El objetivo de este trabajo fue evaluar la contaminación de parques públicos del distrito de Huán... more El objetivo de este trabajo fue evaluar la contaminación de parques públicos del distrito de Huánuco, Perú por huevos de Toxocara canis. En cada uno de los 11 parques fueron tomadas 32 muestras por lo que se evaluaron un total de 352 muestras de tierra en mayo y junio del 2014. La selección de los parques fue al azar. De cada parque se recolectó 2 a 3 kg de tierra, según el método de la doble “W”. Se usó el método de flotación con solución saturada de azúcar. Se consideró positivo cuando se encontró al menos un huevo de T. canis por parque evaluado. De los 11 parques muestreados se encontró huevos de T. canis en el 90,9%. Siete fueron las formas parasitarias acompañantes a T. canis en el suelo. La secuencia de prevalencia parasitaria presentó el siguiente orden descendente: T. canis > huevos tipo Strongylus de Ancylostoma caninum > larvas de A. caninum = Blastocystis hominis > Trichuris vulpis = Entamoeba sp. > Capillaria sp. = Balantidium coli. La riqueza parasitaria fu...
ABSTRACT Dioctophyme renale has a worldwide distribution and has been diagnosed in several wild a... more ABSTRACT Dioctophyme renale has a worldwide distribution and has been diagnosed in several wild and domestic animals as well as in humans. As numerous reports in the literature exist concerning the presence of D. renale in different animal species, as well as its diagnosis, treatment, and confirmation in new geographic areas, we reviewed existing information to contribute to the knowledge of the etiology, biology, epidemiology, pathogenesis, symptoms, diagnosis, treatment, and prevention of D. renale. Results of dioctophymosis may range from asymptomatic infection to even death of the host. Diagnosis is based on data from morphology, imaging, and antibody testing, with surgical treatment being the most effective. A high potential for infection of pets exists when there is overlap with wild parasitized animals; given common risk factors for infections in humans, D. renale should be considered as having zoonotic potential.
The transmission dynamics of the trematode Halipegus occidualis in its definitive host, Rana clam... more The transmission dynamics of the trematode Halipegus occidualis in its definitive host, Rana clamitans, have been examined over a 5-yr period in a North Carolina pond. The breeding season of green frogs coincides with the period of worm recruitment, during which time male frogs are territorial and females show strong site fidelity. This site fidelity allows inferences to be made regarding the suitability of a particular habitat for worm transmission based on frog infection intensities within that habitat. Four foci of infection were identified in the pond by plotting worm infrapopulation size against site of host capture. Sites within infection foci are characterized by shallow water and emergent vegetation, factors favorable for overlapping distributions of the 4 hosts in the life cycle of H. occidualis. Consistent year-to-year worm prevalences and intensities, despite fluctuations in frog population size, are thought to be the result of a relatively constant proportion of the frog population being present in infection foci each year. Removal of worms from heavily infected frogs in the fifth year resulted in further heavy worm recruitment by treated frogs suggesting that site selection can predispose a frog to heavy infection. Further, the sum of removed parasites and those recruited after parasite removal by treated frog hosts was higher than worm infrapopulations observed in previous years, indicating that worm density regulates parasite infrapopulation size in heavily infected frogs.
Individual infrapopulations of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) in the... more Individual infrapopulations of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) in the buccal cavities of their amphibian host (Rana clamitans) were monitored for changes over time. Rates and patterns of parasite maturation, recruitment, and loss were estimated, and the probabilities of infection for definitive hosts in this system were calculated. Although variable, the time required for maturation of immature worms (once in the buccal cavity) was as little as 1 wk. Relatively rapid losses of worms from individual infrapopulations were observed, although this did not appear to inhibit additional recruitment of these trematodes. Also, it was clear that these species overwintered within their amphibian hosts. There was no statistical difference among the 3 sampling years in the probability of acquiring an initial or a subsequent infection with either parasite. However, we suggest that frogs with an existing infrapopulation may have a greater probability of adding worms if those hosts are within certain foci of infection within the pond. The probability of frogs becoming infected in this system increased in late spring and peaked in midsummer. By examining the temporal changes within individual infrapopulations, it is clear that dynamic changes in infrapopulation size and composition may occur, suggesting that rates of trematode transmission may be greater than previously estimated.
The seasonal population dynamics of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) i... more The seasonal population dynamics of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) in their amphibian host, the green frog (Rana clamitans), were examined for 3 yr (weekly, April through October). Frogs were caught, marked, and examined for H. occidualis and H. eccentricus, both of which occur as immatures and adults in the buccal cavity. Frogs were then released and allowed to continue natural recruitment and loss of the parasites. It was thus possible to monitor individual infrapopulations over successive time periods. One-hundred and forty-nine frogs were caught and released, with a total of 328 observations. Overall, the levels of both parasites among male and female frogs were similar, as were levels of infection among adult and juvenile hosts. There was, however, no correlation between the total number of H. occidualis and the body size (snout-vent length) of R. clamitans. In contrast, there was a significant correlation between the total number of H. eccentricus and frog size. Recruitment of both species began in May, peaked in June/July, and ended in July (H. eccentricus) or August (H. occidualis). In general, both the prevalence and relative density of H. occidualis was greater than that of H. eccentricus and may be related to space constraints in the buccal cavity of R. clamitans. Adults of both species were observed from April through October. Following increases in parasite recruitment, infrapopulation sizes declined in September 1992 and in August of 1993 and 1994. Examination of variance to mean ratios indicated that both species were overdispersed in the frogs. Large declines in the variance to mean ratios for H. occidualis after periods of greatest recruitment are most likely associated with the loss of larger infrapopulations, suggesting that there may be density-dependent regulation of infrapopulation size. By monitoring individual hosts using the mark-release-recapture protocol, dynamic changes in parasite infrapopulations were observed, e.g., there were losses of immature worms and rapid changes in infrapopulation sizes, observations that would not be made with typical host-parasite systems.
... I think back on all the times I'd visited salvage yards, wishing for family wealth so I ... more ... I think back on all the times I'd visited salvage yards, wishing for family wealth so I could take a minimum wage job disassembling machines just like Dunwoody's truck. Images of Erector sets,Leggo blocks, toy airplane engines and bicycle rear axles, swirl through my head. ...
... in grebes (Podilymbus podiceps); the latter is autogenic and probably parasitizes an aquatic ... more ... in grebes (Podilymbus podiceps); the latter is autogenic and probably parasitizes an aquatic turtle. ... In this freshwater system, parasite recruitment in both species of pulmonate snails is ... Finally,snail colonization had a clear effect on the trematode component com-munities within ...
Snails (Elimia livescens) from a central Indiana stream were examined for encysted metacercariae ... more Snails (Elimia livescens) from a central Indiana stream were examined for encysted metacercariae of Macravestibulum obtusicaudum (Pronocephalide) to determine the distribution and abundance of this parasite on its second intermediate host. Five samples of snails were collected, with 2 samples being restricted to high-flow (riffle) or low-flow (pool) areas of the stream. Snails (n = 386) were measured for shell length; the shell and the inner and outer surfaces of the operculum (in most samples) were examined for metacercariae. Seventy-five percent of snails (overall) had encysted metacercariae (range, 52-97%), primarily on the opercula. A significantly lower proportion of snails from riffles were infected, and these snails had significantly fewer cysts as well. Snails collected from pools showed up to 10 times as many metacercariae than those from riffles, although there was no significant difference in the proportion of snails with intramolluscan infections of M. obtusicaudum. The inner opercular surface appeared to be the preferred site of encystment in both flow regimes. Differences in microhabitats, in terms of both snails in the stream and metacercariae on the snails, clearly must be considered when evaluating the infection patterns of this trematode.
Pediculosis is one of the most important chronic infestations and more frequent in school in the ... more Pediculosis is one of the most important chronic infestations and more frequent in school in the world. Objective: To determine the epidemiological and clinical factors associated with head lice in schoolchildren of a Public School, San Juan de Miraflores District, Lima, Peru.Cross-analytical conducted in a sample of 138 students distributed by simple random sampling. We applied a data collection sheet and subjected to physical inspection to establish the infestation, which was defined as the presence of at least one louse, nymph or embryo apparently viable. Bivariate analysis was performed with the chi square test was corrected by the Fisher test, multivariate analysis using General Linear Model (GLM), calculating prevalence ratio with confidence intervals at 95%, the association was determined with a value of p <0.05 as significant, we used STATA v.11. We found that 50.7% were women, the predominant age range was between 7-8 years (42.8%). We found 83 (60.01%) pupils infested w...
Intestinal parasites are still a major public health problem in countries with a marked socioecon... more Intestinal parasites are still a major public health problem in countries with a marked socioeconomic inequality as Peru. Is evident in marginalized populations such as Pamplona Alta, in which poor sanitation create a favorable environment for the development of these parasites, especially in children. The aim of this study was to evaluate prevalence of intestinal parasites and determine hemoglobin values in human population of Pamplona Alta. It was a cross sectional study. It covered 363 patients from the villages Niño Jesús, María de los Ángeles, Corazón de María, Alborada, Las Américas, 7 de Enero and Torres Minas located in Pamplona Alta, as part of a health campaign in the months of July and August of 2012. Stool samples were collected were processed through a fresh examination. In addition, Graham test for Enterobius vermicularis and microhematocrit test to rule out anemia. The maximum age was 18 years and 8 months minimum. We found that 264 (72.7%) subjects were infected with...
A fecal parasitological study of the population performing artisanal fishing of Terminal Pesquero... more A fecal parasitological study of the population performing artisanal fishing of Terminal Pesquero de Chorrillos (Fishing Terminal of Chorrillos), Province of Lima, Peru, was conducted aiming at determining the prevalence of endoparasites and their relationship with fishing activity. Fecal samples were examined by the Ritchie's Method and the Spontaneous Sedimentation in Tube Technique. The prevalence of endoparasites was 68%. The only pathogenic protozoa found was Giardia intestinalis (syn. G. lamblia) (Lambl, 1859) Kofoid & Christiansen, 1915 with a 16% prevalence. The helminth parasites found included Hymenolepis nana (Culbertson, 1940) and Ascaris lumbricoides (Linnaeus, 1758), both with a 4% prevalence. Commensal parasites found included Endolimax nana (Wenyon & O´Connor, 1917) at a prevalence reaching 40%, followed by Entamoeba coli (Grassi, 1879) with 28% and finally Iodamoeba butschlii (Prowazek, 1911) with 4%, it is recommended to implement health education strategies an...
Until now, four species of eye trematodes have been found in South America. Of them, Philophthalm... more Until now, four species of eye trematodes have been found in South America. Of them, Philophthalmus lucipetus (synonymized with Philophthalmus gralli) displays a broad host spectrum, with at least 30 bird species (prevalently large water birds), five mammal species and humans serving as definitive hosts, and with snails Fagotia (Microcolpia) acicularis, Amphimelania holandri, Melanopsis praemorsa and Melanoides tuberculata serving as intermediate hosts. When examining a total of 50 birds of ten species in the wetland of Pantanos de Villa, Lima, Peru in July 2011, eye trematodes were identified visually in the edematous conjunctival sac of 11 (48%) out of 23 resident many-colored rush tyrants Tachuris rubrigastra. Based on morphometric characteristics, the trematodes were identified as P. lucipetus. ITS2 and CO1 gene of the examined specimens combined showed a 99% similarity to an Iranian isolate of Philophthalmus sp. from the intermediate host Melanoides tuberculata, an invasive freshwater snail, suggesting that these two isolates represent the same species with a wide geographical range. Moreover, the prevalence of infection with the philophthalmid cercariae was 31% in 744 Melanoides tuberculata examined in Pantanos de Villa in 2010. It is evident that P. lucipetus occurs throughout the world as well as locally, including Eurasia and South America. Here we report this trematode for the first time in Peru, and we were the first to sequence any of the South American eye trematodes. Low host specificity of P. lucipetus and the invasive character of Melanoides tuberculata as a competent intermediate host suggest that eye trematodosis caused by P. lucipetus may emerge frequently in various parts of the world, especially in the tropics. Increase of the zoonotic potential of the P. lucipetus associated with this invasive snail spreading across the world is predictable and should be of interest for further research.
ABSTRACT The effects of temperature on in vitro egg-hatching success, juvenile survival, developm... more ABSTRACT The effects of temperature on in vitro egg-hatching success, juvenile survival, development and behavior of Strongyloides robustus were examined. As culture temperatures declined (25-10 C), both egg hatching and rate of larval development decreased. Hatching occurred as low as 10 C. Eggs showed low resistance to freezing temperatures and no juveniles survived freezing. When exposed to a thermal gradient, filariform juveniles moved toward the higher temperature. The mean temperature at which worms were found was 37.0 ± 3.3 C, which approximates host temperature within a nest. These results suggest that dissimilarities in the prevalences and intensities of infection with S. robustus in the northern and southern flying squirrels, Glaucomys sabrinus and G. volans, respectively, are at least partly due to environmental differences between habitats. Overlap in the squirrels&#39; nest use may facilitate passage of this parasite from one host to the other, but the survival of eggs and infective juveniles may be severely limited by low temperatures. While transmission of S. robustus is limited during winter, summer transmission alone could account for the maintenance of the parasitic infections in these hosts.
The objective of this work was to evaluate the contamination of public parks in the district of H... more The objective of this work was to evaluate the contamination of public parks in the district of Huánuco, Perú with eggs of Toxocara canis. 32 soil samples were taken in each of 11 parks for a total of 352 samples in May and June of 2014. Parks were selected at random. In each park, 2-3 kg soil was collected according to the double “W” method. Flotation with a saturated sugar solution was used. Samples were considered positive when at least one egg of T. canis was found. Of the 11 parks sampled, T. canis eggs were found in 90.9%. Seven parasites were found along with T. canis in the soil. The sequence of parasite prevalence was in the following descending order: T. canis > Strongylus type eggs of Ancylostoma caninum > A. caninum larvae = Blastocystis hominis > Trichuris vulpis = Entamoeba sp. > Capillaria sp. = Balantidium coli. Parasite richness was 2.45 ± 1.21 (1-4) parasites per public park. A significant positive correlation was observed between the area of public par...
El objetivo de este trabajo fue evaluar la contaminación de parques públicos del distrito de Huán... more El objetivo de este trabajo fue evaluar la contaminación de parques públicos del distrito de Huánuco, Perú por huevos de Toxocara canis. En cada uno de los 11 parques fueron tomadas 32 muestras por lo que se evaluaron un total de 352 muestras de tierra en mayo y junio del 2014. La selección de los parques fue al azar. De cada parque se recolectó 2 a 3 kg de tierra, según el método de la doble “W”. Se usó el método de flotación con solución saturada de azúcar. Se consideró positivo cuando se encontró al menos un huevo de T. canis por parque evaluado. De los 11 parques muestreados se encontró huevos de T. canis en el 90,9%. Siete fueron las formas parasitarias acompañantes a T. canis en el suelo. La secuencia de prevalencia parasitaria presentó el siguiente orden descendente: T. canis > huevos tipo Strongylus de Ancylostoma caninum > larvas de A. caninum = Blastocystis hominis > Trichuris vulpis = Entamoeba sp. > Capillaria sp. = Balantidium coli. La riqueza parasitaria fu...
ABSTRACT Dioctophyme renale has a worldwide distribution and has been diagnosed in several wild a... more ABSTRACT Dioctophyme renale has a worldwide distribution and has been diagnosed in several wild and domestic animals as well as in humans. As numerous reports in the literature exist concerning the presence of D. renale in different animal species, as well as its diagnosis, treatment, and confirmation in new geographic areas, we reviewed existing information to contribute to the knowledge of the etiology, biology, epidemiology, pathogenesis, symptoms, diagnosis, treatment, and prevention of D. renale. Results of dioctophymosis may range from asymptomatic infection to even death of the host. Diagnosis is based on data from morphology, imaging, and antibody testing, with surgical treatment being the most effective. A high potential for infection of pets exists when there is overlap with wild parasitized animals; given common risk factors for infections in humans, D. renale should be considered as having zoonotic potential.
The transmission dynamics of the trematode Halipegus occidualis in its definitive host, Rana clam... more The transmission dynamics of the trematode Halipegus occidualis in its definitive host, Rana clamitans, have been examined over a 5-yr period in a North Carolina pond. The breeding season of green frogs coincides with the period of worm recruitment, during which time male frogs are territorial and females show strong site fidelity. This site fidelity allows inferences to be made regarding the suitability of a particular habitat for worm transmission based on frog infection intensities within that habitat. Four foci of infection were identified in the pond by plotting worm infrapopulation size against site of host capture. Sites within infection foci are characterized by shallow water and emergent vegetation, factors favorable for overlapping distributions of the 4 hosts in the life cycle of H. occidualis. Consistent year-to-year worm prevalences and intensities, despite fluctuations in frog population size, are thought to be the result of a relatively constant proportion of the frog population being present in infection foci each year. Removal of worms from heavily infected frogs in the fifth year resulted in further heavy worm recruitment by treated frogs suggesting that site selection can predispose a frog to heavy infection. Further, the sum of removed parasites and those recruited after parasite removal by treated frog hosts was higher than worm infrapopulations observed in previous years, indicating that worm density regulates parasite infrapopulation size in heavily infected frogs.
Individual infrapopulations of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) in the... more Individual infrapopulations of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) in the buccal cavities of their amphibian host (Rana clamitans) were monitored for changes over time. Rates and patterns of parasite maturation, recruitment, and loss were estimated, and the probabilities of infection for definitive hosts in this system were calculated. Although variable, the time required for maturation of immature worms (once in the buccal cavity) was as little as 1 wk. Relatively rapid losses of worms from individual infrapopulations were observed, although this did not appear to inhibit additional recruitment of these trematodes. Also, it was clear that these species overwintered within their amphibian hosts. There was no statistical difference among the 3 sampling years in the probability of acquiring an initial or a subsequent infection with either parasite. However, we suggest that frogs with an existing infrapopulation may have a greater probability of adding worms if those hosts are within certain foci of infection within the pond. The probability of frogs becoming infected in this system increased in late spring and peaked in midsummer. By examining the temporal changes within individual infrapopulations, it is clear that dynamic changes in infrapopulation size and composition may occur, suggesting that rates of trematode transmission may be greater than previously estimated.
The seasonal population dynamics of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) i... more The seasonal population dynamics of Halipegus occidualis and Halipegus eccentricus (Hemiuridae) in their amphibian host, the green frog (Rana clamitans), were examined for 3 yr (weekly, April through October). Frogs were caught, marked, and examined for H. occidualis and H. eccentricus, both of which occur as immatures and adults in the buccal cavity. Frogs were then released and allowed to continue natural recruitment and loss of the parasites. It was thus possible to monitor individual infrapopulations over successive time periods. One-hundred and forty-nine frogs were caught and released, with a total of 328 observations. Overall, the levels of both parasites among male and female frogs were similar, as were levels of infection among adult and juvenile hosts. There was, however, no correlation between the total number of H. occidualis and the body size (snout-vent length) of R. clamitans. In contrast, there was a significant correlation between the total number of H. eccentricus and frog size. Recruitment of both species began in May, peaked in June/July, and ended in July (H. eccentricus) or August (H. occidualis). In general, both the prevalence and relative density of H. occidualis was greater than that of H. eccentricus and may be related to space constraints in the buccal cavity of R. clamitans. Adults of both species were observed from April through October. Following increases in parasite recruitment, infrapopulation sizes declined in September 1992 and in August of 1993 and 1994. Examination of variance to mean ratios indicated that both species were overdispersed in the frogs. Large declines in the variance to mean ratios for H. occidualis after periods of greatest recruitment are most likely associated with the loss of larger infrapopulations, suggesting that there may be density-dependent regulation of infrapopulation size. By monitoring individual hosts using the mark-release-recapture protocol, dynamic changes in parasite infrapopulations were observed, e.g., there were losses of immature worms and rapid changes in infrapopulation sizes, observations that would not be made with typical host-parasite systems.
... I think back on all the times I'd visited salvage yards, wishing for family wealth so I ... more ... I think back on all the times I'd visited salvage yards, wishing for family wealth so I could take a minimum wage job disassembling machines just like Dunwoody's truck. Images of Erector sets,Leggo blocks, toy airplane engines and bicycle rear axles, swirl through my head. ...
... in grebes (Podilymbus podiceps); the latter is autogenic and probably parasitizes an aquatic ... more ... in grebes (Podilymbus podiceps); the latter is autogenic and probably parasitizes an aquatic turtle. ... In this freshwater system, parasite recruitment in both species of pulmonate snails is ... Finally,snail colonization had a clear effect on the trematode component com-munities within ...
Snails (Elimia livescens) from a central Indiana stream were examined for encysted metacercariae ... more Snails (Elimia livescens) from a central Indiana stream were examined for encysted metacercariae of Macravestibulum obtusicaudum (Pronocephalide) to determine the distribution and abundance of this parasite on its second intermediate host. Five samples of snails were collected, with 2 samples being restricted to high-flow (riffle) or low-flow (pool) areas of the stream. Snails (n = 386) were measured for shell length; the shell and the inner and outer surfaces of the operculum (in most samples) were examined for metacercariae. Seventy-five percent of snails (overall) had encysted metacercariae (range, 52-97%), primarily on the opercula. A significantly lower proportion of snails from riffles were infected, and these snails had significantly fewer cysts as well. Snails collected from pools showed up to 10 times as many metacercariae than those from riffles, although there was no significant difference in the proportion of snails with intramolluscan infections of M. obtusicaudum. The inner opercular surface appeared to be the preferred site of encystment in both flow regimes. Differences in microhabitats, in terms of both snails in the stream and metacercariae on the snails, clearly must be considered when evaluating the infection patterns of this trematode.
Pediculosis is one of the most important chronic infestations and more frequent in school in the ... more Pediculosis is one of the most important chronic infestations and more frequent in school in the world. Objective: To determine the epidemiological and clinical factors associated with head lice in schoolchildren of a Public School, San Juan de Miraflores District, Lima, Peru.Cross-analytical conducted in a sample of 138 students distributed by simple random sampling. We applied a data collection sheet and subjected to physical inspection to establish the infestation, which was defined as the presence of at least one louse, nymph or embryo apparently viable. Bivariate analysis was performed with the chi square test was corrected by the Fisher test, multivariate analysis using General Linear Model (GLM), calculating prevalence ratio with confidence intervals at 95%, the association was determined with a value of p <0.05 as significant, we used STATA v.11. We found that 50.7% were women, the predominant age range was between 7-8 years (42.8%). We found 83 (60.01%) pupils infested w...
Intestinal parasites are still a major public health problem in countries with a marked socioecon... more Intestinal parasites are still a major public health problem in countries with a marked socioeconomic inequality as Peru. Is evident in marginalized populations such as Pamplona Alta, in which poor sanitation create a favorable environment for the development of these parasites, especially in children. The aim of this study was to evaluate prevalence of intestinal parasites and determine hemoglobin values in human population of Pamplona Alta. It was a cross sectional study. It covered 363 patients from the villages Niño Jesús, María de los Ángeles, Corazón de María, Alborada, Las Américas, 7 de Enero and Torres Minas located in Pamplona Alta, as part of a health campaign in the months of July and August of 2012. Stool samples were collected were processed through a fresh examination. In addition, Graham test for Enterobius vermicularis and microhematocrit test to rule out anemia. The maximum age was 18 years and 8 months minimum. We found that 264 (72.7%) subjects were infected with...
A fecal parasitological study of the population performing artisanal fishing of Terminal Pesquero... more A fecal parasitological study of the population performing artisanal fishing of Terminal Pesquero de Chorrillos (Fishing Terminal of Chorrillos), Province of Lima, Peru, was conducted aiming at determining the prevalence of endoparasites and their relationship with fishing activity. Fecal samples were examined by the Ritchie's Method and the Spontaneous Sedimentation in Tube Technique. The prevalence of endoparasites was 68%. The only pathogenic protozoa found was Giardia intestinalis (syn. G. lamblia) (Lambl, 1859) Kofoid & Christiansen, 1915 with a 16% prevalence. The helminth parasites found included Hymenolepis nana (Culbertson, 1940) and Ascaris lumbricoides (Linnaeus, 1758), both with a 4% prevalence. Commensal parasites found included Endolimax nana (Wenyon & O´Connor, 1917) at a prevalence reaching 40%, followed by Entamoeba coli (Grassi, 1879) with 28% and finally Iodamoeba butschlii (Prowazek, 1911) with 4%, it is recommended to implement health education strategies an...
Until now, four species of eye trematodes have been found in South America. Of them, Philophthalm... more Until now, four species of eye trematodes have been found in South America. Of them, Philophthalmus lucipetus (synonymized with Philophthalmus gralli) displays a broad host spectrum, with at least 30 bird species (prevalently large water birds), five mammal species and humans serving as definitive hosts, and with snails Fagotia (Microcolpia) acicularis, Amphimelania holandri, Melanopsis praemorsa and Melanoides tuberculata serving as intermediate hosts. When examining a total of 50 birds of ten species in the wetland of Pantanos de Villa, Lima, Peru in July 2011, eye trematodes were identified visually in the edematous conjunctival sac of 11 (48%) out of 23 resident many-colored rush tyrants Tachuris rubrigastra. Based on morphometric characteristics, the trematodes were identified as P. lucipetus. ITS2 and CO1 gene of the examined specimens combined showed a 99% similarity to an Iranian isolate of Philophthalmus sp. from the intermediate host Melanoides tuberculata, an invasive freshwater snail, suggesting that these two isolates represent the same species with a wide geographical range. Moreover, the prevalence of infection with the philophthalmid cercariae was 31% in 744 Melanoides tuberculata examined in Pantanos de Villa in 2010. It is evident that P. lucipetus occurs throughout the world as well as locally, including Eurasia and South America. Here we report this trematode for the first time in Peru, and we were the first to sequence any of the South American eye trematodes. Low host specificity of P. lucipetus and the invasive character of Melanoides tuberculata as a competent intermediate host suggest that eye trematodosis caused by P. lucipetus may emerge frequently in various parts of the world, especially in the tropics. Increase of the zoonotic potential of the P. lucipetus associated with this invasive snail spreading across the world is predictable and should be of interest for further research.
ABSTRACT The effects of temperature on in vitro egg-hatching success, juvenile survival, developm... more ABSTRACT The effects of temperature on in vitro egg-hatching success, juvenile survival, development and behavior of Strongyloides robustus were examined. As culture temperatures declined (25-10 C), both egg hatching and rate of larval development decreased. Hatching occurred as low as 10 C. Eggs showed low resistance to freezing temperatures and no juveniles survived freezing. When exposed to a thermal gradient, filariform juveniles moved toward the higher temperature. The mean temperature at which worms were found was 37.0 ± 3.3 C, which approximates host temperature within a nest. These results suggest that dissimilarities in the prevalences and intensities of infection with S. robustus in the northern and southern flying squirrels, Glaucomys sabrinus and G. volans, respectively, are at least partly due to environmental differences between habitats. Overlap in the squirrels&#39; nest use may facilitate passage of this parasite from one host to the other, but the survival of eggs and infective juveniles may be severely limited by low temperatures. While transmission of S. robustus is limited during winter, summer transmission alone could account for the maintenance of the parasitic infections in these hosts.
The objective of this work was to evaluate the contamination of public parks in the district of H... more The objective of this work was to evaluate the contamination of public parks in the district of Huánuco, Perú with eggs of Toxocara canis. 32 soil samples were taken in each of 11 parks for a total of 352 samples in May and June of 2014. Parks were selected at random. In each park, 2-3 kg soil was collected according to the double “W” method. Flotation with a saturated sugar solution was used. Samples were considered positive when at least one egg of T. canis was found. Of the 11 parks sampled, T. canis eggs were found in 90.9%. Seven parasites were found along with T. canis in the soil. The sequence of parasite prevalence was in the following descending order: T. canis > Strongylus type eggs of Ancylostoma caninum > A. caninum larvae = Blastocystis hominis > Trichuris vulpis = Entamoeba sp. > Capillaria sp. = Balantidium coli. Parasite richness was 2.45 ± 1.21 (1-4) parasites per public park. A significant positive correlation was observed between the area of public par...
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