Religiosity, physical and functional health in older people in Chile.

Objective: To establish the association between different dimensions of religiosity - organizational, non-organizational and intrinsic - and physical and functional health indicators in older people in Chile. Methods: Data from the Fifth Survey on Quality of Life in Old Age 2019 were used. Descriptive and explanatory analyses were performed using logistic, linear and multinomial regression models, with dependent variables being self-perception of health, functional dependence, number of chronic diseases and perception of health compared with other people of the same age. As predictors, indicators of the three dimensions of religiosity (DUREL Scale) were included, controlling for the MOS-SS Social Support Scale, Apgar Family Functioning Scale, educational level, gender, age, and living with a partner. Results: Almost a third of older Chileans attend religious services frequently, and half of them pray frequently. On a range of 1 to 5, the mean intrinsic religiosity is 3.94. 46% perceive their health to be good/very good and about half perceive their health as better than their peers. On 0 to 5, the mean number of chronic diseases is 1.69. 6% are classified as functionally dependent. The only significant relationship observed was between religious attendance and a lower probability of presenting functional dependency; on the other hand, praying increases such probabilities and a relationship between attendance and a better perception of health compared with other people of the same age. Conclusion: Organisational religiosity is a psychosocial resource that is positively associated with the process of successful aging.

Objetivo: Establecer la asociación entre distintas dimensiones de religiosidad - organizacional, no organizacional e intrínseca- y diversos indicadores de salud física y funcional en personas mayores en Chile. Métodos: Se utilizaron datos de la Quinta Encuesta de Calidad de Vida en la Vejez del 2019. Se realizaron análisis descriptivos y explicativos, utilizando modelos de regresión logística, lineal y multinomial, teniendo como variables dependientes autopercepción de salud, dependencia funcional, número de enfermedades crónicas y percepción de la salud en comparación con otras personas de la misma edad. Como predictores se incluyeron indicadores de las tres dimensiones de religiosidad considerada (Escala DUREL), controlando por Escala de Apoyo Social percibido MOS-SS, Escala de Funcionamiento Familiar de Apgar, nivel educativo, género, edad y vivir con una pareja. Resultados: Casi un tercio de los mayores chilenos asiste de manera frecuente a servicios religiosos, y la mitad reza frecuentemente. En un rango de 1 a 5, la media de religiosidad intrínseca es de 3.94. Un 46% se percibe con buena/muy buena salud y cerca de la mitad se percibe con mejor salud que otras personas de la misma edad. En un rango de 0-5, la media de enfermedades crónicas es de 1.69 y un 6% es clasificado como dependiente funcional. Solo se encontró una relación significativa entre asistencia religiosa y una menor probabilidad de presentar dependencia funcional, mientras que por el contrario rezar aumenta dichas probabilidades; además de una relación entre asistencia y mejor percepción de salud en comparación con otras personas de la misma edad. Conclusión: la religiosidad organizacional es un recurso psicosocial que se asocia positivamente con el proceso del envejecimiento exitoso.

Religiosity, physical and functional health in older people in Chile / Religiosidad, salud física y funcional en personas mayores en Chile

Abstract Objective: To establish the association between different dimensions of religiosity - organizational, non-organizational and intrinsic - and physical and functional health indicators in older people in Chile. Methods: Data from the Fifth Survey on Quality of Life in Old Age 2019 were used. Descriptive and explanatory analyses were performed using logistic, linear and multinomial regression models, with dependent variables being self-perception of health, functional dependence, number of chronic diseases and perception of health compared with other people of the same age. As predictors, indicators of the three dimensions of religiosity (DUREL Scale) were included, controlling for the MOS-SS Social Support Scale, Apgar Family Functioning Scale, educational level, gender, age, and living with a partner. Results: Almost a third of older Chileans attend religious services frequently, and half of them pray frequently. On a range of 1 to 5, the mean intrinsic religiosity is 3.94. 46% perceive their health to be good/very good and about half perceive their health as better than their peers. On 0 to 5, the mean number of chronic diseases is 1.69. 6% are classified as functionally dependent. The only significant relationship observed was between religious attendance and a lower probability of presenting functional dependency; on the other hand, praying increases such probabilities and a relationship between attendance and a better perception of health compared with other people of the same age. Conclusion: Organisational religiosity is a psychosocial resource that is positively associated with the process of successful aging

Resumen Objetivo: Establecer la asociación entre distintas dimensiones de religiosidad - organizacional, no organizacional e intrínseca- y diversos indicadores de salud física y funcional en personas mayores en Chile. Métodos: Se utilizaron datos de la Quinta Encuesta de Calidad de Vida en la Vejez del 2019. Se realizaron análisis descriptivos y explicativos, utilizando modelos de regresión logística, lineal y multinomial, teniendo como variables dependientes autopercepción de salud, dependencia funcional, número de enfermedades crónicas y percepción de la salud en comparación con otras personas de la misma edad. Como predictores se incluyeron indicadores de las tres dimensiones de religiosidad considerada (Escala DUREL), controlando por Escala de Apoyo Social percibido MOS-SS, Escala de Funcionamiento Familiar de Apgar, nivel educativo, género, edad y vivir con una pareja. Resultados: Casi un tercio de los mayores chilenos asiste de manera frecuente a servicios religiosos, y la mitad reza frecuentemente. En un rango de 1 a 5, la media de religiosidad intrínseca es de 3.94. Un 46% se percibe con buena/muy buena salud y cerca de la mitad se percibe con mejor salud que otras personas de la misma edad. En un rango de 0-5, la media de enfermedades crónicas es de 1.69 y un 6% es clasificado como dependiente funcional. Solo se encontró una relación significativa entre asistencia religiosa y una menor probabilidad de presentar dependencia funcional, mientras que por el contrario rezar aumenta dichas probabilidades; además de una relación entre asistencia y mejor percepción de salud en comparación con otras personas de la misma edad. Conclusión: la religiosidad organizacional es un recurso psicosocial que se asocia positivamente con el proceso del envejecimiento exitoso.

Leydig cell dysfunction is associated with post-transcriptional deregulation of CYP17A1 in men with Sertoli cell-only syndrome.

STUDY QUESTION: Is the expression of steroidogenic enzyme 17α-Hydroxylase/17,20-Lyase (CYP17A1) down-regulated in Leydig cells (LCs) of men with spermatogenic failure and compensated impairment of LC function, i.e. a low testosterone to LH (T/LH) ratio? SUMMARY ANSWER: Although the transcriptional expression of CYP17A1 is increased, its protein expression is decreased, in isolated LCs of men with spermatogenic failure and reduced serum T/LH. WHAT IS KNOWN ALREADY: Primary spermatogenic defects have been associated with functional and morphological abnormalities of LCs, characterized by decreased serum testosterone (T) levels, decreased T/LH, increased 17ß-estradiol (E2) and E2/T ratio, and larger clusters of LCs (LC hyperplasia). CYP17A1 is a key enzyme in the testosterone pathway and has been implicated in the steroidogenic lesion produced by E2 stimulation. STUDY DESIGN, SIZE, DURATION: We studied 18 azoospermic patients with Sertoli cell-only syndrome (SCOS) and signs of LC dysfunction (cases) and 10 obstructive azoospermic/oligozoospermic men with normal spermatogenesis (controls). The SCOS patients were sub-grouped into 9 cases with T/LH <2 and 9 cases with T/LH ≥2. All of the men underwent testicular biopsy for sperm retrieval at the Reproductive Unit of a University Hospital. PARTICIPANTS/MATERIALS, SETTING, METHODS: The transcriptional expression of CYP17A1 and SF-1 (steroidogenic factor 1) was quantified by SYBR®Green-based qPCR in LCs isolated by laser capture microdissection (LCM), and relative expression to the control pool was assessed. CYP17A1 protein expression was semi-quantified by indirect immunofluorescence (IFI) using Image-Pro Plus v7.0 (Media Cybernetics) in testicular tissue. FSH and LH serum concentrations, and serum and intratesticular T (ITT) and E2 (ITE2) were measured by IRMA and RIA, respectively. MAIN RESULTS AND THE ROLE OF CHANCE: Relative CYP17A1 mRNA expression was increased in cases with T/LH <2 compared to cases with T/LH ≥2, by a mean of 3.3-fold (P = 0.002). No corresponding increase in protein expression was found; in fact, CYP17A1 immunostaining intensity assessed by the Integrated Optical Density (IOD) parameter was lower in the cases with T/LH <2 compared to controls (P = 0.008). Relative SF-1 mRNA expression was similar in both case subgroups. CYP17A1 mRNA expression correlated with ITE2 and intratesticular E2/T (r = 0.536; P = 0.026 and r = 0.542; P = 0.016, respectively), while an inverse association was observed for ITE2 and protein level expression (r = -0.421; P = 0.05). LARGE SCALE DATA: Not applicable. LIMITATIONS REASONS FOR CAUTION: We should interpret the results of the semi-quantification of immunofluorescent staining by Image-Pro Plus software with caution, because it is a semi-quantitative method that may have certain difficulties regarding the disposition of protein in the cells. However, it is not influenced by variations in the number of cells that express the protein, as could be the case of western blot analysis in testicular tissue. WIDER IMPLICATIONS OF THE FINDINGS: Dysfunctional LCs of men with SCOS show post-transcriptional deregulation of CYP17A1, with increased mRNA and decreased protein expression, which may be modulated by increased ITE2 levels. In addition, transcriptional expression of CYP17A1 was not associated with changes in SF-1 mRNA expression. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by the National Fund for Scientific and Technological Development (FONDECYT) of Chile to A.C. [grant number 1120176]. The authors declare no conflict of interest.

[Value of molecular imaging to examine the brain]. / Aportacion de la imagen molecular en la exploracion del cerebro.

TITLE: Aportacion de la imagen molecular en la exploracion del cerebro.

¿Qué necesita el consentimiento informado para ser más efectivo? / What does informed consent need to be more effective?

No disponible

Mental disorder prevalence and associated risk factors in three prisons of Spain.

AIMS: To determine the lifetime and monthly prevalence of people with mental disorders and its association with sociodemographic factors and criminal risk in three Spanish prisons (Ocaña, Madrid I, II and VI). METHOD: Cross-sectional epidemiological study of a sample of 184 inmates. Socio-demographic and criminal data were collected by an ad hoc interview. Mental disorders were assessed with the clinical version of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders Axis I Disorders (SCID-I). RESULTS: Life prevalence of mental disorders was 90.2%. The most common mental disorders and substance abuse or dependence was 72.3%, followed by mood disorder (38.5%) and psychotic disorders (34.2%). Moreover, the prevalence of any mental disorder in the last month was 52.2%. The main psychotic disorder (20.7%) was followed by substance abuse or dependence (18.5%), and mood disorder state (13%). A socio-demographic profile as a risk for each disorder was found. DISCUSSION: The prevalence of people with mental disorders is very high in Spanish prisons, and is associated with a distinct demographic profile. It is essential to continue researching this reality, translating the results into therapeutic and preventive action adapted to the status of inmates to reduce social inequalities in this high priority public health situation.

Respuesta a la carta del director. Sobre el artículo «Prevalencia de trastorno mental y factores de riesgo asociados en tres prisiones de España» / Response to the letter to the editor. About the «Prevalence of mental disorders and associated risk factors in three correctional facilities in Spain»

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Prevalencia de trastorno mental y factores de riesgo asociados en tres prisiones de España / Mental disorder prevalence and associated risk factors in three prison of Spain

Objetivos: Conocer la prevalencia vida y prevalencia mes de personas con trastorno mental y su asociación con factores de riesgo sociodemográficos y penales en tres centros penitenciarios de España (Ocaña I y II y Madrid VI). Material y Método: Estudio epidemiológico descriptivo transversal con una muestra de 184 internos. Los datos sociodemográficos y penales se recogieron mediante una entrevista ad hoc. Los trastornos mentales se evaluaron con la versión clínica de la Structured Clinical Interview for Diagnostic and Statical Manual of Mental Disorders Axis I Disorders (SCID-I). Resultados: La prevalencia vida de trastorno mental fue del 90,2%, siendo los trastornos mentales más frecuentes el abuso o dependencia de sustancias (72,3%), seguidos de los trastornos del estado de ánimo (38,5%) y los trastornos psicóticos (34,2%). La prevalencia de cualquier trastorno mental en el último mes fue del 52,2%, siendo el principal trastorno el psicótico (20,7%) seguido del abuso o dependencia de sustancias (18,5%), y del trastorno del estado de ánimo (13%). Para cada uno de los trastornos se encontró un perfil sociodemográfico como factor de riesgo. Discusión: La prevalencia de las personas con trastorno mental es muy elevada en las prisiones españolas, estando asociada a un perfil sociodemográfico característico. Es esencial continuar investigando esta realidad, traduciendo los resultados en acciones de tipo terapéutico y preventivo, adaptadas al estatus de los internos para reducir las desigualdades sociales en esta situación prioritaria de Salud Pública (AU)

Aims: To determine the lifetime and monthly prevalence of people with mental disorders and its association with socio-demographic factors and criminal risk in three Spanish prisons (Ocaña, Madrid I, II and VI). Method: Cross-sectional epidemiological study of a sample of 184 inmates. Socio-demographic and criminal data were collected by an ad hoc interview. Mental disorders were assessed with the clinical version of the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders Axis I Disorders (SCID-I). Results: Life prevalence of mental disorders was 90.2%. The most common mental disorders and substance abuse or dependence was 72.3%, followed by mood disorder (38.5%) and psychotic disorders (34.2%). Moreover, the prevalence of any mental disorder in the last month was 52.2%. The main psychotic disorder (20.7%) was followed by substance abuse or dependence (18.5%), and mood disorder state (13%). A socio-demographic profile as a risk for each disorder was found. Discussion: The prevalence of people with mental disorders is very high in Spanish prisons, and is associated with a distinct demographic profile. It is essential to continue researching this reality, translating the results into therapeutic and preventive action adapted to the status of inmates to reduce social inequalities in this high priority public health situation (AU)

El trabajo multidisciplinar en el abordaje del dolor crónico. La hipnosis como coadyuvante / Multidisciplinary work in addressing chronic pain assisted by hypnosis

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[Increasing decayed, missing and filled teeth index among school children in Loja, Spain]. / Incremento del índice de dientes permanentes cariados, perdidos por caries y obturados, entre escolares de Loja, España.

OBJECTIVE: To identify the clinical, socioeconomic, dietary, and hygienic predictors of the increasing Decayed, Missing, and Filled Teeth (DMFT) index, in a cohort of school children in Loja, Granada, Spain, during a three-year period (1994-1997). MATERIAL AND METHODS: A retrospective cohort study was conducted in 812 students to measure the DMFT index, using the methods recommended by the World Health Organization. Statistical analysis was conducted using logistic regression models. RESULTS: During the study period, the DMFT index increased from 1.86 to 4.5 for the study cohort as a whole, and from 3.71 to 4.47 among twelve-year olds. The DMFT at mid-period was associated to an increase in the final DMFT. The relative risk for attending school no. 3 was 0.69 (95% CI 0.60-0.8) vs. school no. 4, and 0.78 (95% CI 0.67-0.90) vs. school no. 5. CONCLUSIONS: The final model showed that the DMFT at mid-period was a risk factor for an increase in the DMFT index and that attending school number 3 was a protective factor.

[Serological certification of the interruption of the vectorial transmission of Chagas disease in Chile]. / Certificación serológica de la interrupción de la transmisión vectorial de la enfermedad de Chagas en Chile.

BACKGROUND: In 1999 an International Commission of Experts evaluated the sanitary interventions that started in 1980 to eliminate Triatoma infestans, the biological vector of Chagas disease, to certify if the conditions needed to interrupt the transmission, were achieved. AIM: To report the data used by the International certification commission to certify the interruption of vectorial transmission of Chagas disease in Chile. MATERIAL AND METHODS: A comparative evaluation of the prevalence of Trypanosoma cruzi antibodies in children surveyed between 1994 and 1995 and between 1995 and 1999. RESULTS: In the first period, 5,948 children were surveyed and in the second, 5,069 children were studied. Twenty children (0.4%) were positive for Trypanosoma cruzi antibodies in the second survey. These figures were significantly lower than the 1.1% prevalence detected between 1994 and 1995. In only three of the 20 cases, the transmission through vectors was confirmed, which represents a 99.4% reduction of this way of transmission. CONCLUSIONS: Based on these findings, the Commission certified that Chile is the second country in Latin America to interrupt the vector transmission of Chagas disease. The successful public health program for Chagas disease will have a positive impact improving the quality of life of rural populations, that are most exposed to the disease.

Highly diastereofacial anti-aldol reaction: practical synthesis of optically active anti-2-alkyl-3-hydroxycarboxylic acid ester units.

A variety of esters derived from commercially available norephedrine were used in diastereoselective anti-aldol reactions. The aldol reaction of designed 2-(N-2-methylbenzyl-N-2,4,6-trimethylbenzyl)amino-1-phenylpropanol esters 4a-d with aldehydes furnished anti-2-alkyl-3-hydroxycarboxylic acid esters in excellent diastereomeric ratios (>98:2) when LDA-Cp2ZrCl2 (0.3 equiv) was used for enolization, followed by transmetalation into the zirconium enolate for aldolization. The novel auxiliary 3 for the anti-aldol reaction does not exhibit the ordinary basicity of tertiary amines; 3 can be extracted from acidic media with organic solvents. Its use is, therefore, very advantageous not only for extraction of the aldol products from the acidic water solutions, but also for recovering the chiral auxiliary 3 after the reductive cleavage. Treatment of aldol or 3-protected aldol products with DIBAL-H or LiAlH4 affords the versatile synthons, 2-alkyl-propane-1,3-diols or those 3-protected diols in >98% ee's together with 3 in nearly quantitative recovery.

Evaluation of a Triatoma infestans elimination program by the decrease of Trypanosoma cruzi infection frequency in children younger than 10 years, Chile, 1991-1998.

Chagas disease is widespread in Chile, distributed in rural and periurban areas in the 7 most northern regions of the country. The principal vector of Trypanosoma cruzi is Triatoma infestans. The interruption of the domestic cycle of transmission of T. cruzi has been attempted by health education, human housing improving, and elimination of the vector by means of systematic insecticide spraying of human dwellings. Spraying with insecticides has been supported by Chile's health authorities and has been carried out for the last 12 years. A total of 13,280 children (aged up to 10 years) were randomly selected from 47 counties in the area of Chile endemic for Chagas disease, and blood samples were collected to determine the levels of antibodies to T. cruzi by indirect hemagglutination and enzyme-linked immunosorbent assay tests. The results of the tests were analyzed to determine the changes that occurred after 12 years of insecticide spraying of dwellings to eliminate T. infestans infestation. A total of 142 (1.1%) samples of children showed antibodies to T. cruzi. This rate is significantly lower than the data generated in similar studies conducted in 1982-1985. The following reduction in prevalence rates were observed in each of the 7 endemic regions of the country: region I, 5.5-0.3%; region II, 6.6-0.3%; region III, 9.8-1.0%; region IV, 7.2-2.0%; region V, 5.2-1.9%, Metropolitan region, 1.4-0.6%; and region VI, 1.4-0.4%. Serovigilance of T. cruzi antibodies level represents a novel approach that may allow the evaluation of the impact of the vector elimination program. The results identify regions that need to strengthen the efforts to reduce the insect infestation of dwellings.

Development of an immunoenzymatic assay for the detection of human antibodies against Trypanosoma cruzi calreticulin, an immunodominant antigen.

We have developed an indirect immunoenzymatic assay (ELISA) for the detection of human antibodies against calreticulin (formerly known as Tc45), a dimorphic Trypanosoma cruzi antigen, described in our laboratory. PVC microtitration plates were sensitized with the monoclonal anti-calreticulin antibody (MoAb) and reacted with calreticulin present in a partially purified preparation. The presence of anti-T. cruzi calreticulin IgG in sera from infected individuals was tested. The data generated with this assay were validated by correlation, in a regression analysis, with those obtained by an indirect immunoradiometric assay (IRMA). From the 12 seropositive sera (as defined by a commercial test), eight came out positive and four negative in both assays. The 12 human sera were also analyzed in direct immunometric assays (ELISA and IRMA), where the solid phase was sensitized with a whole parasite extract. The direct ELISA and IRMA correlated positively (P<0.01). Further validation of this ELISA was achieved with an indirect immunofluorescense assay. The high degree of significance obtained when the indirect IRMA and ELISA systems were compared, indicated that the relatively small sample number used (12) was statistically satisfactory for the purposes of this investigation. Thus, the IRMA can be replaced by the ELISA, with advantages mainly derived from the cumbersome manipulation of radioactive wastes. The MoAb used as an antigen capture agent in the ELISA proposed here, recognizes a homologous protein in Trypanosoma rangeli, suggesting that individuals infected with this parasite might have crossreactive antibodies. However, the system retains its diagnostic interest, given the facts that the MoAb does not recognize a homologous protein in Leishmania mexicana, Leishmania donovani, or Crithidia fasciculata.

[Comparison of Trypanosoma cruzi infection in less than 10 years old children from the V Región, Chile, 1982-1995]. / Comparación de la infección por Trypanosoma cruzi en niños menores de 10 años de la V región, Chile. 1982-1995.

Evaluation of desinsectation programs carried out in the two Health Services from the V Region, was undertaken by comparing serologic prevalences of T. cruzi infection age groups exposed to the risk of infection in rural areas during the antivectorial campaign activities (1982 vs 1995). Thus, were studied 2,193 blood samples from children under 10 years of age, proceeding from six chagasic endemic provinces in which antitriatomic domiciliary insecticide sprayings had been performed. Indirect hemagglutination and ELISA tests were carried out to each of the blood samples. A total de 42 (1.9%) children resulted positive. As in five counties no positive cases were detected in the last five years it is possible to assume that vector transmission of T. cruzi should have been interrupted in them. When comparing prevalences existing in 1982 with the present ones, it is possible to observe a 63.5% of reduction of transmission in the V Region, been this reduction higher in the Aconcagua Health Service with 79.6% and lower in the Viña del Mar--Quillota Health Service with 55.6%. According to these results, comparison of prevalence of T. cruzi infection in children less than 10-year-old in diverse periods, allows evaluate the vectorial control of Triatoma infestans programs.

[Frequency of anti-Toxoplasma gondii antibodies in cats from Valdivia city, Chile]. / Frecuencia de anticuerpos anti Toxoplasma gondii en gatos de la ciudad de Valdivia, Chile.

Toxoplasmosis is a parasitic zoonosis. The importance of the cat as related to this parasitosis lies in the fact that it is not only the definite host of the parasite, but responsible for its dissemination through the release of oocysts, which subsequently infect both humans and other animals. The objective of this study was to determine the serological prevalence of Toxoplasma gondii in the feline population of the city of Valdivia (Chile) and to establish the possible epidemiological implications of this prevalence. With these goals in mind the technique of indirect immunofluorescence was implemented to detect anti- T. gondii species--specific IgG. Blood samples from 97 cats (selected using a directed sampling process) from different sectors of Valdivia were collected. The sample included 46 males and 51 females of different ages, Positive and negative control sera obtained from de United States were used to verify the results, observed by UV microscopy. The anti-feline IgG antibody was used as directed by the manufacturer (Sigma). Of the 97 selected cats, 32 were found to be positive with a titre higher than 1:4, a prevalence of 33.0%. The number of infected males as compared to the number of infected females was found to be statistically insignificant, using the chi-square analysis with p less than 0.1. In contrast, a definite correlation between age and seropositivity was found; infection levels were higher in older animals. These results are consistent with those obtained in different studies on this topic that have been performed in different parts of the world. However, they would seem to be in conflict with other, similar studies that have been done recently in Chile; this may be due to the fact that the cats selected for this study were exposed to different climatic conditions than those examined in previous works. In conclusion, it has been determined that in Valdivia exist cats infected by T. gondii, which indicate the presence of the necessary epidemiological conditions for the persistence of this parasitic cycle and the source of infection for humans and other animals.

[Epidemiological status of Chagas disease in the endemic area from Region II of Antofagasta]. / Situación epidemiológica de la enfermedad de Chagas en el área endémica de la II Región de Antofagasta, Chile.

During 1997 a seroepidemiological study on Chagas' disease was carried out in 18 localities of three provinces (Tocopilla, El Loa and Antofagasta) of Region II (20 degrees 56'-26 degrees South Lat.; 70 degrees 38'-67 degrees West Long.), in order to assess the impact of the control program against Triatoma infestans launched in 1988, based on insecticide spraying of dwellings. By means of ELISA and an indirect hemagglutination test for Chagas' disease blood samples from 1,034 children under 10 years of age were examined, arising a 0.5% (3 cases) positivity. Test resulted positive in 2 (0.9%) children from the locality of San Pedro de Atacama and 1 (0.4%) from Calama city, all in the age group 6-10 year-old. However, none of their dwellings were found infested with T. infestants. These results indicate that the control program has a good possibility to prevent new human infections. It is advisable to continue the seroepidemiological and entomological vigilance and remark the necessity of increasing the effort in the study of transmission through other routes, to adopt or reinforce the pertinent preventive measures.

Seroprevalence of Toxoplasma gondii infection in sheep and alpacas (Llama pacos) in Chile.

Serum samples from 408 sheep from different regions of Chile and 447 alpacas (Llama pacos) from the north of the country were tested for Toxoplasma gondii antibodies. The indirect haemagglutination test (IHAT) was used in both species and the indirect immunofluorescence test (IIFT) was also used on the sheep samples in order to compare the performance of the tests in that species. In both tests, titers > or = 1:16 were considered diagnostically significant. Sera from 49 sheep (12%) were positive to T. gondii antibodies by the IHAT. When using the IIFT, 114 sheep sera (28%) were positive. The different results obtained in sheep sera between the tests were significant (p < 0.0001). No differences were observed between geographical locations or sex of the sampled sheep regarding serological detection of T. gondii antibodies in sheep. As expected, adult sheep showed higher T. gondii reactivity than young sheep (p = 0.0008). The corrected prevalence of toxoplasmosis in alpaca was 16.3% (32 positive out of 447). The rather low prevalence in alpacas may be associated with their extensive management as well as the extreme climatic conditions of The Andes which apparently would not be favorable for the transmission of the parasite.