scholarly journals Comparison of Three Serological Methods for the Epidemiological Investigation of TBE in Dogs

2021 ◽  
Vol 9 (2) ◽  
pp. 399
Author(s):  
Philipp Girl ◽  
Maja Haut ◽  
Sandra Riederer ◽  
Martin Pfeffer ◽  
Gerhard Dobler

Tick-borne encephalitis (TBE) virus is an emerging pathogen that causes severe infections in humans. Infection risk areas are mostly defined based on the incidence of human cases, a method which does not work well in areas with sporadic TBE cases. Thus, sentinel animals may help to better estimate the existing risk. Serological tests should be thoroughly evaluated for this purpose. Here, we tested three test formats to assess the use of dogs as sentinel animals. A total of 208 dog sera from a known endemic area in Southern Germany were tested in an All-Species-ELISA and indirect immunofluorescence assays (IIFA), according to the manufacturer’s instructions. Sensitivity and specificity for both were determined in comparison to the micro-neutralization test (NT) results. Of all 208 samples, 22.1% tested positive in the micro-NT. A total of 18.3% of the samples showed characteristic fluorescence in the IIFA and were, thus, judged positive. In comparison to the micro-NT, a sensitivity of 78.3% and a specificity of 98.8% was obtained. In the ELISA, 19.2% of samples tested positive, with a sensitivity of 84.8% and a specificity of 99.4%. The ELISA is a highly specific test for TBE-antibody detection in dogs and should be well suited for acute diagnostics. However, due to deficits in sensitivity, it cannot replace the NT, at least for epidemiological studies. With even lower specificity and sensitivity, the same applies to IIFA.

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1441
Author(s):  
Suelen Basgalupp ◽  
Giovana dos Santos ◽  
Marina Bessel ◽  
Lara Garcia ◽  
Ana Carolina de Moura ◽  
...  

Serological assays emerged as complementary tools to RT-PCR in the diagnosis of SARS-CoV-2 as well as being needed for epidemiological studies. This study aimed to assess the performance of a rapid test (RT) compared to that of serological tests using finger prick blood samples. A total of 183 samples were evaluated, 88 of which were collected from individuals with negative RT-PCR and 95 from positive RT-PCR individuals. The diagnostic performance of RT (WONDFO®) and LUMIT (PROMEGA®) were compared to that of ELISA (EUROIMMUN®) for detecting antibodies against SARS-CoV-2 according to time from symptoms onset. The IgG antibody tests were detected in 77.4% (LUMIT), 77.9% (RT), and 80.0% (ELISA) of individuals. The detection of antibodies against SARS-CoV-2 increases in accordance with increasing time from symptoms onset. Considering only time from symptoms onset >21 days, the positivity rate ranged from 81.8 to 97.0% between the three tests. The RT and LUMIT showed high agreement with ELISA (agreement = 91.5%, k = 0.83, and agreement = 96.3%, k = 0.9, respectively) in individuals who had symptoms 15 to 21 days before sample collection. Compared to that of the ELISA assay, our results show sensitivity ranged from 95% to 100% for IgG antibody detection in individuals with symptoms onset between 15 and 21 days before sample collection. The specificity was 100% in individuals with symptoms onset >15 days before serological tests. This study shows good performance and high level of agreement of three immunoassays for the detection of SARS-CoV-2 antibodies.


Author(s):  
Abdullah Algaissi ◽  
Mohamed A. Alfaleh ◽  
Sherif Hala ◽  
Turki S. Abujamel ◽  
Sawsan S. Alamari ◽  
...  

As the coronavirus disease 2019 (COVID-19), which is caused by the novel coronavirus SARS-CoV-2, continues to spread rapidly around the world, there is an urgent need for validated serological assays to evaluate viral specific antibody responses in COVID-19 patients or recovered individuals. In this study, we established and used indirect Enzyme Linked Immunosorbent Assay (ELISA)-based serological tests to study the antibody response in COVID-19 patients. In order to validate the assays, we determined the cut-off values, sensitivity and specificity of the developed assays using sera collected from COVID-19 patients in Saudi Arabia at different time points after disease onset, as well as sera that are seropositive to other human CoVs; namely MERS-CoV, hCoV-OC43, hCoV-NL63, hCoV-229E, and hCoV-HKU1. The SARS-CoV-2 S1 subunit of the spike glycoprotein and nucleocapsid (N) ELISAs that we developed here not only showed high specificity and sensitivity, but also did not show any cross-reactivity with other CoVs. We also showed that all RT-PCR confirmed COVID-19 patients included in our study developed both virus specific IgM and IgG as early as one week after the onset of disease. The availability of these validated assays will enable us to determine the nature and duration of the antibody response mounted in response to SARS-CoV-2 infection. It will also allow conducting large-scale epidemiological studies to determine evidence of previous exposure to the virus and assess the true extent of virus spread within communities.


1984 ◽  
Vol 93 (1) ◽  
pp. 133-138 ◽  
Author(s):  
Terje Traavik ◽  
Richard Wiger ◽  
Reider Mehl

SUMMARYSmall rodent (vole) sera were collected from three different locations in Norway. One of these was within the distribution area for Ixodes ricinus, and a tick-borne encephalitis (TBE) virus strain had been isolated from ticks collected there (Traavik & Mehl, 1977). The two other locations were outside the I. ricinus area, one in southern Norway, the other at nearly 70° N. The sera were tested for TBE antibodies by hemagglutination inhibition (HI), hemolysis-in-gel (HIG) and complement fixation (CFT). All sera were also tested for HI antibodies to Uukuniemi (UUK) virus, and some positive TBE HI reactions were verified by separation of immunoglobulins and serum lipoproteins in NaBr gradients.Animals containing TBE virus antibodies reacting in all three serological tests and animals with UUK HI antibodies were detected only from the location within the I. ricinus area. From the two locations outside the I. ricinus area we found animals which had antibodies reacting with TBE virus in HI and HIG, but not in CFT. Antibodies to UUK were not detected. The results indicate that flavivirus(es) related to, but not identical with TBE viruses are transmitted by other vectors than I. ricinus in parts of Norway.


Even though tick-borne encephalitis (TBE) has been a notifiable disease in Croatia since 2007, there are no or only limited data available on the occurring tick species in the endemic areas, on the prevalence of TBE virus (TBEV) in ticks, its distribution in Croatia, and its genetic characteristics. Reporting of human cases also is very scarce. The Central European subtype of virus (TBEV-EU) appears to be present in Croatia


Author(s):  
Wilhelm Erber ◽  
Tamara Vuković Janković

Although there are no reliable data on the number of tick-borne encephalitis (TBE) cases or the percentage of infected ticks, based on the geography and the presence of TBE virus (TBEV) in all neighboring countries, it must be assumed that TBEV is present anywhere in Moldova.


2021 ◽  
Vol 9 (6) ◽  
pp. 1172
Author(s):  
Ksenia Tuchynskaya ◽  
Viktor Volok ◽  
Victoria Illarionova ◽  
Egor Okhezin ◽  
Alexandra Polienko ◽  
...  

Currently the only effective measure against tick-borne encephalitis (TBE) is vaccination. Despite the high efficacy of approved vaccines against TBE, rare cases of vaccine failures are well documented. Both host- and virus-related factors can account for such failures. In this work, we studied the influence of mouse strain and sex and the effects of cyclophosphamide-induced immunosuppression on the efficacy of an inactivated TBE vaccine. We also investigated how an increased proportion of non-infectious particles in the challenge TBE virus would affect the protectivity of the vaccine. The vaccine efficacy was assessed by mortality, morbidity, levels of viral RNA in the brain of surviving mice, and neutralizing antibody (NAb) titers against the vaccine strain and the challenge virus. Two-dose vaccination protected most animals against TBE symptoms and death, and protectivity depended on strain and sex of mice. Immunosuppression decreased the vaccine efficacy in a dose-dependent manner and changed the vaccine-induced NAb spectrum. The vaccination protected mice against TBE virus neuroinvasion and persistence. However, viral RNA was detected in the brain of some asymptomatic animals at 21 and 42 dpi. Challenge with TBE virus enriched with non-infectious particles led to lower NAb titers in vaccinated mice after the challenge but did not affect the protective efficacy.


2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Cécile Beck ◽  
Philippe Desprès ◽  
Sylvie Paulous ◽  
Jessica Vanhomwegen ◽  
Steeve Lowenski ◽  
...  

West Nile virus (WNV), Japanese encephalitis virus (JEV), and tick-borne encephalitis virus (TBEV) are flaviviruses responsible for severe neuroinvasive infections in humans and horses. The confirmation of flavivirus infections is mostly based on rapid serological tests such as enzyme-linked immunosorbent assays (ELISAs). These tests suffer from poor specificity, mainly due to antigenic cross-reactivity among flavivirus members. Robust diagnosis therefore needs to be validated through virus neutralisation tests (VNTs) which are time-consuming and require BSL3 facilities. The flavivirus envelope (E) glycoprotein ectodomain is composed of three domains (D) named DI, DII, and DIII, with EDIII containing virus-specific epitopes. In order to improve the serological differentiation of flavivirus infections, the recombinant soluble ectodomain of WNV E (WNV.sE) and EDIIIs (rEDIIIs) of WNV, JEV, and TBEV were synthesised using theDrosophilaS2 expression system. Purified antigens were covalently bonded to fluorescent beads. The microspheres coupled to WNV.sE or rEDIIIs were assayed with about 300 equine immune sera from natural and experimental flavivirus infections and 172 nonimmune equine sera as negative controls. rEDIII-coupled microspheres captured specific antibodies against WNV, TBEV, or JEV in positive horse sera. This innovative multiplex immunoassay is a powerful alternative to ELISAs and VNTs for veterinary diagnosis of flavivirus-related diseases.


2001 ◽  
Vol 356 (1411) ◽  
pp. 1045-1056 ◽  
Author(s):  
Sarah E. Randolph

The two major vector-borne diseases of northern temperate regions, tick-borne encephalitis (TBE) and Lyme borreliosis (LB), show very different epidemiological patterns, but both have increased significantly in incidence since the 1980s. Insight into the temporal dynamics of TBE, gained from statistical analysis of spatial patterns integrated with biological explanation, suggests that the recent increases in TBE cases in Central Europe and the Baltic States may have arisen largely from changes in human behaviour that have brought more people into contact with infected ticks. Under forecast climate change scenarios, it is predicted that enzootic cycles of TBE virus may not survive along the southern edge of their present range, e.g. in Slovenia, Croatia and Hungary, where case numbers are indeed decreasing. New foci, however, are predicted and have been observed in Scandinavia. At the same time, human impact on the landscape, increasing both the habitat and wildlife hosts of ticks, has allowed tick populations to multiply significantly. This probably accounts for a genuine emergence of LB, with its high potential transmission rate, in both the USA and Europe, although the rate of emergence has been exaggerated by improved surveillance and diagnosis.


1977 ◽  
Vol 6 (3) ◽  
pp. 274-279
Author(s):  
Omar O. Barriga

Six diethylaminoethyl-cellulose fractions of a larval Trichinella spiralis extract, an Ascaris suum extract, and a nonrelated protein were used for cutaneous tests in guinea pigs with 8-, 14-, and 73-day-old T. spiralis infections, in guinea pigs with 13-day-old A. suum infections, and in normal guinea pigs. A selected T. spiralis fraction was used in hemagglutination (HA) tests with sera of 8 T. spiralis -infected rabbits, 41 sera of trichinellosis patients positive by bentonite agglutination tests, and 50 sera of clinically healthy persons. Immediate-type cutaneous reactions revealed extensive cross-reactivity between both parasites, although the establishment of conventional limits for considering a reaction positive allowed the specific diagnosis of acute or chronic trichinellosis with different fractions. Delayed-type reactions were specific with all fractions except one, and different fractions reacted during either the acute or the chronic phase of trichinellosis. HA detected anti- Trichinella antibodies in all the rabbits 9 to 10 days postinfection, in all trichinellosis patients, and in none of the healthy people. Correlation between HA and bentonite agglutination titers and other considerations suggest that HA with the selected fraction detects early antibodies. HA inhibition tests with A. suum extract suggest lack of HA cross-reactivity between the A. suum - and T. spiralis -selected fractions. The use of different fractions in diverse tests for clinical or epidemiological studies is suggested.


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