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Aldo Solari - One of the best experts on this subject based on the ideXlab platform.
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within host temporal fluctuations of trypanosoma cruzi discrete typing units the case of the wild reservoir rodent octodon degus
Parasites & Vectors, 2017Co-Authors: Gemma Rojo, Alejandra Sandovalrodriguez, Angelica Lopez, Sylvia Ortiz, Juana P Correa, Miguel Saavedra, Carezza Bottomahan, Pedro E Cattan, Aldo SolariAbstract:Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans. The parasites amplified over time by insect Xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. The determination of O. degus parasitemia before serial Xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by Xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial Xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after Xenodiagnosis procedure.
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Within-host temporal fluctuations of Trypanosoma cruzi discrete typing units: the case of the wild reservoir rodent Octodon degus
Parasites & Vectors, 2017Co-Authors: Gemma Rojo, Angelica Lopez, Sylvia Ortiz, Juana P Correa, Miguel Saavedra, Pedro E Cattan, Alejandra Sandoval-rodríguez, Carezza Botto-mahan, Aldo SolariAbstract:Background Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. Methods After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans . The parasites amplified over time by insect Xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. Results The determination of O. degus parasitemia before serial Xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by Xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. Conclusion Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial Xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after Xenodiagnosis procedure.
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transferability of trypanosoma cruzi from mixed human host infection to triatoma infestans and from insects to axenic culture
Parasitology International, 2015Co-Authors: Sylvia Ortiz, Miguel Saavedra, Inés Zulantay, Aldo SolariAbstract:The etiologic agent of Chagas disease is Trypanosoma cruzi, a protozoan whose life cycle involves obligatory passage through vertebrate and invertebrate hosts in a series of stages. The aim of this study was to explore the transferability of mixed discrete typing units (DTUs) of T. cruzi present in chronic chagasic patients when passed through an invertebrate host during Xenodiagnosis (XD) and then when transferred to axenic cultures to obtain T. cruzi isolates. DTUs of T. cruzi present in these two hosts and axenic cultures were identified by kDNA PCR amplification and subsequent hybridization with DTU-specific probes. Mixtures of Tc I, Tc II, Tc V and Tc VI DTUs were detected in blood samples. However as a result of XD and axenic cultures it was possible to identify mostly Tc V. We conclude that the transferability of an isolate of T.cruzi derived from mixed DTUs present in human blood depends upon the starved invertebrate host used for Xenodiagnosis.
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trypanosoma cruzi detection in blood by Xenodiagnosis and polymerase chain reaction in the wild rodent octodon degus
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Ricardo Campos, Sylvia Ortiz, Carezza Bottomahan, Pedro E Cattan, Mariana Acuna, Aldo SolariAbstract:We detected Trypanosoma cruzi in blood samples of the wild rodent Octodon degus by Xenodiagnosis and a polymerase chain reaction (PCR) using the domestic and wild vectors of Chagas disease, Triatoma infestans and Mepraia spinolai, respectively. We captured 35 rodents and extracted DNA from blood samples and intestinal contents of vectors fed on O. degus. Our results indicate that the percentage of rodents naturally infected with T. cruzi depends on the biologic sample used for PCR and on the vector species for Xenodiagnosis. The PCR with blood samples did not detect T. cruzi DNA, but the PCR with intestinal contents showed that both vectors were positive for T. cruzi. The PCR performed with M. spinolai intestinal contents detected four times more T. cruzi-positive O. degus than the PCR with Triatoma infestans intestinal contents (22.9% and 5.7%, respectively). We report the improvement of T. cruzi detection in sylvatic animals by a combination of PCR and Xenodiagnosis using sylvatic vectors, especially in disease-endemic areas with low parasitemias in mammals.
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Treatment of Trypanosoma cruzi-infected children with nifurtimox: a 3 year follow-up by PCR
The Journal of antimicrobial chemotherapy, 2001Co-Authors: Aldo Solari, María Del Carmen Contreras, Sylvia Ortiz, A. Soto, C. Arancibia, R. Campillay, Salinas P, Rojas A, H. SchenoneAbstract:Patients suffering from Chagas' disease, as determined by positive serological results, were tested for further evidence of Trypanosoma cruzi infection by Xenodiagnosis and PCR. The patients included 67 children aged from 0 to 10 years and 75 adults. All children were positive by PCR on their pre-therapy sample, while only 69% of the seropositive adults and none of the 78 seronegative control adults were PCR positive. Xenodiagnosis was positive in 79% of the children, but only in 21% of the adults. A group of 66 children was treated with nifurtimox, and followed up every 3 months during the first year and every 6 months during the second and third year post-therapy, by PCR, Xenodiagnosis and serology. We concluded that PCR was the most effective test to monitor children for 3 years post-chemotherapy, when all the cases converted from positive to negative. Conventional serology, however, remained positive after that period in most cases. In contrast, conversion to negative Xenodiagnosis occurred very early after treatment.
Ricardo E. Gürtler - One of the best experts on this subject based on the ideXlab platform.
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Microcavia australis (Caviidae, Rodentia), a new highly competent host of Trypanosoma cruzi I in rural communities of northwestern Argentina.
Acta tropica, 2014Co-Authors: M. Carla Cecere, Marta Victoria Cardinal, Juan P. Arrabal, Claudio Moreno, Ricardo E. GürtlerAbstract:Abstract Rodents are well-known hosts of Trypanosoma cruzi but little is known on the role of some caviomorph rodents. We assessed the occurrence and prevalence of T. cruzi infection in Microcavia australis (“southern mountain, desert or small cavy”) and its infectiousness to the vector Triatoma infestans in four rural communities of Tafi del Valle department, northwestern Argentina. Parasite detection was performed by Xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR) from blood samples. A total of 51 cavies was captured in traps set up along cavy paths in peridomestic dry-shrub fences located between 25 and 85 m from the nearest domicile. We document the first record of M. australis naturally infected by T. cruzi . Cavies presented a very high prevalence of infection (46.3%; 95% confidence interval, CI = 33.0–59.6%). Only one (4%) of 23 cavies negative by Xenodiagnosis was found infected by kDNA-PCR. TcI was the only discrete typing unit identified in 12 cavies with a positive Xenodiagnosis. The infectiousness to T. infestans of cavies positive by Xenodiagnosis or kDNA-PCR was very high (mean, 55.8%; CI = 48.4–63.1%) and exceeded 80% in 44% of the hosts. Cavies are highly-competent hosts of T. cruzi in peridomestic habitats near human dwellings in rural communities of Tucuman province in northwestern Argentina.
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the role of sigmodontine rodents as sylvatic hosts of trypanosoma cruzi in the argentinean chaco
Infection Genetics and Evolution, 2014Co-Authors: Marcela M Orozco, Gustavo Fabian Enriquez, Romina Valeria Piccinali, Matias S Mora, Victoria M Cardinal, Ricardo E. GürtlerAbstract:The role of rodents in the sylvatic transmission of Trypanosoma cruzi has seldom been investigated using parasitological and molecular methods. We assessed the occurrence of T. cruzi in wild small rodents from Pampa del Indio, in the Argentinean Chaco, and identified the taxonomic status of positive rodents by sequencing a fragment of cytochrome b gene (cytb) and performing BLAST searches and phylogenetic analyses. A total of 176 Sigmodontinae rodents was captured in six surveys using 5425 trap-nights in a wide range of sylvatic habitats between 2009 and 2011. Host infection was determined by Xenodiagnosis and by polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR) from blood samples. None of the 176 rodents examined was Xenodiagnosis-positive. The prevalence of infection determined by kDNA-PCR from blood samples was 16.2% (95% confidence interval, 10.1–21.9%). Half of the infections detected by kDNA-PCR were confirmed by nuclear satellite DNA-PCR or by kDNA-PCR of the rectal contents of xenodiagnostic bugs. The 24 positive specimens were assigned to eight species, providing the first records of T. cruzi in Akodon montensis, Akodon toba, Graomys chacoensis, and Oligoryzomys chacoensis. The occurrence of T. cruzi infection in Oligoryzomys nigripes, Calomys callosus, Necromys lasiurus and Oecomys sp. (most probably Oecomys mamorae) from the Gran Chaco is also reported for the first time. Although sigmodontine rodents were frequently infected, the intensity of bug rectal infection with T. cruzi was below the detection limit of Xenodiagnosis (subpatent infectiousness to bugs), indicating they had a low reservoir host competence.
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Detection of Trypanosoma cruzi infection in naturally infected dogs and cats using serological, parasitological and molecular methods.
Acta tropica, 2013Co-Authors: Gustavo Fabian Enriquez, Marta Victoria Cardinal, Alejandro G Schijman, Maria Marcela Orozco, Ricardo E. GürtlerAbstract:Abstract Domestic dogs and cats are major domestic reservoir hosts of Trypanosoma cruzi and a risk factor for parasite transmission. In this study we assessed the relative performance of a polymerase chain reaction assay targeted to minicircle DNA (kDNA-PCR) in reference to conventional serological tests, a rapid dipstick test and Xenodiagnosis to detect T. cruzi infection in dogs and cats from an endemic rural area in northeastern Argentina. A total of 43 dogs and 13 cats seropositive for T. cruzi by an immunosorbent assay (ELISA) and an indirect hemagglutination assay (IHA), which had been examined by Xenodiagnosis, were also tested by kDNA-PCR. kDNA-PCR was nearly as sensitive as Xenodiagnosis for detecting T. cruzi -infectious dogs and cats. kDNA-PCR was slightly more sensitive than Xenodiagnosis in seropositive dogs (91% versus 86%, respectively) and cats (77% against 54%, respectively), but failed to detect all of the seropositive individuals. ELISA and IHA detected all Xenodiagnosis-positive dogs and both outcomes largely agreed (kappa coefficient, κ = 0.92), whereas both assays failed to detect all of the Xenodiagnosis-positive cats and their agreement was moderate ( κ = 0.68). In dogs, the sensitivity of the dipstick test was 95% and agreed closely with the outcome of conventional serological tests ( κ = 0.82). The high sensitivity of kDNA-PCR to detect T. cruzi infections in naturally infected dogs and cats supports its application as a diagnostic tool complementary to serology and may replace the use of Xenodiagnosis or hemoculture.
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the sylvatic transmission cycle of trypanosoma cruzi in a rural area in the humid chaco of argentina
Acta Tropica, 2012Co-Authors: Julian A Alvaradootegui, Leonardo A. Ceballos, Uriel Kitron, Marcela M Orozco, Gustavo Fabian Enriquez, Marta Victoria Cardinal, Carolina Cura, Alejandro G Schijman, Ricardo E. GürtlerAbstract:Little is known about the sylvatic transmission cycle of Trypanosoma cruzi in the Gran Chaco ecoregion. We conducted surveys to identify the main sylvatic hosts of T. cruzi, parasite discrete typing units and vector species involved in Pampa del Indio, a rural area in the humid Argentinean Chaco. A total of 44 mammals from 14 species were captured and examined for infection by Xenodiagnosis and polymerase chain reaction amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). Ten (22.7%) mammals were positive by Xenodiagnosis or kDNA-PCR. Four of 11 (36%) Didelphis albiventris (white-eared opossums) and six of nine (67%) Dasypus novemcinctus (nine-banded armadillos) were positive by Xenodiagnosis and or kDNA-PCR. Rodents, other armadillo species, felids, crab-eating raccoons, hares and rabbits were not infected. Positive animals were highly infectious to the bugs that fed upon them as determined by Xenodiagnosis. All positive opossums were infected with T. cruzi I and all positive nine-banded armadillos with T. cruzi III. Extensive searches in sylvatic habitats using 718 Noireau trap-nights only yielded Triatoma sordida whereas no bug was collected in 26 light-trap nights. Four armadillos or opossums fitted with a spool-and-line device were successfully tracked to their refuges; only one Panstrongylus geniculatus was found in an armadillo burrow. No sylvatic triatomine was infected with T. cruzi by microscopical examination or kDNA-PCR. Our results indicate that two independent sylvatic transmission cycles of T. cruzi occur in the humid Chaco. The putative vectors of both cycles need to be identified conclusively.
Sylvia Ortiz - One of the best experts on this subject based on the ideXlab platform.
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within host temporal fluctuations of trypanosoma cruzi discrete typing units the case of the wild reservoir rodent octodon degus
Parasites & Vectors, 2017Co-Authors: Gemma Rojo, Alejandra Sandovalrodriguez, Angelica Lopez, Sylvia Ortiz, Juana P Correa, Miguel Saavedra, Carezza Bottomahan, Pedro E Cattan, Aldo SolariAbstract:Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans. The parasites amplified over time by insect Xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. The determination of O. degus parasitemia before serial Xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by Xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial Xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after Xenodiagnosis procedure.
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Within-host temporal fluctuations of Trypanosoma cruzi discrete typing units: the case of the wild reservoir rodent Octodon degus
Parasites & Vectors, 2017Co-Authors: Gemma Rojo, Angelica Lopez, Sylvia Ortiz, Juana P Correa, Miguel Saavedra, Pedro E Cattan, Alejandra Sandoval-rodríguez, Carezza Botto-mahan, Aldo SolariAbstract:Background Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. Methods After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans . The parasites amplified over time by insect Xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. Results The determination of O. degus parasitemia before serial Xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by Xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. Conclusion Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial Xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after Xenodiagnosis procedure.
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transferability of trypanosoma cruzi from mixed human host infection to triatoma infestans and from insects to axenic culture
Parasitology International, 2015Co-Authors: Sylvia Ortiz, Miguel Saavedra, Inés Zulantay, Aldo SolariAbstract:The etiologic agent of Chagas disease is Trypanosoma cruzi, a protozoan whose life cycle involves obligatory passage through vertebrate and invertebrate hosts in a series of stages. The aim of this study was to explore the transferability of mixed discrete typing units (DTUs) of T. cruzi present in chronic chagasic patients when passed through an invertebrate host during Xenodiagnosis (XD) and then when transferred to axenic cultures to obtain T. cruzi isolates. DTUs of T. cruzi present in these two hosts and axenic cultures were identified by kDNA PCR amplification and subsequent hybridization with DTU-specific probes. Mixtures of Tc I, Tc II, Tc V and Tc VI DTUs were detected in blood samples. However as a result of XD and axenic cultures it was possible to identify mostly Tc V. We conclude that the transferability of an isolate of T.cruzi derived from mixed DTUs present in human blood depends upon the starved invertebrate host used for Xenodiagnosis.
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trypanosoma cruzi detection in blood by Xenodiagnosis and polymerase chain reaction in the wild rodent octodon degus
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Ricardo Campos, Sylvia Ortiz, Carezza Bottomahan, Pedro E Cattan, Mariana Acuna, Aldo SolariAbstract:We detected Trypanosoma cruzi in blood samples of the wild rodent Octodon degus by Xenodiagnosis and a polymerase chain reaction (PCR) using the domestic and wild vectors of Chagas disease, Triatoma infestans and Mepraia spinolai, respectively. We captured 35 rodents and extracted DNA from blood samples and intestinal contents of vectors fed on O. degus. Our results indicate that the percentage of rodents naturally infected with T. cruzi depends on the biologic sample used for PCR and on the vector species for Xenodiagnosis. The PCR with blood samples did not detect T. cruzi DNA, but the PCR with intestinal contents showed that both vectors were positive for T. cruzi. The PCR performed with M. spinolai intestinal contents detected four times more T. cruzi-positive O. degus than the PCR with Triatoma infestans intestinal contents (22.9% and 5.7%, respectively). We report the improvement of T. cruzi detection in sylvatic animals by a combination of PCR and Xenodiagnosis using sylvatic vectors, especially in disease-endemic areas with low parasitemias in mammals.
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Treatment of Trypanosoma cruzi-infected children with nifurtimox: a 3 year follow-up by PCR
The Journal of antimicrobial chemotherapy, 2001Co-Authors: Aldo Solari, María Del Carmen Contreras, Sylvia Ortiz, A. Soto, C. Arancibia, R. Campillay, Salinas P, Rojas A, H. SchenoneAbstract:Patients suffering from Chagas' disease, as determined by positive serological results, were tested for further evidence of Trypanosoma cruzi infection by Xenodiagnosis and PCR. The patients included 67 children aged from 0 to 10 years and 75 adults. All children were positive by PCR on their pre-therapy sample, while only 69% of the seropositive adults and none of the 78 seronegative control adults were PCR positive. Xenodiagnosis was positive in 79% of the children, but only in 21% of the adults. A group of 66 children was treated with nifurtimox, and followed up every 3 months during the first year and every 6 months during the second and third year post-therapy, by PCR, Xenodiagnosis and serology. We concluded that PCR was the most effective test to monitor children for 3 years post-chemotherapy, when all the cases converted from positive to negative. Conventional serology, however, remained positive after that period in most cases. In contrast, conversion to negative Xenodiagnosis occurred very early after treatment.
Ricardo Molina - One of the best experts on this subject based on the ideXlab platform.
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quantifying the infectiousness of post kala azar dermal leishmaniasis toward sand flies
Clinical Infectious Diseases, 2019Co-Authors: Dinesh Mondal, Caryn Bern, Debashis Ghosh, Masud Rashid, Ricardo Molina, Rajashree Chowdhury, Rupen Nath, Prakash Ghosh, Lloyd A. C. Chapman, Abdul AlimAbstract:Background In the Indian subcontinent, visceral leishmaniasis (VL) incidence is on track to reach elimination goals by 2020 in nearly all endemic districts. Although not included in official targets, previous data suggest post-kala-azar dermal leishmaniasis (PKDL) patients can act as an infection reservoir. Methods We conducted Xenodiagnosis on 47 PKDL patients and 15 VL patients using laboratory-reared Phlebotomus argentipes. In direct Xenodiagnosis, flies were allowed to feed on the patient’s skin for 15 minutes. For indirect Xenodiagnosis, flies were fed through a membrane on the patient’s blood. Five days later, blood-fed flies were dissected and examined by microscopy and/or PCR. A 3-mm skin snip biopsy (PKDL) or venous blood VL) was processed by quantitative PCR. Results Twenty-seven PKDL patients (57.4%) had positive results by direct and/or indirect Xenodiagnosis. Direct was significantly more sensitive than indirect Xenodiagnosis (55.3% vs 6.4%, p 1 log10 unit higher than those with negative results (2.88 vs 1.66, p<0.0001). In a multivariable model, parasite load, nodular lesions and positive skin microscopy were significantly associated with positive Xenodiagnosis. Blood parasite load was the strongest predictor for VL. Compared to VL, nodular PKDL was more likely and macular PKDL less likely to result in positive Xenodiagnosis, but neither difference reached statistical significance. Conclusions Nodular and macular PKDL, and VL, can be infectious to sand flies. Active PKDL case detection and prompt treatment should be instituted and maintained as an integral part of VL control and elimination programs.
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Quantifying the Infectiousness of Post-Kala-Azar Dermal Leishmaniasis Toward Sand Flies.
Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2018Co-Authors: Dinesh Mondal, Caryn Bern, Debashis Ghosh, Masud Rashid, Ricardo Molina, Rajashree Chowdhury, Rupen Nath, Prakash Ghosh, Lloyd A. C. Chapman, Abdul AlimAbstract:Background In the Indian subcontinent, visceral leishmaniasis (VL) incidence is on track to reach elimination goals by 2020 in nearly all endemic districts. Although not included in official targets, previous data suggest post-kala-azar dermal leishmaniasis (PKDL) patients can act as an infection reservoir. Methods We conducted Xenodiagnosis on 47 PKDL patients and 15 VL patients using laboratory-reared Phlebotomus argentipes. In direct Xenodiagnosis, flies were allowed to feed on the patient’s skin for 15 minutes. For indirect Xenodiagnosis, flies were fed through a membrane on the patient’s blood. Five days later, blood-fed flies were dissected and examined by microscopy and/or PCR. A 3-mm skin snip biopsy (PKDL) or venous blood VL) was processed by quantitative PCR. Results Twenty-seven PKDL patients (57.4%) had positive results by direct and/or indirect Xenodiagnosis. Direct was significantly more sensitive than indirect Xenodiagnosis (55.3% vs 6.4%, p 1 log10 unit higher than those with negative results (2.88 vs 1.66, p
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infectivity of post kala azar dermal leishmaniasis patients to sand flies revisiting a proof of concept in the context of the kala azar elimination program in the indian subcontinent
Clinical Infectious Diseases, 2017Co-Authors: Ricardo Molina, Dinesh Mondal, Caryn Bern, Debashis Ghosh, Eugenia Carrillo, Severine Monnerat, Jorge AlvarAbstract:: We compared Xenodiagnosis with quantitative polymerase chain reaction in skin biopsies from 3 patients with maculopapular or nodular post-kala-azar dermal leishmaniasis (PKDL). All patients infected sand flies. Parasite loads in skin varied from 1428 to 63 058 parasites per microgram. PKDL detection and treatment are important missing components of the kala-azar elimination program.
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the hare lepus granatensis as potential sylvatic reservoir of leishmania infantum in spain
Veterinary Parasitology, 2012Co-Authors: Ricardo Molina, Maribel Jimenez, Israel Cruz, A Iriso, Ines Martinmartin, O Sevillano, S Melero, Juan A BernalAbstract:Xenodiagnosis of Leishmania infection in hares (Lepus granatensis) from a focus of human leishmaniasis in Fuenlabrada at southwestern Madrid region (Spain) proved that they are infective to Phlebotomus perniciosus. Molecular characterization of isolates obtained from sand flies infected after Xenodiagnosis demonstrates that hares were infected by Leishmania infantum. This is the first evidence of the transmission of L. infantum from hares to sand flies. Moreover the results confirm the role that these animals can play as wild reservoirs of leishmaniasis for the recent outbreak of visceral leishmaniasis in Madrid.
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infectivity to phlebotomus perniciosus of dogs naturally parasitized with leishmania infantum after different treatments
Parasites & Vectors, 2011Co-Authors: Guadalupe Miro, Rosa Galvez, Cristeta Fraile, Miguel Angel Descalzo, Ricardo MolinaAbstract:Background In Europe most dogs with clinical leishmaniosis are treated with leishmanicides, typically antimonials combined with allopurinol and good clinical recovery is observed in a high number of these dogs. Through Xenodiagnosis, the capacity of a treated animal to infect the vector of the disease under treatment is assessed as a measure of the chemotherapeutic efficacy of the drug used. The objective of the present study was to evaluate through direct Xenodiagnosis the infectivity to Phlebotomus perniciosus of dogs naturally parasitized with Leishmania infantum after treatment, and to follow the clinical and parasite course of disease. Thirty two dogs with clinical leishmaniosis were assigned to one of three treatment groups: meglumine antimoniate plus allopurinol (Group A), meglumine antimoniate (Group B) or allopurinol (Group C). During the study, the dogs were examined before treatment (Day 0) and bimonthly thereafter until Day 180 (six months post-treatment onset).
Pedro E Cattan - One of the best experts on this subject based on the ideXlab platform.
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within host temporal fluctuations of trypanosoma cruzi discrete typing units the case of the wild reservoir rodent octodon degus
Parasites & Vectors, 2017Co-Authors: Gemma Rojo, Alejandra Sandovalrodriguez, Angelica Lopez, Sylvia Ortiz, Juana P Correa, Miguel Saavedra, Carezza Bottomahan, Pedro E Cattan, Aldo SolariAbstract:Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans. The parasites amplified over time by insect Xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. The determination of O. degus parasitemia before serial Xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by Xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial Xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after Xenodiagnosis procedure.
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Within-host temporal fluctuations of Trypanosoma cruzi discrete typing units: the case of the wild reservoir rodent Octodon degus
Parasites & Vectors, 2017Co-Authors: Gemma Rojo, Angelica Lopez, Sylvia Ortiz, Juana P Correa, Miguel Saavedra, Pedro E Cattan, Alejandra Sandoval-rodríguez, Carezza Botto-mahan, Aldo SolariAbstract:Background Chagas disease caused by Trypanosoma cruzi is considered a major public health problem in America. After an acute phase the disease changes to a chronic phase with very low parasitemia. The parasite presents high genetic variability with seven discrete typing units (DTUs): TcI-TcVI and Tc bat. The aim of this work is to evaluate fluctuation of parasitemia and T. cruzi DTUs in naturally infected Octodon degus. Methods After animal capture parasitemia was obtained by qPCR and later the animals were evaluated by three serial xenodiagnoses using two insect vector species, Mepraia spinolai and Triatoma infestans . The parasites amplified over time by insect Xenodiagnosis were analyzed by conventional PCR and after that the infective T. cruzi were characterized by means of hybridization tests. Results The determination of O. degus parasitemia before serial Xenodiagnosis by qPCR reveals a great heterogeneity from 1 to 812 parasite equivalents/ml in the blood stream. The T. cruzi DTU composition in 23 analyzed animals by Xenodiagnosis oscillated from mixed infections with different DTUs to infections without DTU identification or vice versa, this is equivalent to 50% of the studied animals. Detection of triatomine infection and composition of T. cruzi DTUs was achieved more efficiently 40 days post-infection rather than after 80 or 120 days. Conclusion Trypanosoma cruzi DTUs composition fluctuates over time in naturally infected O. degus. Three replicates of serial Xenodiagnosis confirmed that living parasites have been studied. Our results allow us to confirm that M. spinolai and T. infestans are equally competent to maintain T. cruzi DTUs since similar results of infection were obtained after Xenodiagnosis procedure.
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trypanosoma cruzi detection in blood by Xenodiagnosis and polymerase chain reaction in the wild rodent octodon degus
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Ricardo Campos, Sylvia Ortiz, Carezza Bottomahan, Pedro E Cattan, Mariana Acuna, Aldo SolariAbstract:We detected Trypanosoma cruzi in blood samples of the wild rodent Octodon degus by Xenodiagnosis and a polymerase chain reaction (PCR) using the domestic and wild vectors of Chagas disease, Triatoma infestans and Mepraia spinolai, respectively. We captured 35 rodents and extracted DNA from blood samples and intestinal contents of vectors fed on O. degus. Our results indicate that the percentage of rodents naturally infected with T. cruzi depends on the biologic sample used for PCR and on the vector species for Xenodiagnosis. The PCR with blood samples did not detect T. cruzi DNA, but the PCR with intestinal contents showed that both vectors were positive for T. cruzi. The PCR performed with M. spinolai intestinal contents detected four times more T. cruzi-positive O. degus than the PCR with Triatoma infestans intestinal contents (22.9% and 5.7%, respectively). We report the improvement of T. cruzi detection in sylvatic animals by a combination of PCR and Xenodiagnosis using sylvatic vectors, especially in disease-endemic areas with low parasitemias in mammals.
