Quick Diagnostic Method Research Articles

A quick diagnostic method for corrosion-inhibition balance and a green slurry for copper chemical mechanical polishing

In this paper, a green inhibitor, adenine, is introduced into the Cu-CMP slurry to prevent the toxic ingestion in the CMP process. Moreover, in order to effectively optimize and control the copper chemical mechanical polishing based on the corrosion-inhibition balance, an expression is proposed to diagnostic the balance quickly via the least square fitting of the experimental data. Based on the corrosion-inhibition balance optimization, a pH-neutral slurry (pH = 6.8 ∼ 7.2) incorporating adenine with a high material removal rate (MRR > 600 nm/min), a low surface roughness (Ra < 1 nm) as well as low surface defects (no micro-scratches, number of surface corrosion pits ≤ 0.02 counts·μm−2, particle residues ≤ 0.98 counts·μm−2) is achieved. This newly developed slurry and the diagnostic method for the corrosion-inhibition balance should be promising for designing the green slurry for Cu-CMP.

Comparison of T cell maturation profiles in the 1st and 5th wave of COVID-19 in the Polish population.

The coronavirus pandemic has become the most critical global health threat of this century and the greatest challenge to the human population. The search for simple and quick diagnostic methods enabling the identification of patients infected with the SARS-CoV-2 virus may be a valuable method to track infection. The aim of the study was the clinical and immunological characterization of patients by assessing the degrees of maturity of T lymphocytes from the 1st and 5th waves of coronavirus disease 2019 (COVID-19) in comparison to a healthy control group (HC). We determined leukocyte and T lymphocyte subpopulations (recent thymic emigrant (RTE), naïve, effector, central memory and effector memory) in patients from the 1st COVID-19 wave (n = 23), the 5th COVID-19 wave (n = 38) and HC (n=20) using a panel of monoclonal antibodies using multiparameter flow cytometry. We observed a lower median proportion of lymphocytes and NK cells, and elevated percentage and number of neutrophils in patients from the 5th wave compared to the 1st. We found a reduced percentage of CD4+ effector memory cells in the 1st wave group compared to the 5th wave (14.1 vs 23.2, p < 0.05), and a higher percentage of RTE and naïve CD8+ cells in the 1st wave compared to the 5th wave (p < 0.05). The effector memory CD8+ cells were highest in the 5th wave compared to both 1st wave and HC patients (respectively, 35.1 vs 18.1 vs 19.3%, p < 0.05). The 5th wave group showed significantly more differences compared to HC. Our results showed a clear increase of effector cells with a simultaneous decrease in virgin T cells in the 5th COVID-19 infection. Monitoring lymphocyte subsets during infection allows assessment of the patient's immune status and of readiness of lymphocytes to respond to the immune response, and may be necessary to improve clinical outcomes.

Association of Cytological and Biochemical Oarameters with Pleural Effusion in Patients attending a Tertiary Care Hospital of Western U.P.

Background: Pleural effusion is the pathological accumulation of fluid in the pleural space. This study was done to assess the association of cytological, biochemical, radiological and microbiological parameters in the evaluation of pleural effusion.Materials and Methods: Present study was done in Saraswathi Institute of Medical Sciences- OPD/IPD ofRespiratory Medicine department. As per the inclusion /exclusion criteria the study included 70 participants.Ethical clearance was taken before the commencement of study. Data was analyzed using SPSS software version 26.Majority of participants in present study were males. Majority belongs to age group 19-29 years with mean age was found to be 34.93 ± 12.99 years. Majority of patients had exudative type of pleural effusion. Lymphocyteswas found to be higher as compare to neutrophils and other cells in Tubercular cases than Non-TB cases. Similar findings were found in other studies too.Conclusion: The present study suggest that a high fluid ADA is a vital diagnostic tool and suggest its usage as a quick diagnostic method to diagnose Tuberculous Pleural Effusion

Lung ultrasound (LUS): a simple, inexpensive, and quick diagnostic method: a literature review

Abstract Introduction Historically, radiologists believed that ultrasound was ineffective for detecting lung and pleural diseases. Today, it is regarded as a diagnosis (imaging) that may be ‘equated’ with advanced methods such as radiography and computed tomography (CT) since it has comparable, if not greater, diagnostic accuracy for specific pathological substrates when compared with cross-sectional radiographic approaches such as CT. We have covered the basic anatomical points and lines, as well as their meanings in the interpretation of ultrasound findings, throughout this article. We have specifically highlighted conditions with high lung ultrasound (LUS) specificity and sensitivity, such as pleural effusion, pneumothorax, and pneumonia. It is also noteworthy that it’s recommended for coronavirus disease 2019 (COVID-19) patients in the diagnosis of interstitial pneumonitis. Following lines such as A, B, C, Z, and E would provide us with information on the patient’s current condition. We identified 15 papers that contained the following keywords: ‘A lines’, ‘B lines’, ‘C lines’, ‘Z lines’, ‘E lines’, ‘pleural effusion’, ‘pneumothorax’, ‘pneumonia’, and ‘coronavirus disease 2019’. Conclusion The use of lung ultrasound will become more widespread. It is vital to train general practitioners and emergency doctors in its use since it provides a quick and reliable reference point for further diagnosis.

Harnessing nutritional immunity and advanced diagnostics for COVID-19 prevention

The ongoing worldwide health crisis caused by the COVID-19 pandemic, which began in Wuhan, China, has led to infections across the globe. Although many vaccines are available, a definitive cure has yet to be found. This study examines methods to lessen the impact of the disease, focusing on preventive actions and strengthening the immune system through diets rich in vitamins and nutrients. Our investigation also considers non-traditional methods, particularly the vital role of early detection in controlling the spread of COVID-19. Accurate diagnostic techniques are essential in this effort. Surprisingly, there is a lack of comprehensive studies on the complex interactions between various vitamins, trace metals, and immunity in relation to COVID-19. Addressing this gap, our review carefully analyzes how diets enriched with vitamin D can boost immunity. Additionally, we explore worldwide challenges that impede the progress of effective and quick diagnostic methods. Our goal is to provide a thorough understanding of the current situation regarding immunity, diagnostic procedures, and treatment approaches for COVID-19. This review not only covers various diagnostic methods for SARS-CoVs but also assesses the effectiveness of different vaccines against COVID-19. Through detailed analysis, we contribute to the ongoing discussion on fighting COVID-19, providing important information for researchers, healthcare workers, and policymakers.

MicroRNAs as Possible Biomarkers for Diagnosis and Therapy of Alzheimer’s Disease by Regulating the Abnormal Expression of Genes Related to Tau

Alzheimer’s disease (AD), the most common dementia with the symptom of deterioration of memory and cognitive functions, becomes one of the prevalent threats globally. Tau hyperphosphorylation is one of major risk factors of AD. At present, there is no effective treatment or quick diagnostic methods for the pre-clinical stage of this disease. MicroRNAs (miRNAs) are small (20-25bp) non-coding, double stranded RNA molecule. They mainly regulate gene expression during the post-transcription by binding to the 3-’UTR of the mRNA then stop translation. Unlike other biomarkers using for Alzheimer’s disease, miRNAs are stable and widely found in body fluids such as serum, tissues, and Cerebrospinal fluid (CSF) and one miRNA can regulate multiple genes. As a result, they are potentially used as diagnosis or therapeutic biomarkers for many diseases including Alzheimer’s disease. Currently, this field that using miRNAs as biomarkers for diagnosis and treatment has been rapidly developed. To examine the mechanism and function of miRNAs and potential in AD, this review summarizes current diagnostic and therapeutic techniques and comparing several microRNAs that especially regulating tau toxicity as practicable diagnostic biomarkers and treatment agents. It is likely to detect different stages of Alzheimer’s disease and reduce Tau hyperphosphorylation if this field of miRNA as biomarkers carries forward.

Transfer Learning-Based Deep Learning Models for Screening Covid-19 Infection from Chest CT Images

As the global prevalence of Covid-19 rises, accurate diagnosis of Covid-19 patients is critical. The biggest issue in diagnosing people who test positive is the non-availability or scarcity of testing kits, as Covid-19 spreads rapidly in the community. To prevent Covid-19 from spreading among humans as an alternative quick diagnostic method, an automatic detection system is required. We propose in this study to employ Convolution Neural Networks to detect corona virus-infected patients using Computed Tomography (CT) images. In addition, we look into the transfer learning of deep convolutional neural networks like VGG16, inceptionV3, and Xception for detecting infection in CT scans.To find the best values for hyper-parameters, we use Bayesian optimization. The study comprises of comparing and analysing the employed pre-trained CNN models. According to the data, all trained models are more than 93 percent correct. Pretrained models such as VGG16, InceptionV3, and Xception have attained more than 97 percent precision. Furthermore, our method introduces novel methods for classifying CT scans in order to detect the Covid-19 infection.

Computer-aided diagnosis of COVID-19 from chest X-ray images using histogram-oriented gradient features and Random Forest classifier.

The decision-making process is very crucial in healthcare, which includes quick diagnostic methods to monitor and prevent the COVID-19 pandemic disease from spreading. Computed tomography (CT) is a diagnostic tool used by radiologists to treat COVID patients. COVID x-ray images have inherent texture variations and similarity to other diseases like pneumonia. Manually diagnosing COVID X-ray images is a tedious and challenging process. Extracting the discriminant features and fine-tuning the classifiers using low-resolution images with a limited COVID x-ray dataset is a major challenge in computer aided diagnosis. The present work addresses this issue by proposing and implementing Histogram Oriented Gradient (HOG) features trained with an optimized Random Forest (RF) classifier. The proposed HOG feature extraction method is evaluated with Gray-Level Co-Occurrence Matrix (GLCM) and Hu moments. Results confirm that HOG is found to reflect the local description of edges effectively and provide excellent structural features to discriminate COVID and non-COVID when compared to the other feature extraction techniques. The performance of the RF is compared with other classifiers such as Linear Regression (LR), Linear Discriminant Analysis (LDA), K-nearest neighbor (kNN), Classification and Regression Trees (CART), Random Forest (RF), Support Vector Machine (SVM), and Multi-layer perceptron neural network (MLP). Experimental results show that the highest classification accuracy (99. 73%) is achieved using HOG trained by using the Random Forest (RF) classifier. The proposed work has provided promising results to assist radiologists/physicians in automatic COVID diagnosis using X-ray images.

The Novel Role of Cytomorphology from Ultrasound-Guided Fine Needle Aspiration Cytology in Evaluating the Status of Prognostic Factors including Estrogen Receptor, Progesterone Receptor and HER2 in Breast Cancer.

It is well established that estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2) could be regarded as prognostic factors in breast cancer. Ultrasound-guided fine needle aspiration cytology (FNAC) has revolutionized the management of cancers, providing less invasive and quick diagnostic method. There are hardly any studies on the correlation between cytomorphology and prognostic biomarkers. We retrospectively analyzed the immunohistochemistry and the fluorescence in situ hybridization of breast cancer specimens from 252 patients, who have been diagnosed as breast cancer at our hospital. Morphological features of cytology smears were scored. The relationship between cytological features and three biomarkers were analyzed. Based on this, we developed a system to predict the status of biomarkers. The results indicated that some cytological parameters, especially the features of nucleoli, were distinctively related to the makers' expression. In the novel scoring system, a cutoff of 12.0 provided a statistical discrimination for cytological grading. We concluded that cytomorphological features were associated with prognostic factors. The HR+ neoplasms showed scattered micronucleoli, while HER2+ neoplasms demonstrated centered macronucleoli. We summarized a scoring system to predict the status of three factors. This may help us to broaden the application of breast cancer cytology.

Development of an Immunochromatographic Strip for Rapid Detection of Mink Enteritis Virus.

Although mink enteritis virus (MEV) is an acute, virulent, and highly contagious pathogen in minks, there is currently a lack of a quick diagnostic method. By conjugating colloidal gold nanoparticles with the MEV-specific monoclonal antibody, monoclonal antibody (MAb) 14, we developed a single-step competitive immunochromatographic strip (ICS) assay for simple determination of MEV. The optimal concentrations of the colloidal gold-coupled MAb 14 (coating antibody), the capture protein (MEV VP2 protein), and the goat anti-mouse antibody were 1.0, 0.8, and 1.0 mg/ml, respectively. The limit of detection was approximately 512 hemagglutination units/100 μl of MEV B strain. Other common viruses of mink were tested to evaluate the specificity of the ICS, and the results showed no cross-reactivity for other pathogens. In comparison with the Anigen Rapid canine parvovirus (CPV) Ag Test Kit (BioNote, Korea) in testing 289 samples, the percentage of agreement and relative sensitivity and specificity of the MEV ICS assay were 94.1, 93.2, and 97.1%, respectively. The ICS test was found to be a sufficiently sensitive and specific detection method for the convenient and rapid detection of MEV.

A Review: Surface Plasmon Resonance-Based Biosensor for Early Screening of SARS-CoV2 Infection

Rapid viral diagnosis is essential to contain the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) in the community and ensure effective patient management. However, the current gold standard for diagnosis of viral disease depends on the time-consuming molecular technique. Surface plasmon resonance (SPR) phenomenon has been widely applied in the analysis of biomolecular interactions and analytes detection, which is currently being investigated as a quick diagnostic method of numerous viral infections. In this regard, researchers have performed experimental studies dedicated to enhancing the sensitivity and specificity of the SPR sensor performance for utilization in the medical diagnostic field. In this review, we summarized various SPR application including the recent advancements and advantages of different types of SPR-based biosensor such prism-based, localized surface plasmon resonance (LSPR), fiber optic, optical grating, and optical waveguide for the detection of SARS-CoV2. We proposed various technical recommendations to improve the sensitivity, accuracy, time response, and cost-saving means of the SPR sensor. A special focus was set for sensitivity enhancement aspects in terms of the type of prism, nanomaterials, support layer with type and shape of optical fibers for early, swift, and ultra-sensitive detection of viral infection. With the highlighted impacts of SPR application, this review frames the current potential and challenges of SPR in comparison to the current gold standard of viral infection diagnostic strategy.

Rapid Detection of Coronavirus (COVID-19) Using Microwave Immunosensor Cavity Resonator.

This paper presents a rapid diagnostic device for the detection of the pandemic coronavirus (COVID-19) using a micro-immunosensor cavity resonator. Coronavirus has been declared an international public health crisis, so it is important to design quick diagnostic methods for the detection of infected cases, especially in rural areas, to limit the spread of the virus. Herein, a proof-of-concept is presented for a portable laboratory device for the detection of the SARS-CoV-2 virus using electromagnetic biosensors. This device is a microwave cavity resonator (MCR) composed of a sensor operating at industrial, scientific and medical (ISM) 2.45 GHz inserted in 3D housing. The changes of electrical properties of measured serum samples after passing the sensor surface are presented. The three change parameters of the sensor are resonating frequency value, amplitude and phase of the reflection coefficient |S11|. This immune-sensor offers a portable, rapid and accurate diagnostic method for the SARS-CoV-2 virus, which can enable on-site diagnosis of infection. Medical validation for the device is performed through biostatistical analysis using the ROC (Receiver Operating Characteristic) method. The predictive accuracy of the device is 63.3% and 60.6% for reflection and phase, respectively. The device has advantages of low cost, low size and weight and rapid response. It does need a trained technician to operate it since a software program operates automatically. The device can be used at ports’ quarantine units, hospitals, etc.

A Comprehensive Overview On The Most Recent Trends In Covid-19 Diagnosis, Treatment Options And Vaccine Development Status

The global pandemic produced by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was first appeared in Wuhan, China, in December 2019 and which then spread rapidly, made it difficult to find or develop effective medications for its prevention and treatment. Therefore, the first stage is necessitating the use of a precise and quick diagnostic method to detect SARS-CoV-2 infected patient followed by effective patient isolation and the commencement of early treatment, which can range from supportive therapy to specialised medications such corticosteroids, antiviral medications, antibiotics, and the recently introduced convalescent plasma. Despite the extraordinary developments in advanced medicinal system, no confirmed viable medicines exist at this time. Rapid research on SARS CoV-2 epidemiology has led to the discovery of certain new targets for prospective therapeutic treatments. Many therapeutic options have been evaluated, and clinical studies are proceeding at a breakneck speed. However, there is a lot of room for more study into finding cost-effective and safer medicines, vaccinations, and measures to ensuring that COVID-19 preventive and treatment programmes are available to everyone. The goal of this study is to compile all of the current advancements in the worldwide medical system in the fight against COVID-19.

The role of bio-detection dogs in the prevention and diagnosis of infectious diseases: A systematic review

Infectious diseases have been lately considered as one of the most important global risks, which negatively impact not only the health but also the socioeconomic conditions of countries. Globalization influences the spread of infectious diseases as a result of increased travelling and interaction in humans. Thus, it is highly important to prevent and diagnose new infectious diseases by using accurate and quick diagnostic methods. Bio-detection dogs have a great potential to accurately diagnose infectious disease as they have a great ability to sense disease-specific volatile organic compounds (VOCs) originate from infectious agents and/or pathophysiological processes in the human body. The use of these dogs to detect infectious diseases has come to focus in particular after the recent global health crisis due to the SARS-CoV-2 infection. This review discusses the potential use of bio-detection dogs in the prevention and diagnosing of infectious diseases. Moreover, factors affecting the scent of the disease, e.g. VOCs, are tried to be highlighted.

Causes and Control Measures of Apple Replant Problem

Replant problem is a situation resulting in suppression of growth and poor productivity of the trees planted on old orchard sites and makes the plantations un-economical. It is a serious malady throughout the world in some fruit crops where the new plantations are done at the old orchard sites. Although replant problem is known to exist for many decades but greater attention was paid to this phenomenon only when Thompson (1959) while working at East Malling Research Station, United Kingdom observed poor growth of apple and cherry on old plantation sites. This observation strongly stimulated replant research in different parts of the world. Western Himalayan states of India are also facing the replant problem where majority of apple orchards have out lived their economic life and new plantations are being done at the same site. The incidence of apple replant disease on various sites has been observed 25–70 per cent. It is comparatively easy to prevent the replant problem than to control it because of unknown exact etiology and complex nature of malady due to the presence of different biotic and abiotic factors associated with the problem. Nature and intensity of the incidence is highly variable from country to country and even region to region and there is lack of quick diagnostic methods. The problem is difficult to control with one method and require integrated management practices for effective control.

Development of an Immunochromatographic Strip for Rapid Detection of Canine Adenovirus.

Although canine adenovirus (CAdV) is highly prevalent in dogs, there is currently a lack of a quick diagnostic method. In this study, we developed a rapid immunochromatographic strip (ICS) assay using colloidal gold coupled to CAdV-2-specific monoclonal antibodies (mAbs). BALB/c mice were immunized with a purified CAdV-2 suspension, and four mAbs (belonging to two different epitopes) were generated and designated as 2C1, 7D7, 10D1, and 4G1. Western blot and protein spectral analysis indicated that the hexon protein of CAdV-2 recognized all four mAbs. The colloidal gold-coupled 7D7 and 2C1 mAbs were chosen for inclusion in the rapid ICS assay. The optimal concentrations of the coating antibody (2C1), the capture antibody (7D7), and the goat anti-mouse antibody were 1.0 mg/ml, 10 μg/ml, and 2.0 mg/ml, respectively. The limit of detection was approximately 2.0 × 102 tissue culture infective dose (TCID50)/ml. Other common canine viruses were tested to evaluate the specificity of the ICS, and positive results were observed for only CAdV-1 and CAdV-2. The ICS test was conducted on 360 samples to detect CAdV, and the results were compared with those of polymerase chain reaction (PCR) tests. The ICS test was found to be a sufficiently sensitive and specific detection method for the convenient and rapid detection of CAdV.

Characterization and on-line adjustment of the sagittal-bent Laue crystal profile.

The sagittal-bent Laue monochromator can provide an ideal way to focus high-energy X-ray beams. However, the anticlastic curvature induced by sagittal bending has a great influence on the crystal performance. Thus, characterizing the bent-crystal shape is very important for predicting the performance of the bent-crystal monochromator. In this paper the crystal profile is measured by off-line optical metrology and on-line X-ray experiments. The off-line results showed that the bent-crystal surface could be well fitted to a saddle surface apart from a redundant cubic term which was related to the different couples applied on the crystal. On-line characterization of the meridional and the sagittal radius of the bent crystal includes double-crystal topography and ray-tracing measurement. In addition, the double-crystal topography experiment could be used as a quick diagnostic method for the bending condition adjustment. The sagittal radius of the bent crystal was characterized through a ray-tracing experiment by using a particularly designed tungsten mask. Moreover, rocking curves under different bending conditions were measured as well. The results were highly consistent with analytical results derived from the elastic theory. Furthermore, radii along different vertical positions under various bending conditions were measured and showed a quadratic relationship between the vertical positions and the meridional radii.

First imported case of Zika virus infection into Jiangsu Province, China, returning from Ecuador

We report a case of laboratory-confirmed Zika virus (ZIKV) infection imported into China from Ecuador. This is the first documented imported case with ZIKV infection into Jiangsu, and the first imported case into China from Ecuador nationwide. The patient developed fever, rash, conjunctivitis and joint pain after returning. However, due to the less specific clinical symptoms and lack of quick diagnostic methods in elementary healthcare facilities, this imported case was not identified during her first two medical consultations. ZIKV RNA was detected in the urine sample rather than serum sample of the case, and anti-ZIKV IgM was detected from her serum samples collected 4 and 6 days after her onset of symptom. Case isolation and clearance of mosquito-breeding places were implemented instantly when the case was identified. No more human infections were found during a follow-up of 14 days since the case’s isolation. This incident highlights the important role of urine sample in the diagnosis of ZIKV infection and the urgent need for efficient rapid diagnostic method for clinical healthcare providers.

Asociación de infección por Chlamydia trachomatis con el diagnóstico de cervicitis aguda

Introducción: la infección por Chlamydia trachomatis es la enfermedad de transmisión sexual más frecuente en el mundo y causa una importante morbilidad en las mujeres. Actualmente existen pocos estudios sobre su prevalencia en nuestra población, por lo que se hace pertinente la implementación de un estudio piloto que aporte información sobre su frecuencia en mujeres asintomáticas y con cervicitis aguda. Objetivo: determinar la asociación existente entra la infección por Chlamydia trachomatis y la presencia de cervicitis aguda en la población consultante a los servicios de urgencias y consulta externa del Hospital Universitario de Santander (HUS). Metodología: estudio de casos y controles en el cual se incluyeron 284 pacientes mayores de edad, no embarazadas y que no estuvieran menstruando, atendidas en el HUS. Se tomaron como casos las pacientes con diagnóstico de cervicitis aguda y controles aquellas sin el mismo. En los dos grupos se realizó un frotis endocervical al cual se aplicó un método de diagnóstico rápido para infección por Chlamydia trachomatis, Bioline Chlamydia SD®. Resultados: el promedio de edad fue de 32.08 y 28.82 para casos y controles, con una diferencia promedio de 3.27, p = 0.001. También hubo diferencias al evaluar estado civil; 82.40% de los controles tiene un vínculo marital frente al 71.83% de los casos, p = 0.014; ocupación, más estudiantes en el grupo de cervicitis que en los casos, p = 0.020; y consumo de alcohol, 21.13% de pacientes con cervicitis, contra 11.27% de los controles, p = 0.024. La prevalencia de infección por Chlamydia en los controles fue de 7.04% y 11.97% en los casos, p = 0.157. Al buscar una asociación entre cervicitis aguda y la infección por Chlamydia esta no se encuentra, OR = 1.79 (IC 95% 0.74 – 4.55). Esta falta se asociación se mantiene luego de ajustar los potenciales factores confusores (OR = 1.71, IC 95% 0.72 – 4.04). En el análisis multivariado solo el consumo de alcohol persiste asociado con la presencia de cervicitis, OR = 4.442 (IC 95% 1.362 – 14.215). Conclusiones: no se encontró asociación entre la infección por Chlamydia trachomatis y el diagnóstico de cervicitis aguda. Se encontró una prevalencia similar en los dos grupos, además no se encontraron diferencias sociodemográficas. El único factor de riesgo con una asociación fuerte para colonización por la bacteria y cervicitis aguda fue la historia de consumo de alcohol. [Jaimes-Bravo JM. Asociación de infección por Chlamydia trachomatis con el diagnóstico de cervicitis aguda. MedUNAB 2015; 18 (2): 116-124]

Evaluation of false negativity of the Widal test among culture proven typhoid fever cases

The Widal test is the most common, specific and quick diagnostic method available in the world for diagnosis of typhoid fever; however, false negativity is one of the obstructive features of the test. The aim of this study was to evaluate the associated factors with Widal test negativity in an endemic area. Widal test negativity was retrospectively analyzed among culture-proven typhoid fever cases. The potential features including age, gender, previous antibiotic usage, duration of symptoms, leucopoenia, hematocrit value, and erythrocyte sedimentation rate (ESR) were evaluated for association with Widal test negativity. A total of 166 culture-proven typhoid fever cases (93 or 56.0% males) were included in the study. The mean age +/- SD was 23.3 +/- 10.6 years. Mean time of interval between first symptom and test performance time was 10.6 +/- 7.8 days. The Widal test (STO and/or STH) was found positive in 75 cases (45.2%). The statistical analyses revealed that none of these variables were significant for false negativity of the Widal test. Age was found to be a possible factor for a false negative Widal test (p=0.06). Of existing compatible clinical findings, age should be considered in cases of Widal test negativity.