ABSTRACT
An indirect hemagglutination test (IHAT) and an ELISA test for trichinosis using as antigen a larvae soluble fraction from Trichinella spiralis was carried out for the detection of IgG, IgM and IgA specific antibodies in 113 serum samples from patients confirmed or suspected to have trichinosis by strong clinical and epidemiological evidences (Group 1). The same test were also performed on 110 serum samples corresponding to patients without strong enidences of having trichinosis (Group II). In Group 1 the correponding sensitivities for RHAI, ELISA IgG, ELISA IgM, ELISA IgA were: 82.3-85.8-88.5 and 88.5 percent respectively. Seventeen patients were tested again a week after the first analysis (10 of them corresponded to negative ones), increasing the positivity: 23.5-100.0;35.3-100.0;41.2-100.0 and 41.2-100.0 percent for RHAI, ELISA IgG, ELISA IgM and ELISA IgA, respectively. Other two patients were followed-up for 5 years. IHAT and ELISA IgG remained positive, whereas ELISA IgM and ELISA IgA were constantly negative betweeen 17 and 32 months in one case, and between 48 and 60 months in the other (this last one had presented a severe clinic disease). In the group II, four patients were positive with IHAT, however only one for ELISA IgA, the latter also presented ELISA IgM near the cut off. The use of ELISA IgG, ELISA IgM and ELISA IgA in the immunodiagnosis of trichinosis is discussed
Subject(s)
Humans , Male , Adolescent , Adult , Female , Child, Preschool , Middle Aged , Trichinella spiralis , Trichinellosis , Enzyme-Linked Immunosorbent Assay , Hemagglutination Tests , Immunologic Tests , Trichinella spiralis , TrichinellosisABSTRACT
San Juan de la Costa County (40 45ïSouth lat., 73 19ïWest long.) is located in the Osorno province, South of Chile. Is population is 11,445. The basic economic activities are agriculture, cattle raising, fishery, timber production and manufacture of wood and coal. According to official reports, the incidence of human hydatidosis in Chile and Osorno province, in 1999, was 1.8 and 12.5 per 100,000 respectively. In order to contribute to a better knowledge of the epidemiology of human hydatidosis, an indirect hemagglutination test (IHAT) and ELISA IgG for hydatidosis were performed to 533 randomized people. Three (0.56 percent) resulted positive. Parallelly, a socio-epidemiological survey on hydatidosis was carried out: the majority of people had some basic knowledge about some aspects of hydatidosis transmission. Some considerations on the correspondig prophy latic measures are mentioned
Subject(s)
Humans , Male , Adolescent , Adult , Female , Child, Preschool , Middle Aged , Echinococcosis , Chile , Echinococcosis , Echinococcus , Educational Status , Enzyme-Linked Immunosorbent Assay , Seroepidemiologic Studies , Socioeconomic Factors , Hemagglutination TestsABSTRACT
In order to stablish the current prevalence by eggs of Toxocara canis, 110 squares of five zones of the Metropolitan Region of Santiago city were examined by a flotation in saturated zinc solution modified method. Samples were taken from different kinds of soil in the four seasons of the year and they were preserved under anaerobic conditions over 2 years. 18,2 percent of samples resulted positive to Toxara canis eggs and 24,4 percent were positive to nematodes larvae. No viable eggs were found. Western zone is the most contaminated of the city and autumn is the season in which we obtained higher recovery of eggs. Silty clay sample soil seems to be better than sandy soils on maintenance of studied eggs
Subject(s)
Humans , Recreational Zones , Environmental Pollution , Toxocara canis , Anaerobic Digestion , Parasite Egg Count , Prevalence , Toxocara canisABSTRACT
Toxoplasmosis, a world wide zoonotic infection, is generally asymptomatic and benign in immunocompetent individuals, but it can be serious in immunodeficiencies particulary in patients with acquired immunodeficiency syndrome and in children infected in utero. So, it is important to dispose methods which permit discriminate between recent and chronic infections. In order to contribute to improve the diagnosis of toxoplasmosis ELISA IgG, IgG, IgM, IgA and ELISA IgG, avidity were performed in 15 and 24 sera from patients suspectec of having acute and chronic infection respectively, according dye test (DT) titres. ELISA IgG was positive in both groups, ELISA IgM was positive in 78,6 and 58,3 percent respectively, while ELISA IgA was positive in 85,7 and 33,3 percent of recent and chronic group respectively. In those sera with low IgG avidity (18,8 percent) we found specific IgM in 71,5 and 4,2 percent and IgA in 78,6 and 0,0 percent of recent and chronic groups respectively. Parallelly, 208 sera samples were clasified according to the results of DT, indirect hemagglutination and complement fixation tests in the following groups: acute (97), intermediate (36), chronic (35) and negative (40). The results were: acute (96,9-64,9-55,6 and 65,9 percent); intermediate (97,2-63,8-44,4 and 47,2 percent); chronic (45,7-42,8-5,7 and 34,3 percent) for IgG, IgM, IgA and low IgG avidity respectively. The use of both acute markers, IgA and low IgG avidity in the diagnosis of toxoplasmosis is discussed
Subject(s)
Humans , Immunologic Tests/methods , Toxoplasmosis/diagnosis , Antigens, Protozoan , Enzyme-Linked Immunosorbent Assay , Immunoglobulin A , Immunoglobulin G , Immunoglobulin M , Complement Fixation Tests , Hemagglutination Tests , Toxoplasma/immunologyABSTRACT
Chile is located in the southwestern border of South America. The country is 4,329 km long and 96-342 wide. From north to south it is divided into five marked different biogeographical zones: deserts, steppes, bushes, forests (cattle raising) and austral (sheep raising). Population (june 1999) 15,017,760 (14,6 percent rural). Human hydatidosis is endemic in Chile. According to Ministry of Health information about 320 cases are registered each year. In order to find out the likely prevalence of human hydatidosis in Chile, a series of serosurveys was carried out in 1988-1997 throughout the total country. By using the indirect hemagglutination reaction and ELISA for hydatidosis (test with good sensibility and specificity) 60,790 unselected apparently healthy persons: 41,399 from urban areas (16,428 blood donors, 13,894 delivering mothers and 11,077 middle grade schoolchildren) and 19,361 from rural areas from randomly selected family groupings were studied. A total individuals 82 (136/100,000) resulted positive: 36 (87/100,000) urban and 46 (241/100,000) rural, being the prevalence higher in rural areas, particularly in the southern austral zone (mean 1068/100,00). These figures agree with those observed in clinical epidemiological studies. In conformity with the present results, in the whole country 17,002 individuals should have hydatidosis: 10,318 urban and 6,784 rural. All these possible infected people, not necessarily should present pathology in the future, as it has been observed in autopsies from unselected individuals, performed at the Medico Legal Service in Santiago, in whom 71,3 percent of diagnosed hydatidosis with hydatid cysts in many different locations, was an autopsy finding
Subject(s)
Humans , Echinococcosis/epidemiology , Age Distribution , Seroepidemiologic Studies , Sex DistributionABSTRACT
An ELISA test for trichinosis using as antigen a larvae soluble fraction from trichinella spiralis was carried out for the detection of IgM and IgA specific antibodies in 45 serum samples from patients confirmed or suspected to have trichinosis by strong clinical and epidemiological evidences. All the patients had positive serology detected by precipitin test, bentonite floculation test, indirect hemagglutination tes and ELISA IgG test. The cut off value was determined using two criteria. Criterion A was determined in each plate, using three positive controls and two negative ones; the average of the negative controls and the weakest positive control, muliplied by a 1,2 factor was, considered the cut off value. Criterion B was determinated using the average plus three standard deviations from 64 apparently halthy persons serum samples. In both cases, three serum dilutions (1:10, 1:100 and 1:500) were used. The sensitivity of ELISA IgM was 100,0, 93,3 and 82,2 percent using serum dilution of 1:10, 1:100 and 1:500 respectively (criterion A) and 100,0, 97,8 and 95,6 percent for the same dilutions (criterion B), whereas the values for ELISA IgA were: 100,0 91,1 and 86,7 percent (criterion A) and 100,0 100,0 and 91,1 percent (criterion B). In order to find out the specificity of ELISA IgM and ELISA IgA, additional 118 serum samples from individuals with other parasitoses, such as cysticercoss (18) hydatidosis (39), fascioliasis (12), toxocariasis (30), Chagaïs disease (12) and individuals with non specif eosinophilia (7), were also tested. ELISA IgM presentes a specificity of 92,3, 93,4 and 97,3 percent (criterion A) and 96,2, 97,8 and 97,8 percent (criterion B) whereas the results for ELISA IgA were 97,8, 98,9 and 99,4 percent (criterion A) and 98,4 percent for the 1:10 and 1:100 dilutions and 100,0 percent for the 1:500 dilution (criterion B). The positive predictive values of ELISA IgM were 76,3, 77,8 and 88,1 percent (criterion A) and 86,5, 91,7 and 91,5 percent (criterion B) whereas the negative ones were 100,0, 98,3 and 95,7 percent (criterion A) and 100,0, 99,4 and 98,9 percent (criterion B). The positive predictive values of ELISA IgA were 91,8, 95,3 and 97,5 percent (criterion A) and 93,8, 93,8 and 100,0 percent (criterion B) whereas the negatives ones were: 100,0, 97,9 and 96,8 percent (criterion A) and 100,0, 100,0 and 97,8 percent (criterion B). The use of ELISA IgM and ELISA IgA in the inmunodiagnosis of trichinosis is discussed
Subject(s)
Humans , Enzyme-Linked Immunosorbent Assay/standards , Trichinellosis/diagnosis , Immunoglobulin A/isolation & purification , Immunoglobulin M/isolation & purification , Sensitivity and SpecificityABSTRACT
A serological survey was carried out in Osorno X Región, Chile (40º 21'-40º 46' south lat, and 73º 26'-72º-46' west long.). An indirect hemagglutination test (IHAT) for toxoplasmosis was performed to 305 persons, 160 blood donors and 145 with sexuallly transmitted diseases (STD).The age the surveyed persons (167 males and 138 females) varied between 10 and 72 years. IHAT titers >16 were considered as positive. The general prevalence was 20.3 percent, 21.2 percent in blood donors and 19.3 percent in persons with some STD, with no differences between males and females. However, significant differences between males and females with STD were found (35.6 percent and 8.1 percent respectively). No differences between urban and rural inhabitants were found, with a slight higher prevalence in the urban ones. No antibodies against toxoplasma gondii were detected in six AIDS patients. The importance of performing toxoplasmosis immnuodiagnosis and individual profilaxis to avoid the infection in high risk group are recommended
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Sexually Transmitted Diseases/epidemiology , Toxoplasma/isolation & purification , Toxoplasmosis/epidemiology , Age Distribution , Blood Donors/statistics & numerical data , Chile/epidemiology , Seroepidemiologic Studies , Sex Distribution , Hemagglutination Tests , Toxoplasma/pathogenicity , Toxoplasmosis/etiologyABSTRACT
Las embarazadas adolescentes constituirían por su condición etárea una población de alto riesgo de infección por agentes relevantes en el binomio madre-hijo. Se investigó en 139 embarazadas adolescentes, la prevalencia de anticuerpos anti Toxoplasma gondii, Trypanosoma cruzi, Virus hepatitis B (VHB), citomegalovirus (CMV), Virus rubéola (VR) y Virus de la Inmunodeficiencia humana (VIH), así como la presencia de marcadores de infección en sus recién nacidos (RN) de riesgo. Se utilizaron las técnicas de Sabin y Feldman, fijación del complemento, ELISA, hemoaglutinación indirecta y xenodiagnóstico. Se detectó 30.9 por ciento de seropositivas para T. gondii, siendo estas madres y sus RN IgM negativos. Se detectaron dos madres con Acs anti T. cruzi (1.4 por ciento) y uno de los RN presentaba parásitos circulantes. En relación al estudio virológico, se detectó un 93,5 por ciento de madres seropositivas para CMV siendo sus RN IgM negativos, un 90,6 por ciento de las adolescentes eran antirrubéola positivas y se detectó un caso de adolescentes positiva para VIH. Las prevalencias establecidas en este grupo de embarazadas, no son significativamente diferentes a las encontradas en la población general de embarazadas
Subject(s)
Humans , Female , Pregnancy , Adolescent , Pregnancy Complications, Infectious/diagnosis , Pregnancy in Adolescence/blood , Cross-Sectional Studies , Health Surveys , Biomarkers/blood , Parasitic Diseases/epidemiology , Pregnancy, High-Risk/blood , Infant, Newborn/microbiology , Toxoplasma/isolation & purification , Virus Diseases/epidemiologySubject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Chagas Cardiomyopathy/diagnosis , Chagas Disease/complications , Toxoplasma/pathogenicity , Toxoplasmosis/complications , Electrocardiography/methods , Rural Population , Hemagglutination Tests/methods , Immunologic Tests/methodsABSTRACT
La enfermedad de Chagas, producida por el Trypanosoma cruzi y transmitida por triatominos hematófagos, existe en América desde el sur de Estados Unidos hasta Chile y Argentina. Existe en sectores rurales y periurbanos de la mitad norte de Chile, siendo su prevalencia del 16,9%. Constantes migraciones rural-urbanas han contribuído a su propagación hacia sectores urbanos. Para investigar el impacto de dichas migraciones sobre la población susceptible de donar sangre y el probable incremento del riesgo de transmisión del T. cruzi vía transfusional se efectuaron encuestas seroepidemiológicas en donantes de 22 hospitales de la mitad norte de Chile. Mediante la reacción de hemaglutinación indirecta se examinaron 16.841 donantes encontrándose un 2,7% de positividad, porcentaje que permitió estimar que habría 126.477 potenciales donantes de sangre infectados por T. cruzi en los sectores urbanos estudiados. Estos hechos refuerzan la necesidad que en bancos de sangre de las regiones endémicas del país se efectúe rutinariamente serología para enfermedad de Chagas, para adoptar o reforzar medidas preventivas pertinentes