Comparison of fluorescent antibody test, immunohistochemistry, and PCR testing for diagnostic confirmation of neurolisteriosis in 25 goats.

Neurolisteriosis, a common disease of small ruminants, is most often caused by Listeria monocytogenes. Here we describe 25 cases of caprine neurolisteriosis diagnosed in our laboratory over a 5-y period and compare our fluorescent antibody test (FAT) results with immunohistochemistry (IHC) and polymerase chain reaction (PCR) testing for diagnostic confirmation. Neurohistologic changes consistent with neurolisteriosis affected the pons in all cases, extending rostrally to the mesencephalon in 6 cases, caudally to the medulla oblongata in 6 cases, and/or dorsally to the cerebellum in 4 cases. Acute inflammatory changes were observed in 17 cases, and included neuroparenchymal microabscesses, neuronal necrosis and neuronophagia, axonal swelling, microgliosis and astrogliosis, and perivascular neutrophils with macrophages, lymphocytes, and plasma cells that occasionally extended to the leptomeninges. Subacute-to-chronic changes (8 cases) consisted of neuroparenchymal and perivascular clusters of macrophages with rare neutrophils, lymphocytes, and plasma cells admixed with glial nodules. Bacterial bacilli were observed within neutrophils or macrophages in H&E-stained tissue sections in 4 cases. Gram stain highlighted gram-positive bacilli in 13 cases. Neurolisteriosis was confirmed by FAT in 2 cases, by IHC in 19 cases, and by PCR in 20 cases.

Comparison of the Accuracy of HSV1 and HSV2 Antibody Tests with PCR in the Diagnosis of Recurrent Genital Herpes.

Objective: To assess the accuracy of HSV1and HSV2 antibody testing in identifying genital herpes infection. Methods: A cohort of 299 patients previously diagnosed with recurrent genital herpes, confirmed via PCR, were tested using ELISA for HSV1 and HSV2 IgM and IgG antibodies. The study compared the accuracy of HSV1 and HSV2 antibody tests in diagnosing genital herpes. Results: Among 299 patients, 14 tested positives for HSV1 DNA. Of these, 9 had HSV1 IgG antibodies, but none had HSV2 IgG antibody. Among 278 patients with HSV2 DNA, 149 had HSV1 IgG, 9 had HSV2 IgG, and 97 had both. Seven patients had both HSV1 and HSV2 DNA; 3 had HSV1 IgG, 1 had HSV2 IgG, and 3 had both. The accuracy of HSV1 IgG for HSV1 infection was 64.2%, and for HSV1 and HSV2 co-infection, 85.7%. The accuracy of HSV2 IgG for HSV2 infection was 38.1%, and for HSV1 and HSV2 co-infection, 57.1%. The combined antibody positivity accuracy was 34.9%. Conclusion: Genital herpes is primarily caused by HSV2 (92.98%). A smaller percentage is HSV1 (4.67%) or co-infection (2.34%). Despite relatively low diagnostic accuracy (34.9-85.7%) for antibody detection, combined antibody testing is necessary. Herpes DNA testing is recommended for accurate diagnosis. Absence of antibodies does not rule out genital herpes and clinical assessment is essential.

Twenty-year evolution of Leishmania infantum infection in dogs in Valdeorras (Galicia, Northwestern Spain): implication of climatic factors and preventive measures.

BACKGROUND: Abiotic factors play a significant role in the evolution of Leishmania infantum infection due to its vectorial nature. This study aims to assess the evolution in the detection of new L. infantum infection cases in Valdeorras (Ourense, Northwestern Spain) over a 20-year period and how different climatic variables and preventive measures may have affected it. METHODS: Indirect immunofluorescence antibody tests (IFAT) were performed on serum samples collected from dogs attending the 'Servicios Veterinarios de Sil' veterinary clinic (Valdeorras, Northwestern Spain) between May 2003 and April 2023 to detect L. infantum exposure. The percentage of new cases of L. infantum infection was calculated from May of one year to April of the following year. Climatic conditions in the region, global sales of ectoparasiticides and the number of vaccines against L. infantum delivered in the veterinary clinic from 2003 to 2022 were recorded. Statistical analyses were conducted to determine the associations between these factors and the percentage of new cases of L. infantum infection. RESULTS: A total of 2909 dogs were assessed, and 3785 IFAT tests were performed between May 2003 and April 2023. The mean percentage of new seropositive cases over the 20-year period studied was 21.65 ± 10.8%, with a decline from the beginning to the end of the period studied. The percentage was significantly higher between May 2003 and April 2008 compared with the other periods (May 2008 to April 2013, May 2013 to April 2018 and May 2018 to April 2023). There was a positive correlation between the percentage of new cases of L. infantum infection and the maximum relative humidity in winter. Conversely, there was a negative correlation between the percentage of new cases and sales of ectoparasiticides and vaccination against L. infantum. CONCLUSIONS: This study is one of the longest evaluations of the evolution of L. infantum infection in a fixed location and its association with external factors including climatic conditions and preventive measures. The results confirm that Valdeorras is a high-risk area for L. infantum infection. The use of ectoparasiticides and vaccines against L. infantum has been shown to play a significant role in preventing L. infantum infection, highlighting the crucial role of veterinarians in the fight against this disease.

Seroprevalence and risk factors of Toxoplasma gondii in goats (Capra hircus) in the state of Espírito Santo, Southeast Brazil.

Toxoplasma gondii is described as a potential cause of abortion in goats and as a threat to public health. To estimate the prevalence of goats infected by T. gondii, in different cities in the Espírito Santo State, and to identify possible risk factors for infection a serological study was conducted. A total of 146 goat serum samples from the cities of Cariacica, Serra and Vila Velha were analyzed. The presence of IgG Class Immunoglobulins was serologically evaluated by Immunofluorescence antibody test (IFAT) and by Enzyme-linked Immunosorbent Assay (ELISA). The seroprevalence of anti-T. gondii was 46.6% (68/146) in both techniques and the same samples got the same results in both techniques. Among the analyzed sera, 70.6% (48/68) exhibited high-avidity IgG antibodies, and 29.4% (20/68) exhibited low-avidity IgG antibodies, suggesting that the infection was chronic in the infected animals. Female sex, age group over two years old, water from the public supply system, storage of food and supplies in an open and unprotected place, and the presence of a domestic cat on the property were identified as risk factors for T. gondii infection in goats. The state of Espirito Santo has a high frequency of infected goats, and this is the first research on caprine toxoplasmosis seroepidemiology in that region.

High diagnostic accuracy of quantitative SARS-CoV-2 spike-binding-IgG assay and correlation with in vitro viral neutralizing activity.

Background: Antibody testing can easily evaluate the clinical status of patients, aid in the diagnosis of multisystem inflammatory syndrome, and monitor the immunity level in the population. However, the applicability of serological tests in detecting antibodies against the severe acute respiratory syndrome 2 (SARS-CoV-2) spike-binding protein remains limited. This study aimed to quantify both serum-derived neutralizing immunoglobulin-G (IgG) antibody activity and the amount of anti-SARS-CoV-2 Spike-IgG (S-IgG) in convalescent sera/plasmas and evaluate the direct correlation between the in vitro IgG-EC50 values and S-IgG values. Methods: We evaluated the neutralizing activity of purified IgG (IgG-EC50), quantified S-IgG in the serum/plasma of consecutive COVID-19 convalescent individuals using a cell-based virus-neutralizing assay, and determined the correlation between IgG-EC50 and S-IgG. In addition, we evaluated rational cut-off values using the receiver operating characteristic (ROC) curve and calculated the sensitivity and specificity of the quantitative S-IgG assay for moderate and high IgG-EC50. Results: A high correlation was observed between S-IgG and IgG-EC50 with a Spearman's ρ value of -0.748 (95 % confidence interval [CI]: -0.804-0.678). Using an IgG-EC50 of 50 µg/mL and 20 µg/mL as the cut-off values for moderate and high in vitro neutralizing activity, respectively, the Youden's index values of 287.5 binding antibody units (BAU)/mL and 454.1 BAU/mL determined from the ROC curve showed the highest diagnostic accuracy, with Kappa values of 0.884 (95 % CI: 0.823-0.946) and 0.920 (95 % CI: 0.681-0.979), respectively. Conclusions: Quantitative S-IgG tests are a useful and convenient tool for estimating in vitro virus-neutralizing activity, with a high correlation with IgG-EC50 when the rational cut-off value is carefully determined.

Estimating cutoff values for diagnostic tests to achieve target specificity using extreme value theory.

BACKGROUND: Rapidly developing tests for emerging diseases is critical for early disease monitoring. In the early stages of an epidemic, when low prevalences are expected, high specificity tests are desired to avoid numerous false positives. Selecting a cutoff to classify positive and negative test results that has the desired operating characteristics, such as specificity, is challenging for new tests because of limited validation data with known disease status. While there is ample statistical literature on estimating quantiles of a distribution, there is limited evidence on estimating extreme quantiles from limited validation data and the resulting test characteristics in the disease testing context. METHODS: We propose using extreme value theory to select a cutoff with predetermined specificity by fitting a Pareto distribution to the upper tail of the negative controls. We compared this method to five previously proposed cutoff selection methods in a data analysis and simulation study. We analyzed COVID-19 enzyme linked immunosorbent assay antibody test results from long-term care facilities and skilled nursing staff in Colorado between May and December of 2020. RESULTS: We found the extreme value approach had minimal bias when targeting a specificity of 0.995. Using the empirical quantile of the negative controls performed well when targeting a specificity of 0.95. The higher target specificity is preferred for overall test accuracy when prevalence is low, whereas the lower target specificity is preferred when prevalence is higher and resulted in less variable prevalence estimation. DISCUSSION: While commonly used, the normal based methods showed considerable bias compared to the empirical and extreme value theory-based methods. CONCLUSIONS: When determining disease testing cutoffs from small training data samples, we recommend using the extreme value based-methods when targeting a high specificity and the empirical quantile when targeting a lower specificity.

Investigation of the association between the Enferplex bovine tuberculosis antibody test and the future risk of bovine tuberculosis in irish cattle in infected herds: a pilot field study.

The Single Intradermal Comparative Tuberculin Test (SICTT) and the interferon-gamma (IFN-γ) assay are the approved diagnostic tests for bovine tuberculosis (bTB) in Ireland. The aim of this pilot study was to explore if there was any added diagnostic benefit from applying the Enferplex bTB test (an antibody test) in severe bTB herd breakdowns after the removal of cattle that had tested positive to the SICTT and the IFN-γ test. In addition to the normal bTB testing and management protocols, the animals in these herds that tested negative to SICTT and the IFN-γ test were followed forward for a period of two years. All animals were tested by Enferplex at enrolment. The time to subsequent bTB detection (diagnosed with SICTT/IFN-γ tests or detection of visible lesions at routine slaughter) for animals that tested positive or negative to the Enferplex bTB test at the start of the study was compared using Kaplan-Meier survival curves and Cox based survival models. Of the 484 enrolled animals (from 11 herds), 171 (35.3%) and 151 (31.1%) initially tested positive in the Enferplex assay under the high sensitivity and high specificity interpretation settings respectively. The results of the survival analysis showed that there was no difference in the survival time to a positive diagnosis with bTB during the follow-up period between animals initially classified as positive and negative by the Enferplex test. Further research is warranted to explore the potential benefit of using the Enferplex test in other scenarios.

Successful Treatment of Warm Autoimmune Hemolytic Anemia with a Positive Donath-Landsteiner Test Using Rituximab.

Paroxysmal cold hemoglobinuria (PCH) is a rare disease in adults, and its concurrent presentation with warm-type autoimmune hemolytic anemia (AIHA) has not yet been reported. We encountered a 19-year-old woman with AIHA and a positive Donath-Landsteiner test result identified by a hemolytic attack during blood transfusion. She also showed positive results for the direct Coombs and Donath-Landsteiner antibody tests. After treatment with prednisolone followed by rituximab, the AIHA improved, and the Donath-Landsteiner antibody test result turned negative. Clinicians should be aware that patients may present with concurrent warm-type AIHA and PCH and consider rituximab for its treatment.

Comparative analysis of contemporary anti-double stranded DNA antibody assays for systemic lupus erythematosus.

Objective: Elevated double-stranded DNA (dsDNA) antibody levels in blood serum are considered a disease-specific marker in systemic lupus erythematosus (SLE), correlate with disease activity and the incidence of lupus nephritis, and can be detected in up to 86% of all SLE cases. Despite the high clinical relevance, the variety of dsDNA antibody testing methods with heterogenous performance in clinical use remains challenging. This study is the first to prospectively investigate the performance of two of today's most commonly applied anti-dsDNA testing methods head-to-head under real-world conditions, as well as their correlation with other clinical and serological disease parameters in SLE patients. Methods: In this prospective study, all SLE patients undergoing treatment at the Department of Rheumatology at the University Hospital Bonn within a 13-months period (n=41) and control patients without connective-tissue disease (n=51) were consecutively enrolled and examined. For all study participants' serum samples both anti-dsDNA-NcX enzyme-linked immunoassay testing EUROIMMUN, Luebeck, Germany) and the fluorescence immunoassay ELiA dsDNA (Thermo Fisher Scientific, Waltham, USA) were performed. In addition, demographic data, further laboratory values and disease activity parameters were recorded. Clinical disease activity was assessed by SLEDAI-2K. Results: Both assays showed high specificity (anti-dsDNA-NcX ELISA: 0.9, ELiA dsDNA: 0.959), but there were notable differences in sensitivity (anti-dsDNA-NcX ELISA: 0.51, ELiA dsDNA: 0.38). Pearsons's correlation yielded a positive correlation between anti-dsDNA concentrations and CRP concentrations for the anti-dsDNA-NcX ELISA (R=0.22; p=0.038) and a mild-to-moderate inverse correlation between concentrations of anti-dsDNA and complement C4 for the ELiA dsDNA test (R=-0.22; p=0.045) when SLE and control patients were considered together. Other than, no significant correlation between anti-dsDNA concentrations and clinical or laboratory findings was found for either test procedure. Conclusion: Both anti-dsDNA antibody assays represent reliable examination methods with high specificity for the diagnosis of SLE that fulfill EULAR/ACR requirements. However, the anti-dsDNA-NcX ELISA showed superior sensitivity and significant correlation with disease activity (as measured by CRP concentrations).

Ante-mortem and Post-mortem Diagnosis Modalities and Phylogenetic Analysis of Rabies Virus in Domestic and Wild Animals of Gujarat, India.

In the present study, total of 32 ante-mortem (AM) samples (saliva = 18 and corneal smears = 14) from six animal species (cattle = 5; camel = 1; goat = 1; horse = 1; buffalo = 4; dog = 6) and 28 post-mortem (PM) samples of domestic (cattle = 6; camel = 1; goat = 1; buffalo = 5; dog = 7) and wild animals (lion = 4, mongoose = 2; bear = 1; leopard = 1) were examined for rabies diagnosis in Gujarat, India. Direct fluorescent antibody test (dFAT) and reverse transcriptase polymerase chain reaction (RT-PCR) were applied on AM samples, whereas along with dFAT and RT-PCR, histopathological examination, immunohistochemistry (IHC) and real time PCR (qPCR) were used for PM diagnosis. Nucleotide sequencing of full nucleoprotein (N) and glycoprotein (G) genes were carried out upon representative amplicons. In AM examination, 7/18 saliva and 5/14 corneal impressions samples were found positive in dFAT and 8/18 saliva samples were found positive in RT-PCR. In PM examination, 14/28 samples showed positive results in dFAT and IHC with unusual large fluorescent foci in two samples. In histopathology, 11/28 samples showed appreciable lesion and Negri bodies were visible in 6 samples, only. Out of 23 brain samples examined. 12 samples were found positive in N gene RT-PCR and qPCR, and 10 samples in G gene RT-PCR. Phylogenetic analysis of N gene revealed that test isolates (except sample ID: lion-1; lion, Gir) form a close group with sequence ID, KM099393.1 (Mongoose, Hyderabad) and KF660246.1 (Water Buffalo, Hyderabad) which was far from some south Indian and Sri Lankan isolates but similar to Indian isolates from rest of India and neighboring countries. In G gene analysis, the test isolates form a close group with sequence ID, KP019943.1. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01126-0.

Performance evaluation of Espline HTLV-I/II, a newly developed rapid immunochromatographic antibody test for different diagnostic situations.

IMPORTANCE: The World Health Organization estimated that 5-10 million people are infected with human T-cell leukemia virus type 1 (HTLV-1). This number is likely to be underestimated because reliable endemic data are available for only approximately 1.5 billion people worldwide. The point-of-care test is a powerful tool for the easy and quick detection of infections without the requirement for expensive instruments and laboratory equipment. Espline HTLV-I/II, a newly developed rapid immunochromatographic antibody test that was evaluated in this study, might significantly advance our understanding of the global epidemiology of HTLV-1 infection.

Evidence of Horse Exposure to Anaplasma phagocytophilum, Borrelia burgdorferi, and Leishmania infantum in Greece through the Detection of IgG Antibodies in Serum and in an Alternative Diagnostic Sample-The Saliva.

Among the various zoonotic pathogens that infect horses, Anaplasma phagocytophilum, Borrelia spp. and Leishmania spp. have gained scientific interest, and relevant molecular and serological studies in horses have been conducted worldwide. Moreover, human and veterinary medicine have extensively applied alternatives to serum diagnostic samples-such as saliva-for detecting pathogens or antibodies. In this study, we investigated the exposure of horses in Greece to A. phagocytophilum, B. burgdorferi, and L. infantum, and we assessed the diagnostic accuracy of saliva compared to serum in detecting IgG antibodies against the abovementioned pathogens. Paired saliva and serum samples were collected from 317 horses from different regions in Greece. The paired samples were examined using the indirect fluorescent antibody test (IFAT) for detecting IgG antibodies against A. phagocytophilum, B. burgdorferi, and L. infantum. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were determined to assess the validity of saliva as an alternative to serum. The receiver operating characteristic (ROC) curve revealed that the optimal cut-off value for detecting antibodies against all the examined pathogens in saliva was 1/10. Higher seropositivity rates were found for B. burgdorferi (15.14%) and A. phagocytophilum (14.19%) compared to L. infantum (1.26%). The detection of IgG antibodies using IFAT in saliva samples had a good test performance compared to serum. The two sample types had a substantial to almost perfect agreement. Although the sensitivity was moderate (70.83-75.56%) in all cases, the specificity was almost perfect to perfect (99.63-100%). This study provides the first evidence that horses in Greece are exposed to A. phagocytophilum and B. burgdorferi and confirms that the seroprevalence of L. infantum in horses in Greece remains low. Our findings suggest that saliva sampling coupled with IFAT could be successfully applied for detecting IgG antibodies against these important zoonotic pathogens in large-scale epidemiological studies in horses, at the population level, as an alternative to serum.

Anti-Leishmania spp. antibody detection in domestic cats from a visceral leishmaniasis transmission area.

Feline leishmanial infection is reported worldwide, but the epidemiological role of domestic cats in the leishmaniasis cycle remains unclear, and cats might act as cryptic reservoir hosts in endemic areas with no feline leishmaniosis cases. Considering that, a serological screening for anti-Leishmania spp. antibodies was performed by indirect immunofluorescence antibody test (IFAT) in 389 necropsied cats' serum samples from a new visceral leishmaniasis transmission area with no feline leishmanial infection reported to unveil if the cats are being exposed to the parasite. The overall seroprevalence for Leishmania spp. was 11.05% (43/389). No association was found between sex, neutering status, age group, breed, coat length, feline immunodeficiency virus (FIV) infection, and Leishmania spp. antibody detection. A positive association was found with coat color (cats within the orange spectrum with white [particolor]) (OR = 2.47, CI 95% 1 - 6.13, P = 0.044) and a negative association (OR = 0.38, CI 95% 0.18 - 0.79, P = 0.01) between feline leukemia virus (FeLV) infection and IFAT positivity for Leishmania spp. Therefore, it is concluded that the seroprevalence found was greater than 10%, indicating contact of the protozoan with cats in the region served.

Performance of two commercial serological assays for bovine tuberculosis using plasma samples.

In the bovine tuberculosis diagnosis, the use of plasma samples (already available for IFNÉ£ assays) in serological tests might facilitate the work in the field. Here, the performance of two commercial serological tests (ELISA IDEXX M. bovis Ab test and Enferplex Bovine TB antibody test) were evaluated using plasma samples from cattle in Belgium. Specificity values estimated from 567 plasma samples collected from bTB-free cattle were 98.4% when using the ELISA IDEXX M. bovis Ab test, and were 96.5% and 93.3% when using the high specificity and high sensitivity settings of the Enferplex Bovine TB antibody test, respectively. Sensitivity values were calculated relative to SICCT-positive (N = 117) and IFNÉ£-positive (N = 132) animals originating from M. bovis-infected herds. Overall, the multiplexed Enferplex Bovine TB antibody test had better sensitivity (mean: 32.5% and 43.4% for the high specificity and sensitivity settings, respectively) compared to the ELISA IDEXX M. bovis Ab test (mean: 12%). Data obtained from plasma samples in the current study were compared to a previous study using both serological tests with sera. In conclusion, both serological tests showed comparable performance with both matrix; although overall specificity values with the Enferplex Bovine TB antibody test were lower when using plasma samples than sera.

Trends in Participation in Rubella Antibody Testing among Working-Aged Men during Annual Health Check-Ups from 2019 to 2022 in Japan.

In 2019, the Japanese government established a scheme for rubella antibody testing of men born between 1962 and 1978 during workplace health check-ups. However, the use of vouchers for rubella antibody testing was limited. Health check-up data analyses are needed to determine the reason why rubella antibody testing is not widely used. In this study, we aimed to describe changes in rubella antibody test-taking behavior during health check-ups during the first 3 years of the rubella catch-up campaign in Japan. In 2019, 2020, and 2021 (2020 in some areas) vouchers were sent to men born during the fiscal years 1972-1978, 1966-1971, and 1962-1965, respectively. We calculated the prevalence in men born between 1962 and 1978 who underwent rubella antibody testing during mandatory health check-ups under the Industrial Health and Safety Act. Rubella antibody testing uptake was relatively high (approximately 15%) in all three age groups soon after the distribution of the vouchers and then declined to below 2% during the second and third years. Further population-based approaches with continuous public engagement are required in workplaces to effectively promote and expand the rubella vaccination program in Japan.

Baseline Seroprevalence of SARS-CoV-2 Specific Antibodies in Hot Spot Areas of Great Tunis, up to 3 Months Post Disease Onset in Tunisia.

The extent of the SARS-CoV-2 circulation and the COVID-19 epidemic in Tunisia three months after virus circulation was unknown. The aim of this study was to determine the extent of SARS-CoV-2 infection among household contacts of confirmed COVID-19 cases living in Hot spot areas of Great Tunis, Tunisia by estimating the seroprevalence of antibodies anti SARS-CoV-2 and to identify factors associated to seroprevalence at the first stage of the pandemic in order to guide decision making and to constitute a baseline for further longitudinal analysis of protective immunity to SARS-CoV-2. The National Observatory of New and Emerging Diseases (ONMNE), Ministry of Health Tunisia (MoH), with the support of the Office of the World Health Organization Representative in Tunisia and the WHO Regional Office for the Eastern Mediterranean (EMRO)), conducted a household cross-sectional survey on April 2020 in Great Tunis (Tunis, Ariana, Manouba and Ben Arous). The study was based on the WHO seroepidemiological investigation protocol for SARS-CoV-2 infection. SARS-CoV-2 specific antibodies (IgG and IgM) were qualitatively detected using a lateral immunoassay that detect SARS-CoV-2 nucleocapsid protein and administered by the interviewers. The included subjects were confirmed COVID-19 cases and their households contacts resided in hot spot areas (cumulative incidence rate ≥ 10 cases/100,000 inhabitants) of Great Tunis. Results: In total, 1165 subjects were enrolled: 116 confirmed COVID-19 cases (43 active cases and 73 convalescents cases) and 1049 household contacts resided in 291 households. The median age of participants was 39.0 with 31 years' interquartile range (Min = 8 months; Max = 96 years). The sex ratio (M/F) was 0.98. Twenty-nine per cent of participants resided in Tunis. The global crude seroprevalence among household contacts was 2.5% (26/1049); 95% CI 1.6-3.6%, 4.8%; 95% CI 2.3-8.7% in Ariana governorate and 0.3%; 95% CI 0.01%-1.8% in Manouba governorate. In multivariate analysis, the associated factors independently related to seroprevalence were age ≥25 years (aOR = 5.1; 95% CI 1.2-22.0), history of travel outside Tunisia since January 2020 (aOR = 4.6; 95% CI 1.7-12.9), symptomatic illness in the previous four months (aOR = 3.5; 95% CI 1.4-9.0) and governorate of residence (p = 0.02). The low seroprevalence estimated among household contacts in Great Tunis reflect the effect of public health measures early taken (national lockdown, borders closed, remote work), the respect of non-pharmaceutical interventions and the efficacy of COVID-19 contact-tracing and case management at the first stage of the pandemic in Tunisia.

[Platelet Transfusion Strategies for MASPAT-Matched Platelet Transfusion Failed Patient with Allogeneic Hematopoietic Stem Cell Transplantation].

OBJECTIVE: To investigate the causes of ineffectiveness of platelet transfusion with monoclonal antibody solid phase platelet antibody test (MASPAT) matching in patients with allogeneic hematopoietic stem cell transplantation and explore the strategies of platelet transfusion. METHODS: A case of donor-specific HLA antibodies (DSA) induced by transfusion which ultimately resulted in transplantation failure and ineffective platelet transfusion with MASPAT matching was selected, and the causes of ineffective platelet transfusion and platelet transfusion strategy were retrospectively analyzed. RESULTS: The 32-year-old female patient was diagnosed as acute myeloid leukemia (high risk) in another hospital with the main symptoms of fever and leukopenia, who should be admitted for hematopoietic stem cell transplantation after remission by chemotherapy. In the course of chemotherapy, DSA was generated due to platelet transfusion, and had HLA gene loci incompatible with the donor of the first transplant, leading to the failure of the first transplant. The patient received platelet transfusion for several times before and after transplantation, and the results showed that the effective rate of MASPAT matched platelet transfusion was only 35.3%. Further analysis showed that the reason for the ineffective platelet transfusion was due to the missed detection of antibodies by MASPAT method. During the second hematopoietic stem cell transplantation, the DSA-negative donor was selected, and the matching platelets but ineffective transfusion during the primary transplantation were avoided. Finally, the patient was successfully transplanted and discharged from hospital. CONCLUSIONS: DSA can cause graft failure or render the graft ineffective. For the platelet transfusion of patients with DSA, the platelet transfusion strategy with matching type only using MASPAT method will miss the detection of antibodies, resulting in invalid platelet transfusion.

Epidemiological characteristics of bovine besnoitiosis (Besnoitia besnoiti) in a beef cattle farm: a cross-sectional serological assessment.

Background: Bovine besnoitiosis is an emerging disease caused by the protozoa Besnoitia besnoiti that can have a serious economic impact on affected farms. The fact that there is no effective vaccine nor treatment, along with the lack of consistent epidemiologic data, renders the implementation of preventive medicine and control strategies much harder. Objectives: A cross-sectional serological assessment was performed to better understand the distribution and prevalence of this parasite in a large beef cattle farm in Portugal and to establish some epidemiological characteristics of besnoitiosis. Methods: A random blood sampling of 450 animals from a farm that keeps around 2,000 cattle head was performed and sera were submitted to an indirect immunofluorescent antibody test (IFAT). Data on breed, age, sex, and birthplace of the tested animals and their mothers were recorded. Results: The overall prevalence of positive animals was 16.89%, with significant differences between under 1-year-old calves (4.8%) and adults (19.67%). A higher antibody prevalence was shown in animals 1-2 years and >7 years old, in Salers breed and in cows imported from France or whose mothers had come from this country. Calves under 1 year old and crossbreed animals with ancestry born in the current farm presented the lowest antibody prevalence. Discussion and conclusions: The most significant risk factors revealed were age (>7 years old) and breed (Salers). Genetic studies should be carried out in order to confirm whether indeed there is a breed susceptibility to bovine besnoitiosis. We suggest that similar studies should be performed across southern Europe to establish strong epidemiologic data that would allow a rigorous transnational control program to be launched.

Prevalence of HCV Antibody and its Associated Factors: A Study from Sentinel Hospitals in China.

Objective: The prevalence and related factors of serum anti-HCV in different regions and hospitals have not been studied extensively in China. We used routine screening data to determine the prevalence of HCV antibody in hospital patients, evaluate the epidemic trend of hepatitis C and formulate screening strategies. Methods: Patient information and HCV antibody testing results were collected from January 2017 to December 2019 in 77 HCV sentinel hospitals in China. Univariate and multivariate logistic regression was used to determine the characteristics and associations. Results: HCV antibody prevalence rates were distinct among patients in different departments, with a range of 0.33%-6.93%. Patients who were admitted to the liver disease-related departments (a OR = 10.76; 95% CI, 10.27-11.28), Internal Medicine (a OR = 2.87; 95% CI, 2.75-3.00), and Department of Surgery (a OR = 1.95; 95% CI, 1.87-2.04), were more likely to be tested for HCV antibody positive. HCV antibody prevalence was associated with patients aged 45 years and older (a OR = 2.74; 95% CI, 2.69-2.80), testing in infetious disease hospitals (a OR = 2.33; 95% CI, 2.26-2.40) and secondary hospitals (a OR = 1.72; 95% CI, 1.69-1.75). Patients in sentinel hospitals of the Northeast (a OR = 12.75; 95% CI, 12.40-13.11), the Central (a OR = 1.65; 95% CI, 1.61-1.70), and the West (a OR = 1.78; 95% CI, 1.73-1.83) China had higher HCV prevalence than those who were in the Eastern coastal area. Conclusion: Those who were over 45 years old and saw doctors for liver diseases, and invasive diagnosis and treatment should be referred to HCV antibody testing.