scholarly journals A systematic review of molecular diagnostic methods for the detection of arboviruses in clinical specimens in Brazil and the importance of a differential diagnosis

2013 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Marcos Lázaro Moreli ◽  
Vivaldo Gomes da Costa
2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jean Pierre Rutanga ◽  
Therese Nyirahabimana

Bacterial bloodstream infection (bBSI) represents any form of invasiveness of the blood circulatory system caused by bacteria and can lead to death among critically ill patients. Thus, there is a need for rapid and accurate diagnosis and treatment of patients with septicemia. So far, different molecular diagnostic tools have been developed. The majority of these tools focus on amplification based techniques such as polymerase chain reaction (PCR) which allows the detection of nucleic acids (both DNA and small RNAs) that are specific to bacterial species and sequencing or nucleic acid hybridization that allows the detection of bacteria in order to reduce delay of appropriate antibiotic therapy. However, there is still a need to improve sensitivity of most molecular techniques to enhance their accuracy and allow exact and on time antibiotic therapy treatment. In this regard, we conducted a systematic review of the existing studies conducted in molecular diagnosis of bBSIs, with the main aim of reporting on clinical significance and benefits of molecular diagnosis to patients. We searched both Google Scholar and PubMed. In total, eighteen reviewed papers indicate that shift from conventional diagnostic methods to molecular tools is needed and would lead to accurate diagnosis and treatment of bBSI.


2015 ◽  
Vol 139 (8) ◽  
pp. 1020-1023 ◽  
Author(s):  
Kennon Miller ◽  
Susan M. Harrington ◽  
Gary W. Procop

Context New molecular diagnostic tests are attractive because of the potential they hold for improving diagnostics in microbiology. The value of these tests, which is often assumed, should be investigated to determine the best use of these potentially powerful tools. Objective To investigate the usefulness of broad-range polymerase chain reaction (PCR), followed by sequencing, in mycobacterial infections. Design We reviewed the test performance of acid-fast bacilli (AFB) PCR and traditional diagnostic methods (histopathology, AFB smear, and culture). We assessed the diagnostic effect and cost of the unrestricted ordering of broad-range PCR for the detection and identification of mycobacteria in clinical specimens. Results The AFB PCR was less sensitive than culture and histopathology and was less specific than culture, AFB smear, and histopathology. During 18 months, $93 063 was spent on 183 patient specimens for broad-range PCR and DNA sequencing for mycobacteria to confirm one culture-proven Mycobacterium tuberculosis infection that was also known to be positive by AFB smear and histopathology. In this cohort, there was a false-negative AFB PCR for M tuberculosis and a false-positive AFB PCR for Mycobacterium lentiflavum. Conclusion Testing of AFB smear–negative specimens from patients without an inflammatory response supportive of a mycobacterial infection is costly and has not been proven to improve patient care. Traditional diagnostics (histopathology, AFB smear, and culture) should remain the primary methods for the detection of mycobacteria in clinical specimens.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chandan Mishra ◽  
Suneeta Meena ◽  
Jitendra Kumar Meena ◽  
Suman Tiwari ◽  
Purva Mathur

AbstractSARS-CoV-2 has posed an unprecedented challenge to the world. Pandemics have been caused previously by viruses of this family like Middle East Respiratory Corona Virus (MERS CoV), Severe Acute Respiratory Syndrome Corona Virus (SARS CoV). Although these viruses are primarily respiratory viruses, but they have been isolated from non-respiratory samples as well. Presently, the detection rate of SARS‐CoV‐2 RNA from different clinical specimens using Real Time Reverse Transcriptase Polymerized Chain Reaction (qRT‐PCR) after onset of symptoms is not yet well established. Therefore, the aim of this systematic review was to establish the profile of detecting SARS‐CoV‐2, MERS CoV, SARS CoV from different types of clinical specimens other than the respiratory using a standard diagnostic test (qRT‐PCR). A total of 3429 non-respiratory specimens were recorded: SARS CoV (total sample—802), MERS CoV (total sample—155), SARS CoV-2 (total sample—2347). Out of all the samples studied high positive rate was seen for saliva with 96.7% (14/14; 95% CI 87.6–100.0%) for SARS CoV and 57.5% (58/250; 95% CI − 1.2 to 116.2%) for SARS CoV-2, while low detection rate in urine samples for SARS CoV-2 with 2.2% (8/318; 95% CI 0.6–3.7%) and 9.6% (12/61; 95% CI − 0.9 to 20.1%) for SARS CoV but there was relatively higher positivity in urine samples for MERS CoV with detection rate of 32.4% (2/38; 95% CI − 37.3 to 102.1%). In Stool sample positivity was 54.9% (396/779; 95% CI 41.0–68.8%), 45.2% (180/430; 95% CI 28.1–62.3%) and 34.7% (4/38; 95% CI − 29.5 to 98.9%) for SARS CoV-2, MERS CoV, and SARS CoV, respectively. In blood sample the positivity was 33.3% (7/21; 95% CI 13.2–53.5%), 23.7% (42/277; 95% CI 10.5–36.9%) and 2.5% (2/81; 95% CI 0.00–5.8%) for MERS CoV, SARS CoV-2 and SARS CoV respectively. SARS‐CoV‐2 along with previous two pandemic causing viruses from this family, were highly detected stool and saliva. A low positive rate was recorded in blood samples. Viruses were also detected in fluids along with unusual samples like semen and vaginal secretions thus highlighting unique pathogenic potential of SARS‐CoV‐2.


Author(s):  
Jason Derry Onggo ◽  
James Randolph Onggo ◽  
Mithun Nambiar ◽  
Andrew Duong ◽  
Olufemi R Ayeni ◽  
...  

ABSTRACT This study aims to present a systematic review and synthesized evidence on the epidemiological factors, diagnostic methods and treatment options available for this phenomenon. A multi-database search (OVID Medline, EMBASE and PubMed) was performed according to PRISMA guidelines on 18 June 2019. All studies of any study design discussing on the epidemiological factors, diagnostic methods, classification systems and treatment options of the wave sign were included. The Newcastle–Ottawa quality assessment tool was used to appraise articles. No quantitative analysis could be performed due to heterogeneous data reported; 11 studies with a total of 501 patients with the wave sign were included. Three studies examined risk factors for wave sign and concluded that cam lesions were most common. Other risk factors include alpha angle >65° (OR=4.00, 95% CI: 1.26–12.71, P=0.02), male gender (OR 2.24, 95% CI: 1.09–4.62, P=0.03) and older age (OR=1.04, 95% CI: 1.01–1.07, P=0.03). Increased acetabular coverage in setting of concurrent cam lesions may be a protective factor. Wave signs most commonly occur at the anterior, superior and anterosuperior acetabulum. In terms of staging accuracy, the Haddad classification had the highest coefficients in intraclass correlation (k=0.81, 95% CI: 0.23–0.95, P=0.011), inter-observer reliability (k=0.88, 95% CI: 0.72–0.97, P<0.001) and internal validity (k=0.89). One study investigated the utility of quantitative magnetic imaging for wave sign, concluding that significant heterogeneity in T1ρ and T2 values (P<0.05) of acetabular cartilage is indicative of acetabular debonding. Four studies reported treatment techniques, including bridging suture repair, reverse microfracture with bubble decompression and microfracture with fibrin adhesive glue, with the latter reporting statistically significant improvements in modified Harris hip scores at 6-months (MD=19.2, P<0.05), 12-months (MD=22.0, P<0.05) and 28-months (MD=17.5, P<0.001). No clinical studies were available for other treatment options. There is a scarcity of literature on the wave sign. Identifying at risk symptomatic patients is important to provide prompt diagnosis and treatment. Diagnostic techniques and operative options are still in early developmental stages. More research is needed to understand the natural history of wave sign lesions after arthroscopic surgery and whether intervention can improve long-term outcomes. Level IV, Systematic review of non-homogeneous studies.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sawsan Ismail ◽  
Munawar Hraib ◽  
Rana Issa ◽  
Thanaa Alassi ◽  
Zuheir Alshehabi

Abstract Background Ovarian steroid cell tumors represent a rare category of sex cord-stromal tumors that constitute less than 0.1% of all ovarian tumors. These neoplasms are classified into three main subtypes according to the cell of origin: Leidyg cell tumors, stromal luteomas, and steroid cell tumors not otherwise specified (SCTs-NOS). The latter subtype is defined as a neoplasm of an uncertain lineage that mostly affects middle-aged women, whereas it’s rare in younger ages. Case presentation We report a case of a 21-year-old virgin female who presented to our hospital with complaints of mild abdominal pain, hirsutism, and oligomenorrhea for more than a year. Before her current admission, the patient had attended an external gynecologic clinic where she had been prescribed oral contraceptives to regulate her periods. Nevertheless, on presentation to our institution, physical examination revealed abdominal tenderness with a palpable pelvic mass and mild hirsutism in the thigh. Ultrasonography demonstrated a large left ovarian mass measuring 154 × 104 mm, and compressing the uterus. Therefore, a unilateral salpingo-oophorectomy was performed, and interestingly, pathologic examination of the large aforementioned mass alongside with immunohistochemical correlation revealed the diagnosis of a large ovarian steroid cell tumor-not otherwise specified with a unique combination of benign and malignant features. Conclusions Although ovarian steroid cell tumors represent a rare category, they must be considered in the differential diagnosis for mild virilization symptoms in young females due to the importance of early diagnosis and management. In this manuscript, we aimed to present the first case report from Syria that highlights the crucial role of detailed morphological examination for challenging cases despite the difficulties in differential diagnosis, and the absence of ancillary techniques. Furthermore, we managed to discuss a brief review of diagnostic methods, histological characteristics, and treatment recommendations.


2021 ◽  
Vol 9 (4) ◽  
pp. 850
Author(s):  
José Esteban Muñoz-Medina ◽  
Concepción Grajales-Muñiz ◽  
Angel Gustavo Salas-Lais ◽  
Larissa Fernandes-Matano ◽  
Constantino López-Macías ◽  
...  

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico’s first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.


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