scholarly journals COVID-19 Microbiological and Radiological Diagnostics

2021 ◽  
Vol 40 (3) ◽  
pp. 97-106
Author(s):  
Karlo Jeličić ◽  
Oktavija Đaković Rode ◽  
Klaudija Višković ◽  
Armin Mehmedović ◽  
Ivan Christian Kurolt

The purpose of this paper is to present SARS-CoV-2 diagnostic methods and their optimal implementation. The main routine microbiological diagnostic tools are molecular and serological methods. Sensitivity and utilisation of molecular methods is the best at the disease onset, while serological methods are the best if used at least 5-7 days after disease onset. Positive molecular test result (real-time polymerase chain reaction; RT-PCR) must be interpreted in the clinical presentation context. A sampling site for molecular analysis is based on disease severity; upper and lower respiratory tract samples are used for mild and severe presentations, respectively. Virus cultivation is the only method of proving the existence of a viable virus in a tissue sample, but due to the method complexity, it is not a part of a routine process. Ground glass opacities with or without reticular pattern and/or consolidation are typical findings for COVID-19 pneumonia. Multi-slice computerized tomography (MSCT) is a superior radiological method for performing X-ray of the chests.

2011 ◽  
Vol 12 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Nazar M Abdalla

Objective: This study aimed to identify cases of leishmaniasis in the Nuba Mountain area, which is situated in a unique geographical site located in the centre of Sudanese leishmania belt. Wide range of investigations are available for detection of leishmania cases, but still the most reliable and easy test used as screening and epidemiological tool in field studies needs to be evaluated. The most commonly used conventional diagnostic methods direct microscopy and culture have some drawbacks in diagnosing subclinical cases of leishmaniasis. Materials and methods: In this study, comparative properties of various immune-diagnostic tools with Polymerase Chain Reaction used in sub-clinical leishmaniasis isolates were explored. The immune-diagnostic tools involved in this study include- Leishmanin Skin Test (LST), Enzyme Linked Immunosorbent Assay (ELISA) and Direct Agglutination Test (DAT). The study was conducted in the Green Valley village (Rashad Province, South Kordofan State) with a population of 332. Most of the villagers presented with sub-clinical form of leishmaniasis with minor symptoms and signs without the features found in clinical form of visceral leishmaniasis such as fever, diarrhoea, epistaxis, enlarged lymph nodes, spleen and liver. In this study we collected demographic, clinical and epidemiological data using special questionnaire. Leishmanin skin test (LST), ELISA, DAT and PCR for parasite DNA detection were used. Result: The final positive cases detected by PCR were 32 out of 332 belong to L. donovani species. The final positive cases detected by LST were 51.2% of the total population under study, while 11 out of the 37 tested samples were positive by ELISA. All of the 332 villagers showed negative readings by DAT with exception of three individuals who were positive with very high titers. Conclusion: DNA etxtraction and amplification with primers can be a good screening tool in subclinical leishmaniasis isolates. Keyword: Sub-clinical; Leishmaniasis; Leishmanin Skin Test; ELISA; DAT; PCR. DOI: 10.3329/jom.v12i1.5422J Medicine 2011; 12 : 34-39


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ladina Keller ◽  
Chandni Patel ◽  
Sophie Welsche ◽  
Tobias Schindler ◽  
Eveline Hürlimann ◽  
...  

Abstract Background Accurate, scalable and sensitive diagnostic tools are crucial in determining prevalence of soil-transmitted helminths (STH), assessing infection intensities and monitoring treatment efficacy. However, assessments on treatment efficacy comparing traditional microscopic to newly emerging molecular approaches such as quantitative Polymerase Chain Reaction (qPCR) are scarce and hampered partly by lack of an established diagnostic gold standard. Methods We compared the performance of the copromicroscopic Kato-Katz method to qPCR in the framework of a randomized controlled trial on Pemba Island, Tanzania, evaluating treatment efficacy based on cure rates of albendazole monotherapy versus ivermectin-albendazole against Trichuris trichiura and concomitant STH infections. Day-to-day variability of both diagnostic methods was assessed to elucidate reproducibility of test results by analysing two stool samples before and two stool samples after treatment of 160 T. trichiura Kato-Katz positive participants, partially co-infected with Ascaris lumbricoides and hookworm, per treatment arm (n = 320). As negative controls, two faecal samples of 180 Kato-Katz helminth negative participants were analysed. Results Fair to moderate correlation between microscopic egg count and DNA copy number for the different STH species was observed at baseline and follow-up. Results indicated higher sensitivity of qPCR for all three STH species across all time points; however, we found lower test result reproducibility compared to Kato-Katz. When assessed with two samples from consecutive days by qPCR, cure rates were significantly lower for T. trichiura (23.2 vs 46.8%), A. lumbricoides (75.3 vs 100%) and hookworm (52.4 vs 78.3%) in the ivermectin-albendazole treatment arm, when compared to Kato-Katz. Conclusions qPCR diagnosis showed lower reproducibility of test results compared to Kato-Katz, hence multiple samples per participant should be analysed to achieve a reliable diagnosis of STH infection. Our study confirms that cure rates are overestimated using Kato-Katz alone. Our findings emphasize that standardized and accurate molecular diagnostic tools are urgently needed for future monitoring within STH control and/or elimination programmes.


2018 ◽  
Vol 38 (02) ◽  
pp. 226-237 ◽  
Author(s):  
Mitashee Das ◽  
Kelly Dooley ◽  
Amita Gupta ◽  
Kiran Thakur

AbstractCentral nervous system (CNS) involvement of tuberculosis (TB) is the most severe manifestation of TB and accounts for approximately 5 to 10% of all extrapulmonary TB (EPTB) cases and approximately 1% of all TB cases. TB meningitis (TBM) is the most common form of CNS TB, though other forms occur, often in conjunction with TBM, including intracranial tuberculomas, tuberculous brain abscesses, and spinal tubercular arachnoiditis. CNS TB often presents with nonspecific clinical features that mimic symptoms of other neurological conditions, often making diagnosis difficult. Defining neuroimaging characteristics of TBM include thick basal meningeal enhancement, hydrocephalus, and parenchymal infarctions most commonly involving the basal ganglia and internal capsule. Traditional cerebrospinal fluid sample analysis frequently requires lengthy times-to-result and have low sensitivity. Given the pitfalls of conventional CNS TB diagnostic methods, various molecular-based methods, including immunoassays and polymerase chain reaction (PCR)-based assays have emerged as alternative diagnostic tools due to their rapidity, sensitivity, and specificity. Expert panels on TBM have recently emphasized the need for standard research procedures with updated case definitions and standardized study methods, which will hopefully pave the way for more robust multicenter international studies. In this article, we review the epidemiology, diagnosis, molecular factors associated with disease presentation and outcome, and treatment of CNS TB.


2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii12-ii12
Author(s):  
Tomoya Irikura ◽  
Kohei Fukuoka ◽  
Makiko Mori ◽  
Koichi Oshima ◽  
Yuki Arakawa ◽  
...  

Abstract A novel risk stratification of medulloblastoma has been proposed based on retrospective data from patients undergoing standard treatment. However, it remains unclear whether the classification is applicable to patients receiving reduced-dose craniospinal irradiation (CSI). We performed molecular diagnosis and copy number analysis using methylation array on patients with standard-risk medulloblastoma treated with 18 Gy CSI at our institution. Nine tumor samples were available for analysis from seven patients who had a median age of 7.4 years at disease onset and a median observation period of 73 months. Three patients had recurrence, and another patient developed radiation-induced glioblastoma. From the three recurrent cases, one was molecularly diagnosed as SHH subtype with MYCN amplification; another case was a Group 4 tumor without favorable prognostic chromosomal aberrations, and the remaining patient experienced a very late relapse despite low-risk stratification. Of the recurrence-free cases, one was classified as WNT subtype, and another was a Group 4 tumor with chromosome 7 gain, and loss of chromosomes 8 and 11, both of which were associated with good prognosis. Methylation analysis also unveiled the fact that the recurrent tumor diagnosed as relapsing medulloblastoma by conventional diagnostic tools was in fact a radiation-induced glioblastoma. Our data suggested that the new risk stratification may be useful for cases treated with CSI reduced to 18 Gy. However, due to the presence of the late-relapsed case stratified to low risk, further investigations with a larger cohort should be required to confirm the data.


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.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Gustavo Henrique Pereira Boog ◽  
João Vitor Ziroldo Lopes ◽  
João Vitor Mahler ◽  
Marina Solti ◽  
Lucas Tokio Kawahara ◽  
...  

Abstract Purpose Increasing incidences of syphilis highlight the preoccupation with the occurrence of neurosyphilis. This study aimed to understand the current diagnostic tools and their performance to detect neurosyphilis, including new technologies and the variety of existing methods. Methods We searched databases to select articles that reported neurosyphilis diagnostic methods and assessed their accuracy, presenting sensitivity and specificity values. Information was synthesized in tables. The risk of bias was examined using the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy recommendations. Results Fourteen studies were included. The main finding was a remarkable diversity of tests, which had varied purposes, techniques, and evaluation methodologies. There was no uniform criterion or gold standard to define neurosyphilis. The current basis for its diagnosis is clinical suspicion and cerebrospinal fluid analysis. There are new promising tests such as PCR tests and chemokine measurement assays. Conclusions The diagnosis of neurosyphilis is still a challenge, despite the variety of existing and developing tests. We believe that the multiplicity of reference standards adopted as criteria for diagnosis reveals the imprecision of the current definitions of neurosyphilis. An important next step for the scientific community is to create a universally accepted diagnostic definition for this disease.


Author(s):  
Valentina Angelini ◽  
Alberta Villanacci ◽  
Angelo Belotti ◽  
Francesca Castagnoli ◽  
Barbara Frittoli ◽  
...  

Abstract Background The purpose of this case report is to emphasize the importance of curing any clinical radiological elements in this historical period, especially in the area of endemic to coronavirus disease 19 (COVID-19) such as Lombardy and to stress the importance of the management of the asymptomatic patient, their crucial role in the spread of contagion. Case presentation We reported the case of incidental diagnosis of interstitial pneumonia by first finding on whole-body MR (WB-MR) in the patient affected by multiple myeloma (MM), with a negative respiratory symptoms at the time and with previous (1 month before) negative chest X-ray. The patient was promptly subjected to chest CT, which confirmed the suspicion of interstitial COVID-19 pneumonia and, in hospitalization, performed nasopharyngeal swabs for real-time polymerase chain reaction (RNA-PCR), with a doubtful outcome. Once the bacterial nature of the alterations was serologically and radiologically excluded, the patient was definitively diagnosed with COVID-19 and appropriately treated in hospitalization. Conclusion The clinical choices must, therefore, to make use of all the diagnostic tools available and full knowledge of the limitation of each of them.


1990 ◽  
Vol 36 (10) ◽  
pp. 1741-1746 ◽  
Author(s):  
W E Highsmith ◽  
G L Chong ◽  
H T Orr ◽  
T R Perry ◽  
D Schald ◽  
...  

Abstract The cystic fibrosis (CF) gene has been recently cloned, and a deletion of 3 basepairs (bp) of DNA was found on most of the CF chromosomes. This deletion leads to the synthesis of a protein that lacks a phenylalanine residue at position 508. Using two polymerase chain reaction protocols to study the frequency of this mutation in a series of 192 CF patients, we found the mutation on 72% of affected chromosomes. We then used this value to calculate the predictive value of a negative test result in a population-based screening program for CF carrier status. Haplotype analysis with the polymorphic markers XV.2c and KM-19 on 239 CF chromosomes revealed that 90.7% of CF chromosomes with the deletion had a single haplotype. This haplotype was also associated with 60.4% of CF chromosomes with unknown mutations. These values can be used to calculate the probability of whether an individual from the general population is a carrier of any CF mutation.


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 293
Author(s):  
Idalécia Cossa-Moiane ◽  
Hermínio Cossa ◽  
Adilson Fernando Loforte Bauhofer ◽  
Jorfélia Chilaúle ◽  
Esperança Lourenço Guimarães ◽  
...  

Cryptosporidium is one of the most important causes of diarrhea in children less than 2 years of age. In this study, we report the frequency, risk factors and species of Cryptosporidium detected by molecular diagnostic methods in children admitted to two public hospitals in Maputo City, Mozambique. We studied 319 patients under the age of five years who were admitted due to diarrhea between April 2015 and February 2016. Single stool samples were examined for the presence of Cryptosporidium spp. oocysts, microscopically by using a Modified Ziehl–Neelsen (mZN) staining method and by using Polymerase Chain Reaction and Restriction Fragment Length Polymorphism (PCR-RFLP) technique using 18S ribosomal RNA gene as a target. Overall, 57.7% (184/319) were males, the median age (Interquartile range, IQR) was 11.0 (7–15) months. Cryptosporidium spp. oocysts were detected in 11.0% (35/319) by microscopy and in 35.4% (68/192) using PCR-RFLP. The most affected age group were children older than two years, [adjusted odds ratio (aOR): 5.861; 95% confidence interval (CI): 1.532–22.417; p-value < 0.05]. Children with illiterate caregivers had higher risk of infection (aOR: 1.688; 95% CI: 1.001–2.845; p-value < 0.05). An anthroponotic species C. hominis was found in 93.0% (27/29) of samples. Our findings demonstrated that cryptosporidiosis in children with diarrhea might be caused by anthroponomic transmission.


Sign in / Sign up

Export Citation Format

Share Document