Pomphorhynchus laevisin its intermediate hostEchinogammarus stammeriin the River Brenta, Italy

1999 ◽  
Vol 73 (2) ◽  
pp. 95-102 ◽  
Author(s):  
B.S. Dezfuli ◽  
E. Rossetti ◽  
C.M. Bellettato ◽  
B.J. Maynard

Infection rates of larvalPomphorhynchus laevisMu¨ller, 1776 (Acanthocephala) were studied in its intermediate hostEchinogammarus stammeriS. Karaman, 1931 (Amphipoda). Crustaceans were collected monthly, from July 1990 to July 1997, at two sites on the River Brenta (northern Italy). Of over 50,000E. stammeriexamined, more than 24% were parasitized withP. laevislarvae. The differences in the prevalence of infection between the two stations were significant. The intensity of infection varied from one to 15 acanthocephalans per host. Amphipods with multiple infections constituted 28–32% of each monthly sample. During the 7 years of investigation, the prevalence of infection typically reached its highest and lowest levels in the summer and spring months, respectively. Acanthocephalan larvae showed no preference for host sex. Infected ovigerous females ofE. stammeriwere found carrying eggs or juveniles in their brood pouches, but had fewer and smaller eggs.Pomphorhynchus laevislarvae co-occurred withAcanthocephalus clavula(Dujardin, 1845) and also with the tapewormCyathocephalus truncatus(Pallas, 1781) in the same host.

1991 ◽  
Vol 65 (1) ◽  
pp. 1-7 ◽  
Author(s):  
J. de Bont ◽  
J. Vercruysse ◽  
D. van Aken ◽  
V. R. Southgate ◽  
D. Rollinson

ABSTRACTInfectivity and cercarial production of Indoplanorbis exustus related to variation of miracidial dose (1, 4, 10 or 20) with Schistosoma nasale and S. spindale from Sri Lanka were studied. The intermediate host-parasite relationships of the two schistosome species showed marked differences under the conditions of observation recorded in this study. Prepatent death rates (PDR) were on average higher for S. spindale (30%) than for S. nasale (10%). The size of the miracidial dose to which snails had been exposed had no effect on PDR. The infection rates (IR) were on average higher for S. nasale (41%) compared with S. spindale (27%). Highest IR occurred after exposure to 4 miracidia in S. nasale infections (79%) and after exposure to 10 miracidia in S. spindale infections (6O%). The highest daily average cercarial production per snail was recorded for S. nasale at a level of 4 miracidia (1311), and for S. spindale at a level of 10 miracidia (1615). At low level (1 or 4 miracidia) of exposure, I. exustus showed a better compatibility with S. nasale than with S. spindale. An opposite tendency was observed at higher levels (10 or 20 miracidia) of exposure. Unsuccessful infections of Lymnaea luteola with either S. nasale or S. spindale indicate that this species is not involved in transmission.


Parasitology ◽  
1974 ◽  
Vol 68 (2) ◽  
pp. 271-284 ◽  
Author(s):  
A. E. Rumpus ◽  
C. R. Kennedy

The respiration rates of individual Gammarus pulex infected by larval Pomphorhynchus laevis were investigated with particular reference to the stage of development of the host and parasite and to the water temperature. At 20°C the oxygen consumption of Gammarus of all sizes was reduced by an average of 19·3 % by the presence of cystacanths of the parasite, but was unaffected by the presence of acanthellae. It is considered that the small size of this larval stage, in relation to that of its host, is responsible for the failure to detect an effect. Multiple infections did not exert any greater effect upon host respiration than single cystacanths, nor did it appear that the parasite had different effects upon hosts of different sexes. At 10°C no significant differences were observed between the respiration rates of infected and uninfected gammarids. The parasite was probably still depressing the host respiration rate at this temperature, but the oxygen uptake of G. pulex is so low that the differences between infected and uninfected individuals were too small to be detected. The parasite has a direct effect upon the physiological processes of the host, but neither the mechanism of this nor the reasons for the different effects found in different host-parasite systems are yet understood. Despite the pronounced effect of P. laevis on respiration of individual hosts, its effect upon the oxygen consumption of a natural host population is small since only a small proportion of the population carries infections and water temperatures remain below 10°C for over half the year.


2006 ◽  
Vol 80 (4) ◽  
pp. 369-375 ◽  
Author(s):  
A. Maldonado Júnior ◽  
R. Gentile ◽  
C.C. Fernandes-Moraes ◽  
P.S. D'Andrea ◽  
R.M. Lanfredi ◽  
...  

AbstractThe water ratNectomys squamipesis endemic in Brazil and found naturally infected withSchistosoma mansoni. Helminth communities, their prevalences, intensity of infection and abundance inN. squamipesin an endemic area of schistosomiasis in the state of Rio de Janeiro, Brazil were studied. Four species of nematodes (Physaloptera bispiculata, Syphacia venteli,Hassalstrongylus epsilonandLitomosoides chagasfilhoi) were recovered in 85.3%, two trematodes (Schistosoma mansoniandEchinostoma paraensei) in 38.8% and one cestode species (Raillietinasp.) in 1.7% of rats examined. Rats were infected with up to five helminth species each, and these were highly aggregated in distribution. ForH. epsilonandS. venteli, intensities and abundances were higher in adult male and subadult female hosts, respectively.Hassaltrongylus epsilon,P. bispiculata,S. venteliandS. mansoniwere classified as dominant species,L. chagasfilhoiandE. paraenseias co-dominant andRaillietinasp. as subordinated. No significant correlation was found in the intensity of infecton between each pair of helminth species.Schistosoma mansoniwas not related to any other helminth species according to their infection rates, althougthS. mansoniwas well established in the natural helminth comunity of the water rat.


2008 ◽  
Vol 82 (1) ◽  
pp. 81-84 ◽  
Author(s):  
E.A. Mendes ◽  
W.S. Lima ◽  
A.L. de Melo

AbstractThe development ofFasciola hepaticafrom two species of definitive hosts, i.e. cattle (Bos taurus) and a marmoset (Callithrix penicillata) in the snailLymnaea columellawas determined based on the production of rediae and cercariae and snail survival rate. More rediae and cercariae at 60–74 days post-infection were produced by snails infected by cattle-derived miracidia (cattle group) than by those infected by marmoset-derived miracidia (marmoset group). Among theL. columellaparasitized by the marmoset group, the survival rate and the percentage of positive snails were higher than among those parasitized by the cattle group. Eggs ofF. hepaticareleased in cattle faeces were significantly bigger than those released in marmoset faeces. Miracidia originating from parasites that completed their development in cattle were more efficient in infecting the intermediate host. These results suggest that vertebrate-host origin influences the eggs produced by the parasite and the infection rates in the snail hostL. columella.


1976 ◽  
Vol 33 (4) ◽  
pp. 711-731 ◽  
Author(s):  
Wilfred Templeman ◽  
V. M. Hodder ◽  
A. M. Fleming

The lumpfish, Cyclopterus lumpus, was found to be a common intermediate host of the larvae of the copepod, Lernaeocera branchialis, in the Newfoundland and neighboring areas. Large numbers of these larvae occurred on the gills of lumpfish from inshore Newfoundland areas from the latter half of June to the first half of August, whereas only minor infection was found in any month in offshore areas. Some larvae of the year reached the final or seventh stage on the intermediate host in May on the west coast of Newfoundland and in June on the east coast. By July on the west coast and early August on the east coast, this was by far the most numerous stage present. The larvae were attached mainly near the tips of the gill filaments. Most larvae were attached to the gills of the first two branchial arches, less to those of the third, and much less to those of the fourth. There were more larvae on the right than on the left gills. Infection of the final host Atlantic cod (Gadus morhua), by stage-7 female L. branchialis was apparently mainly inshore.Adult L. branchialis on Atlantic cod, typically located near the anterior ventral apex of the branchial arches, were numerous throughout the year in the areas of high infection. Infection rates of cod with the adult parasite were usually considerably higher near the coast than farther offshore, the rates declining with distance from the coast. Rates of infection with the adult parasite usually increased from the smaller to intermediate cod lengths and declined rapidly at greater lengths. Infection rates were found useful as evidence of inshore and offshore migrations of cod. Infection with the copepod apparently delayed sexual maturity in cod. Most infected cod (86%) had one adult copepod and declining numbers (12–0.05%) possessed two to five adult copepods. The Greenland cod, G. ogac, was the only other fish of the area found to be highly infected with adult L. branchialis.


1995 ◽  
Vol 69 (3) ◽  
pp. 267-268 ◽  
Author(s):  
M. Veith ◽  
G. Erpelding

AbstractInfection of Salamandra salamandra larvae (Amphibia: Urodela) with the fish acanthocephalan Pomphorhynchus laevis was detected in a fish-free mountain brook. Gammarus fossarum was found to be the intermediate host. The parasites were probably inadvertently introduced through fish breeding practices. Evidence was obtained that Pomphorhynchus laevis persists, at least for several months, in postmetamorphic fire salamanders.


2015 ◽  
Vol 114 (7) ◽  
pp. 2535-2541 ◽  
Author(s):  
Wenceslaus Luoga ◽  
Fadlul Mansur ◽  
Ann Lowe ◽  
Ian R. Duce ◽  
David. J. Buttle ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Nektarios D. Giadinis ◽  
Elias Papadopoulos ◽  
Shawkat Q. Lafi ◽  
Vasiliki Papanikolopoulou ◽  
Sofia Karanikola ◽  
...  

This study aimed at investigating the occurrence ofCryptosporidiumspp. in diarrheic goat kids in Greece and the risk factors associated with cryptosporidiosis. Altogether, 292 diarrheic 4–15-day-old goat kids from 54 dairy goat herds of Northern Greece were examined. Oocysts ofCryptosporidiumspp. were detected in 223 of 292 (76.4%) goat kids and the intensity of infection was scored as “high” in 142 samples, “moderate” in 45 samples, and “low” in 36 samples. Larger herds (>200 animals) had higher infection rates than smaller ones, although this difference was not statistically significant. Significantly higher infection rates were observed in herds during late kidding season (1 January to 30 April) compared to the early one (1 September to 31 December). These results suggest that cryptosporidiosis is very common in diarrheic goat kids in Greece, especially in large herds during the late parturition season.


1988 ◽  
Vol 22 (5) ◽  
pp. 462-463 ◽  
Author(s):  
Luiz Candido de Souza Dias ◽  
Carmen M. Glasser ◽  
Arnaldo Etzel ◽  
Urara Kawazoe ◽  
Sumie Hoshino-Shimizu ◽  
...  

The epidemiology and control of schistosomiasis mansoni in the Municipality of Pedro de Toledo (State of S. Paulo, Brazil) since 1980, has been studied. In 1980 the prevalence evaluated by stool exams (Kato-Katz method) was 22.8% and no statistical difference at 5.0% level was observed between rural and urban zones. The intensity of infection was low (58.5 eggs/g of faeces); the highest prevalence and intensity of infection rates were observed within the group of from 5 to 29 years of age, respectively. The transmission of schistosomiasis usually occurred during leisure time. The majority of the carriers of the parasite were asymptomatic. Of the B. tenagophila examined only 0.4% were found to be infected. The control programme has been intensified from 1981 on resulting in a sharp decrease in the prevalence from 22.8% in 1980 to 6% at the present time. This result shows that, in spite of the control programme there is a residual human prevalence. A beginning has been made on the investigation into the possible causes of this residual prevalence (6.0% was maintained through out 1987).


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