Taenia solium: Socioeconomic changes and prevalence evolution in four endemic communities in northwestern Mexico.

In Mexico, for the past 30 years, a continuous decrease in the incidence of clinical taeniosis/cysticercosis has been documented. This work aimed to determine the influence of improvement in socioeconomic conditions on the prevalence of Taenia solium in four endemic communities in northwestern Mexico. This study was carried out in two phases. First, documentary information (1989-2018) was collected about the prevalence of Theridion solium in the federal entity of Sinaloa State. Second, a pilot study was performed in four communities of Sinaloa, which had an endemic history of Taenia transmission. In each community, a risk factor questionnaire was applied, and serum and stool samples were collected for convenience in a non-probabilistic way. Anti-cysticercus antibodies and adult worm coproantigen were determined. The documentary analysis showed the incidence of taeniosis and cysticercosis to have decreased by 98 and 53%, respectively, while the human development index increased by 5% (1992-2017). Our data suggest that the risk of parasitic transmission is low, although female sex was a risk factor for reporting tremors or seizures (prevalence rate 2.1336, CI: 1.1821-3.8508) and background of tapeworm infection (prevalence rate 1.2893, CI: 0.9795-1.6972). No tapeworms or eggs were found while examining stool samples, but protozoa cysts were observed in four samples. Unexpectedly, only one of the 79 stool samples was positive for coproantigens. This positive result was confirmed in a second sample. However, the evaluation of a third sample was negative. No antibodies were found in human (n = 377) or pig (n = 69) samples. These data suggest parasite transmission has been interrupted and could be possibly associated with improving socioeconomic conditions. Further studies are needed to determine the real prevalence of zoonoses in Mexico.

Kinetics of Eosinophils during Development of the Cellular Infiltrate Surrounding the Nurse Cell of Trichinella spiralis in Experimentally Infected Mice.

We study the kinetics of eosinophils during the development of the cellular infiltrate surrounding the nurse cell of Trichinella spiralis (T. spiralis) in experimentally infected mice. Male CD1 mice were experimentally infected with 50 viable muscle larvae of the MSUS/MEX/91/CM-91 T. spiralis strain. Tongues and diaphragms were obtained daily from days 13 to 39 post infection. Diaphragms were compressed and subjected to Giemsa stain. Tongues were histologically sectioned and stained with erythrosine B or hematoxylin and eosin. The cellular infiltrate and the nurse cell-larva complex were detected by optical microscopy since day 16 post infection. The size of the larva increased exponentially during the course of the infection. The kinetics of eosinophils showed a multimodal trend, with a bimodal predominance. The maximum peaks were reached on days 21 and 27 post infection. The results of this study demonstrate that eosinophils occur abundantly in two transcendent moments of the T. spiralis life cycle: first, when the stage 1 larva invades the myocyte and second when the nurse cell-larva complex has been fully developed. These results help one to understand the immunobiology of T. spiralis, highlighting the importance of eosinophils in the survival of the larva in skeletal muscle. Further studies are needed to characterize the cell populations that comprise the cellular infiltrate during the development of the mother cell.

Comparative analysis of antibodies and lymphocytes in pulmonary tuberculosis patients with negative and positive cultures.

INTRODUCTION: The sputum smear or the culture are the definitive diagnosis of pulmonary tuberculosis. Only a fraction of clinical patients are culture-confirmed. METHODOLOGY: A total of 24 clinical cases (40 ± 14 years old) with positive smear and negative co-morbidity were studied. Cases were selected from 600 patients who attended the pneumology service over two years. A sputum sample was cultured in Löwenstein-Jensen medium with consequent amplification of the rrnA V2 promoter, the differentiation region 4, and the IS6110 insertion sequence of Mycobacterium tuberculosis. After the culture result, the patients were divided into negative (n = 14) or positive (n = 10) culture groups. In addition, 30 samples from healthy donors (45 ± 10 years) were studied. The numbers of CD4, CD8 and CD19 lymphocytes were determined by flow cytometry. Levels of IgA and IgG to M. tuberculosis were measured by ELISA. RESULTS: IgG and IgA levels were detected in patients with positive culture, while only IgA was found in patients with negative cultures. The lymphocyte populations in the two groups were similar.  The presence of a pleural apical cap was found more frequently in patients with negative- (57%) than with positive cultures (10%). CONCLUSIONS: The isotype profile in patients with positive cultures was both IgA and IgG positive, while in patients with negative culture, only IgA was found. The results will contribute to improve the diagnostic algorithm and appropriate treatment of patients with clinical tuberculosis. Further studies are needed to determine if this profile is predictive of the outcome of isolation.

Frequency of Helminth Eggs in Faeces of Puppies Living in Urban or Rural Environments of Mexico City.

BACKGROUND: The dog, Canis familiaris, a domestic animal that maintains close contact with humans and other animals, is considered as a potential source of zoonotic parasites. The current study aimed to determine the frequency of helminth eggs in feces of puppies of dog living in urban or rural environments of Mexico City between spring and summer of 2013. METHODS: Stool samples (n=180) were analyzed by sedimentation with formalin-ether. Samples were collected from puppies living in the urban zone (n=90; stray animals) or in the rural environment (n=90; stray animals, animals with owner and animals confined to a canine control center). RESULTS: Eggs of Toxocara canis (41%), Ancylostoma caninum (8%) and Dipylidium caninum (3%) were found in the rural environment but none in the urban zone. A frequency of 19% of Toxocara eggs was found in the canine control center, while, in stray puppies, the frequency was of 12% and 10% in animals with owner. Eggs of Toxocara were found in 33% samples of puppies with history of antiparasitic treatment. CONCLUSION: This study supports the observation of helminth population reduction in urban environments. Further studies are needed to identify the factors that affect the development and transmission of helminth eggs in urban environments.

Transición parasitaria: experiencia en un hospital pediátrico de tercer nivel (1990-2010) / Parasitological transition: Experience in a third-level pediatric hospital (1990-2010)

ResumenINTRODUCCIÓN: Hace algunos años, el motivo principal para la solicitud del diagnóstico parasitológico era la sospecha de una etiología de base parasitaria. En la actualidad, el motivo de consulta y la solicitud del diagnóstico se encuentran asociados con una comorbilidad hemato-oncológica, autoinmune, inmunodeficiente o una condición postrasplante.MÉTODO: Se analizaron los resultados del laboratorio de parasitología clínica del Hospital Infantil de México Federico Gómez de enero de 1990 a diciembre del 2010, para obtener la frecuencia y distribución de parásitos y comensales por año y década.RESULTADOS: Se analizaron 211,600 muestras del periodo estudiado, con una media anual de 10,100 y desviación estándar de 3,500. El porcentaje de parásitos y comensales fue del 37.73%, y la frecuencia de positividad solo a parásitos fue del 21.4%. La diferencia de proporciones entre décadas resultó significativa, con una p < 0.0001.CONCLUSIONES: La tendencia en el comportamiento de las parasitosis intestinales durante el periodo estudiado mostró un cambio tanto en frecuencia como en género y especie de los agentes reportados. La generación de información de carácter epidemiológico es necesaria para conocer la tendencia de las parasitosis y de sus variaciones a través del tiempo.

AbstractBACKGROUND: In recent years, the main reason for parasitological diagnosis was suspicion of a parasitic etiology. Currently, diagnosis and consultation are associated with co-morbidity with a hemato-oncological, autoimmune, immunodeficiency or post-transplant condition.METHODS: Results collected from the Parasitology Laboratory of the Hospital Infantil de Mexico Federico Gómez from January 1990 to December 2010 were analyzed to determine the frequency and distribution of parasites and commensals per year and decade.RESULTS: There were 211,600 samples analyzed with a statistical media of 10,100 and a standard deviation of 3,500 samples. Percentage of observations for parasitic structures as well as commensals was 37.73% according to Pearson Chi square with a significant difference among percentages between decades (p < 0.0001).CONCLUSIONS: Behavioral tendency of intestinal parasitosis during the last two decades shows a change in frequency and genera from the agents that were reported at this pediatric health care level. The processing of epidemiologic information is important in order to determine the response of the parasitosis and its variations over time.

[Parasitological transition: Experience in a third-level pediatric hospital (1990-2010)]. / Transición parasitaria: experiencia en un hospital pediátrico de tercer nivel (1990-2010).

BACKGROUND: In recent years, the main reason for parasitological diagnosis was suspicion of a parasitic etiology. Currently, diagnosis and consultation are associated with co-morbidity with a hemato-oncological, autoimmune, immunodeficiency or post-transplant condition. METHODS: Results collected from the Parasitology Laboratory of the Hospital Infantil de Mexico Federico Gómez from January 1990 to December 2010 were analyzed to determine the frequency and distribution of parasites and commensals per year and decade. RESULTS: There were 211,600 samples analyzed with a statistical media of 10,100 and a standard deviation of 3,500 samples. Percentage of observations for parasitic structures as well as commensals was 37.73% according to Pearson Chi square with a significant difference among percentages between decades (p<0.0001). CONCLUSIONS: Behavioral tendency of intestinal parasitosis during the last two decades shows a change in frequency and genera from the agents that were reported at this pediatric health care level. The processing of epidemiologic information is important in order to determine the response of the parasitosis and its variations over time.

Isolation of IgG antibodies to Toxocara in ankylosing spondylitis patients with acute anterior uveitis.

PURPOSE: Since few reports had been published on the prevalence of toxocariasis in ankylosing spondylitis (AS) patients with acute non-granulomatous anterior uveitis (ANGAU), the aim of this work was to determine the presence of antibodies against Toxocara canis in AS patients with ANGAU. METHODS: Thirty-six patients (14 female and 22 male) with AS were enrolled in the study. The history of ANGAU was accepted only if diagnosed by an ophthalmologist. The detection of IgG antibodies to T. canis was determined by enzyme-linked immunosorbent assay. In addition, antibodies to Ascaris lumbricoides were also tested to verify non-specific reactions. RESULTS: The prevalence of ANGAU in the AS patients was 58% (21 / 36), and 38% (8 / 21) of the patients with ANGAU were positive for antibodies to Toxocara, while 7% (1 / 15) of AS patients without ANGAU were positive for T. canis (p = 0.038, two tails; mid-p exact). No antibodies were detected to A. lumbricoides antigens in the serum samples of patients with AS. CONCLUSIONS: These data suggest that the seroprevalence of antibodies to T. canis is high in Mexican patients with AS-associated uveitis, suggesting a chronic asymptomatic toxocariosis, which could be associated with the pathogenesis of ANGAU; however, further larger-scale studies are needed to confirm this observation.

Taeniasis and cysticercosis prevalence in a small village from Northeastern Brazil.

UNLABELLED: Although not considered as an endemic region, the Northeast of Brazil has the necessary conditions for the development of taeniasis-cysticercosis complex. In a previous paper, we demonstrated that Mulungu do Morro municipality, in the State of Bahia, has a high seroprevalence to cysticercosis in epileptic patients. OBJECTIVE: to determine the prevalence of taeniasis and positive cysticercosis serology in the population of Mulungu do Morro. METHOD: blood and stool samples were collected from a random sampling of the population, by family. The identification of antibodies against T. solium cysticerci was made by EITB and T. solium antigens were identified using a polyclonal antibody-capture ELISA. RESULTS: the cysticercosis seroprevalence was 1.6% (C.I. = 0.8 to 2.8%) and the taeniasis prevalence 4.5% (C.I. = 3.0 to 6.5%). Seropositivity to cysticercosis was higher among those who lived in a house of a person testing positive for coproantigen, p=0.017. CONCLUSION: our results demonstrate that the taeniasis-cysticercosis complex is endemic in Mulungu do Morro. We believe that all areas in the world with the same socio-economic and sanitary characteristics are likely to have high prevalence of this parasite.

Taeniasis and cysticercosis prevalence in a small village from Northeastern Brazil

Although not considered as an endemic region, the Northeast of Brazil has the necessary conditions for the development of taeniasis-cysticercosis complex. In a previous paper, we demonstrated that Mulungu do Morro municipality, in the State of Bahia, has a high seroprevalence to cysticercosis in epileptic patients. OBJECTIVE: to determine the prevalence of taeniasis and positive cysticercosis serology in the population of Mulungu do Morro. METHOD: blood and stool samples were collected from a random sampling of the population, by family. The identification of antibodies against T. solium cysticerci was made by EITB and T. solium antigens were identified using a polyclonal antibody-capture ELISA. RESULTS: the cysticercosis seroprevalence was 1.6 percent (C.I. = 0.8 to 2.8 percent) and the taeniasis prevalence 4.5 percent (C.I. = 3.0 to 6.5 percent). Seropositivity to cysticercosis was higher among those who lived in a house of a person testing positive for coproantigen, p=0.017. CONCLUSION: our results demonstrate that the taeniasis-cysticercosis complex is endemic in Mulungu do Morro. We believe that all areas in the world with the same socio-economic and sanitary characteristics are likely to have high prevalence of this parasite