scholarly journals COVID-19, A New Outlook on Pandemic Symptoms and Diagnostic Approach

2022 ◽  
Vol 02 (01) ◽  
Author(s):  
María Fernanda Calderón Hernádez ◽  
Keyword(s):  
Diabetes Mellitus ◽  
Risk Factors ◽  
Polymerase Chain Reaction ◽  
Latin America ◽  
Diagnostic Methods ◽  
Chain Reaction ◽  
Specificity And Sensitivity ◽  
Polymerase Chain ◽  
Effective Diagnosis ◽  
Age And Sex

Background: The main objective of this research is to learn the symptoms that occur in this pathology, since we are currently still fighting COVID-19, because of this, it is important to keep us informed about the different diagnostic methods available, which help us reach an earlier and more effective diagnosis. Various articles have been compiled to identify as soon as possible the active cases and thus reduce the number of infections. Materials and methods: This research was conducted on the basis of scientific articles and books, related to COVID-19. Methods: This research was conducted based on 15 scientific articles and 3 books, related to COVID-19. Results: The most important risk factors are diabetes mellitus, hypertension, obesity, age and sex. The most common symptoms in Latin America are dry cough, fatigue, sore throat, and fever. The preferred diagnostic test for COVID-19 is the polymerase chain reaction for its specificity and sensitivity Conclusions: As a conclusion, the main objective of the research was achieved, which is to inform the reader about the most relevant symptoms of SARS-CoV-2 in order to improve the identification of suspected cases. Furthermore, we compare various diagnostic methods that exist to date and determine that PCR is the most specific and sensitive.

Comparison of Droplet Digital Polymerase Chain Reaction (ddPCR) and Real-Time Quantitative Polymerase Chain Reaction (qPCR) in Detecting Neonatal Invasive Fungal Infections

2021 ◽  
Vol 11 (3) ◽  
pp. 373-379
Author(s):  
Huitao Li ◽  
Xueyu Chen ◽  
Xiaomei Qiu ◽  
Weimin Huang ◽  
Chuanzhong Yang
Keyword(s):  
Polymerase Chain Reaction ◽  
Limit Of Detection ◽  
Quantitative Polymerase Chain Reaction ◽  
Diagnostic Methods ◽  
Chain Reaction ◽  
Fungal Isolation ◽  
Blood Samples ◽  
Fungal Strains ◽  
Polymerase Chain ◽  
Digital Polymerase Chain Reaction

Invasive fungal infection (IFI) is the leading cause of death in neonatal patients, yet the diagnosis of IFI remains a major challenge. At present, most IFI laboratory diagnostic methods are based on classical, but limited, methods such as fungal isolation and culture and histopathological examination. Recently, quantitative polymerase chain reaction (qPCR) and droplet digital polymerase chain reaction (ddPCR) technology have been adopted to quantify nucleic-acid identification. In this study, we established qPCR and ddPCR assays for IFI diagnosis and quantification. qPCR and ddPCR were carried out using identical primers and probe for the amplification of 18S rRNA. Assay results for three fungal strains were positive, whereas ten non-fungal strains had negative results, indicating 100% specificity for both ddPCR and qPCR methods. Genomic DNA of Candida albicans was tested after a serial dilution to compare the sensitivity of the two PCR methods. The limit of detection of ddPCR was 3.2 copies/L, which was a ten-fold increase compared with that of the qPCR method (32 copies/L). Blood samples from 127 patients with high-risk factors and clinical symptoms for IFI were collected from a NICU in Shenzhen, China, and analyzed using qPCR and ddPCR. Thirty-four blood samples from neonates had a proven or probable diagnosis of IFI, and 25 of these were positive by qPCR, whereas 30 were positive by ddPCR. Among the 93 blood samples from neonates who had a possible IFI or no IFI, 24 were positive using qPCR, and 7 were positive using ddPCR. In conclusion, ddPCR is a rapid and accurate pan-fungal detection method and provides a promising prospect for IFI clinical screening.

scholarly journals BAALC and ERG Expression in Egyptian Patients with Acute Myeloid Leukemia, Relation to Survival and Response to Treatment

2016 ◽  
Vol 4 (2) ◽  
pp. 264-270 ◽  
Author(s):  
Aml Soliman ◽  
Asmaa Abdel Aal ◽  
Reham Afify ◽  
Noha Ibrahim
Keyword(s):  
Polymerase Chain Reaction ◽  
Acute Myeloid Leukemia ◽  
Reverse Transcription ◽  
Myeloid Leukemia ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Polymerase Chain ◽  
Age And Sex ◽  
Acute Myeloid

AIM: Aim was to detect Brain and Acute Leukemia, Cytoplasmic (BAALC) and ETS-related gene (ERG) expression in patients with acute myeloid leukemia (AML) as well as to study their biologic and prognostic impact on the disease outcome and survival.PATIENTS AND METHODS: The current study was carried out on 44 patients with denovo acute myeloid leukemia, as well as 44 age and sex matched controls. The quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was performed for estimation of BAALC and ERG expression.RESULTS: The current study was carried out on 44 patients with denovo acute myeloid leukemia, as well as 44 age and sex matched controls. The quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay was performed for estimation of BAALC and ERG expression. BAALC was expressed in 36 (81.82%) of AML cases versus 10 (22.72%) of the control group which was highly statistically significant (P < 0.001). While ERG was positive in 39(88.64%) of cases and 8(18.18 %) of controls and that was also highly statistically significant (P < 0.001).CONCLUSION: Further researches still needed to clarify the role of BAALC and ERG in the pathogenesis of leukemia and their importance as targets for treatment of AML.

scholarly journals UTILITY OF ANTIGEN DETECTION TEST AND POLYMERASE CHAIN REACTION IN THE DIFFERENTIATION OF TUBERCULOUS AND NON-TUBERCULOUS MYCOBACTERIA

2017 ◽  
Vol 10 (6) ◽  
pp. 289
Author(s):  
Yogita Singh ◽  
Raji Vasanth ◽  
Shrikala Baliga ◽  
Dhanashree B
Keyword(s):  
Polymerase Chain Reaction ◽  
False Negative ◽  
Diagnostic Methods ◽  
Clinical Samples ◽  
Chain Reaction ◽  
College Hospital ◽  
Medical College ◽  
Negative Results ◽  
Polymerase Chain ◽  
Mycobacterium Spp

Objectives: Cultivation and identification of mycobacteria to species level remains difficult and time-consuming. Hence, easy and rapid diagnostic methods are necessary for the differentiation of Mycobacterium tuberculosis (MTB) from non-tuberculous mycobacteria (NTM). The present study aims to detect and differentiate MTB from NTM isolated from clinical samples by immunochromatographic test (ICT) and polymerase chain reaction (PCR). Methods: Over a period of 1 year, clinical samples (n=496) received from suspected cases of TB, at the Department of Microbiology, Kasturba Medical College Hospital, Mangalore were cultured to isolate Mycobacterium spp. Identification of all the isolates was done by conventional biochemical technique, ICT, and PCR. Results: Among the 496 samples processed, 49 (9.87%) were acid-fast bacilli smear positive and 59 (11.89%) samples showed the growth of Mycobacterium spp. Among these, 10 were rapid growers, 49 were slow-growing mycobacteria, out of which 30 were MTB as identified by conventional biochemical reaction. Out of 59 Mycobacterial isolates subjected to ICT for the detection of MPT 64 antigen, only 28 were identified as MTB. However, all the 30 isolates were correctly identified as MTB by PCR. Conclusion: Hence, PCR is essential for rapid differentiation of non-tuberculous Mycobacterium from MTB. False negative results seen with immunochromatographic MPT 64 antigen assay could be due to mutations within the mpt64 gene. Further studies are necessary to characterize these PCR-positive and immunochromatographic assay negative MTB isolates.

scholarly journals Comparative Study of Immune-Diagnostic Tools with Polymerase Chain Reaction in Sub-Clinical Leishmaniasis Isolates

2011 ◽  
Vol 12 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Nazar M Abdalla
Keyword(s):  
Polymerase Chain Reaction ◽  
Skin Test ◽  
Diagnostic Methods ◽  
Diagnostic Tools ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clinical Form ◽  
Chain Reaction ◽  
Leishmanin Skin Test ◽  
Wide Range ◽  
Polymerase Chain

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

scholarly journals Comparison of polymerase chain reaction and microscopy for the detection of Fasciola spp. in the fecal matter of domestic bovines in Kalasin Province, Thailand

2021 ◽  
pp. 2878-2882
Author(s):  
Sirikanda Thanasuwan ◽  
Anupong Tankrathok
Keyword(s):  
Polymerase Chain Reaction ◽  
False Negative ◽  
Economic Losses ◽  
Rrna Gene ◽  
28S Rrna ◽  
Chain Reaction ◽  
Fecal Matter ◽  
Specificity And Sensitivity ◽  
Polymerase Chain ◽  
Fasciola Spp

Background and Aim: Fasciola spp. are important foodborne trematodes and waterborne zoonotic parasites that cause health problems and economic losses worldwide, including in Thailand. Fasciola spp. are usually detected by sedimentation or the formalin-ethyl acetate concentration technique (FECT) under microscopy, which is less specific and sensitive. Accurate detection is important to detect real incidence for protection against and elimination of fasciolosis in the area. This study aimed to determine the distribution of Fasciola spp. and compare the specificity and sensitivity of FECT under microscopy to that of polymerase chain reaction (PCR) in cattle feces. Materials and Methods: The study was conducted in Kalasin Province, Thailand. Feces of 46 cattle were investigated for infection with Fasciola spp. To detect infection, FECT under microscopy and PCR amplification of the 28S rRNA gene of Fasciola spp. were used to identify egg parasites. Results: Feces of 16 of 46 (34.78%) cattle were positive for Fasciola spp. using FECT under microscopy, whereas PCR showed that 67.39% (31 of 46) were positive for Fasciola spp. False-negative results were as high as 32.61% when diagnosed under microscopy. Conclusion: This study confirmed the infection of cattle with Fasciola spp. in Kalasin Province, indicating that PCR demonstrated higher sensitivity and specificity when diagnosing infection. FECT under microscopy can still be used as a primary and traditional method for diagnosis. However, relapse cases of Fasciola spp. and Paramphistomum spp. should be diagnosed by microscopy combined with PCR. This is the first report on the molecular distribution of fecal samples in cattle in Kalasin Province.

scholarly journals Longest reported case of symptomatic COVID-19 reporting positive for over 230 days in an immunocompromised patient in the United States

2021 ◽  
Vol 9 ◽  
pp. 2050313X2110400
Author(s):  
Bilal Chaudhry ◽  
Lidiya Didenko ◽  
Maaria Chaudhry ◽  
Andrew Malek ◽  
Kirill Alekseyev
Keyword(s):  
Risk Factors ◽  
Polymerase Chain Reaction ◽  
Immunocompromised Patient ◽  
The United States ◽  
Immunocompromised Patients ◽  
Chain Reaction ◽  
Viral Shedding ◽  
Time Period ◽  
Increased Risk ◽  
Polymerase Chain

Coronavirus 2019 (COVID-19) pneumonia was first noted in Wuhan, China. Since the start of the pandemic, there have been millions of cases diagnosed. The average time from onset of symptoms to testing negative SARS-CoV-2 via reverse transcription polymerase chain reaction is roughly 25 days. In patients who continually test positive for COVID-19, it is essential to determine precisely which risk factors contribute to the increase in viral shedding duration. We present a case about a 62-year-old man who has persistently tested positive for COVID-19 for more than 230 days. We followed his treatment course, in which he had been hospitalized multiple times since the onset of symptoms back in April 2020. We have determined that patients with immunosuppression, especially those taking corticosteroids, are at increased risk of prolonged viral shedding. It is essential to continually monitor these immunocompromised patients as they required a greater time period in order to have an appropriate immune response in which antibodies are created.

scholarly journals DETEKSI BAKTERI PENYEBAB PENYAKIT TYPHUS PADA MANUSIA DENGAN POLYMERASE CHAIN REACTION

2011 ◽  
Vol 1 (1) ◽  
pp. 45
Author(s):  
Muktiningsih Nurjayadi ◽  
Fera Kurnia Dewi ◽  
Dahlia Dahlia ◽  
S, Restu.N S ◽  
Fitri W
Keyword(s):  
Polymerase Chain Reaction ◽  
Detection Method ◽  
Serological Test ◽  
Research Result ◽  
Salmonella Typhi ◽  
Detection Methods ◽  
Chain Reaction ◽  
Specificity And Sensitivity ◽  
Dna Fragment ◽  
Polymerase Chain

Salmonella typhi is bacteria that cause typhoid disease in humans. In Indonesia, the morbidity number of typhoid disease tends to be increase. Thus, it has been requiring the alternative for handling or preventing that disease. Recently, the detection method commonly uses for S. typhi detection is Serological test. The weakness of this method is often producing less accurate and not specific detection. The previous research was successfully discovered S. typhi gene that codes protein which is contributed at adherents or colonization those bacteria in epithelial human cell. That result was base to develop detection on S. typhi method by Polymerase chain reaction (PCR). The aim of this research is developing a specific and accurate detection method for S. typhi bacteria by PCR. The research result is performed successfully to amplify the fimbrial-C S. typhi gene using pairs of primer FW-INT 2- REV-1A NEW which was designed and synthesized in previous step. That success showed by the finding of the DNA fragment of 0.2 kilobase (kb) proffers to size of DNA fragment which is hopefully in using S. typhi genome as a template. Specificity and sensitivity test for those primers are still conducting to reproducibility results. Base on the results can be concluded that the research have successfully conducted in developing S. typhi detection method using pairs of S. typhi fimbrial-C primer. Hopefully, the studied of developing detection methods was conducted better compare with former detection methods.Keywords: S. typhi detection method, fim-C S. typhi gene, PCRAbstrakSalmonella typhi merupakan bakteri penyebab penyakit tifus pada manusia. Di Indonesia, angka morbiditas penderita penyakit typhus cenderung meningkat, sehingga diperlukan suatu alternatif untuk penanganan atau pencegahan penyakit tersebut. Sampai saat ini metode deteksi S. typhi yang banyak digunakan adalah uji serologi. Kelemahan metode ini adalah sering menghasilkan deteksi yang kurang akurat dan tidak spesifik. Pada penelitian yang dilakukan sebelumnya, telah berhasil ditemukan gen fimbrial-C S. typhi pengkode protein yang berperan dalam penempelan S. typhi pada usus manusia, hasil ini dijadikan landasan untuk pengembangan metode deteksi menggunakan teknik PCR. Tujuan penelitian ini mengembangkan metode deteksi yang akurat dan spesifik untuk bakteri penyebab penyakit typhus pada manusia. Hasil penelitian menunjukkan bahwa telah berhasil dilakukan amplifikasi gen fimbrial-C S. typhi menggunakan pasangan primer hasil perancangan yaitu FW-INT 2- REV-1A NEW. Keberhasilan tersebut ditunjukkan dengan diperolehnya pita DNA berukuran 0.2 kilo basa (kb) sesuai dengan ukuran pita DNA yang diharapkan dengan menggunakan template DNA genom bakteri S. typhi. Uji sensitivitas dan spesifisitas terhadap primer hasil rancangan sedang di kaji lebih lanjut untuk memperoleh reprodusibiltas hasil pengujian. Berdasarkan hasil yang diperoleh dapat disimpulkan bahwa telah berhasil dilakukan pengembangan metode deteksi S. typhi menggunakan pasangan primer fimbrial-C S. typhi. Pengkajian pengembangan metode deteksi yang dihasilkan ini diharapkan dapat lebih baik dibanding beberapa metode deteksi yang sudah ada.Kata Kunci: Metode Deteksi Bakteri typhus, fim-C S. typhi, PCR

Epidemiology of Epizootic Lymphangitis of cart horses in Northern Ethiopia Using Conventional diagnostic Methods and Nested Polymerase Chain Reaction

2019 ◽  
Author(s):  
Birhanu Hadush Abera ◽  
Molla Michaelay ◽  
Habtamu Taddele ◽  
Nigus Abebe ◽  
Abrha Tesfay ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Clinical Examination ◽  
Roc Curve ◽  
Nested Pcr ◽  
Control Measure ◽  
Diagnostic Methods ◽  
Northern Ethiopia ◽  
Chain Reaction ◽  
Nested Polymerase Chain Reaction ◽  
Polymerase Chain

Abstract Background: Epizootic lymphangitis (EL), caused by Histoplasma capsulatum variety farciminosum (HCF) is a contagious chronic disease of equines characterized by development of nodular lesions in the lymph nodes, lymphatic vessels and skin. This disease is the most important diseases of equines in Ethiopia causing a significant economic loss, particularly cart pulling equines. Todate there is no sound diagnostic nor control measure implemented in the country. Furthermore, there is a shortage of data on the epidemiology of the disease in different regions of the country including northern Ethiopia. This study was conducted to investigate the epidemiology of EL in northern Ethiopia using the conventional methods and the nested polymerase chain reaction (PCR). Methods: A total of 191 cart-horses were enrolled and used as sources of pus and blood samples. The blood was used for the extraction of the DNA of HCF from buffy coat for nested PCR while the pus samples were cultured on Sabourauds Dextrose Agar for isolation. Statistical Package for Social Sciences (SPSS) version 21 was used for data analysis by applying logistic regression, receiver operating characteristic (ROC) curve and Cohen’s kappa coefficient test. In addition, the level of agreement between the clinical examination and the nested PCR was evaluated. Results: Infection with HCF was confirmed in 44% (84/191) of the horses using nested PCR. Subclinical infection was observed in 18.18% (22/121) of the apparently healthy horses. Considering nested PCR as a gold standard, the sensitivity and specificity of the clinical examination were 74% and 95%, respectively while the area under the ROC curve (AUR) was 0.83 (95% confidence interval, 0.77, 0.896). Moreover, a moderate (k=0.675) agreement was observed between the nested PCR and clinical examination.Conclusions: The findings of the present study showed the wide spread occurrence of EL in northern Ethiopia and the advantage of the nested PCR in detecting of the infection of HCF even before the clinical symptoms are apparent.

Accuracy of real-time polymerase chain reaction to detect Schistosoma mansoni – infected individuals from an endemic area with low parasite loads

Parasitology ◽  
2020 ◽  
Vol 147 (10) ◽  
pp. 1140-1148
Author(s):  
Fernanda do Carmo Magalhães ◽  
Samira Diniz Resende ◽  
Carolina Senra ◽  
Carlos Graeff-Teixeira ◽  
Martin Johannes Enk ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Schistosoma Mansoni ◽  
Real Time ◽  
Diagnostic Methods ◽  
Control Measures ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Cross Sectional ◽  
Intestinal Schistosomiasis ◽  
Polymerase Chain

AbstractDue to the efforts to control schistosomiasis transmission in tropical countries, a large proportion of individuals from endemic areas present low parasite loads, which hinders diagnosis of intestinal schistosomiasis by the Kato-Katz (KK) method. Therefore, the development of more sensitive diagnostic methods is essential for efficient control measures. The aim was to evaluate the accuracy of a real-time polymerase chain reaction (RT-PCR) to detect Schistosoma mansoni DNA in fecal samples of individuals with low parasite loads. A cross-sectional population-based study was conducted in a rural community (n = 257) in Brazil. POC-CCA® was performed in urine and feces were used for RT-PCR. In addition, fecal exams were completed by 18 KK slides, saline gradient and Helmintex techniques. The combined results of the three parasitological tests detected schistosome eggs in 118 participants (45.9%) and composed the consolidated reference standard (CRS). By RT-PCR, 117 out of 215 tested samples were positive, showing 91.4% sensitivity, 80.2% specificity and good concordance with the CRS (kappa = 0.71). RT-PCR identified 86.9% of the individuals eliminating less than 12 eggs/g of feces, demonstrating much better performance than POC-CCA® (50.8%). Our results showed that RT-PCR is a valuable alternative for the diagnosis of intestinal schistosomiasis in individuals with very low parasite loads.

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