Genotyping of Leptospira interrogans isolates from Mexican patients.

The aim of this study was genotypically characterize Leptospira sp. clinical isolates from Mexico which were previously identified as Leptospira interrogans serovar Pomona (POM) by phenotypic methods. The Random Amplified Polymorphic DNA (RAPD) method was used for DNA amplification with five oligonucleotides. A dendrogram was constructed using the Unweighted Pair Group Method Analysis (UPGMA). During the genotypic characterization, the studied isolates constituted a group which was associated with the reference strain L. interrogans serovar Pomona. The Minimum Spanning Networks (MST) analysis revealed the same cluster between Mexican isolates and the reference strain POM. Clinical isolates identified as L. interrogans serovar POM have a clonal reproduction type, suggesting that this clone is distributed in different regions of Mexico.

Canine leishmaniasis in México: the detection of a new focus of canine leishmaniasis in the state of Guerrero correlates with an increase of human cases

Background. In Mexico, a steady increase of patients with visceral leishmaniasis has been reported, especially in the states of Chiapas and Guerrero, yet only limited information exists on canine leishmaniasis in areas of visceral leishmaniasis in Mexico. A veterinary report of dogs with nonhealing cutaneous lesions in Pungarabato, Guerrero led us to investigate the possible presence of Leishmania infection in an area where Lutzomyia longipalpis and Lutzomyia evansi, both vectors of Leishmania infantum, have been described. Methods. We analyzed skin lesions of 25 dogs by immunohistochemistry and PCR. Results. We found a 60% prevalence of Leishmania-infected dogs, the infection rate being higher in males than females. Thus, we established a new focus of canine leishmaniasis, and although to date no patients have been reported in this municipality, it is close to and shares the same ecological characteristics of dry tropical forests as regions where visceral leishmaniasis has been reported in Mexico. We also include updated information of localities of visceral leishmaniasis in Mexico as well as the distribution of possible sand fly vectors. Conclusions. Our data show the need to ascertain the magnitude of this new focus in view of the current data on human visceral leishmaniasis, a disease that is surging in Mexico.

Daño miocárdico grave por leptospirosis: informe de un caso fatal en México / Severe myocardial damage caused by leptospirosis: report of a fatal case in Mexico

Chagasic cardiomyopathy is a common disease in Latin America, however similar clinical pictures exist that can be confused with this, as they give negative results to the tests that detects T. cruzi, like non Chagasic rural endemic chronic cardiopathy, highly common in Venezuela. Using histopathology techniques, "idiopathic cardiomyopathy" is frequently found as the cause of death when the etiology of this disease is not known. This paper presents the case of a man of 26-years-old who died of dilated cardiomyopathy secondary to leptospirosis. Clinically, in addition to the cardiac failure, jaundice, hyperbilirubinemia, transaminases increase, proteinuria and hematuria were present. Initially it was suspected Chagasic cardiomyopathy but the epidemiologic background and the parasitologic and serologic tests for T. cruzi gave negative results. The dark field microscopy videorecording of blood and urine samples, argentic impregnation and immunohistochemistry tests as well as haemoculture in EMJH medium were positive for L. interrogans serovar Pomona. Postmortem we confirmed the presence of leptospira in different tissues through of histopathology, argentic impregnation, indirect immunofluorescence and immunohistochemistry.

[Severe myocardial damage caused by leptospirosis. Report of a fatal case in Mexico]. / Daño miocárdico grave por leptospirosis. Informe de un caso fatal en México.

Chagasic cardiomyopathy is a common disease in Latin America, however similar clinical pictures exist that can be confused with this, as they give negative results to the tests that detects T. cruzi, like non Chagasic rural endemic chronic cardiopathy, highly common in Venezuela. Using histopathology techniques, "idiopathic cardiomyopathy" is frequently found as the cause of death when the etiology of this disease is not known. This paper presents the case of a man of 26-years-old who died of dilated cardiomyopathy secondary to leptospirosis. Clinically, in addition to the cardiac failure, jaundice, hyperbilirubinemia, transaminases increase, proteinuria and hematuria were present. Initially it was suspected Chagasic cardiomyopathy but the epidemiologic background and the parasitologic and serologic tests for T. cruzi gave negative results. The dark field microscopy videorecording of blood and urine samples, argentic impregnation and immunohistochemistry tests as well as haemoculture in EMJH medium were positive for L. interrogans serovar Pomona. Postmortem we confirmed the presence of leptospira in different tissues through of histopathology, argentic impregnation, indirect immunofluorescence and immunohistochemistry.

Apuntes para la historia de la enfermedad de Chagas en México / Notes for the history of Chagas' disease in Mexico

El trabajo intenta resumir los datos históricos más importantes sobre el conocimiento de la enfermedad de Chagas en México y su correlación con otros países latinoamericanos, desde el descubrimiento de los triatóminos, de los cuales se desconocía en ese entonces su capacidad de transmisión, hasta los recientes trabajos sobre eliminación de la transmisión vectorial y por hemotransfusión, así como los intentos de mejorar el diagnóstico de la enfermedad, utilizando métodos de biología molecular. Entre los datos más importantes sobre México, se citan los de los descubrimientos de la enfermedad de Chagas, de los transmisores y reservorios, así como la forma en que la Campaña Nacional de Erradicación Palúdica, simultáneamente al control de la malaria, evitó que México se convirtiera en un país hiperchagásico, mediante los rociados periódicos intradomiciliarios con DDT y otros insecticidas, la existencia de Chagas visceral y congénito, así como otros datos seroepidemiológicos obtenidos por la encuesta serológica nacional, los de riesgo de transmisión de Trypanosoma cruzi por hemotransfusión, además de los principales trabajos de los autores mexicanos más reconocidos, desde Mazzotti hasta nuestros días. También se hace un reconocimiento al único investigador que ha logrado simultáneamente, descubrir al transmisor, al agente etiológico y a la enfermedad: Carlos Chagas. Finalmente, en vista de que se están detectando casos frecuentes de miocardiopatía aparentemente chagásica negativos por serología y otros métodos diagnósticos a T. cruzi, y positivos, incluso por cultivo a Leptospira interrogans, se hace hincapié en el diagnóstico de esta bacteriosis en ese tipo de enfermos.

This work attempts to summarize the most important historical data concerning knowledge on Chagas' disease in Mexico and its correlation with other Latin-American countries, from the discovery of triatomines, whose transmission capacity was unknown at the time to recent works that treat elimination forms of transmission by vectors and blood transfusion, as well as intents to improve disease diagnosis by means of molecular biology. Among the most important data on Mexico, we mention those related with the discovery of Chagas' disease and its disease transmitters and reservoir, and the manner in which the Campaña Nacional de Erradicacion Paludica simultaneously controls malaria and Chagas' disease, which avoided Mexico becoming to be a hyperchagasic country. This national campaign employed the method of periodic spraying of DDT and other insecticides within the population's households. Thus, we additionally have noted the existence of visceral and congenital Chagas' disease. Other important information comprises epidemiologic data obtained through the Encuesta Nacional Seroepidemiologica vs Enfermedad de Chagas and the Encuesta sobre el Riesgo de Transmision de Trypanosoma cruzi by Hemotransfusion, in addition to the mains works of the most widely recognized Mexican authors from Mazzotti to date. We also attempt to recognize herein the sole researcher who achieved simultaneous discovery of the disease's transmitter, its etiologic agent, and the disease itself: Carlos Chagas. Finally, in view of that fact that at present frequent detection has occurred of cases of cardiomyopathy apparently due to Chagas' disease that are, on the one hand, negative for serology test and other diagnostic means for T. cruzi and that on the other hand have been confirmed as positive for Leptospira interrogans by tests including Leptospira isolates, we emphasize the importance of diagnosing the presence of this bacteria in the previously mentioned type of patient.

[Diagnosis of chronic leptospirosis, comparison between the microscopic agglutination and three confirmatory diagnostic techniques]. / Diagnóstico de leptospirosis crónica, comparación entre la aglutinación microscópica y 3 técnicas diagnósticas confirmatorias.

In spite of the fact that the serology and, particularly, the microscopic agglutination technique are the most recommended methods to diagnose leptospirosis, they frequently fail in the diagnosis of individual cases and in outbreaks, where the diagnosis is frequently made post-mortem by argentic and immunohistochemical impregnation,. These techniques are also unable to diagnose chronic leptospirosis, since the antibody titres are very low (< or = 1:80) in it. Due to this fact, and to the need of a reliable and appropriate lab diagnosis, a comparative study of dark field videorecording, supported by argentic impregnation and immunohistochemistry in blood and urine was conducted against a serology by microscopic agglutination technique in 60 patients with chronic leptospirosis. Dark field videorecording, argentic impregnation, and immunohistochemistry proved to be be much more sensible than the microscopic agglutination technique, in addition to be comparable among themselves. We recommended videorecording to achieve a fast, early, and economical diagnosis, particularly, if we associate it with immunohistochemistry or argentic impregnation. Likewise, in the culture of these samples, 2 strains of 82 % of positive primoculture were obtained, and an electronic microphotography was possible to attain in the peripheral blood of one of the studied cases, which guarantees the study and confirms the existence of chronic leptospirosis.

[Leptospira, does it simulate or cause leukemia?]. / Leptospira simulador o causante de leucemia?

Two cases of chronic leptospirosis in bicitopenic and pancitopenic patients, respectively, with mucocutaneous and visceral bleedings were presented. They were diagnosed myeloblastic leukemia M3 and acute lymphoblastic leukemia L2 by bone marrow aspiration and they were treated as such at the hematology department of a general hospital. Both patients died after one of them had considerably improved on being treated with sodium crystalline penicillin at high doses. The histopathological studies could not demonstrate the presence of neoplastic cells in bone marrow but leptospiras were found by means of silver stained preparations (Warthin - Starry) and immunofluorescence, both in this organ and in other tissues studied: kidney., spleen, liver and lungs. The histopathological diagnoses were generalized leptospirosis with medullary aplasia and generalized leptospirosis with myelodisplastic syndrome, respectively. It was reviewed the possibility that leptospira could cause leukemoid syndromes and/or leukemia. Based on these results, it is recommended to hematologists, infectologists, pathologists, and others, to use again the technques of argentic impregnation, immunohystochemistry and immunofluorescence to study the bone marrow and other tissues in order to detect the possible presence of leptospira that would allow to treat the patients more effectively, particularly, patients like these that had serological titres considered negatives so as to avoid the false security existing in the official health institutions about the minimum or null impact that leptospirosis cause in public health, which imply the absence of control systems for this spirochetosis.

[Differential diagnosis between toxoplasmosis and leptospirosis of 26 Mexican cases with posterior uveitis]. / Diagnóstico diferencial entre toxoplasmosis y leptospirosis de 26 casos mexicanos de uveitis posterior.

26 patients with active posterior uveitis were studied by methodologies for the confirmation of leptospirosis. ELISA-IgG was positive in 10 patients and MAT in 21. Leptospiras were observed in blood and urine. The results suggest that posterior uveitis may be caused by pathogenic leptospiras.

[Mimic diseases accompanying leptospirosis]. / Enfermedades simuladas y acompaãantes de leptospirosis.

400 patients were studied by microscopic videorecording in dark field and MAT. The videorecording in blood was positive in 93 % and, in urine, in 95 %. Of the total of cases, 96 % presented antibody titers. The wide symptomatic range gave origin to more than 50 different diagnoses in the studied patients, who were confirmed that they suffered from chronic leptospirosis by the diverse tests made.

Seroepidemiological studies of cutaneous leishmaniasis in the Campeche State of Mexico

Seroepidemiological studies of cutaneous leismaniasis were carried out in 169 individuals in a rural area of the Campeche State of Mexico. Fifty showed cutaneous lesions suggestive of leishmaniasis, 70 per cent were parasite positive and 96 per cent skin test positive. An overall 40 per cent positivity to skin test with Montenegro's antigen was found. Most of the effected individuals were males from 11 to 30 years-old. Antibodies were determined by immunoflurescent antibody test (IFA) and by Western blot. Two antigen preparations were used, one from a Leishmania mexicana strain which produced localized cutaneous leishmaniasis (LCL) and the other from a diffuse cutaneous leishmaniasis (DCL). In the general population from the area of study 19 per cent gave positive IFA tests with DCL antigen and 20 per cent with LCL antigen while for patients 67 per cent gave positive IFA tests with DCL and 71 per cent with LCL. By Western blot analysis most of the patients recognized more antigens in the DCL than in the LCL strain. In the DCL strain 78 per cent of patients recognized a 105 kDa, 34 per cent a 139 kDa and 26 per cent a 205 kDa MW antigen. In the LCL strain 40 per cent of patients recognized a 205 kDa and 22 per cent a 175 kDa antigens.