ABSTRACT
Abstract Alterations of ecosystems have deep effects on the distribution of parasites. Big cities of Argentina present structural features that favor the presence of synanthropic species, acting as source of zoonotic diseases, for example in urban rodents: the Norway rat (Rattus norvegicus) and the black rat (R. rattus). One of the important zoonotic pathogens related are the RNA virus Hantavirus, with high prevalence rates in South America. The aim of this study was to explore and identify the presence of Hantavirus in urban rodents from Gran La Plata, Argentina. The presence of anti-hantavirus IgG antibodies was determined by the Enzyme-Linked Immunosorbent Assay. Six samples turned out positive for Seoul virus (SEOV, p= 14.3%). These are the first records of SEOV in urban rodents in Gran La Plata. It represents the first report in R. rattus in Argentina, and in America. This situation underscores the inequality and historical forgetfulness of a portion of society, calling for urgent action to be taken in this regard.
ABSTRACT
RESUMEN Objetivo: Diversos estudios realizados sobre el linfoma de Hodgkin (LH) han determinado la expresión de la proteína de muerte programada (PD-L1) en las células de Reed-Sternberg-Hodgkin (HRS), con resultados variables. Esta proteína ha adquirido relevancia por su papel en la respuesta inmunitaria en las neoplasias malignas. El objetivo de este trabajo fue determinar la expresión inmunohistoquímica de PD-L1 en las HRS y su relación con la edad, sexo, estadio clínico y supervivencia global en una cohorte de pacientes peruanos. Materiales y métodos: Se evaluaron 25 biopsias de pacientes con diagnóstico de LH, lo que permitió determinar la expresión inmunohistoquímica de PD-L1 en las HRS en asociación con la sobrevida global (SG) y los datos clínicos de los pacientes. Resultados: Todos los casos mostraron expresión de PD-L1 en más del 1 %. No hubo diferencia estadística significativa en la SG cuando se comparó dos grupos de acuerdo con la expresión de PD-L1 con punto de corte en 50 %, ni tampoco con el estadio clínico (EC), la edad y el sexo. Conclusiones: Se ha encontrado una alta expresión de PD-L1 en los tumores con LH previos al tratamiento. No se ha encontrado asociación entre la expresión de PD-L1, la SG, la edad, el sexo o el EC. Son necesarios otros estudios con mayor cantidad de pacientes para reevaluar el impacto pronóstico de la expresión de esta proteína en LH.
ABSTRACT Objective: Various studies on Hodgkin's lymphoma (HL) have determined programmed death-ligand 1 (PD-L1) expression in Hodgkin and Reed-Sternberg (HRS) cells, with variable results. This protein has gained relevance for its role in the immune response in malignant neoplasms. This work aimed to determine PD-L1 immunohistochemical expression in HRS cells and its relationship with age, sex, clinical stage and overall survival (OS) in a cohort of Peruvian patients. Materials and methods: Twenty-five (25) biopsies from patients diagnosed with HL were assessed, which allowed determining PD-L1 immunohistochemical expression in HRS cells in relation to OS and clinical data of the patients. Results: All cases showed PD-L1 expression in more than 1 % of tumor cells. There was no statistically significant difference in OS when two groups were compared in terms of PD-L1 expression with a cut-off point of 50 %, clinical stage (CS), age and sex. Conclusions: High PD-L1 expression was found in pre-treatment HL tumors. No association was found between PD-L1 expression, OS, age, sex or CS. Further studies with a larger number of patients are necessary to reassess the prognostic impact of the expression of this protein in HL.
ABSTRACT
NTRODUCCIÓN: Los roedores sinantrópicos, representados por el ratón doméstico (Mus musculus), la rata parda (Rattus norvegicus) y la rata negra (Rattus rattus), representan un riesgo importante para la salud. En Sudamérica, la fragmentación socioeconómica se refleja en marcadas diferencias entre centros urbanos y áreas periféricas, y se asocia a un registro heterogéneo. El objetivo fue relevar datos por encuestas a los habitantes de dos barrios del Gran La Plata con características contrastantes para explorar, describir y evaluar la percepción en relación con la presencia de roedores en domicilio, peridomicilio y barrio como vehículos de transmisión de enfermedades. MÉTODOS: A partir de un diseño descriptivo exploratorio, se confeccionaron y realizaron encuestas siguiendo la técnica de muestreo estratificado. Se consideraron las variables género y grupo, de tal manera que la muestra tuviese la misma distribución. La información se transfirió a una base de datos y se analizó a través de IBM SPSS Statistics V25. RESULTADOS: Existe una preocupación común respecto al rol de los roedores urbanos como reservorios y fuentes de infección de patologías zoonóticas. En el barrio más vulnerable, la presencia de roedores fue más frecuente que en el centro de la ciudad. DISCUSIÓN: Este estudio provee un abordaje diferente en relación con roedores y patologías asociadas, considerando la percepción social y revelando su importancia para los programas de manejo y control.
Subject(s)
Parasites , Rodentia , Social Perception , Zoonoses , NoxaeABSTRACT
BACKGROUND Intermediate hosts are key organisms in maintaining parasite life cycles, because they can act as amplifiers in the transmission from natural reservoirs to humans. One of the most important groups of intermediate hosts for zoonotic nematode infections are gastropods,slugs and snails. These are essential organisms in the larval development of Angiostrongylus species. OBJECTIVES The objective of this paper is to review reports of Angiostrongylus spp. in naturally infected gastropods from the Americas, taking into account the diagnostic methods used in their identification, to be able to provide more accurate list of their intermediate hosts. We also discuss the factors that aid the dispersion of Angiostrongylus spp. in the Americas. METHODS This study reviews scientific publications and book sections on Angiostrongylus spp. in the Americas, including original works assessing larvae of Angiostrongylus in intermediate hosts. The eligible reports were classified accordingly to their geographical location, year of first record, and the larvae identification methodologies used. Digital repositories were used for the search. The bioecological characteristics of the main intermediate hosts are summarised. FINDINGS A total of 29 gastropod species that are naturally infected with Angiostrongylus spp. have been reported as intermediate hosts, 16 of which are land snails, two are freshwater snails, and 11 land slugs. MAIN CONCLUSIONS This study highlights the importance of integrative studies, analysing both the etiological agent and its transmission dynamic in the environment, the biological and ecological characteristics of the hosts, and the impact on host populations. It is necessary to increase interdisciplinary studies to determine the potential epidemiological health risk of angiostrongyliasis in the Americas, and thus be able to establish prevention, monitoring and contingency strategies in the region.
Subject(s)
Humans , Animals , Snails/parasitology , Strongylida Infections/diagnosis , Gastropoda/parasitology , Angiostrongylus/isolation & purification , Americas , Zoonoses , Angiostrongylus cantonensis , Disease Vectors , Gastropoda/physiologyABSTRACT
Abstract Toxoplasma gondii and Neospora caninum are closely related coccidian parasites (phylum Apicomplexa). This is the first study from urban synanthropic rodent species that involved serological and molecular diagnosis of T. gondii and N. caninum infection, and genotyping of T. gondii in Argentina. A total of 127 rodent samples were trap captured: Mus musculus (n = 78), Rattus norvegicus (n = 26) and Rattus rattus (n = 23). Antibodies against T. gondii and N. caninum were detected by IFAT in 32.8% (40/122) and 0.8% (1/122) of rodent samples, respectively, demonstrating contact with these protozoans. Additionally, T. gondii DNA was detected in 3.3% (4/123) of rodent central nervous system samples and 2 samples were genotyped by multilocus nPCR-RFLP. Neospora caninum DNA was not detected by PCR. The 2 genotyped samples were type III allele for all markers except for SAG-1 (type I for Rat1Arg and type II/III for Rat2Arg) and were identified as #48 and #2 (likely) according to the allele combinations reported on Toxo DB (Toxo-DB). The results of the present study revealed a wide distribution of T. gondii and less for N. caninum, in synanthropic rats and mice in the studied area.
Resumo Toxoplasma gondii e Neospora caninum são parasitas coccídeos intimamente relacionados (filo Apicomplexa). Este é o primeiro estudo de espécies de roedores sinantrópicos urbanos, o qual envolveu diagnósticos sorológicos e moleculares da infecção por T. gondii e N. caninum e genotipagem de T. gondii na Argentina. Um total de 127 amostras de roedores foram obtidas: Mus musculus (n = 78), Rattus norvegicus (n = 26) e Rattus rattus (n = 23). Anticorpos contra T. gondii e N. caninum foram detectados pela IFAT em 32,8% (40/122) e 0,8% (1/122) das amostras de roedores, respectivamente, demonstrando contato com esses protozoários. Adicionalmente, o DNA de T. gondii foi detectado em 3,3% (4/123) das amostras do sistema nervoso central de roedores e duas amostras foram genotipadas por nPCR-RFLP multilocus. O DNA de N. caninum não foi detectado por PCR. As 2 amostras genotipadas eram do tipo III para todos os marcadores, exceto para SAG-1 (tipo I para Rat1Arg e tipo II / III para Rat2Arg) e foram identificadas como # 48 e # 2 (provavelmente) de acordo com as combinações de alelos relatadas no Toxo DB (Toxo-DB). Os resultados do presente estudo indicam uma ampla distribuição de T. gondii e menor para N. caninum , em ratos e camundongos sinantrópicos na área estudada.
Subject(s)
Animals , Rats , Rodentia/parasitology , Toxoplasma/genetics , Toxoplasma/immunology , Neospora/genetics , Neospora/immunology , Argentina , Rodentia/classification , Urban Population , Polymorphism, Restriction Fragment Length , Antibodies, Protozoan/blood , Polymerase Chain Reaction , DNA, Protozoan/blood , Genotype , MiceABSTRACT
BACKGROUND Angiostrongyliasis is an infection caused by nematode worms of the genus Angiostrongylus. The adult worms inhabit the pulmonary arteries, heart, bronchioles of the lung, or mesenteric arteries of the caecum of definitive host. Of a total of 23 species of Angiostrongylus cited worldwide, only nine were registered in the American Continent. Two species, A. cantonensis and A. costaricensis, are considered zoonoses when the larvae accidentally parasitise man. OBJECTIVES In the present study, geographical and chronological distribution of definitive hosts of Angiostrongylus in the Americas is analysed in order to observe their relationship with disease reports. Moreover, the role of different definitive hosts as sentinels and dispersers of infective stages is discussed. METHODS The study area includes the Americas. First records of Angiostrongylus spp. in definitive or accidental hosts were compiled from the literature. Data were included in tables and figures and were matched to geographic information systems (GIS). FINDINGS Most geographical records of Angiostrongylus spp. both for definitive and accidental hosts belong to tropical areas, mainly equatorial zone. In relation to those species of human health importance, as A. cantonensis and A. costaricensis, most disease cases indicate a coincidence between the finding of definitive host and disease record. However, in some geographic site there are gaps between report of definitive host and disease record. In many areas, human populations have invaded natural environments and their socioeconomic conditions do not allow adequate medical care. MAIN CONCLUSIONS Consequently, many cases for angiostrongyliasis could have gone unreported or unrecognised throughout history and in the nowadays. Moreover, the population expansion and the climatic changes invite to make broader and more complete range of observation on the species that involve possible epidemiological risks. This paper integrates and shows the current distribution of Angiostrongylus species in America, being this information very relevant for establishing prevention, monitoring and contingency strategies in the region.
Subject(s)
Strongylida Infections/parasitology , Strongylida Infections/epidemiology , Angiostrongylus/classification , Disease Reservoirs , Disease Notification , Geographic Information SystemsABSTRACT
To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.
Subject(s)
Animals , Male , Angiostrongylus/physiology , Heart/parasitology , Host Specificity/physiology , Lung/parasitology , Rodent Diseases/parasitology , Sigmodontinae/parasitology , Argentina , Host-Parasite Interactions/physiology , Lung/pathology , Myocardium/pathology , Rodentia/parasitology , Sampling Studies , Species SpecificityABSTRACT
Aspects related to hatching, time-lapse between presenting the blood meal and beginning of feeding, feeding time, postfeed defecation delay,life time, mortality and fecundity for each stage of Meccus picturatus, life-cycle were evaluated and compared in two cohorts of M. picturatus fed on hens or rabbits. The hatching rate observed for each of the two studied groups of eggs was 78.1 percent (n = 2298) on the group fed on hens and 82.1 percent (n = 2704) on that fed on rabbits, and the average time of hatching was 20 days. Mean time-lapse for beginning feeding was under 3 min in nymphal stages and postfeed defecation delay was under 10 min in all stages, in both cohorts. Mean feeding time was significantly (P < 0.05) shorter in triatomines fed on hens than on rabbits. A similar number of nymphs of each cohort, 69 fed on hens (34.5 percent) and 68 fed on rabbits (34 percent), completed the cycle. No significantly (P > 0.05) differences were recorded among the average times from NI to adult in the cohort fed on hens (196.8 ± 15.8 days) and the average time in the cohort fed on rabbits (189.5 ± 22.9). The average span in days for each stage fed on hens was not significantly different to the average span for each stage fed on rabbits. The number of blood meals at each nymphal stage varied from 1 to 6 in both cohorts. The mortality rates were higher on fifth nymphal stage, in both cohorts. No significant (P > 0.05) differences were recorded on mortality rates on most nymphal stages of both cohorts. The average number of eggs laid per female from the cohort fed on hens in a 9-month period was 791.1, whereas the average number of eggs in the cohort fed on rabbits was 928.3