scholarly journals Diagnosis of west Nile neuroinvasive disease in humans

2018 ◽  
Vol 11 (1) ◽  
pp. 79-90
Author(s):  
Ivana Hrnjaković Cvjetković ◽  
Vesna Milošević ◽  
Tamaš Petrović ◽  
Dušan Petrić ◽  
Gordana Kovačević ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Real Time ◽  
Cross Reactivity ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serum Samples ◽  
West Nile ◽  
Igm Antibodies ◽  
Neuroinvasive Disease ◽  
Viremia Level

West Nile virus (WNV) is arbovirus distributed all around the world. In humans, 80% of infection cases are asymptomatic. In 20% of infected people, a febrile self-limiting illness is reported. WNV has the potential for fatal neuroinvasive disease. In 1% of cases, the infection may result in neuroinvasive disease with permanent neurological consequences or death outcome. Neurological forms may vary presenting with encephalitis, meningitis, meningoencephalitis or acute flaccid paralysis. Outbreaks with neurological forms of WNV infection were recorded in different areas of Greece, Italy, Romania, Hungary and Serbia. During the period from 2013 to 2016, 114 samples of cerebrospinal fluid and 107 serum samples were taken from 114 patients suspected of WNV neuroinvasive disease (WNND). The presence of specific anti-WNV IgM and IgG antibodies in cerebrospinal fluid (CSF) and sera samples were tested by WNV IgM and IgG ELISA (Euroimmun, Germany). In addition, 48 samples of CSF or/and serum of people with suspected WNV infection were examined by commercial molecular tests - real time RT-PCR (WNV Real-TM, Sacace biotechnologies, Italy). The IgM antibodies against WNV were present in 25.4% (29/114) of CSF samples, and in 31.8% (34/107) of serum samples tested from 114 patients suspected of WNND. The IgG antibodies against WNV were detected in 3.5% (4/114) of CSF samples, and in 11.2% (12/107) of serum samples. The WNV RNA was detected by real time RT-PCR test in 7 out of 48 (14.6%) CSF or/and serum samples. In this study, detection of IgM antibodies in CSF is more frequent than detection of WNV RNA in CSF or serum samples. WNV RNA detection in CSF is confirmatory diagnostic test but has limited utility in the diagnosis of WNV neuroinvasive disease due to low viremia level at the time of clinical presentation of the disease. The limitations in the use of ELISA IgM test are linked to cross - reactivity among flaviviruses and long persistence of IgM antibodies in the serum and CSF.

scholarly journals EVALUATION OF ELEVEN IMMUNOCHROMATOGRAPHIC ASSAYS FOR SARS-CoV-2 DETECTION: INVESTIGATING DENGUE CROSS-REACTION

2020 ◽  
Author(s):  
Beatriz Araujo Oliveira ◽  
Lea Campos de Oliveira ◽  
Franciane Mendes de Oliveira ◽  
Geovana Maria Pereira ◽  
Regina Maia de Souza ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
High Sensitivity ◽  
Diagnostic Techniques ◽  
Cross Reactivity ◽  
Cross Reaction ◽  
List Type ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Good Agreement

AbstractBackgroundCOVID-19 disease (Coronavirus disease 2019) caused by SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) is widespread worldwide, affecting more than 11 million people globally (July 6th, 2020). Diagnostic techniques have been studied in order to contain the pandemic. Immunochromatographic (IC) assays are feasible and low cost alternative for monitoring the spread of COVID-19 in the population.MethodsHere we evaluate the sensitivity and specificity of eleven different immunochromatographic tests in 98 serum samples from confirmed cases of COVID-19 through RT-PCR and 100 negative serum samples from blood donors collected in February 2019. Considering the endemic situation of Dengue in Brazil, we also evaluated the cross-reactivity with Dengue using 20 serum samples from patients with confirmed diagnosis for Dengue collected in early 2019 through four different tests.ResultsOur results demonstrated agreement between immunochromatographic assays and RT-PCR, especially after 10 days since the onset of symptoms. The evaluation of IgG and IgM antibodies combined demonstrated a strong level of agreement (0.85) of IC assays and RT-PCR. It was observed cross-reactivity between Dengue and COVID-19 using four different IC assays for COVID-19 diagnosis. The specificity of IC assays to detected COVID-19 IgM antibodies using Dengue serum samples varied from 80% to 85%; the specificity of IgG detection was 100% and total antibody was 95%.ConclusionsWe found high sensitivity, specificity and good agreement of IC assays, especially after 10 days onset of symptoms. However, we detected cross-reactivity between Dengue and COVID-19 mainly with IgM antibodies demonstrating the need for better studies about diagnostic techniques for these diseases.HighlightsImmunochromatographic assays demonstrated high sensitivity and specificity and good agreement with the gold-standard RT-PCR;Increase in sensitivity and specificity of assays using samples collected after the 10th day of symptoms;Cross-reaction with Dengue serology in evaluation of IgM.

Detection of West Nile virus genome and specific antibodies in Iranian encephalitis patients

2011 ◽  
Vol 140 (8) ◽  
pp. 1525-1529 ◽  
Author(s):  
S. CHINIKAR ◽  
A. JAVADI ◽  
B. ATAEI ◽  
H. SHAKERI ◽  
M. MORADI ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Acute Flaccid Paralysis ◽  
Virus Genome ◽  
Loss Of Consciousness ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
West Nile Fever ◽  
West Nile ◽  
Neuroinvasive Disease ◽  
History Of

SUMMARYWest Nile virus (WNV) is a mosquito-borne flavivirus which circulates in birds, horses and humans. An estimated 80% of WNV infections are asymptomatic. Fewer than 1% of infected persons develop neuroinvasive disease, which typically presents as encephalitis, meningitis, or acute flaccid paralysis. This study was conducted from January 2008 to June 2009 in Isfahan, Iran. Patients attending the emergency department with fever and loss of consciousness were consecutively included. Cerebrospinal fluids (CSF) were initially analysed through bacteriology and biochemistry examinations, resulting in those with evidence of meningitis being excluded. Patients' CSF and serum were diagnosed by serological and molecular assays. A total of 632 patients with fever and loss of consciousness were tested by CSF analyses. Samples of the remaining patients (39·4%) were referred for WNV investigation. Three (1·2%) of the patients were positive for both serum and CSF by RT–PCR, and six (2·4%) were positive only for IgG antibodies. History of insect bite, and blood transfusion and transplantation were risk factors for being positive by RT–PCR (P=0·048) and being IgG positive (P=0·024), respectively. The results of this study showed that the prevalence of West Nile fever is low in patients with encephalitis.

Detection of a novel bunyavirus associated with fever, thrombocytopenia and leukopenia syndrome in Henan Province, China, using real-time reverse transcription PCR

2013 ◽  
Vol 62 (7) ◽  
pp. 1060-1064 ◽  
Author(s):  
Xueyong Huang ◽  
Licheng Liu ◽  
Yanhua Du ◽  
Hongxia Ma ◽  
Yujiao Mu ◽  
...  
Keyword(s):  
Real Time ◽  
Reverse Transcription ◽  
High Sensitivity ◽  
Cross Reactivity ◽  
Henan Province ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Serum Samples ◽  
Reverse Transcription Pcr

A novel bunyavirus associated with fever, thrombocytopenia and leukopenia syndrome (FTLS) was discovered in Henan Province, China. Here, we report the development of an assay for this novel bunyavirus based on real-time reverse transcription PCR (RT-PCR). The assay exhibited high sensitivity and specificity without cross-reactivity towards 13 other viruses that cause similar symptoms. To evaluate the performance of this assay in detecting clinical samples, we analysed 261 serum samples from patients in Henan Province between 2007 and 2010. Of these samples, 91.95 % were bunyavirus positive. Compared with serological assays, the real-time PCR assay was much more sensitive in identifying infected patients 1 to 7 days after the onset of symptoms.

scholarly journals Serologic Diagnosis of Lyme Borreliosis by Using Enzyme-Linked Immunosorbent Assays with Recombinant Antigens

2000 ◽  
Vol 38 (5) ◽  
pp. 1735-1739 ◽  
Author(s):  
Louis A. Magnarelli ◽  
Jacob W. Ijdo ◽  
Steven J. Padula ◽  
Richard A. Flavell ◽  
Erol Fikrig
Keyword(s):  
Lyme Borreliosis ◽  
Erythema Migrans ◽  
Cross Reactivity ◽  
Immunoglobulin M ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Recombinant Antigens ◽  
Igm Antibodies ◽  
Antibody Reactivity ◽  
Immunosorbent Assays

Class-specific enzyme-linked immunosorbent assays (ELISAs) with purified recombinant antigens of Borrelia burgdorferi sensu stricto and Western blot analyses with whole cells of this spirochete were used to test human sera to determine which antigens were diagnostically important. In analyses for immunoglobulin M (IgM) antibodies, 14 (82%) of 17 serum samples from persons who had erythema migrans reacted positively by an ELISA with one or more recombinant antigens. There was frequent antibody reactivity to protein 41-G (p41-G), outer surface protein C (OspC), and OspF antigens. In an ELISA for IgG antibodies, 13 (87%) of 15 serum samples had antibodies to recombinant antigens; reactivity to p22, p39, p41-G, OspC, and OspF antigens was frequent. By both ELISAs, serum specimens positive for OspB, OspE, and p37 were uncommon. Analyses of sera obtained from persons who were suspected of having human granulocytic ehrlichiosis (HGE) but who lacked antibodies to ehrlichiae revealed IgM antibodies to all recombinant antigens of B. burgdorferi except OspB and IgG antibodies to all antigens except OspE. Immunoblotting of sera from the study group of individuals suspected of having HGE reaffirmed antibody reactivity to multiple antigens of B. burgdorferi. There was minor cross-reactivity when sera from healthy subjects or persons who had syphilis, oral infections, or rheumatoid arthritis were tested by ELISAs with p37, p41-G, OspB, OspC, OspE, and OspF antigens. Although the results of class-specific ELISAs with recombinant antigens were comparable to those recorded for assays with whole-cell antigen and for individuals with confirmed clinical diagnoses of Lyme borreliosis, immunoblotting is still advised as an adjunct procedure, particularly when there are low antibody titers by an ELISA.

scholarly journals Significance of IgG avidity test in diagnosis of west Nile virus infection

2017 ◽  
Vol 70 (11-12) ◽  
pp. 395-401
Author(s):  
Ivana Hrnjakovic-Cvjetkovic ◽  
Jelena Radovanov ◽  
Gordana Kovacevic ◽  
Aleksandra Patic ◽  
Natasa Nikolic ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Virus Infection ◽  
Acute Infection ◽  
Late Phase ◽  
West Nile Virus Infection ◽  
Igg Antibodies ◽  
Serum Samples ◽  
West Nile ◽  
Igm Antibodies ◽  
Igg Avidity

Introduction. Serological tests appear to be the method of choice for establishing the diagnosis in the late phase of West Nile virus infection. Long persistence of IgM antibodies against West Nile virus is described and may be a problem for determination of the time of acquisition of West Nile virus infection. The aim of the study was to estimate the significance of IgG avidity determination in establishing the diagnosis of West Nile virus infection. Material and Methods. In a study 56 serum samples seropositive against West Nile virus were included. 24 serum samples were collected in 2012 from healthy residents of South-Backa district and 32 serum samples were collected in 2014 from 124 patients suspected of having West Nile virus infection. Commercial enzyme-linked immunosorbent tests were used for the detection of West Nile virus-specific IgM and IgG antibodies and IgG avidity. Results. Out of 124 patients suspected of having West Nile virus infection, 32 (25.8%) were seropositive for West Nile virus antibodies. Acute infection was laboratory confirmed in 15 (46.9%) cases. All patients with acute infection were West Nile virus IgM positive, 13 (85%) were West Nile virus IgG positive, and 2 (15%) had a borderline result for West Nile virus IgG antibodies. Out of 32 seropositive patients the presence of IgM antibodies was determined in 22 (68.7%). In a group of samples with high IgG avidity values, 6 were IgM positive, while 8 were IgM negative. Conclusion. West Nile virus IgM and IgG antibody serological assays alone are not sufficient for the accurate and reliable diagnosis of WNV infection. West Nile virus IgG avidity testing is necessary to ensure the differential diagnosis of acute from past West Nile virus infection.

scholarly journals Investigations, actions and learning from an outbreak of SARS-CoV-2 infection among healthcare workers in the United Kingdom

2020 ◽  
pp. 175717742097679
Author(s):  
Kordo Saeed ◽  
Emanuela Pelosi ◽  
Nitin Mahobia ◽  
Nicola White ◽  
Christopher Labdon ◽  
...  
Keyword(s):  
Real Time ◽  
Healthcare Workers ◽  
Healthcare Facility ◽  
Rt Pcr ◽  
Serum Samples ◽  
The United Kingdom ◽  
Key Issues ◽  
Current Infection ◽  
Polymerase Chain ◽  
A Current

Background: We report an outbreak of SARS coronavirus-2 (SARS-CoV-2) infection among healthcare workers (HCW) in an NHS elective healthcare facility. Methodology: A narrative chronological account of events after declaring an outbreak of SARS-CoV-2 among HCWs. As part of the investigations, HCWs were offered testing during the outbreak. These were: (1) screening by real-time reverse transcriptase polymerase chain reaction (RT- PCR) to detect a current infection; and (2) serum samples to determine seroprevalence. Results: Over 180 HCWs were tested by real-time RT-PCR for SARS-CoV-2 infection. The rate of infection was 15.2% (23.7% for clinical or directly patient-facing HCWs vs. 4.8% in non-clinical non-patient-facing HCWs). Of the infected HCWs, 57% were asymptomatic. Seroprevalence (SARS-CoV-2 IgG) among HCWs was 13%. It was challenging to establish an exact source for the outbreak. The importance of education, training, social distancing and infection prevention practices were emphasised. Additionally, avoidance of unnecessary transfer of patients and minimising cross-site working for staff and early escalation were highlighted. Establishing mass and regular screening for HCWs are also crucial to enabling the best care for patients while maintaining the wellbeing of staff. Conclusion: To our knowledge, this is the first UK outbreak report among HCWs and we hope to have highlighted some key issues and learnings that can be considered by other NHS staff and HCWs globally when dealing with such a task in future.

scholarly journals Update Management of Chikungunya

2017 ◽  
Vol 12 (2) ◽  
pp. 82-85
Author(s):  
Khan Mohammad Arif
Keyword(s):  
Viral Infection ◽  
Real Time ◽  
Real Time Pcr ◽  
Rainy Season ◽  
Joint Pain ◽  
Chikungunya Virus ◽  
Striking Feature ◽  
Igg Antibodies ◽  
Igm Antibodies ◽  
Artificial Water

Chikungunya is a viral infection first detected after an outbreak in Tanzania in 1952. Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that belongs to the Togaviridae family. Incidence increases in rainy season. Exact pathogenesis is not clearly understood. Fever and arthralgia/arthritis is the striking feature of Chikungunya fever1. Few patient may develop neurological and other complication. Joint pain may persist for several years. Investigations for confirmation are Real-time PCR, Virus specific IgM antibodies and IgG antibodies. Treatments are supportive. Most patients recover completely. Death is very rare. Reducing natural & artificial water filled container habitats is the principal step of prevention.Faridpur Med. Coll. J. Jul 2017;12(2): 82-85

Clinical and diagnostic manifestations of tickborne mixed infection in combination with COVID-19

2021 ◽  
Vol 66 (11) ◽  
pp. 689-694
Author(s):  
A. L. Shutikova ◽  
G. N. Leonova ◽  
A. F. Popov ◽  
M. Yu. Shchelkanov
Keyword(s):  
Lyme Disease ◽  
Erythema Migrans ◽  
Clinical Manifestations ◽  
Underlying Disease ◽  
Laboratory Diagnostics ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Chronic Encephalitis ◽  
Tbev Strain

The coexistence of various pathogens inside the patient’s body is one of the poorly studied and current issues. The aim of the study is to identify the relationship between the indicators of complex laboratory diagnostics and the clinical manifestations of a mixed disease during subsequent infection with the SARS-CoV-2 virus using the example of a case of chronic encephalitis-borreliosis infection. Seven blood serum samples were collected from the patient over the course of a year. For the etiological verification of the causative agents of TBE, Lyme disease and COVID-19, the methods of ELISA and PCR diagnostics were used. The patient was diagnosed with Lyme disease on the basis of the detection of IgG antibodies to Borrelia 5 months after the onset of the disease, since she denied the tick bite. In the clinical picture, there was an articular syndrome and erythema migrans. Later, IgG antibodies to the TBEV were found in the blood. Throughout the study, IgM antibodies to Borrelia were not detected. The exacerbation of Lyme disease could be judged by the clinical manifestations of this disease and by the growth of specific IgG antibodies. A feature of this case was that during an exacerbation of the Lyme disease, an infection with the SARS-CoV-2 virus occurred. Treatment (umifenovir, hydroxychloroquine, azithromycin, ceftriaxone) was prescribed, which improved the condition of the underlying disease, decreased joint pain, decreased IgG levels to borrelia. However, during this period, serological markers of TBEV appear: antigen, IgM antibodies, and the titer of IgG antibodies increases. Most likely, this was facilitated by the switching of the immune system to the SARS-CoV-2 virus, with the simultaneous suppression of borrelia with antibiotics and the appointment of hydroxychloroquine, which has an immunosuppressive effect. Despite the activation of the virus, clinical manifestations of TBE were not observed in the patient, which is most likely associated with infection with a weakly virulent TBEV strain. The further course of tick-borne infections revealed the dominant influence of B. burgdorferi in relation to TBEV. Laboratory studies have shown that suppression of the activity of the borreliosis process by etiotropic treatment subsequently led to the activation of the persistent TBEV.

scholarly journals West Nile Virus and Related Flavivirus in European Wild Boar (Sus scrofa), Latium Region, Italy: A Retrospective Study

Animals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 494
Author(s):  
Angela Petruccelli ◽  
Tiziana Zottola ◽  
Gianmarco Ferrara ◽  
Valentina Iovane ◽  
Cristina Di Russo ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Wild Boar ◽  
Specific Antibody ◽  
Central Italy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Serum Samples ◽  
West Nile ◽  
Wild Boars ◽  
European Wild Boar

Background: A retrospective sero-survey for evidence of West Nile virus (WNV) infection in European wild boar (Sus scorfa) was conducted in the Latium region, Italy, on stored serum samples of the period November 2011 to January 2012. Methods: Sera were collected from 168 European wild boars and screened for antibodies to WNV and other Flaviviruses by competitive enzyme linked immunosorbent assay (cELISA). All sera positive for Flavivirus antibodies by cELISA were further examined by virus neutralization test (VNT). To test the presence of Flavivirus RNA in samples, an RT-PCR was performed using a pan-Flavivirus primers pair. Results: Thirteen wild boars (7.73%) were seropositive for Flaviviruses. The hemolysis of serum samples limited the interpretation of the VNT for 7 samples, confirming the presence of specific antibody against WNV in a single European wild boar serum sample. The presence of ELISA positive/VNT negative samples suggests the occurrence of non-neutralizing antibodies against WNV or other antigen-related Flaviviruses. No samples resulted positive for Flavivirus by RT-PCR assay. Conclusion: Although a moderately high percentage of animals with specific antibody for WNV has been detected in wild boar in other surveillance studies in Europe, this has not been reported previously in Italy. Together, these data indicate that European wild boar are exposed to WNV and/or other related-Flavivirus in central Italy and confirm the usefulness of wild ungulates, as suitable Flavivirus sentinels.

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