19 research outputs found

    Chagas Disease in the Yucatan Peninsula, Mexico

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    American trypanosomiasis or Chagas disease is caused by the protozoan Trypanosoma cruzi, which affects a wide variety of hosts including the man, until now treatment options or vaccines developed are not enough to control or prevent infected cases. The main way of transmission is vectorial, through insects of the Reduviidae family, as well by congenital transmission, blood/organ transplants or oral transmission. Chagas disease are considered as endemic in many areas due to the presence and lack of control of insect vectors. Many touristic places in Latin America are located in endemic areas; however, there is a nonexistence of knowledge by touristic service providers about the theme. For that reason, there is a latent risk that tourists who come to vacation in endemic areas are exposed get the infection. The risk factors are well identified, and this allows that well-defined prevention strategies can be established in order to avoid the presentation of cases in visitors to the tourist zones. This chapter aimed to describe the situation of Chagas disease in touristic areas of the Caribbean of America Latina as and to provide a brief review of information that allows visitors to know about the epidemiology and potential risks of this infection

    Multiplex Real-Time PCR Assay Using TaqMan Probes for the Identification of Trypanosoma cruzi DTUs in Biological and Clinical Samples

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    Background: Trypanosoma cruzi has been classified into six Discrete Typing Units (DTUs), designated as TcI–TcVI. In order to effectively use this standardized nomenclature, a reproducible genotyping strategy is imperative. Several typing schemes have been developed with variable levels of complexity, selectivity and analytical sensitivity. Most of them can be only applied to cultured stocks. In this context, we aimed to develop a multiplex Real-Time PCR method to identify the six T. cruzi DTUs using TaqMan probes (MTq-PCR).Methods/Principal Findings: The MTq-PCR has been evaluated in 39 cultured stocks and 307 biological samples from vectors, reservoirs and patients from different geographical regions and transmission cycles in comparison with a multi-locus conventional PCR algorithm. The MTq-PCR was inclusive for laboratory stocks and natural isolates and sensitive for direct typing of different biological samples from vectors, reservoirs and patients with acute, congenital infection or Chagas reactivation. The first round SL-IR MTq-PCR detected 1 fg DNA/reaction tube of TcI, TcII and TcIII and 1 pg DNA/reaction tube of TcIV, TcV and TcVI reference strains. The MTq-PCR was able to characterize DTUs in 83% of triatomine and 96% of reservoir samples that had been typed by conventional PCR methods. Regarding clinical samples, 100% of those derived from acute infected patients, 62.5% from congenitally infected children and 50% from patients with clinical reactivation could be genotyped. Sensitivity for direct typing of blood samples from chronic Chagas disease patients (32.8% from asymptomatic and 22.2% from symptomatic patients) and mixed infections was lower than that of the conventional PCR algorithm.Conclusions/Significance: Typing is resolved after a single or a second round of Real-Time PCR, depending on the DTU. This format reduces carryover contamination and is amenable to quantification, automation and kit production.This work received financial support from the Ministry of Science and Technology of Argentina [PICT 2011-0207 to AGS] and the National Scientific and Technical Research Council in Argentina (CONICET) [PIP 112 2011-010-0974 to AGS]. Work related to evaluation of biological samples was partially sponsored by the Pan-American Health Organization (PAHO) [Small Grants Program PAHO-TDR]; the Drugs and Neglected Diseases Initiative (DNDi, Geneva, Switzerland), Wellcome Trust (London, United Kingdom), SANOFI-AVENTIS (Buenos Aires, Argentina) and the National Council for Science and Technology in Mexico (CONACYT) [FONSEC 161405 to JMR]

    In Vivo Activity Of (8-Hydroxymethylen) - Trieicosanyl Acetate Against Trypanosoma Cruzi During Acute Phase Of The Infection

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    The antiprotozoal activity in vivo against Trypanosoma cruzi of (8-hydroxymethylen)-trieicosanyl acetate was evaluated in BALB/c mice during the acute phase of Chagas’ disease (15 days after infection). Animals were treated during 15 days at doses of 16.8 and 33.6 µg/g, reduced parasitemia of 77.6 and 64.1% was observed respectively, in comparison with positive control mice (allopurinol 8.5 µg/g) which reduced only 29.7%. Also, amastigote nests in cardiac tissue were significant reduced in treated mice groups. The regression of effect induced after the suppression of the treatment with the compound was evaluated; animals were infected and simultaneously began the treatment with the compound during 20 days (16.8 and 33.6 µg/g). Mice were monitored after the end of the treatment for one more week. A good antitrypanosomal response was observed (66.1 and 68.9% less than untreated mice) during treatment, but 8 days after suspension of treatment, parasitemia level increased, reducing only 58.6 and 56.29 % respectively in treated animals compared with no treated.L'activité in vivo contre antiprotozoaires Trypanosoma cruzi de (8-hydroxymethylen)-acétate de trieicosanyl a été évaluée chez des souris BALB / c pendant la phase aiguë de la maladie de Chagas (15 jours après l'infection). Les animaux ont été traités pendant 15 jours à des doses de 16,8 et 33,6 mg / g, la parasitémie réduite de 77,6 et 64,1% a été observée, respectivement, en comparaison avec les souris de contrôle positif (allopurinol 8,5 mg / g), qui réduit que de 29,7%. En outre, les nids amastigote dans le tissu cardiaque ont été réduits dans les groupes importants chez les souris traitées. La régression de l'effet induit après la suppression du traitement avec le composé a été évalué, les animaux ont été infectés et, simultanément, a commencé le traitement avec le composé pendant 20 jours (16,8 et 33,6 mg / g). Les souris ont été suivis après la fin du traitement pour une semaine de plus. Une bonne réponse a été observée antitrypanosomal (66,1 et 68,9% de moins que les souris non traitées) en cours de traitement, mais 8 jours après la suspension du traitement, le niveau de la parasitémie a augmenté, réduisant seulement 58,6 et 56,29% respectivement chez les animaux traités par rapport à aucun traitement

    In Vivo Antiprotozoal Activity of the Chloroform Extract from Carica papaya Seeds against Amastigote Stage of Trypanosoma cruzi during Indeterminate and Chronic Phase of Infection

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    In order to evaluate the antiprotozoal activity of the chloroform extract of Carica papaya seeds during the subacute and chronic phase of infection of Trypanosoma cruzi, doses of 50 and 75 mg/kg were evaluated during the subacute phase, including a mixture of their main components (oleic, palmitic, and stearic acids). Subsequently, doses of 50 and 75 mg/kg in mice during the chronic phase of infection (100 dpi) were also evaluated. It was found that chloroform extract was able to reduce the amastigote nests numbers during the subacute phase in 55.5 and 69.7% (P > 0.05) as well as in 56.45% in animals treated with the mixture of fatty acids. Moreover, the experimental groups treated with 50 and 75 mg/kg during the chronic phase of the infection showed a significant reduction of 46.8 and 53.13% respectively (P < 0.05). It is recommended to carry out more studies to determine if higher doses of chloroformic extract or its administration in combination with other antichagasic drugs allows a better response over the intracellular stage of T. cruzi in infected animal models and determine if the chloroform extract of C. papaya could be considered as an alternative for treatment during the indeterminate and chronic phase of the infection

    Antitrypanosomal Activity Of Senna Villosa In Infected Balb/C Mice With Trypanosoma Cruzi During The Sub Acute Phase Of Infection

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    Antitrypanosomal activity of chloroform extract of Senna villosa leaves was evaluated in the sub acute phase of mice infected with Trypanosoma cruzi . Oral doses of 3.3, 6.6 and 13.2 µg/g were tested during 15 days on infected mice BALB/c, beginning treatment 40 days after infection to evaluate specifically the antitrypanosomal activity over the amastigote form of the parasite. Two different amount of parasites (100 and 500) were inoculated to 25 mice for each doses tested. At the end of the assay the animals were sacrificed and cardiac and skeletal tissue sections were stained with hematoxylin-eosin (HE) for identification and quantification of amastigote nest. In mice infected with 100 parasites, a significant reduction in the number of amastigote nest was observed in cardiac tissue of treated animals at all doses evaluated (p<0.05). An important reduction of amastigote nest was also observed in treated animals and infected with 500 parasites in comparison with no treated mice or treated with allopurinol.Activité antitrypanosomal de chloroforme extrait de feuilles Senna villosa a été évaluée dans la sous phase aiguë de souris infectées par Trypanosoma cruzi . Des doses orales de 3,3, 6,6 et 13,2 µg / g ont été testés pendant 15 jours sur des souris infectées BALB /c, le début du traitement 40 jours après l&apos;infection d&apos;évaluer précisément l&apos;activité antitrypanosomal sur la forme amastigote du parasite. Deux montant différent de parasites (100 et 500) ont été inoculés à 25 souris pour chaque doses testées. À la fin de l&apos;essai les animaux ont été sacrifiés et des coupes de tissus cardiaques et squelettiques ont été colorées à l&apos;hématoxyline- éosine (HE) pour l&apos;identification et la quantification du nid amastigote. Chez les souris infectées avec 100 parasites, une réduction significative du nombre de nids amastigote a été observée dans le tissu cardiaque des animaux traités à toutes les doses évaluées (p <0,05). Une réduction importante du nid amastigote a également été observée chez les animaux traités et infectés avec 500 parasites par rapport à pas de souris traitées ou traitées avec l&apos;allopurinol

    Antitrypanosomal Activity of Senna Villosa in Infected Balb/C Mice with Trypanosoma Cruzi During the Sub Acute Phase of Infection

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    Antitrypanosomal activity of chloroform extract of Senna villosa leaves was evaluated in the sub acute phase of mice infected with Trypanosoma cruzi. Oral doses of 3.3, 6.6 and 13.2 µg/g were tested during 15 days on infected mice BALB/c, beginning treatment 40 days after infection to evaluate specifically the antitrypanosomal activity over the amastigote form of the parasite. Two different amount of parasites (100 and 500) were inoculated to 25 mice for each doses tested. At the end of the assay the animals were sacrificed and cardiac and skeletal tissue sections were stained with hematoxylin-eosin (HE) for identification and quantification of amastigote nest. In mice infected with 100 parasites, a significant reduction in the number of amastigote nest was observed in cardiac tissue of treated animals at all doses evaluated (p<0.05). An important reduction of amastigote nest was also observed in treated animals and infected with 500 parasites in comparison with no treated mice or treated with allopurinol

    THE OCCURRENCE OF TOXOPLASMA GONDII ANTIBODIES IN BACKYARD PIGS AND CATS FROM AN ENDEMIC TROPICAL AREA OF MEXICO

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    In Mexico, backyard animal production system is an important source of food for domestic consumption as in many other developing countries and is characterized by a virtually nonexistent sanitary management. With the objective to evaluate the prevalence and risk factors associated with antibodies against T. gondii in pigs and cats from an endemic area in the Mexican tropics, a cross-sectional study was performed in 30 backyard pigs and 50 cats. Pigs and cats were blood sampled and tested by an indirect IgG ELISA to detect antibodies against T. gondii. Seropositivity rate in cats were of 100 % (50/50) and were identified a 75 % (23/30) of positives pigs. Results indicate a very high level of circulation of the agent in the area and a high risk of pigs to become infected. It is concluded that cats and pigs maintained under backyard had high seroprevalence to T. gondii. It is necessary implement sanitary measures in the management of backyard to avoid transmission to people consuming pork meat from backyard systems

    Eficacia de la amplificación de la polimerasa con recombinasa para diagnosticar la infección por Trypanosoma cruzi en perros con alteraciones cardíacas en un área endémica de México.

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    Chagas disease is a lingering Public Health problem in Latin America with ∼5.7 million people infected with Trypanosoma cruzi. Transmission is still taking place in most countries of the Americas, including the United States. Dogs are frequently infected with T. cruzi and its high infection prevalence is associated with increased risk of Chagas disease in humans. The city of Mérida in the Yucatan peninsula is endemic for Chagas disease and canines are frequently infected with T. cruzi. The objective of this study was to evaluate the performance of a qualitative point of care (POC) molecular test (RPA-LF, recombinase polymerase amplification-lateral flow) developed in our laboratory for identifying infected dogs. We used retrospective samples of dogs that came for consultation because of cardiac alterations and proved to be infected with T. cruzi as determined by enzyme-linked immunosorbent assay (ELISA), Western blot, and quantitative PCR (qPCR). The analytical sensitivity indicated that RPA-LF amplified T. cruzi DNA in samples containing almost equal to one to two parasites per reaction. Serial twofold dilutions of T. cruzi epimastigotes showed that the test had 95% (19/20) repeatability at concentrations of two parasites per reaction. The test showed no cross reactivity with human DNA or other protozoan parasites (Trypanosoma rangeli, Leishmania spp., and Plasmodium spp.). RPA-LF had the capacity to amplify all discrete typing units (DTUs I-VI) of T. cruzi that circulate in domestic or extradomestic environments. The RPA-LF had 93.2% (95% confidence interval 87.2-98.1) sensitivity and excellent agreement with qPCR used as gold standard (Cohen's Kappa test = 0.963). ELISA was positive in 96.6% (85/88) of dogs, which together with the molecular tests confirmed the frequent contact with infected triatomine bugs in the city of Mérida. These preliminary results on the diagnostic efficacy of the RPA-LF deserve further large-scale field testing of this POC test for T. cruzi infection in endemic areas
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