scholarly journals Comparison of Diagnostic Tests for Detection of Bovine Rotavirus a in Calf Feces

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shama Ranjan Barua ◽  
Shariful Islam ◽  
А.М.А.М. Zonaed Siddiki ◽  
Md Masuduzzaman ◽  
Mohammad Alamgir Hossain ◽  
...  

AbstractBovine rotavirus A (BRVA) is a frequent causative agent of diarrhea in neonatal calves. Accurate and rapid diagnosis is crucial to prevent calf mortality from BRVA induced diarrhea. Currently, variety of diagnostic methods are being used to detect BRVA from calves’ feces: antibody-based rapid test and ELISA, and molecular-based RT-PCR and RT-qPCR. The aim of the study was to evaluate the accuracy (sensitivity and specificity) of the rapid test (Immunochromatography), ELISA, and RT-PCR assays, using RT-qPCR as the gold standard, in detection of BRVA in diarrheic calves’ fecal samples. One hundred (n=100) clinically diarrheic fecal samples were tested with four different diagnostic tools. The percent of samples positive by rapid test, ELISA, RT-PCR and RT-qPCR was 10%, 16%, 17%, and 33%, respectively. The agreement between different assays was 75% to 99%. The highest agreement was observed between ELISA and RT-PCR assay (99%). The lowest agreement was recorded (75%) between rapid test and RT-qPCR. The sensitivity of the rapid test, ELISA, and RT-PCR were 30%, 49%, and 52%, respectively when compared to the reference test (RT-qPCR), whereas specificity was 100% for all assays. In conclusion, none of the frequently used diagnostic tests showed a satisfactory level of sensitivity to identify BRVA in calves’ feces. Therefore, the use of a more sensitive rapid test should be used to identify infected calves in field conditions in order to prevent calf mortality from rotaviral diarrhea.

2021 ◽  
Vol 21 ◽  
Author(s):  
Akansha Bhatt ◽  
Zeeshan Fatima ◽  
Munindra Ruwali ◽  
Saif Hameed

: The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by SARS-COV-2 has afflicted millions of lives globally and disrupted almost all the activities of mankind. Under such pressing circumstances when there are no effective therapeutics available, fast and accurate diagnosis of the corona virus is the only way out to limit the transmission. Since the inception of COVID-19, the demand of diagnostic tests has increased day by day and RT-PCR is the commonly used screening test which is not only time consuming but requires sophisticated resources. To address the increasing rate of spread of COVID-19, there is an urgent need of more diagnostic tools as the researches on vaccines is still at rudimentary level. This review summarizes an inventory on the diverse and currently available diagnostic methods based on nucleic acid and serology along with some of those working on novel principles viz. CRISPR, biosensors and NGS. Additionally, a gist of accessible diagnostic kits that are already approved by US & European authorities for the diagnosis of COVID-19 are also suggested that will help in selecting most effective tests under the given scenario. Taken together, this review will pave way for further strengthening the researches in the rapid and safer diagnostics of SARS-COV-2.


Author(s):  
Andrea Springer ◽  
Antje Glass ◽  
Julia Probst ◽  
Christina Strube

AbstractAround the world, human health and animal health are closely linked in terms of the One Health concept by ticks acting as vectors for zoonotic pathogens. Animals do not only maintain tick cycles but can either be clinically affected by the same tick-borne pathogens as humans and/or play a role as reservoirs or sentinel pathogen hosts. However, the relevance of different tick-borne diseases (TBDs) may vary in human vs. veterinary medicine, which is consequently reflected by the availability of human vs. veterinary diagnostic tests. Yet, as TBDs gain importance in both fields and rare zoonotic pathogens, such as Babesia spp., are increasingly identified as causes of human disease, a One Health approach regarding development of new diagnostic tools may lead to synergistic benefits. This review gives an overview on zoonotic protozoan, bacterial and viral tick-borne pathogens worldwide, discusses commonly used diagnostic techniques for TBDs, and compares commercial availability of diagnostic tests for humans vs. domestic animals, using Germany as an example, with the aim of highlighting existing gaps and opportunities for collaboration in a One Health framework.


2020 ◽  
Vol 9 (5) ◽  
Author(s):  
T. O. C. Faleye ◽  
U. E. George ◽  
C. Simsek ◽  
O. A. Arowolo ◽  
O. M. Adewumi ◽  
...  

In 2018, a 26-month-old girl, fully vaccinated with Rotarix in 2016, presented with fever, diarrhea, and vomiting. A rapid test showed that her feces contained rotavirus A (RVA). VP7 reverse transcription-PCR (RT-PCR) and Illumina sequencing showed that a G1P[8] strain with a Wa-like genotype constellation was the etiologic agent. This is the first near-complete RVA genome sequence from Nigeria.


Author(s):  
Alice Berger ◽  
Marie Therese Ngo Nsoga ◽  
Francisco Javier Perez-Rodriguez ◽  
Yasmine Abi Aad ◽  
Pascale Sattonnet-Roche ◽  
...  

AbstractBackgroundAntigen-detecting rapid diagnostic tests for SARS-CoV-2 offer new opportunities for the quick and laboratory-independent identification of infected individuals for control of the SARS-CoV-2 pandemic.MethodsWe performed a prospective, single-center, point of care validation of two antigen-detecting rapid diagnostic tests (Ag-RDT) in comparison to RT-PCR on nasopharyngeal swabs.FindingsBetween October 9th and 23rd, 2020, 1064 participants were enrolled. The Panbio™Covid-19 Ag Rapid Test device (Abbott) was validated in 535 participants, with 106 positive Ag-RDT results out of 124 positive RT-PCR individuals, yielding a sensitivity of 85.5% (95% CI: 78.0–91.2). Specificity was 100.0% (95% CI: 99.1–100) in 411 RT-PCR negative individuals. The Standard Q Ag-RDT (SD Biosensor, Roche) was validated in 529 participants, with 170 positive Ag-RDT results out of 191 positive RT-PCR individuals, yielding a sensitivity of 89.0% (95%CI: 83.7–93.1). One false positive result was obtained in 338 RT-PCR negative individuals, yielding a specificity of 99.7% (95%CI: 98.4–100). For individuals presenting with fever 1-5 days post symptom onset, combined Ag-RDT sensitivity was above 95%.InterpretationWe provide an independent validation of two widely available commercial Ag-RDTs, both meeting WHO criteria of ≥80% sensitivity and ≥97% specificity. Although less sensitive than RT-PCR, these assays could be beneficial due to their rapid results, ease of use, and independence from existing laboratory structures. Testing criteria focusing on patients with typical symptoms in their early symptomatic period onset could further increase diagnostic value.FundingFoundation of Innovative Diagnostics (FIND), Fondation privée des HUG, Pictet Charitable Foundation.


Author(s):  
Vandana Gupta ◽  
Anju Nayak ◽  
Madhu Swamy ◽  
R.V. Singh ◽  
Vishnu Gupta ◽  
...  

Background: Bovine Rotavirus is one of the most important viral etiological agent responsible for causing neonatal diarrhea incurring severe economic loss to farmers. The presence of large genome size, segmented nature and absence of proof reading activity of RNA polymerase leads to frequent reassortment and thus emergence of new G and P types with ability of interspecies transmission. Methods: During an epidemiological study (July 2016 to July 2019) 200 diarrheic fecal samples were screened for Bovine Rotavirus A using ELISA and RNA-PAGE. Further, twenty two positive samples for RVA were subjected to molecular detection for VP6, VP4 and VP7 genes. Result: Ten (20/200) and 11(22/200) percent diarrheic fecal samples were found positive using ELISA and RNA-PAGE respectively. Twenty samples found positive in ELISA were also found positive in RNA-PAGE. Amongst which 22 (100%) samples were found positive for VP6, while 15 (68.18%) samples showed amplification for VP4 and VP7 gene. All Rotavirus A positive samples were genotyped by multiplex RT-PCR assay. G1G3 was found to be most predominant (53.33%) followed by G3 (26.66%), while one sample each showed the presence of G1G5 and G3G8 (6.66%). Ten samples showed mixed genotype (66.66%). One sample was non typeable (6.66%). Among the P types, P[11] was the most predominant (73.33%), while one sample each showed the presence of P[5] and P[5]P[11] (6.66%) and 02 samples were non typeable (13.33%). The G and P genotype combination determined in 12 samples were as follows; G3P [11] found in two samples (16.66%), G3P[5] in 01(08.33%), G1G5P[11] in 01(08.33%), G1G3P[11] in 07 (58.33%), while 01 (08.33%) sample had mixed genotype G1G3P[5]P[11] combination.


Author(s):  
Gayatri Kashyap ◽  
R. Singh ◽  
Y. S. Malik ◽  
R. K. Agrawal ◽  
K. P. Singh ◽  
...  

To understand the pathology of natural cases of rotavirus (RVA) in bovine calves, a total of 40 cases below 6 months died due to diarrhoea were studied, out of which 7 cases (17.5%) turned positive for RVA by RT-PCR. Histopathology of small intestine showed loss of villous enterocytes, blunting and fusion of villi, elongation of crypts and mononuclear cells infiltration in the lamina-propria. The mesenteric lymph nodes were severely depleted of lymphocytes. These changes were corroborated with presence of RVA antigen in sections by dFAT and nucleic acid by RT-PCR. The fluorescent signals were more in mesenteric lymph nodes than in intestine. Besides, 115 rectal fecal samples were also collected from calves for RVA detection by RT-PCR using VP6 gene specific sets of primers. Dead carcasses of calves (n= 40) belonged to organized dairy farm of Bareilly, while rectal fecal samples belonged to both organized (n= 38) and unorganized farms (n= 77) of Bareilly and Gwalior. The overall occurrence of RVA was 19.3% (30/155), comprising 5/37 cases (13.5%) from Gwalior (MP) and 25/118 cases (21.1%) from Bareilly (UP). These findings suggest the infection of RVA widely prevalent in calves and have potential to escape from the intestinal site to mesenteric lymph nodes.


2020 ◽  
Vol 9 (5) ◽  
pp. 1515 ◽  
Author(s):  
Matteo Riccò ◽  
Pietro Ferraro ◽  
Giovanni Gualerzi ◽  
Silvia Ranzieri ◽  
Brandon Michael Henry ◽  
...  

SARS-CoV-2 is responsible for a highly contagious infection, known as COVID-19. SARS-CoV-2 was discovered in late December 2019 and, since then, has become a global pandemic. Timely and accurate COVID-19 laboratory testing is an essential step in the management of the COVID-19 outbreak. To date, assays based on the reverse-transcription polymerase chain reaction (RT-PCR) in respiratory samples are the gold standard for COVID-19 diagnosis. Unfortunately, RT-PCR has several practical limitations. Consequently, alternative diagnostic methods are urgently required, both for alleviating the pressure on laboratories and healthcare facilities and for expanding testing capacity to enable large-scale screening and ensure a timely therapeutic intervention. To date, few studies have been conducted concerning the potential utilization of rapid testing for COVID-19, with some conflicting results. Therefore, the present systematic review and meta-analysis was undertaken to explore the feasibility of rapid diagnostic tests in the management of the COVID-19 outbreak. Based on ten studies, we computed a pooled sensitivity of 64.8% (95%CI 54.5–74.0), and specificity of 98.0% (95%CI 95.8–99.0), with high heterogeneity and risk of reporting bias. We can conclude that: (1) rapid diagnostic tests for COVID-19 are necessary, but should be adequately sensitive and specific; (2) few studies have been carried out to date; (3) the studies included are characterized by low numbers and low sample power, and (4) in light of these results, the use of available tests is currently questionable for clinical purposes and cannot substitute other more reliable molecular tests, such as assays based on RT-PCR.


Parasitology ◽  
2014 ◽  
Vol 141 (14) ◽  
pp. 1912-1917 ◽  
Author(s):  
MARIA P. REBOLLO ◽  
MOSES JOHN BOCKARIE

SUMMARYLymphatic filariasis (LF), which is highly endemic in 73 countries worldwide, is targeted for elimination by 2020. The strategy for achieving this goal is based on 4 sequential programmatic steps: mapping, Mass drug administration (MDA) implementation, post-MDA surveillance and verification of LF elimination. All 4 stages of the implementation process are dependent on the availability of user friendly and highly sensitive rapid diagnostic tools. By the end of 2012, 59 countries had completed mapping for LF and Eritrea was the only country yet to start the process. Rolling out new diagnostic tools to facilitate the mapping process will enable an accelerated shrinking of the LF map to zero endemic countries by 2020. When the Global Programme to Eliminate Lymphatic Filariasis was launched in 2000, diagnostic tools for LF were limited to clinical examination, detection of microfilaria (MF) by microscopy in night blood samples and detection of antibodies to native-antigen preparations. There has been a significant improvement in the traditional LF diagnostic methods in recent years and some new tools are now available. This paper provides an update on the human diagnostic tests available for LF and their current applications as tools in mapping and transmission monitoring. The values of entomological indicators and parasite detection and speciation methods applied to vector populations are also discussed.


2020 ◽  
Vol 8 (2) ◽  
pp. 66-72
Author(s):  
Ahmad Nazaktabar ◽  
Omid Madadgar

Background: Rotavirus (RV) is one of the most important causes of diarrhea in the calf and human neonates. Rotaviruses are divided into nine different serogroups, of which group A is more important compared to other groups. Objective: This study was performed because of the lack of information about the importance and prevalence of bovine rotaviruses B (RVB) and C (RVC) and human genotypes of rotavirus A (RVA) in the bovine population in Iran. Phylogenetic analysis of VP6 of bovine RVA was the second aim of the present study. Materials and Methods: A total of 581 stool specimens were collected from diarrheic calves of 14 provinces and were analyzed by reverse transcription polymerase chain reaction (RT-PCR) and 485 of them were investigated by PAGE electrophoresis to determine the frequency of three rotaviruses A (RVA), B (RVB), and C (RVC). The presence of human G and P genotypes in Iranian bovine population was also evaluated using semi-nested multiplex RT-PCR. Results: RVA was detected by RT-PCR (VP6 gene detection) in 16.2% (94/581) and by PAGE in 22.16% (108/485) and no positive cases of RVB and RVC were confirmed by polyacrylamide gel electrophoresis (PAGE). This study showed that non-A RV groups (B and C) have little role in calf diarrhea in Iran. The results of the phylogenetic study of VP6 sequences of rotaviruses A identified in this study showed that they all belonged to genotype I2 and were classified into three different branches. Specimen isolated in Zanjan showed the highest difference (maximum identity of 94%) with other sequences and clustered along with the Japanese strain, R22. Human G and P genotypes were not found in the studied samples. Conclusion: The results showed that non-A rotaviruses and human genotypes of RVA are of little importance in calf rotavirus diarrhea in Iran. Also, there is the first phylogenetic study of rotavirus A VP6 protein in Iran.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7851
Author(s):  
Koena L. Moabelo ◽  
Darius R. Martin ◽  
Adewale O. Fadaka ◽  
Nicole R. S. Sibuyi ◽  
Mervin Meyer ◽  
...  

The coronavirus disease 2019 (COVID-19) pandemic has gained worldwide attention and has prompted the development of innovative diagnostics, therapeutics, and vaccines to mitigate the pandemic. Diagnostic methods based on reverse transcriptase-polymerase chain reaction (RT-PCR) technology are the gold standard in the fight against COVID-19. However, this test might not be easily accessible in low-resource settings for the early detection and diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The lack of access to well-equipped clinical laboratories, requirement for the high level of technical competence, and the cost of the RT-PCR test are the major limitations. Moreover, RT-PCR is unsuitable for application at the point-of-care testing (PoCT) as it is time-consuming and lab-based. Due to emerging mutations of the virus and the burden it has placed on the health care systems, there is a growing urgency to develop sensitive, selective, and rapid diagnostic devices for COVID-19. Nanotechnology has emerged as a versatile technology in the production of reliable diagnostic tools for various diseases and offers new opportunities for the development of COVID-19 diagnostic systems. This review summarizes some of the nano-enabled diagnostic systems that were explored for the detection of SARS-CoV-2. It highlights how the unique physicochemical properties of nanoparticles were exploited in the development of novel colorimetric assays and biosensors for COVID-19 at the PoCT. The potential to improve the efficiency of the current assays, as well as the challenges associated with the development of these innovative diagnostic tools, are also discussed.


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