An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of IgG antibodies to purified sheep hydatic cyst fluid antigen in 56 sera of confirmed cases of hydatidosis. The cut-off value was determined using serum samples from 80 healthy persons, employing two serum dilutions (1:100 and 1:500) with two and three standard deviations (SD). This assay was compared with the indirect hemagglutination test (IHAT). The sensitivity of ELISA-IgG was 94.3% for hepatic cysts and 92.9% for pulmonary cysts, whereas the values for IHAT were 77.1 and 64.3% respectively. According to Mac Nemar test, both method presented statistical significance (p < 0.05). In order to find out the specificity, additional 70 serum samples from individuals with other parasitoses, such as cysticercosis (30), trichinosis (26) and fascioliasis (14) were also tested. IHAT presented a specificity of 92.7% and for ELISA-IgG the specificity using a cut-off of mean + 3 SD was 99.3 and 100.0% with sera dilution of 1:100 and 1:500 respectively when a cut-off of mean + 2 SD was considered, we found a specificity of 91.3 and 97.3% for 1:100 and 1:500 dilutions. The use of ELISA-IgG and purified antigen in the diagnosis of human hydatidosis is discussed.

Adolescent↗

PubMedDate not supplied

[Trichinosis outbreak in Purranque County, X Region, Chile. October-November, 1992].

An outbreak of trichinosis occurred in Purranque County, X Region, Chile, between october and november of 1992, which involved 36 persons. The incubation period, determined by the clinical picture and laboratory assays, fluctuated between 10 and 12 days. Myalgias (88.9%) and palpebral oedema (86.1%), were the most important symptoms, followed by fever (44.4%) and headache (33.3%). Eosinophils count ranged from two to 42% the first week, and this value raised to 55% the second week of the outbreak. Anti-Trichinella spiralis antibodies were determined by some serological tests such as: precipitin test (PT), bentonite flocculation test (BFT) and indirect hemagglutination test (IHAT) in sera from 28 patients at the beginning of the outbreak. PT was positive in 46.4% of the cases, followed by IHAT (21.4%) and BFT (3.6%). After 15 days, the three tests were performed in sera from 12 patients. At that time, the positivity was elevated in all of them: PT (100.0%), BFT (66.7%) and IHAT (91.7%). It is believed that the outbreak had its origin in infected pork meat that was consumed raw or insufficiently cooked without a previous veterinary inspection.

Adolescent↗

PubMedDate not supplied

[Epidemiology of trichinosis in Chile. Prevalence study by immunodiagnostic reactions].

In the period 1983-1994 a series of seroepidemiological surveys, by using immunodiagnostic tests for trichinosis, was carried out in 138 localities and health institutions from the 13 regions of the country. Thus, a total of 12,882 randomly selected persons, with different sex and age distribution, were submitted to precipitin test and indirect hemagglutination test for trichinosis. One hundred and ninety one (1.5%) persons resulted positive for trichinosis. Higher rates of infection were observed in central and southern Chile. No differences of positivity, according to age sex, but constant increase parallel to age of the individual were detected. The general prevalence rate of infection of 1.5% is in a reasonable accordance with the prevalence of 2.0% found in human corpses in 1992.

Adolescent↗

PubMedDate not supplied

[Comparison of the frequency of electrocardiographic changes in groups of apparently healthy persons with a positive serology for Chagas' disease, for toxoplasmosis or for both parasitoses].

In order to compare the frequency of electrocardiographical abnormalities among apparently healthy persons with Trypanosoma cruzi and Toxoplasma gondii infections, electrocardiogram (EKG) and the corresponding indirect hemagglutination tests (IHAT) were performed to 13,444 randomly selected rural and suburban inhabitants from the seven first regions of Chile which are located in the geographic area of distribution of Chagas' disease in the country. The IHAT for each parasitosis resulted positive (titers > or = 1:16) for Chagas' disease alone in 1,289 (9.6%), for toxoplasmosis alone in 3,519 (26.2%) and for the two infections in 994 (7.4%). EKG abnormalities of all type (AAT) and suggestive of a chagasic etiology (ASChE) were found in 18.5 and 8.3% respectively of the T. cruzi infected group, in 10.9 and 3.2% of the T. gondii infected group, in 18.9 and 4.8% of the group simultaneously infected by the two parasites, whereas AAT and ASChE were found in 7.9 and 1.8% of the IHAT negative group. All the corresponding percentage differences between abnormal EKG had a statistical significance (p < 0.05). Besides the increasing of the IHAT positivity, for each infection parallels to the age grouping of the studied persons, a similar situation was observed in the frequence of the AAT and ASChE mainly among people aged > or = 50 years. As T. cruzi and T. gondii infections sometimes isoletely adopt a high virulence and overlap in a proportion higher than 43.0% in Chagas' disease endemic areas, it is advisable to consider these etiologic possibilities in the presence of patients with a myocardiopathy of dubious interpretation, particularly when AIDS is involved.

Adolescent↗

PubMedDate not supplied

[Frequency of electrocardiographic alterations in apparently healthy persons with indirect hemagglutination reaction positive for toxoplasmosis].

An indirect hemagglutination test (IHAT) for toxoplasmosis and electrocardiogram (EKG) were performed to 11,161 apparently healthy inhabitants with negative IHAT for Chagas' disease, from 259 rural and periurban localities sited in the first seven regions of Chile (geographic area of distribution of Chagas' disease in the country). The age of the 11,161 examined people ranged between 5 and 94 years, being 4,518 males and 6,643 females. The IHAT for toxoplasmosis was considered positive with titers > or = 1:16. This test resulted positive in 3,519 (31.1%) persons (30.8% in males and 32.0% in females). Positivity of the IHAT increased from 21.2%, in the youngest group (< 10 years) up to 46.9% in the oldest group (> or = 60 years). Different types of EKG alterations were observed in 10.9% of the IHAT positive individuals and in 7.9% of the IHAT negative ones. In both groups the percentages of altered EKG increased parallel with age. The overall difference of percentages of altered EKG in IHAT positive and IHAT negative persons has a statistical significance with p < 0.001. This study suggest the convenience to consider toxoplasmosis as a cause of chronic myocardiopathy in epidemiological studies on Chagas' disease, because a possible Toxoplasma gondii infection may contribute to overincrease the magnitude of the impact of Trypanosoma cruzi in the generation of the quoted myocardiopathy.

Adolescent↗

PubMedDate not supplied

[Epidemiology of Chagas disease in Chile. Frequency of human Trypanosoma cruzi infection by age groups and regions].

Chagas' disease is endemic in rural-periurban sections of the northern half of Chile which includes the first seven political-administrative regions of the country (18 degrees 30'-34 degrees 36' South lat.). Data concerning to the results of an indirect hemagglutination test for Chagas' disease performed to 15,418 rural-periurban and 45,119 urban inhabitants fron the chagasic endemic regions are presented. Migrations from rural-periurban to urban areas have contributed to the dissemination of Trypanosoma cruzi infection. General rates of infection for rural-periurban (r-p) and urban (u) sections were 16.7% and 1.9% respectively. The higher prevalence rates were detected in Region III with 27.2% (r-p) and 3.9 (u) and Region IV with 24.7% (r-p) and 3.5% (u), while the lower prevalence rates corresponded to Region VI with 7.0% (r-p) and 0.8% (u). Serological positivity increased parallelly with age in all regions.

Adolescent↗