scholarly journals Toscana Virus: Ten Years of Diagnostics in Portugal

2021 ◽  
Vol 34 (13) ◽  
Author(s):  
Fátima Amaro ◽  
Líbia Zé-Zé ◽  
Maria Teresa Luz ◽  
Maria João Alves
Keyword(s):  
Polymerase Chain Reaction ◽  
Neurological Disease ◽  
Immunofluorescence Assay ◽  
Toscana Virus ◽  
Chain Reaction ◽  
Serum Samples ◽  
Neurotropic Viruses ◽  
Vector Borne ◽  
Polymerase Chain ◽  
Febrile Syndrome

Introduction: Toscana virus (TOSV) is an emerging sandfly-borne virus within the Phlebovirus genus. Although most infections caused by this virus present as asymptomatic or with minimal symptomatology, TOSV may emerge as a febrile disease or sporadic cases of neurological disease such as meningitis or meningoencephalitis. This pathogen is distributed throughout the Mediterranean basin, along with the spatial distribution of its recognized sandfly vector, Phlebotomus perniciosus. Portugal, after Italy, was the second country considered endemic for this virus, with the first case of acquired infection published in 1985. Although little is known about the circulation of this virus in Portugal, the laboratory diagnosis of TOSV is available at the Centre for Vectors and Infectious Diseases Research of the National Institute of Health Dr. Ricardo Jorge (CEVDI/INSA), since 2007. The aim of this study is to report the results of the diagnosis of TOSV at the CEVDI/INSA, between 2009 and 2018.Material and Methods: The diagnosis of TOSV in the CEVDI/INSA is included in the arboviruses and vector-borne neurotropic viruses panels or can be performed, when specified, for TOSV only. Direct detection is made in cerebrospinal fluid samples and is available for TOSV by specific real-time reverse transcription polymerase chain reaction followed by conventional real-time reverse transcription polymerase chain reaction for sequencing purposes, if positive. For indirect diagnosis, performed in serum samples, an in-house immunofluorescence assay for the detection of IgM and IgG antibodies against TOSV is used. A commercial immunofluorescence assay consisting in a mosaic of four phleboviruses is also available, in which, in addition to TOSV, antibody detection for sandfly fever Naples virus, sandfly fever Sicilian virus and sandfly fever Cyprus virus can be done. All diagnostic tests requested by clinicians to the CEVDI/INSA for arboviruses, neurotropic viruses and/or TOSV between January 2009 and December 2018, were included in this study.Results: During the study period, the CEVDI/INSA received samples from 608 patients with diagnostic requests for TOSV. Five acute TOSV infections and one acute sandfly fever Sicilian virus infection were confirmed in serum samples. Three other patients had serological evidence of previous contact with the virus. Two of the six patients with acute infection developed febrile syndrome, and the other four presented with neurological disease: meningitis (n = 2), meningoencephalitis (n = 1) and severe depression of consciousness (n = 1). These infections were most likely acquired in the districts of Faro (3), Lisbon (2) and Setúbal (1).Discussion: In Portugal, the number of laboratory diagnostic requests for TOSV is low when compared to the numbers of requests for other less prevalent vector-borne viruses. The Faro district presented the highest number of TOSV-specific diagnostic requests which seems to indicate a higher level of recognition by clinicians in that region. Febrile syndrome and neurological disease were the clinical manifestations that were present in acute cases. In this study, in addition to the Faro district, recent infections were also detected in the districts of Lisbon and Setúbal. It is probable that TOSV may be distributed throughout the mainland territory since its main vector is present from north to south. In 2017, the sandfly fever Sicilian virus was associated for the first time with human disease in our country, thus alerting to the circulation of this phlebovirus.Conclusion: Even though the number of identified cases in Portugal is low, TOSV circulates and causes disease in our country. The diagnosis of this and other phleboviruses should not be neglected in the differential diagnosis of febrile syndrome and viral meningitis and meningoencephalitis, especially during the warmer months, when the vector’s activity is higher.

scholarly journals Diagnosis of human herpesvirus 6B primary infection by polymerase chain reaction in young children with exanthematic disease

2011 ◽  
Vol 44 (3) ◽  
pp. 306-308 ◽  
Author(s):  
Ivna de Melo Magalhães ◽  
Rebeca Vasquez Novo Martins ◽  
Renata Oliveira Vianna ◽  
Solange Artimos Oliveira ◽  
Silvia Maria Baeta Cavalcanti
Keyword(s):  
Polymerase Chain Reaction ◽  
Primary Infection ◽  
Human Herpesvirus ◽  
Immunofluorescence Assay ◽  
Control Group ◽  
Case Group ◽  
Chain Reaction ◽  
Serum Samples ◽  
Polymerase Chain ◽  
And Control

INTRODUCTION: Exanthem subitum is a classical rash disease of early childhood caused by human herpesvirus 6B (HHV-6B). However, the rash is frequently misdiagnosed as that of either measles or rubella. METHODS: In this study, a nested multiplex polymerase chain reaction (PCR) was used to diagnose HHV-6B primary infection, differentiate it from infections caused by HHV-6A and compare it to antibody avidity tests. The samples were separated into case group and control group according to the results of the indirect immunofluorescence assay (IFA) technique. RESULTS: From the saliva samples analyzed, HHV-6A DNA was detected in 3.2% of the case group and in 2.6% of the control group. Regarding HHV-6B, PCR detected viral DNA in 4.8% of the case group and in 1.3% of the control group. Among the serum samples studied, a frequency of 1.7% was determined for HHV-6A in the case group and 1.2% in the control group. PCR did not detect HHV-6B DNA in serum samples. The sensitivity and specificity of the PCR technique ranged from 0% to 4.8% and 97.5% to 100%, respectively, compared to IFA. CONCLUSIONS: The PCR technique was not suitable for diagnosing primary infection by HHV-6B in children with exanthematic disease and should not substitute the IFA.

scholarly journals Evaluation of the Reverse Transcription-Polymerase Chain Reaction/Probe Test of Serum Samples and Immunohistochemistry of Skin Sections for Detection of Acute Bovine Viral Diarrhea Infections

2002 ◽  
Vol 14 (4) ◽  
pp. 303-307 ◽  
Author(s):  
Julia F. Ridpath ◽  
Sharon K. Hietala ◽  
Steve Sorden ◽  
John D. Neill
Keyword(s):  
Polymerase Chain Reaction ◽  
Polymerase Chain Reaction Amplification ◽  
Clinical Signs ◽  
Bovine Viral Diarrhea ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Serum Samples ◽  
Viral Diarrhea ◽  
Persistent Infections ◽  
Polymerase Chain

Bovine viral diarrhea viruses (BVDV) cause both acute and persistent infections. While diagnostic tests have been designed to detect animals persistently infected (PI) with BVDV, the reliability of these tests in detecting acute BVDV infections is not known. It is also possible that acute BVDV infections may be confused with persistent infections in surveys for PI animals. In this study, 2 tests presently in use in diagnostic laboratories to test for PI animals, polymerase chain reaction amplification followed by probe hybridization (RT-PCR/probe) of serum samples and immunohistochemical detection of viral antigen in skin biopsies (IHC), were evaluated for their ability to detect acute BVDV infections. Sixteen colostrum-deprived, BVDV-free, and BVDV-antibody-free calves were infected with 6 different BVDV strains. Clinical signs, seroconversion, and virus isolation indicated that inoculated animals did replicate virus. Virus could be detected in 19% (3/16) of acutely infected animals by the RT-PCR/probe technique. No acutely infected animals were positive by IHC.

Molecular Detection of Leptospira Species Serotypes in Iranian Stray Dogs

2019 ◽  
Author(s):  
Saam Torkan ◽  
Hassan Momtaz
Keyword(s):  
Public Health ◽  
Polymerase Chain Reaction ◽  
Chain Reaction ◽  
Serum Samples ◽  
Blood Samples ◽  
Stray Dogs ◽  
Wide Range ◽  
Leptospira Spp ◽  
Polymerase Chain ◽  
Leptospira Species

Background and Aims: Leptospirosis is a spirochetal disease with public health importance globally. This disease affects a wide range of domestic and wild animals. Dogs are one of the species most sensitive to Leptospira canicola and Leptospira icterohaemorrhagiae. The present study was concluded to evaluate the prevalence rate of Leptospira species and L. canicola and L. icterohaemorrhagiae serovars in Iranian stray dogs. Materials and Methods: One-hundred and twenty blood samples were first taken from stray dogs. Then the samples were transferred to the laboratory. Sera were extracted from blood samples and genomic DNA was extracted. DNA samples were subjected to conventional polymerase chain reaction. Positive samples for Leptospira spp. were analyzed for presence of L. canicola and L. icterohaemorrhagiaeserovars using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: Nine samples out of 120 serum samples (7.5%) were positive for the flagella gene of the Leptospira spp. Prevalence of Leptospira spp. in serum samples of male and female dogs were 5.4% and 10.86%, respectively. Prevalence of L. canicola and L. icterohaemorrhagiae serovars were 55.55% and 33.33%, respectively. We found that 11.11% of samples were positive for both serovars. Two to three and 3-4 year old dogs had the highest prevalence of Leptospira spp. Conclusions: The considerable prevalence of leptospirta spp. and also their zoonotic serovars among Iranian stray dogs represented an important public health issue regarding the contact of healthy human with these dogs. Identification of infected dogs and their vaccination can inhibit the distribution of Leptospira spp.

scholarly journals Validation of real-time polymerase chain reaction versus conventional polymerase chain reaction for diagnosis of brucellosis in cattle sera

2021 ◽  
Vol 14 (1) ◽  
pp. 144-154
Author(s):  
Nour H. Abdel-Hamid ◽  
Eman I. M. Beleta ◽  
Mohamed A. Kelany ◽  
Rania I. Ismail ◽  
Nadia A. Shalaby ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Roc Curve ◽  
Diagnostic Performance ◽  
Rt Pcr ◽  
Conventional Pcr ◽  
Chain Reaction ◽  
Serum Samples ◽  
Polymerase Chain ◽  
Pcr Targeting ◽  
Pcr Techniques

Background and Aim: Different polymerase chain reaction (PCR) techniques have and are still being used for the direct detection of Brucella DNA in serum samples of different animal species and humans without being validated or properly validated, resulting in discrepancies. Thus, this study aimed to evaluate the diagnostic performance of the TaqMan Real- Time-PCR (RT-PCR) targeting the bcsp31 gene versus conventional PCR for the accurate diagnosis of brucellosis at the genus level in cattle sera. Materials and Methods: One hundred and eighty-four serum samples were collected from bacteriologically positive and negative cows with ages ranging from 1 to 5 years old at some infected private farms in the Nile Delta under quarantine measures as well as brucellosis free farms. These samples were classified into four groups after serological diagnosis and investigated by TaqMan RT-PCR and conventional PCR targeting the IS711 gene for Brucella DNA detection. The diagnostic performance characteristics of both PCR techniques were estimated considering the bacteriological results as a gold standard. Results: TaqMan RT-PCR revealed superiority over conventional PCR; it was able to detect Brucella DNA in 95% (67/70) and 89% (25/28) of the cattle sera samples belonging to Group 1 (serologically and bacteriologically positive) and Group 2 (serologically negative but bacteriologically positive), respectively. On evaluating the diagnostic performance, TaqMan RT-PCR showed superior diagnostic sensitivity (93.9%), diagnostic specificity (88.4%), performance index (182.3), almost perfect kappa agreement (0.825±0.042), strong positive correlation (r=0.826), high accuracy based on the receiver operating characteristic (ROC) curve, and area under the ROC curve (0.911) at p<0.05 and CI of 95%. Conclusion: A cattle serum sample is not the metric of choice for targeting Brucella genomic DNA by conventional PCR. The time-saving and rapid TaqMan RT-PCR method revealed a better diagnostic performance in the detection of Brucella DNA in cattle sera. Such performance offered by TaqMan RT-PCR may be considered a step toward the possibility of using such technology in the direct differentiation between Brucella-infected and -vaccinated cattle immunized by smooth vaccines from cattle sera using primers specific for such vaccines.

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