An antigen in normal avian cells which confuses virological and serological tests

1975 ◽  
Vol 4 (4) ◽  
pp. 255-269
Author(s):  
B. W. Calnek
Keyword(s):  
Author(s):  
Gerhard Dobler

• TBE appears with non-characteristic clinical symptoms, which cannot be distinguished from oth-er forms of viral encephalitis or other diseases. • Cerebrospinal fluid and neuro-imaging may give some evidence of TBE, but ultimately cannot confirm the diagnosis. • Thus, proving the diagnosis “TBE” necessarily requires confirmation of TBEV-infection by detec-tion of the virus or by demonstration of specific antibodies from serum and/or cerebrospinal fluid. • During the phase of clinic symptoms from the CNS, the TBEV can only rarely be detected in the cerebrospinal fluid of patients. • Most routinely used serological tests for diagnosing TBE (ELISA, HI, IFA) show cross reactions resulting from either Infection with other flaviviruses or with other flavivirus vaccines.


TBE appears with non-characteristic clinical symptoms, which cannot be distinguished from other forms of viral encephalitis or other diseases. Cerebrospinal fluid and neuro-imaging may give some evidence of TBE, but ultimately cannot confirm the diagnosis. Thus, proving the diagnosis “TBE” necessarily requires confirmation of TBEV-infection by detection of the virus or by demonstration of specific antibodies from serum and/or cerebrospinal fluid. During the phase of clinic symptoms from the CNS, the TBEV can only rarely be detected in the cerebrospinal fluid of patients. Most routinely used serological tests for diagnosing TBE (ELISA, HI, IFA) show cross reactions resulting from either infection with other flaviviruses or with other flavivirus vaccines.


2020 ◽  
Vol 23 (9) ◽  
pp. 629-632
Author(s):  
Hamid Reza Shamsollahi ◽  
Mostafa Amini ◽  
Shaban Alizadeh ◽  
Saharnaz Nedjat ◽  
Ali Akbari-Sari ◽  
...  

Background: The Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) epidemic broke out in December 2019 and is now characterized as a pandemic. Effective control of this infectious disease requires access to diagnostic techniques, for both case finding and epidemic size estimation. The molecular technique is routinely used worldwide. Although it is the "standard" case detection and management method, it has its own shortcomings. Thus, some easy-to-use rapid serological tests have been developed. Methods: One hundred and fourteen positive RT-PCR-diagnosed patients were tested by VivaDiag Kit, a brand of rapid serological kits available in hospitals affiliated to Tehran University of Medical Sciences (TUMS), Tehran, Iran. Frozen serum specimens taken from healthy people in summer and fall 2019 were also tested as negative controls. Results: Test sensitivity was 47.9% (95% confidence interval [CI]: 38.8-56.9) for IgM and 47.0% (95% CI: 38.0–56.0) for IgG. There was no difference between IgG and IgM seropositivity except in one case. Specificity was calculated as 99.0% (95% CI: 96.4–99.9) for IgM and of 100.0% (95% CI: 0.98.2–100.0) for IgG. Sensitivity was higher in men and older participants. Conclusion: This test can be used for epidemiological investigations, especially for the estimation of the level of infection in the community, after it is properly corrected for sensitivity and specificity. The low sensitivity could be attributed to the technical limitations of the kit or low levels of antibodies after infection. The different sensitivity in age and sex groups supports the hypothesis that different people show different immune responses to this virus.


2012 ◽  
Vol 31 (12) ◽  
pp. 1350-1352
Author(s):  
Hong-xia MA ◽  
Yun-heng ZHOU ◽  
Lin YANG ◽  
Bin HUANG ◽  
Lie-ying FAN
Keyword(s):  

Author(s):  
Mahmoud Ahmed Ebada ◽  
Notila Fayed ◽  
Souad Alkanj ◽  
Ahmed Wadaa Allah

: Enterovirus D68 (EV-D68) is a single-stranded positive-sense RNA virus, and it is one of the family Picornaviridae. Except for EV-D68, the family Picornaviridae has been illustrated in literature. EV-D68 was first discovered and isolated in California, USA, in 1962. EV-D68 has resulted in respiratory disorders’ outbreaks among children worldwide, and it has been detected in cases of various neurological diseases such as acute flaccid myelitis (AFM). A recent study documented a higher number of EV-D68 cases associated with AFM in Europe in 2016 compared to the 2014 outbreak. EV-D68 is mainly diagnosed by quantitative PCR, and there is an affirmative strategy for EV-D68 detection by using pan-EV PCR on the untranslated region and/or the VP1 or VP2, followed by sequencing of the PCR products. Serological tests are limited due to cross-reactivity of the antigens between the different serotypes. Many antiviral drugs for EV-D68 have been evaluated, and showed promising results. In our review, we discuss the current knowledge about EV-D68 and its role in the development of AFM.


Author(s):  
Sara Abolghasemi ◽  
Mohammad Alizadeh ◽  
Ali Hashemi ◽  
Shabnam Tehrani

Introduction: Epididymo-orchitis is a common urological disease among men. Little is known about the clinical and epidemiological aspects of the disease in Iran. Thus, the present study was aimed to investigate the etiology, clinical sequelae and risk factors of patients with epididymo-orchitis in Tehran, Iran. Materials and Methods: Patients presenting with epididymo-orchitis were prospectively analyzed in order to study the etiology and pattern of the disease. Bacteriological, molecular and serological tests were undertaken to look for Chlamydia trachomatis, Neisseria gonorrhoeae, Brucella spp., Mycoplasma spp, and other bacteria. Results: Fifty patients with epididymo-orchitis were evaluated according to their clinical symptoms, duration of symptoms, physical examination, and laboratory studies. The mean age of the patients was 53 years. Fever, dysuria, pain in the flanks, urinary frequency and discharges occurred in 58.0%, 50.0%, 50.0%, 28.0% and 6.0%, respectively. Bacterial pathogen was identified in 26% (13/50) of patients by urine culture. Escherichia coli was the etiological agent in 11/13 patients (84.6%). Two out of 50 patients (4.0%) were also positive for Chlamydia trachomatis. Two samples were serologically positive for Brucella spp. High Mean age, fever, urinary frequency, history of the underlying disease and history of urinary tract infections were found to have a significant association with the positive bacteriologic urine culture (P<0.05). Conclusions: The most common clinical manifestations were fever, dysuria, and abdominal pain. E. coli and C. trachomatis were the major causative agents. Use of a set of diagnostic approaches including clinical symptoms, urine culture and more precise techniques such as PCR should be taken into consideration for the definitive diagnosis.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1530.1-1530
Author(s):  
G. Kaynar ◽  
O. C. İçaçan ◽  
S. Çelik ◽  
M. Yalçin Mutlu ◽  
C. Bes

Background:Purpura are lesions that occur after bleeding on the skin, mucous or serosal surfaces. Purpura can be classified into 2 subgroups; which are linked to thrombocytopenia and non-trombocytopenic purpura. While thrombocytopenic purpura often occurs due to a hematological disease; in non-trombocytopenic purpura etiological causes are very variable, and systemic vasculitis has an important place among them.Objectives:The demographic features of the patients applying with purpura and the underlying causes and diseases were aimed to be revealed.Methods:44 consecutive patients (22 women, 22 men) who were admitted to the hospital in the last 6 months, due to purpura were evaluated. Average age of patients was 49.6 ± 19.6 years. Patients were questioned about a recent infection, drug use, concomitant or underlying diseases. The serological tests and other laboratory tests for etiology were performed and biopsy was taken from the skin lesions which are appropriate.Results:While 4 (9%) patients had widespread purpura on the trunk-upper-lower extremities, in 22 (50%) patients purpuric lesions were limited only to the lower limb. The period between the onset of the first symptom and the admission to the hospital was longer than 4 weeks in 35 (79.5%) patients, and shorter than 1 week in 9 (20.5%) patients. 24 (54%) patients had an anamnesis of infection 2-3 weeks before purpura, and 20 (45%) patients had an anamnesis of drug use. The most common accompanying symptom was abdominal pain and was present in 15 (34%) patients. Biopsy was performed from the skin lesion in 37 patients. Histopathological examination of all was compatible with leukocytoclastic vasculitis. In indirect immunofluorescence staining, 17 were found to be IgA positive. 2 (4.5%) patients were diagnosed PR3-ANCA positive granulomatosis with polyangiitis. 1 patient had Hepatitis B virus infection was detected in 1 patient (2.2%), HIV infection was detected in 1 patient (2.2%) and malignancy was detected in 1 patient (2.2%).Conclusion:In our study, the most common reason was found as IgA vasculitis in patients presenting with palpable purpura. Although vasculitic involvement was limited to the skin in most patients, organ-threatening systemic vasculitis was detected in a few patients. Patients applying with Purpura should be questioned for infection and drug use, should be examined for underlying diseases including systemic vasculitis, and closely monitored for organ involvement.Disclosure of Interests:None declared


Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 869
Author(s):  
Amedeo De Nicolò ◽  
Valeria Avataneo ◽  
Jessica Cusato ◽  
Alice Palermiti ◽  
Jacopo Mula ◽  
...  

Recently, large-scale screening for COVID-19 has presented a major challenge, limiting timely countermeasures. Therefore, the application of suitable rapid serological tests could provide useful information, however, little evidence regarding their robustness is currently available. In this work, we evaluated and compared the analytical performance of a rapid lateral-flow test (LFA) and a fast semiquantitative fluorescent immunoassay (FIA) for anti-nucleocapsid (anti-NC) antibodies, with the reverse transcriptase real-time PCR assay as the reference. In 222 patients, LFA showed poor sensitivity (55.9%) within two weeks from PCR, while later testing was more reliable (sensitivity of 85.7% and specificity of 93.1%). Moreover, in a subset of 100 patients, FIA showed high sensitivity (89.1%) and specificity (94.1%) after two weeks from PCR. The coupled application for the screening of 183 patients showed satisfactory concordance (K = 0.858). In conclusion, rapid serological tests were largely not useful for early diagnosis, but they showed good performance in later stages of infection. These could be useful for back-tracing and/or to identify potentially immune subjects.


Author(s):  
João Calado ◽  
Mariana Verdelho Machado

Celiac disease (CD) is a systemic disease triggered by gluten ingestion in genetically predisposed individuals. It manifests primarily as an autoimmune enteropathy associated with specific circulating autoantibodies and a human leukocyte antigen haplotype (HLA-DQ2 or HLA-DQ8). It afflicts roughly 1% of the population, though the majority of patients remain undiagnosed. Diarrhea and malabsorption are classic manifestations of CD; however, both children and adults can be paucisymptomatic and present extraintestinal manifestations such as anemia, osteoporosis, and abnormal liver tests. CD screening is not recommended for the general population, and it should be focused on high-risk groups. CD diagnosis is challenging and relies on serological tests, duodenal histology, and genetic testing. Particularly difficult presentations to manage are seronegative patients, seropositive patients without villus atrophy, and patients who have started a gluten-free diet before the diagnostic workup. The only proven treatment is a lifelong gluten-free diet. We present an in-depth review on the physiopathology and management of CD, with a particular emphasis on diagnostic challenges.


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