the French Atlantic coast (English Channel and Bay of Biscay). 0-group sole were infected with 3 genera of digenean metacercariae, Timoniella spp. (Acanthostomidae), Prosorhynchus crucibulum and Prosorhynchus sp. A (Bucephalidae), Podocotyle sp. (Opecoelidae), and an unidentified species of Digenea. Parasite infection levels in the English Channel nurseries were lower, and the community composition was different from Bay of Biscay nurseries. We hypothesize that the difference between geographic areas was due to differences in first intermediate host communities and, to a lesser extent, because of lower temperatures in the English Channel compared to the Bay of Biscay. For the Bay of Biscay nurseries, mean total parasite abundance was strongly negatively correlated with mean annual river flow. This relationship may be the result of the more upstream location of 0-group sole nurseries in estuaries so that fish were further from local points of parasite transmission than those in embayed nurseries. Digenean metacercariae load may be influenced by 3 major local factors, i.e. abundance and proximity of the first intermediate hosts and cercariae dispersal capacities.     

Reconstructing the spread of Dirofilaria immitis in California coyotes

Dirofilaria immitis is a filarial nematode parasite that is currently widely enzootic in dog and coyote (Canis latrans) populations of California. Weak historical evidence suggests that the initial focus of D. immitis in California occurred 3 decades ago in the Sierra Nevada foothills (SNF) and spread to other parts of California thereafter. However, this hypothesis is difficult to evaluate because of the lack of epidemiological studies on heartworm in California before 1970. We investigated this hypothesis by comparing D. immitis prevalence in coyotes between initial (1975-1985) and current (2000-2002) surveys in the SNF and 2 coastal regions. In the SNF, prevalence of heartworm was not significantly different between initial (35%, n = 169) and current (42%, n = 60) surveys (P = 0.17), suggesting the existence of a stable enzootic focus in the initial survey period. In contrast, current prevalence was 4 times higher than initial prevalence in the northern Coast Range foothills (44 vs. 10%; n = 119, 107; P < 0.001) and in the south San Francisco Bay foothills (32 vs. 8%; n = 31, 59; P = 0.005), suggesting that initial surveys were made during the early stages of colonization. Dirofilaria immitis prevalence, intensity, and abundance was similar in a coastal location in Mendocino County between 1994-1996 and 1999-2002, suggesting some degree of stability in this enzootic focus. Collectively, these findings support the hypothesis that D. immitis established itself initially in California coyotes living in the SNF and subsequently expanded its range of enzootic foci in central California.     

Phenology of recruitment and infection patterns of Ascocotyle pachycystis, a digenean parasite in the sheepshead minnow, Cyprinodon variegatus

In northwest Florida, Cyprinodon variegatus are parasitized by Ascocotyle pachycystis, a digenean parasite that forms metacercarial cysts in the lumen of the bulbus arteriosus. Field experiments revealed that fish accumulated parasites at an uneven rate within the highly seasonal trematode recruitment period. Older (= larger) fish had higher rates of parasite recruitment and higher parasite prevalences and densities (numbers of metacercariae per individual fish) than did younger (= smaller) fish. Nearly all adults were parasitized (prevalence range 70-100%), and parasite densities ranged from zero to 6800 per fish. Parasite distributions were clumped (= aggregated) in fish of all age classes but were less heterogeneous in early juveniles and adults than they were in late juveniles. Parasites affected the population dynamics of sheepshead minnows by causing reduced winter survivorship, as evidenced by an increase in the average size of fish and a decrease in the average infection intensity over the winter. This revised version was published online in July 2006 with corrections to the Cover Date.