Performance of Five Serological Tests in the Diagnosis of Visceral and Cryptic Leishmaniasis: A Comparative Study

Introduction: Leishmaniasis is a major health problem and its diagnosis still represents a challenge. Since consistent evidence on the comparison of serological methods is lacking, our work aims to compare five serological tests for the diagnosis of visceral and asymptomatic leishmaniasis in southern France, a region where leishmaniasis is endemic. Methodology: Serum samples from 75 patients living in Nice, France were retrospectively analyzed. They included patients affected by visceral leishmaniasis (VL; n = 25), asymptomatic carriers (AC; n = 25) and negative controls (n = 25). Each sample was tested using two immunochromatographic tests (ICT; IT LEISH® and TruQuick IgG/IgM®), an indirect fluorescent antibody test (IFAT) and two Western Blotting (WB; LDBio BIORAD® and an in-house method). Results: Diagnosis of VL with IFAT and TruQuick® showed the highest diagnostic performance parameters. IFAT had 100% sensitivity and specificity, while TruQuick had 96% sensitivity and 100% specificity. Finally, the two tests showed high accuracy (100% for IFAT and 98% for TruQuick) for the AC group. WB LDBio® was the only method able to detect Leishmania latent infection, with a sensitivity of 92%, and a specificity of 100%, with a Negative Predictive Value (NPV) of 93%. This performance is reflected in the high accuracy of the test. Conclusions: The data obtained with TruQuick® supports its application in the rapid diagnosis of leishmaniasis in endemic areas, a feature not shown by IFAT despite its high diagnostic performance. Regarding the diagnosis of asymptomatic leishmaniasis, the best results were obtained with WB LDBio®, confirming previous studies

Argyrophilic nucleolar organizer regions and bromodeoxyuridine and h3-thymidine labelling indices in colorectal cancer

The count of argyrophilic nucleolar organizer regions (AgNORs) has been proposed as a useful method for evaluating cell replication in human tumours. The current study was undertaken to compare AgNOR values in colorectal cancers with two better established methods for investigating cell proliferation such as bromodeoxyuridine (BrdUrd) and (3)[H]-thymidine ((3)[H]dT) labelling indices (LIs). Because some concern still exists regarding accuracy and reproducibility of AgNOR quantifying methods, we carried out a control study by independently repeating the same measurements (number, area and area per silver-stained NOR particle) in two centres with different operators and computer-assisted image analysers on 40 colorectal carcinomas. AgNOR values recorded in the two centres were strictly correlated (r = 0.75; P < 0.001 for number; r = 0.62, P < 0.01 for area; r = 0.63, P < 0.001 for area per silver-stained NOR particle) and the range of values were almost identical, Then, AgNOR values were compared with BrdUrd and (3)[H]dT LIs, respectively obtained by in vivo incorporation and in vitro incubation in the same series of colorectal carcinomas. No correlation was found between AgNOR values and BrdUrd or (3)[H]dT LIs. BrdUrd and (3)[H]dT LIs were instead reciprocally significantly correlated, No evident correlation was seen between LIs or AgNOR values and clinico-pathological parameters of the tumour. In conclusion, in colorectal neoplasms, AgNOR values did not appear to relate with more direct parameters of cell proliferation. It follows that AgNOR reliability as a biomarker of cell proliferation remains questionable

Neural processing of emotions in traumatized children treated with eye movement desensitization and reprocessing therapy: a hdEEG study

Eye Movement Desensitization and Reprocessing (EMDR) therapy has been proven efficacious in restoring affective regulation in Post-Traumatic Stress Disorder (PTSD) patients. However, its effectiveness on emotion processing in children with complex trauma has yet to be explored. High density Electroencephalography (hdEEG) was used to investigate the effects of EMDR on brain responses to adults\u27 emotions on children with histories of early maltreatment. Ten school-aged children were examined before (T0) and within one month after the conclusion of EMDR (T1). hdEEGs were recorded while children passively viewed angry, afraid, happy, and neutral faces. Clinical scales were administered at the same time. Correlation analyses were performed to detect brain regions whose activity was linked to children\u27s traumatic symptom-related and emotional-adaptive problem scores. In all four conditions, hdEEG showed similar significantly higher activity on the right medial prefrontal and fronto-temporal limbic regions at T0, shifting towards the left medial and superior temporal regions at T1. Moreover, significant correlations were found between clinical scales and the same regions whose activity significantly differed between pre- and post-treatment. These preliminary results demonstrate that, after EMDR, children suffering from complex trauma show increased activity in areas implicated in high-order cognitive processing when passively viewing pictures of emotional expressions. These changes are associated with the decrease of depressive and traumatic symptoms, and with the improvement of emotional-adaptive functioning over time

SARS-CoV-2 transmission patterns in educational settings during the Alpha wave in Reggio-Emilia, Italy

: Different monitoring and control policies have been implemented in schools to minimize the spread of SARS-CoV-2. Transmission in schools has been hard to quantify due to the large proportion of asymptomatic carriers in young individuals. We applied a Bayesian approach to reconstruct the transmission chains between 284 SARS-CoV-2 infections ascertained during 87 school outbreak investigations conducted between March and April 2021 in Italy. Under the policy of reactive quarantines, we found that 42.5% (95%CrI: 29.5-54.3%) of infections among school attendees were caused by school contacts. The mean number of secondary cases infected at school by a positive individual during in-person education was estimated to be 0.33 (95%CrI: 0.23-0.43), with marked heterogeneity across individuals. Specifically, we estimated that only 26.0% (95%CrI: 17.6-34.1%) of students and school personnel who tested positive during in-person education caused at least one secondary infection at school. Positive individuals who attended school for at least 6 days before being isolated or quarantined infected on average 0.49 (95%CrI: 0.14-0.83) secondary cases. Our findings provide quantitative insights on the contribution of school transmission to the spread of SARS-CoV-2 in young individuals. Identifying positive cases within 5 days after exposure to their infector could reduce onward transmission at school by at least 30%

Co-circulation of SARS-CoV-2 Alpha and Gamma variants in Italy, February and March 2021

Background. Several SARS-CoV-2 variants of concern (VOC) have emerged through 2020 and 2021. There is need for tools to estimate the relative transmissibility of emerging variants of SARS-CoV-2 with respect to circulating strains.AimWe aimed to assess the prevalence of co-circulating VOC in Italy and estimate their relative transmissibility.Methods. We conducted two genomic surveillance surveys on 18 February and 18 March 2021 across the whole Italian territory covering 3,243 clinical samples and developed a mathematical model that describes the dynamics of co-circulating strains.Results. The Alpha variant was already dominant on 18 February in a majority of regions/autonomous provinces (national prevalence: 54%) and almost completely replaced historical lineages by 18 March (dominant across Italy, national prevalence: 86%). We found a substantial proportion of the Gamma variant on 18 February, almost exclusively in central Italy (prevalence: 19%), which remained similar on 18 March. Nationally, the mean relative transmissibility of Alpha ranged at 1.55-1.57 times the level of historical lineages (95% CrI: 1.45-1.66). The relative transmissibility of Gamma varied according to the assumed degree of cross-protection from infection with other lineages and ranged from 1.12 (95% CrI: 1.03-1.23) with complete immune evasion to 1.39 (95% CrI: 1.26-1.56) for complete cross-protection.Conclusion. We assessed the relative advantage of competing viral strains, using a mathematical model assuming different degrees of cross-protection. We found substantial co-circulation of Alpha and Gamma in Italy. Gamma was not able to outcompete Alpha, probably because of its lower transmissibility

Estimation of the incubation period and generation time of SARS-CoV-2 Alpha and Delta variants from contact tracing data

Quantitative information on epidemiological quantities such as the incubation period and generation time of SARS-CoV-2 variants is scarce. We analyzed a dataset collected during contact tracing activities in the province of Reggio Emilia, Italy, throughout 2021. We determined the distributions of the incubation period for the Alpha and Delta variants using information on negative PCR tests and the date of last exposure from 282 symptomatic cases. We estimated the distributions of the intrinsic generation time using a Bayesian inference approach applied to 9724 SARS-CoV-2 cases clustered in 3545 households where at least one secondary case was recorded. We estimated a mean incubation period of 4.9 days (95% credible intervals, CrI, 4.4-5.4) for Alpha and 4.5 days (95%CrI 4.0-5.0) for Delta. The intrinsic generation time was estimated to have a mean of 7.12 days (95% CrI 6.27-8.44) for Alpha and of 6.52 days (95%CrI 5.54-8.43) for Delta. The household serial interval was 2.43 days (95%CrI 2.29-2.58) for Alpha and 2.74 days (95%CrI 2.62-2.88) for Delta, and the estimated proportion of pre-symptomatic transmission was 48-51% for both variants. These results indicate limited differences in the incubation period and intrinsic generation time of SARS-CoV-2 variants Alpha and Delta compared to ancestral lineages