RESUMEN
Congenital transmission of T. cruzi in Cochabamba affects 6% of newborns from infected mothers. Only limited information is available on the type of transmitted parasites. However, it is well established that T. cruzi isolated from various vectors as well from host animals are highly heterogeneous. In our presentation we analyse aspects of molecular heterogeneity of T. cruzi and we review methods used for the molecular typing of T. cruzi lineages. Experimentally, we performed the PCR amplification of [quot ]Sequence-characterised region Markers[quot ] for typing T. cruzi isolated from umbilical blood of newborns in Cochabamba. We compared these results with those we obtained from general infected population. All 16 analysed, congenitally infected samples were of lineage IId. Our data also indicated that this lineage was found in about 80% of samples originated from general infected population in Cochabamba.
Asunto(s)
Animales , Humanos , Enfermedad de Chagas/congénito , Heterogeneidad Genética , Trypanosoma cruzi/genética , ADN Protozoario/análisis , Enfermedad de Chagas/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Trypanosoma cruzi/clasificación , Trypanosoma cruzi/aislamiento & purificaciónRESUMEN
In the endemic regions of Bolivia the infection of the feminine population in fertile age by T. cruzi is frequent (20 to 50 % of the women in fertile age) and the rate of fetal maternal transmission is of approximately 5%. A great percentage of infected women do not transmit the infection to the fetus. The intention of the present study carried out at the Maternal-Infantile Hospital Germán Urquidi of Cochabamba (Bolivia) is to contribute to the knowledge regarding the pregnancy and birth of a newborn of Chagas infected women who do not transmit the infection to the fetus. 2124 mothers and 2,155 newborns were studied. The prevalence of infection by T. cruzi among these pregnant women is of 26,3%. Two groups of mothers were studied: 554 that presented infection by T. cruzi (group M+B-) and 1520 not infected (group control M-B-). Both groups of mothers are comparable in their anthropometric and obstetrical antecedents. The mothers (M+B+) are in average older than those not infected (p<0.05), which will probably have an influence on the number of gestations and abortion antecedents, which were of p<0.05 and p=0.01 respectively. Among the different anthropometric and biological parameters studied in newborns of groups M+B- and M-B -, no statistically significant differences between both groups were found. It can be inferred that the chronic maternal infection by T. cruzi seems to have no clinical influence, neither on the course of the pregnancy nor during birth, if a group of T. cruzi infected mothers is compared to a non infected group.
Asunto(s)
Femenino , Humanos , Recién Nacido , Embarazo , Adulto , Complicaciones Parasitarias del Embarazo/epidemiología , Enfermedad de Chagas/epidemiología , Transmisión Vertical de Enfermedad Infecciosa , Resultado del Embarazo , Antropometría , Puntaje de Apgar , Bolivia/epidemiología , Estudios de Casos y Controles , Enfermedad de Chagas/diagnóstico , Enfermedad de Chagas/transmisión , PrevalenciaRESUMEN
Pathogens may impair reproduction in association or not with congenital infections. We have investigated the effect of acute infection with Trypanosoma cruzi, the protozoan agent of Chagas disease, on reproduction of female mice. In the acute, parasitemic, phase of the infection, female mice were totally unable to reproduce. Most of them (80%) were infertiles and did not develop any gestation. In the few gravid infected mice, implantation numbers were as in uninfected control mice. However, their fetuses presented a weight meanly reduced by 40% as compared to those of uninfected females, and all of them died during the gestation or whithin 48 h after birth. Such massive mortality did not result from congenital infection, which did not occur. The infertility and the fetal mortality occuring early in gestation (resorptions) were significantly correlated with a high maternal parasitemia, whereas later fetal mortality was associated with the presence of intracellular parasites in the utero-placental unit. The decidua was particularly receptive to T. cruzi multiplication, since this tissue harboured 125 fold more amastigotes than the maternal heart or other placental tissues. In addition, placentas of dead fetuses presented histopathological lesions (inflammatory infiltrates, fibrine deposits and ischemic necrosis). Such harmfull effects of acute infection were not observed when female mice were in the chronic phase of the infection, since these reproduce normally. Their fetuses only suffered from moderate and reversible growth retardation. These results indicate that, following the maternal parasite burden, T. cruzi infection may induce very deleterious effects on gestation.
Asunto(s)
Animales , Femenino , Embarazo , Enfermedad de Chagas/complicaciones , Infertilidad/parasitología , Muerte Fetal/parasitología , Complicaciones Parasitarias del Embarazo , Trypanosoma cruzi , Enfermedad Aguda , Enfermedad Crónica , Ratones , Ratones Endogámicos BALB C , Muerte Fetal/patología , Necrosis , Placenta/parasitología , Trypanosoma cruzi/patogenicidadRESUMEN
PCR is a potentially interesting diagnostic tool to detect congenital T. cruzi infection. We have compared the sensitivity and capacity of a battery of T. cruzi PCR primers to detect the complete spectrum of known T. cruzi lineages, in order to improve and simplify the detection of infection in neonatal blood. We found that the primers Tcz1/Tcz2, targeting the 195 bp satellite repeat, detected all the parasitic lineages with the same sensitivity For all other tested primers (nDNA primers: BP1/BP2, 01/02, Pon1/ Pon2 and Tca1/Tca2; kDNA primers: S35VS36, 121/122), either, the intensity of amplicons varied according to T. cruzi lineages, or the assess were less sensitive. In order to better assess such PCR protocol, we assayed 311 samples of neonatal blood previously tested with parasitological methods. Reliability of our PCR test was demonstrated since all the 18 blood samples from newborns with congenital T. cruzi infection were positive, whereas the remaining samples (30 from control newborns of uninfected mothers and 262 out of 263 from babies, parasitologically negative, born from infected mothers) were negative. As our PCR method is simple, reliable, robust and cheap, it appears suitable for the detection of T. cruzi infection in neonatal blood.
Asunto(s)
Animales , Humanos , Recién Nacido , Enfermedad de Chagas/congénito , Enfermedad de Chagas/diagnóstico , Reacción en Cadena de la Polimerasa/normas , Trypanosoma cruzi/aislamiento & purificación , ADN Protozoario/sangre , Transmisión Vertical de Enfermedad Infecciosa , Cartilla de ADN , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Sangre Fetal/parasitología , Trypanosoma cruzi/genéticaRESUMEN
This study compares the levels of specific antibodies IgM and IgA for Chagas in samples of blood from newborns. Three groups of cord blood samples have been analysed: a group of 42 samples from newborns, displaying positive parasitemia, of seropositive mothers (M+B+), 68 samples from newborns with negative parasitemia whose mothers were seropositive (M+B-) and a group of 45 control newborns coming from mothers with negative serology for Chagas. From the 42 M+B+ samples with congenital Chagas disease, 81 and 82.9% displayed detectable levels of IgM and IgA antibodies, respectively In the M+B- group, 70.6 and 33.8% presented antibodies of IgM and IgA classes, respectively, whereas in the control group M-B-, we detected 6% and 11.1% of IgM and IgA antibodies, respectively. The calculated sensitivity of detection of congenital cases using IgM or IgA antibodies was of 82.9% and 80.9% respectively, whereas the specificity of detection was of 29.4% for IgM antibodies and of 66.1% for IgA antibodies.
Asunto(s)
Animales , Humanos , Recién Nacido , Enfermedad de Chagas/congénito , Enfermedad de Chagas/diagnóstico , Inmunoglobulina A/sangre , Inmunoglobulina M/sangre , Trypanosoma cruzi/inmunología , Estudios de Casos y Controles , Enfermedad de Chagas/inmunología , Ensayo de Inmunoadsorción Enzimática , Sensibilidad y EspecificidadRESUMEN
The aim of this study was to validate the method of microhematocrit tube, as a rapid method to estimate the parasitemia in blood and to associate the parasites concentration with the morbidity and mortality of new born children with congenital Chagas diseases. Our results were determined experimentally and shown that the detection limit of the microhematocrit tube method is 40 parasites/ml when at least one of the four observed tubes is positive. Besides, it was also established that when the four examined tubes are positive the parasitemia in blood reaches more than 100 parasites/ml. It is important to highlight the modification made by our laboratory in the microscopic observation of the microhematocrit tubes with respect to the methodology used by previous investigators. A positive association exists between a high number of parasites in blood and the morbi-mortality of the newly born children with congenital chagas. The results of positive association between the parasitic load and the morbility and mortality could constitute an argument to understand the possible role of the parasite in the pathology of the disease.
Asunto(s)
Humanos , Animales , Masculino , Femenino , Recién Nacido , Ratones , Recuento de Huevos de Parásitos/métodos , Enfermedad de Chagas/congénito , Enfermedad de Chagas/parasitología , Parasitemia , Trypanosoma cruzi/aislamiento & purificación , Peso al Nacer , Bolivia/epidemiología , Enfermedad de Chagas/diagnóstico , Hematócrito/instrumentación , Hematócrito/métodos , Parasitemia/mortalidad , Sensibilidad y Especificidad , Cordón UmbilicalRESUMEN
In Bolivia, the prevalence of infection by T. cruzi in women in fertile age can vary between 20 and 60%. The present study made in the Maternity Germin Urquidi of Cochabamba - Bolivia, it has demonstrated, that 19.9% of the mothers who go to this hospitable center to be taken care of in the childbirth, they are carrying of the infection and that 4,6% of them, they are going to transmit, by transplacentaria route, the infection to its babies. Of the 71 children born with congenital Chagas, only 47,8 % present/display some type of alteration or of development(Apgar to 1 minute low, BPN, prematuridad, pathological dismadurez) or signs (SDR, hepatomegalia, esplenomegalia, neurological signs, cardiomegalia, anasarca, petequias). When investigating the effect of the differences in the vectorial density (low, medium and high) of the zone of maternal residence, on the transmission of the infection of the mother infected to the fetus, we concluded that the rate of transmission of the congenital infection of T. cruzi is not modified by the level of endemicidad of the zone of maternal residence. By another infected new born sides whose mothers reside in zones of high endemicidad present/display, most frequently and of significant way, Apgar to 1 minute < to 7, low weight when being born and prematuridad or an association of these alterations with respiratory syndrome of distress or anasarca, when one compares them with new born of resident mothers in the zones of loss or medium endemicidad, mortality in this group is greater. These results suggest calls to account it of the mothers, in areas of high endemicidad, she is associate with a serious increase in the risk of Disease of newborn severe and mortal congenital Chagas in.
Asunto(s)
Humanos , Animales , Masculino , Femenino , Embarazo , Recién Nacido , Adulto , Enfermedad de Chagas/congénito , Enfermedades Endémicas , Transmisión Vertical de Enfermedad Infecciosa , Insectos Vectores/fisiología , Complicaciones Parasitarias del Embarazo , Puntaje de Apgar , Bolivia/epidemiología , Demografía , Enfermedad de Chagas/epidemiología , Enfermedad de Chagas/transmisión , Factores Epidemiológicos , Densidad de Población , Prevalencia , Trypanosoma cruzi/fisiologíaRESUMEN
The mechanisms of congenital transmission of Chagas disease remain largely unknown. To better understand the role of maternal immunology during pregnancy in congenital Chagas transmission, we studied the cytokine production and the parasitic load in three groups of mothers: infected mothers who transmitted the disease to their babies (M+B+-), infected mothers who did not transmit the disease to their babies (M+B-) and not infected mothers as a control group (M-B-). M+B+ mothers produced less IFNgamma and more IL-10 than the M+B- mothers, and they are not able to produce IL-2. M+B+ mothers showed a higher parasitic load. These results, indicated that the congenital Chagas transmission is associated with an immunological imbalance and a high parasitic load in the M+B+ mothers.
Asunto(s)
Animales , Femenino , Humanos , Embarazo , Citocinas/biosíntesis , Complicaciones Infecciosas del Embarazo/inmunología , Enfermedad de Chagas/inmunología , Enfermedad de Chagas/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Trypanosoma cruzi/fisiología , Citocinas/inmunología , Enfermedad de Chagas/parasitología , Inmunidad Celular , Interferón gamma/biosíntesis , Interferones/biosíntesis , Portador Sano/inmunologíaRESUMEN
We have investigated if maternal T. cruzi infection could induce in utero innate and/or adaptive immune responses in uninfected neonates by measuring specific IgM and IgA antibodies in cord blood plasma, and by performing phenotypic and functional studies of umbilical cord blood cells of their newborns (M+B- group). We detected T. cruzi-specific IgM and IgA antibodies in M+B- cord blood, indicating they had mounted in utero a strong B cell response, although they are not infected. On the other hand, circulating T cells of such uninfected neonates displayed a low level of activation, as seen bya slightly increased expression of the activation markers CD45RO on CD4+ T cells and HLA-DR on CD8+ T cells, although the proportion of CD4+ and CD8+ T cells was unmodified as compared to newborns from uninfected mothers (MB- group). This activation did not give rise to a proliferative response upon stimulation by T. cruzi antigens in vitro. However, M+B- cells produced low levels of lymphokines (IFN-gamma and IL-13) upon mitogenic stimulation, which was not the case of M-B- newborn cells. Beside this, M+B- blood cells produced higher levels of inflammatory cytokines (IL-1b, IL-6, TNF-alpha) than M-B- cells when stimulated with the T. cruzi lysate or LPS, suggesting the over-activation of the innate response in M+B- newborns. Monocytes participated in such inflammatory response since M+B- purified cord blood monocytes produced higher levels of TNF- when incubated with LPS or a T. cruzi lysate than M-B- cells. Altogether, these results show that, even in the absence of congenital infection, maternal T. cruzi infection triggers in utero both adaptive and innate immune responses in their babies. This indicates that parasite circulating antigens have been transferred from mothers to their fetuses.
Asunto(s)
Animales , Femenino , Humanos , Recién Nacido , Embarazo , Enfermedad de Chagas/inmunología , Enfermedad de Chagas/transmisión , Transmisión Vertical de Enfermedad Infecciosa , Inmunidad Materno-Adquirida/inmunología , Linfocitos B/inmunología , Linfocitos T/inmunología , Sangre Fetal/inmunología , Citocinas/biosíntesis , Complicaciones Parasitarias del Embarazo/diagnóstico , Enfermedad de Chagas/congénito , Inmunidad Celular , Inmunoglobulina A , Inmunoglobulina MRESUMEN
We have developed an experimental model of vaccination against the infection with the protozoa Trypanosoma cruzi, the agent of Chagas disease in Latin America. Vaccination was performed with Trypanosoma rangeli, a non-pathogenic protozoa sharing many antigens with T. cruzi. It strongly protected BALB/c mice, sharply reducing parasitaemia and mortality rate of the acute T. cruzi infection. The aim of the present work was to complete our previous study on the production of IFN-gamma and IL-10 in this vaccination model by investigating the production of IL-12p35 and p40, IL-18, TNF, TNF soluble receptors (sTNFR), and nitric oxide (NO), factors known to play a key role in the outcome of T. cruzi infection. We show that the protection obtained against the acute T. cruzi infection was surprisingly associated with reduced circulating levels of IL-18 and NO, whereas the release of IL-12p40 was enhanced in comparison to non-vaccinated infected animals. IL-12p35 remained undetectable in infected animals, vaccinated or not. The balance between sTNFR and TNF suggested a decrease of TNF bioactivity in vaccinated mice. These results show that the protection induced by the vaccination with T. rangeli against a challenging infection with T. cruzi is not associated with the strong type 1 immune response usually involved in the control of intracellular pathogens, particularly questioning the protective role of NO during the acute phase of T. cruzi infection.