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IgG avidity assays have been developed for several parasitic diseases although there are no researches focused in strongyloidiasis diagnosis. Definitive diagnosis of strongyloidiasis is based on the presence of Strongyloides larvae in stool, but majority of cases involve low and irregular larval output. While limitations of serological assays for strongyloidiasis are well known, characteristics of persons who are misdiagnosed based on negative coproparasitological tests have been little explored. The aim of the present study was to evaluate the use of IgG avidity to detect patients with active strongyloidiasis and to characterize sources of disagreement between serology and coproparasitology. A total of 80 serum samples was analyzed, 40 from patients with Strongyloides larvae in stool (G1) and 40 from individuals with negative coproparasitology, but positive serology (G2). Serum samples were analyzed in an indirect IgG avidity ELISA using urea 6M in serial double dilutions from 1:80 to 1:2560. Avidity index (AI) was calculated to each serum dilution and analyzed as screening AI (serum dilution of 1:160) or mean AI of different serum dilutions that had a positive result. Statistical analyzes were performed by Mann–Whitney's (U) and Fisher's exact tests. At screening dilution, median of AI was 68% in G1 and 88% in G2 (P75% (P

In this study, we determined the avidity index (AI) of anticytomegalovirus (CMV) immunoglobulin G (IgG) and the anti-CMV immunoglobulin M (IgM) profile in 124 pregnant women, 87 of whom were considered at risk of transmitting CMV infection to their offspring and 37 of whom were at no risk. IgG avidity and blot for IgM were performed on two serum samples from each woman, at 6-18 weeks' gestation and at 20-23 weeks' gestation. Pregnancy outcomes were monitored. The results obtained showed that the determination of anti-CMV IgG avidity at 6-18 weeks' gestation can identify all women who would have an infected fetus/newborn (100% sensitivity), whereas IgM detected by blot had poorer results (69% sensitivity). Interestingly, at 20-23 weeks' gestation, the sensitivity of IgM detection by blot was higher than that obtained by avidity (75 % and 63%, respectively) and the combination of IgG avidity and IgM by blot yielded the best results (81% sensitivity).

Splenectomy is closely associated with a lifetime risk of pneumococcal and other encapsulated bacterial infections. In this study, it was aimed to investigate the change of antibody levels after vaccination against Streptococcus pneumoniae according to age, gender, years after splenectomy and the possible effect of splenectomy on IgG avidity. In addition the education and awareness levels of the participants about post-splenectomy vaccination and infectious diseases were also analyzed. In the first of the three phases of this study, 32 individuals with splenectomy were enrolled. The awareness of the patients about the possible risks after splenectomy was investigated with a simple questionnaire. Routine laboratory test results were obtained and clinical examinations were performed. In the second stage, total Ig values of 29 splenectomy patients were determined. In the third phase, 14 splenectomy and 5 healthy volunteers were vaccinated according to the Vaccination Practices Advisory Committee (ACIP) guidelines. Pneumococcal-specific antibody levels and IgG avidity were detected by enzyme linked immunosorbent assay (ELISA). It was determined that 68.8% of the splenectomized patients were unaware of their vaccination status and 78.2% of them were unaware of the increased risk of infectious diseases in asplenic conditions. . According to the hospital information management system, all 31 (96.87%) patients, except one, were vaccinated with PPV23. As expected, vaccinated patients exhibited high levels of vaccine-specific antibody production with IgG, IgG2, and IgA antibody concentrations of 321 ± 76.68 mg/l, 73.07 ± 8.273 mg/l, and 117.8 ± 14.94 mg/l, respectively, but unvaccinated patients had very low antibody (IgG, IgG2 and IgA antibody concentrations were 11.5 mg/l, 1.3 mg/l and 1.2 mg/l, respectively) levels. Although there was no correlation between antibody titers and gender, age groups or presence of fever history, the decrease in total IgG, IgG2 and IgA titers were strongly correlated with the time since splenectomy. Antibody titers were found to be significantly lower in splenectomized patients vaccinated more than 10 years ago. Routine laboratory results were at normal levels except for low platelet count. On the other hand, both splenectomized and healthy control subjects displayed similar IgG avidity index values (%61.8 ve %64.4% inhibition in control and splenectomized subjects, respectively) after the vaccination schedule. It was shown that post-splenectomy vaccination with PPV23 induced high levels of pneumococcus-specific antibody production that can last for more than five years. It was determined that more efforts should be made to increase the level of knowledge about pneumococcal and other overwhelming post-splenectomy infections (OPSI) as the awareness of the patients about the risks of infection after splenectomy was poor. In particular, patients with splenectomy operation more than 10 years ago should be very careful about being asplenic as they were determined to have significantly lower level of vaccine-specific antibody production. Our study was also the first to show that splenectomy does not alter IgG avidity induced by pneumococcal vaccination. © 2022 Ankara Microbiology Society. All rights reserved.

Para verificar a ocorrência da toxoplasmose em Cascavel, Paraná, cidade próxima a região onde ocorreu o maior surto epidêmico descrito mundialmente, 334 amostras de soros de gestantes foram triadas pelo ensaio imunoenzimático comercial IgG no Laboratório Municipal de Cascavel, e confirmadas no Instituto de Medicina Tropical de São Paulo por imunofluorescência IgG, ensaio imunoenzimático e avidez de IgG in house. A soropositividade pelo IgG comercial foi 54,2%, pela imunofluorescência 54,8% e pelo IgG in house 53,9%, com boa concordância entre imunofluorescência/IgG comercial (Kappa=0,963781; co-positividade=97,8%; co-negatividade=98,7%) e imunofluorescência/IgG in house (Kappa=0,975857; co-positividade=97,8%; co-negatividade=100%). A evidência de infecção aguda nas gestantes foi similar tanto pela avidez de IgG (2,4% ao ano) como pela análise estatística de tendência (teste χ2) por faixa etária (2% ao ano), sugerindo que a triagem sorológica pré-natal e a vigilância epidemiológica são imprescindíveis para redução do risco da toxoplasmose na região, embora sem evidência de surto epidêmico. In order to investigate the incidence of toxoplasmosis in Cascavel, Paraná, a city near the region where the largest reported epidemic outbreak in the world occurred, 334 serum samples from pregnant women were screened using a commercial IgG immunoenzymatic assay at the Municipal Laboratory in Cascavel and were confirmed at the Institute of Tropical Medicine in São Paulo, by means of IgG immunofluorescence, immunoenzymatic assaying and the in-house IgG avidity test. The IgG seropositivity from the commercial test was 54.2%, from immunofluorescence 54.8% and from the in-house IgG 53.9%, with good agreement between immunofluorescence and the commercial IgG test (kappa = 0.963781; co-positivity = 97.8%; co-negativity = 98,7%) and between immunofluorescence and the in-house IgG (kappa = 0.975857; co-positivity = 97.8%; co-negativity = 100%). The evidence of acute infection among the pregnant women was similar, as estimated both by IgG avidity (2.4%/year) and by statistical trend analysis (χ2 test) according to age group (2%/year). This suggests that prenatal serological screening and epidemiological surveillance are essential for reducing the risk of toxoplasmosis in the region, although without evidence of an epidemic outbreak.

Background: Toxoplasma specific IgM antibodies; the common serologic marker in diagnosis of acute toxoplasmosis has its own limitations. Confirmatory testing with other markers, introduced as a complementary tool in distinguish acute and chronic infections is unusual in Iran. In the present study, we investigated the cor-relation between the results of IgM ELISA, IgA ELISA, and IgG avidity tests in the diagnosis of toxoplasmosis to demonstrate the necessity of confirmatory testing in serodiagnosis of infection in the country. Methods: A total of 107 positive Toxoplasma IgG and IgM sera were obtained from patients referred to private laboratories and stored at -20 ºC for futures use. Sero-logic tests were set up in duplicate to analyze the serum levels of IgG, IgM, IgA, and IgG avidity antibodies using commercial ELISA kits. The results were pre-sented as semi quantitative for IgG, IgM and IgA ELISA, and Relative Avidity In-dex in percentage for IgG avidity test. Pearson’s correlation coefficient (rp) was applied to analyze the data. Results: Of 107 serum samples, T. gondii specific IgM and IgA antibodies were positive in 67.3% and 53.3%, respectively. Besides, 29.9% of the sera displayed low avidity for IgG antibodies. The rp was - 0.572 (P