BACKGROUND: Tuberculosis (TB) poses a major public health challenge, particularly in children. A substantial proportion of children with TB disease remain undetected and unconfirmed. Therefore, there is an urgent need for a highly sensitive point-of-care test. This study aims to assess the performance of serological assays based on various antigen targets and antibody properties in distinguishing children (0-18 years) with TB disease (1) from healthy TB-exposed children, (2) children with non-TB lower respiratory tract infections, and (3) from children with TB infection.
METHODS: The study will use biobanked plasma samples collected from three prospective multicentric diagnostic observational studies: the Childhood TB in Switzerland (CITRUS) study, the Pediatric TB Research Network in Spain (pTBred), and the Procalcitonin guidance to reduce antibiotic treatment of lower respiratory tract infections in children and adolescents (ProPAED) study. Included are children diagnosed with TB disease or infection, healthy TB-exposed children, and sick children with non-TB lower respiratory tract infection. Serological multiplex assays will be performed to identify M. tuberculosis antigen-specific antibody features, including isotypes, subclasses, Fc receptor (FcR) binding, and IgG glycosylation.
CONCLUSIONS: The findings from this study will help to design serological assays for diagnosing TB disease in children. Importantly, those assays could easily be developed as low-cost point-of-care tests, thereby offering a potential solution for resource-constrained settings.
RESULTS:
UNASSIGNED: NCT03044509.

Equine leishmaniasis is a neglected tropical disease caused by the protozoan of the Leishmania genus, and it has been reported in several countries around the world, especially Brazil. Therefore, the present investigation aims to conduct a cross-sectional study to determine the prevalence, spatial distribution, and associated factors with seropositivity for Leishmania spp. in draft horses from the Distrito Federal, Brazil. The serological survey was conducted on 411 animals, employing the Indirect Immunofluorescence Test (IFA) and Enzyme-Linked Immunosorbent Assay (ELISA). The Kappa (κ) and gross agreement indexes evaluated the Leishmania spp. seropositivity by IFA and ELISA test. The statistical analysis was performed using the Chi-square test and logistic regression. The spatial analysis showed the areas with the highest number of seropositive and the Moran autocorrelation analyses between the spatial distribution and the epidemiological model\'s explanatory variables. A 27.01 % co-positivity was observed with a κ index of 52.64 %. The final model considered the variables: access to water bodies (p-value = 0.008, Odds Ratio (OR) = 2.26, Confidence Interval (CI) = 1.24-4.13), the absence of the use of ectoparasiticide (p-value = 0.008, OR = 1.93 CI = 1.18-3.15) and traveling animal (p-value = 0.059, OR = 1.54, CI = 0.98-2.41). The Kernel map showed hot areas with a high concentration of nine positive animals per area and some lighter areas ranging from five to seven positive animals per area where control measures should be performed. The Moran autocorrelation analysis was significant for the variables: traveling animal (Moran\'s I = 0.540 and pseudo-p-value = 0.001) and the absence of use ectoparasiticide (Moran\'s I = 0.259 and pseudo-p-value = 0.005). The current study exposes a high seroprevalence of Leishmania spp. in horses in the Distrito Federal, Brazil. Moreover, it proposes that traveling animal, the access to water bodies and the absence of the use of ectoparasiticide are significantly associated with seropositivity for Leishmania spp. in draft horses, which may contribute to the implementation of prophylactic and controls measures where leishmaniasis is already stalled.

In view of the potential gravity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection for patients with cancer, epidemiological data are vital to assess virus circulation among patients and staff of cancer centres. We performed a prospective study to investigate seroprevalence of SARS-CoV-2 antibodies among staff and patients with cancer at a large cancer centre, at the end of the period of first national lockdown in France and to determine factors associated with the risk of SARS-CoV-2 infection.
After the first lockdown, all medical and non-medical staff, as well as all patients attending the medical oncology department were invited to undergo serological testing for SARS-CoV-2 between 11 May and 30 June 2020. All participants were also invited to complete a questionnaire collecting data about their living and working conditions, and for patients, medical management during lockdown.
A total of 1,674 subjects (663 staff members, 1011 patients) were included. Seroprevalence was low in both staff (1.8%) and patients (1.7%), despite more features of high risk for severe forms among patients. None of the risk factors tested in our analysis (working or living conditions, comorbidities, management characteristics during lockdown) was found to be statistically associated with seroprevalence in either staff or patients. There was no significant difference in the proportion of symptomatic and asymptomatic subjects between staff and patients. Only fever, loss of smell, and loss of taste were significantly more frequent among seropositive patients, in both staff and patients.
We report very low seroprevalence of antibodies against SARS-CoV-2 in the staff (caregiving and non-caregiving) and patients of a large cancer care centre in which strict hygiene, personal protection, and social distancing measures were implemented.

The differential diagnosis of hepatic cystic echinococcosis (CE) may be challenging. When imaging is insufficient, serology can be applied, but no consensus diagnostic algorithm exists. We evaluated the performances of nine serological tests commercialized in Europe for the diagnosis of \"echinococcosis\". We performed a diagnostic accuracy study using a panel of sera from patients with hepatic CE (n = 45 \"liquid\" content stages, n = 25 \"solid\" content stages) and non-CE focal liver lesions (n = 54 with \"liquid\" content, n = 11 with \"solid\" content). The diagnosis and staging of CE were based on ultrasound (gold standard). Nine commercial seroassays (5 ELISA, 2 WB, 1 Chemiluminescence Immunoassay [CLIA] and 1 Immunochromatographic test [ICT]) were the index tests. Sensitivity (Se) ranged from 43 to 94% and from 31 to 87%, and specificity (Sp) from 68 to 100% and from 94 to 100%, when borderline results were considered positive or negative, respectively. Three seroassays (2 ELISA, 1 WB) were excluded from further analyses due to poor performances. When tests were combined, Sp was 98-100%. The best results were obtained using the WB-LDBIO alone (Se 83%) or as a third test after two non-WB tests (Se 67-86%). A validated WB or two non-WB tests, read with stringent criteria (borderline = negative and considered positive only if concordant positive), possibly confirmed by the WB, appear sensible approaches.

UNASSIGNED: Fascioliasis is a neglected zoonotic disease, caused by Fasciola species in human and livestock. We aimed to detect the seroprevalence of human fascioliasis Gorgan City, Golestan Province, northern Iran using ELISA method in 2017.
UNASSIGNED: Overall, 612 serum samples were analyzed. A relevant questionnaire for demographic data was obtained for all cases. An indirect ELISA test was used to detect IgG antibodies against Fasciola in the sera. The data analysis was performed employing SPSS program version 21.
UNASSIGNED: Eleven cases (1.79%) were seropositive for fascioliasis. The seroprevalence of fascioliasis was 1.9% and 1.1% among males and females, respectively. There was no statistically significant association between the fascioliasis and analyzed variables such as sex, age, residence, job, education, etc.
UNASSIGNED: This study was conducted only on the people referring to the Reference Laboratory of Gorgan. It cannot be distributed to the whole city. Thus, due to importance of the disease, finding the seroprevalence of fascioliasis in a comprehensive survey in Golestan Province should be accounted in further studies.

Experimental serological tests were developed to determine anti-tularensis antibodies in humans in immunochromatography formats (LF-test LPS Ft15) and enzyme immunoassay (ELISA LPS Ft15) using as an antigen highly purified LPS F. tularensis 15 NIIEG. Analysis was conducted of the sensitivity and specificity of the developed tests and commercial tularemia antigen «RNGA-Tul-AG» (production Stavropol research anti-plague Institute) in comparison with the commercial reference antigen, registered in the Russian Federation for the quantitative determination of human IgG tularemia - «ELISA classic Francisella tularensis IgG» SERION, Germany (IgG SERION ELISA). A study of human blood serum vaccinated against tularemia showed that the sensitivity and specificity of detection of anti-tularemia antibodies by «ELISA LPS Ft15» were 97.7 and 100%, compared with «ELISA IgG series». When determining antitularemia antibodies with the diagnosis «LF-test LPS Ft15», these parameters were compared to «ELISA IgG series» 94.3 and 100%. The sensitivity and specificity of «RNGA-Tul-AG» made compared to the «IgG ELISA, SERION» of 59.1% and 80%.

The diagnosis of Mycobacterium avium complex pulmonary disease (MAC-PD) is sometimes complicated and time-consuming. A serodiagnostic kit that measures the serum levels of IgA antibodies against the glycopeptidolipid (GPL) core is commercially available and has good diagnostic accuracy for MAC-PD. However, the significance of measurement of GPL core IgA antibody levels in monitoring for chemotherapy response in patients with MAC-PD was not well investigated. Thirty-four treatment naive MAC-PD patients who were started on multidrug chemotherapy were enrolled. Their antibody levels were prospectively measured at regular intervals. The relationships between their antibody levels and the therapeutic outcomes were examined. The patients were classified into three groups (conversion, recurrence, and nonconversion) based on the bacteriological outcomes after chemotherapy. There were no significant differences in the antibody levels before treatment between the culture conversion (n = 19), recurrence (n = 7), and nonconversion (n = 8) groups (P = 0.9881). The levels decreased significantly after the chemotherapy (P < 0.0001). Recurrence and/or worsening of chest radiography findings were observed in cases whose antibody levels subsequently increased after cessation of the chemotherapy. No significant difference in the percent decrease in antibody levels by the chemotherapy was observed between the culture conversion and recurrence groups (P = 0.9338). The initial antibody levels are not a predictor of therapeutic outcomes, and also the percent decrease in antibody levels is not a sufficient indicator of the cessation of chemotherapy. However, serial measurements of antibody levels may allow objective monitoring of disease activity in individual MAC-PD patients.

The gold standard for the diagnosis of sporotrichosis consists of the isolation and identification of the fungus from clinical exudates and/or biopsy specimens. However, new technologies offer several advantages over the traditional methods because they are noninvasive and more sensitive in the differential diagnosis of infectious diseases. In the present study, we performed a validation, impact evaluation, and analysis of the applicability of an enzyme-linked immunosorbent assay (ELISA) for the diagnosis of sporotrichosis in different groups of patients in comparison with the reference protocols for the evaluation of diagnostic tests for infectious diseases. We used 177 serum samples that were collected between 1998 and 2008 from patients in a geographic area related to the Rio de Janeiro outbreak of sporotrichosis. The ELISA had a low rate of cross-reactivity based on the reference values for diagnostic tests, and the analysis of the receiver operating characteristic curve revealed an area under the curve of 0.9154. Furthermore, higher accuracy was observed in the serodiagnosis of infections in special groups of patients such as pediatric and human immunodeficiency virus-positive patients. We concluded that this ELISA had a good clinical serological correlation and, therefore, can be considered a new diagnostic tool applicable to all clinical presentations of sporotrichosis.

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