The evaluation of low cut-off index values of Elecsys® HIV combi PT assay in predicting false-positive results.

OBJECTIVE: To analyze the results of different cut-off index (COI) values of Elecsys® HIV combi PT assay and to assess the role of COI in reducing the frequency of false-positive results. METHODS: We conducted a retrospective study of samples analyzed by Elecsys® HIV combi PT assay, a 4th-generation ECLIA, between 2016 and 2017. A total amount of 379 122 samples were collected for HIV (Human Immunodeficiency Virus) screening. RESULTS: A total of 379 122 samples were analyzed. 2528 (0.67%) were positive by Elecsys® HIV combi PT. Of these, 468 were false-positive results, and most of them (94.87%) were in samples with 1 < COI < 15. The false-positive rate was 0.12%. Patients with false-positive samples were more distributed in elder (P < .001) and female (P < .001) than true-positive specimens. The median COI in true-positive specimens was (385.20), which is significantly higher than false-positive specimens (2.08). The consistency between Elecsys® HIV combi PT assay and 3rd-generation and positive predictive value (PPV) increased with higher COI values. Cancer, infection, and neurological diseases were considered the potential confounding factors of HIV false-positive results (19.44%, 11.11%, and 6.62%, respectively). CONCLUSION: Samples with low COI values, especially those contain confounding factors, need to be further scrutinized to determine whether the confounding factors may cause false-positive problem. In addition, the hypothesis that low COI values may predict false-positive results is valid.

Prevention of congenital Chagas disease by screening of mothers and monitoring of serological tests of neonates: the seven years' experience.

Approximately 14000 immigrants coming from the Cochabamba area of Bolivia, with an increased risk of congenital Chagas Disease (CD), are currently living in Bergamo, Italy. According to the World Health Organization (WHO) recommendation (2011), prevention of congenital CD involves testing all pregnant women at risk of infection and performing follow-up of their newborns. In our study, all pregnant women of Latin American origin were tested for the presence of Trypanosoma cruzi antibodies and children, born to mothers found to be positive, were followed up after delivery. T. cruzi antibodies were detected using a chemiluminescence immunoassay. The test was also performed on siblings and fathers of children with CD, and women of childbearing age to prevent the congenital infection, as proposed by 2011 WHO recommendation. In the study period 1105 patients were tested for CD, using a serological test: 934 (85%) were females and 171 (15%) were males. Of the 62 newborns, from mothers who tested positive, 28 were females and 34 were males. The number of positive adults and siblings identified was 148 (14%). Among the adults and siblings born between 1991 and 2011 only 3 (2%) of females tested positive to serological test. All neonates, with the exception of one, were classified as non-infected according to the follow-up of index value of CD serology. This study confirms the usefulness of serological tests and of their index value as follow-up. The difference of positivity rate for CD antibodies between people born before and after 1990 should be further investigated to generate information that potentially improve the prevention and control of CD.

Heterogeneous patterns of COVID-19 transmission in an Urban set up - sero-epidemiological survey data from Ujjain, Madhya Pradesh (a central Indian city).

In the wake of rising number of SARS-CoV-2 cases, the Government of India had placed mass-quarantine measures, termed as "lockdown" measures from end-March 2020. The subsequent phase-wise relaxation from July 2020 led to a surge in the number of cases. This necessitated an understanding of the true burden of SARS-CoV-2 in the community. Consequently, a sero-epidemiological survey was carried out in the central Indian city of Ujjain, Madhya Pradesh. This article details the processes of data acquisition, compilation, handling, and information derivation from the survey. Information on socio-demographic and serological variables were collected from 4,883 participants using a multi-stage stratified random sampling method. Appropriate weightage was calculated for each participant as sampling fraction derived from Primary Sampling Unit (PSU), Secondary Sampling Unit (SSU) and Tertiary Sampling Unit (TSU). The weightage was then applied to the data to adjust the findings at population level. The comprehensive and robust methodology employed here may act as a model for similar future endeavours. At the same time, the dataset can also be relevant for researchers in fields such as data science, epidemiology, virology and earth modelling.

Two cases of a non-progressive hepatic form of glycogen storage disease type IV with atypical liver pathology.

Glycogen storage disease type IV (GSD IV) is a rare inborn metabolic disorder characterized by the accumulation of amylopectin-like glycogen in the liver or other organs. The hepatic subtype may appear normal at birth but rapidly develops to liver cirrhosis in infancy. Liver pathological findings help diagnose the hepatic form of the disease, supported by analyses of enzyme activity and GBE1 gene variants. Pathology usually shows periodic acid-Schiff (PAS) positive hepatocytes resistant to diastase. We report two cases of hepatic GSD IV with pathology showing PAS positive hepatocytes that were mostly digested by diastase, which differ from past cases. Gene analysis was critical for the diagnosis. Both cases were found to have the same variants c.288delA (p.Gly97GlufsTer46) and c.1825G > A (p.Glu609Lys). These findings suggest that c.1825G > A variant might be a common variant in the non-progressive hepatic form of GSD IV.