Blood Droplets Research Articles

Influence of thermal effects on the dynamic behavior of blood droplets on a superhydrophobic surface

The high temperatures generated during the operation of high-frequency surgical electrodes can cause biological tissues (especially blood) to crust and adhere to the electrode surface, seriously affecting the quality and efficiency of the procedure. Currently, an effective anti-adhesion approach is to construct superhydrophobic microstructures on the electrode surface. However, the micro-mechanisms of antiadhesion under the influence of high temperatures are still incomplete. Herein, this study focuses on the dynamic growth and evolution of blood droplets on a superhydrophobic microstructured surface (SMS) under thermal effects above 100 °C. The research demonstrated that as the substrate temperature increases gradually, the internal fluid perturbation of the blood droplets intensifies, and the air layer trapped by the SMS is subjected to thermal expansion. Consequently, the SMS is unable to provide sufficient adhesion for the growth of the blood coagulum, leading to a significant decrease in the stability of its binding to the substrate and thus the formation of self-desorption. Particularly, it was discovered for the first time that the shell wall of the blood coagulum is layered, a phenomenon related to mass transfer in the Marangoni flow within the droplet under thermal effects. These detailed findings facilitate comprehension of the anti-adhesion mechanism of SMSs, thereby providing a theoretical foundation for the optimization of future surgical electrodes.

Blood-feeding stable flies, Stomoxys calcitrans (Diptera: Muscidae), are attracted to, and transmit Staphylococcus aureus (Bacillales: Staphylococcaceae), a causal agent of bovine mastitis: a laboratory pilot study.

Stable flies, Stomoxys calcitrans (Linnaeus) (Diptera: Muscidae), are common blood-feeding ectoparasites of cows and thus potential vectors of the skin-dwelling bacterium Staphylococcus aureus, a causal agent of bovine mastitis which inflicts udder inflammation in cows. Our objectives were to determine whether stable flies (i) are attracted to disease-causing strains of S. aureus, and (ii) transmit S. aureus from infected blood to sterile blood. In 3-chamber olfactometers, five of eight S. aureus strains grown on agar and tested versus sterile agar attracted female stable flies. When flies ingested droplets of blood inoculated with S. aureus at doses of 0 (control), 105 (low), 107 (medium), and > 109 (high) colony-forming units per milliliter and subsequently ingested sterile blood, they transmitted S. aureus to the sterile blood. The dose of S. aureus in blood droplets fed upon by flies during their first feeding bout dose-dependently affected the amount of bacteria that flies transmitted to sterile blood during their second feeding bout, but the time elapsed between feeding bouts (0h, 1h, 8h, and 24h) had no effect on the amount of microbes transmitted to sterile blood. Our data infer the existence of a positive feedback loop. First, stable flies carrying S. aureus and feeding on cows transmit S. aureus, thereby causing mastitis. As S. aureus bacteria of afflicted cows proliferate, they attract even more flies which, in turn, worsen the infection. This type of feedback loop underscores the need for effective stable fly control tactics that curtail the incidence of bovine mastitis in cows.

Light curing infection control barriers: do some types jeopardize the concept of conventional bulk-fill composites?

BackgroundUsing infection control barriers (ICBs) on light curing units (LCUs) became mandatory to achieve proper infection control measures without jeopardizing the integrity of the restorations, especially at deeper layers. This study explored the effect of two ICBs on the irradiance of the LCU, as well as the degree of conversion (DC) and flexural strength (FS) of two types of bulk-fill composites. Water vapor permeability (WVP) of both barriers was also assessed to evaluate the capability of such barriers to prevent transmission of blood and saliva droplets and aerosols.MethodsTwo bulk-fill composites (X-tra fil and Tetric N- ceram) and two ICBs (Pinnacle Cure sleeve and Sanita wrapping film) were used in this study. Light irradiance was recorded per experimental condition using spectroradiometer. For DC and FS, specimens of 4 mm thickness were prepared. Each specimen was composed of two separable upper and lower layers of thickness 2 mm. DC and FS were measured using Infra-red spectroscopy and three-point loading test respectively. WVP was investigated using the cup method. Means and standard deviations were calculated, and the data were statistically analyzed using factorial analysis of variance test (α = 0.05).ResultsLight irradiance showed highest values using no ICBs and lowest values using Pinnacle curing sleeve. Both bulk-fill composites showed higher DC mean values without ICBs and when using Sanita wrapping film for both upper and lower layers of the specimens compared to Pinnacle curing sleeve. The upper layers of composite specimens showed higher DC compared to lower layers for all experimental conditions. Both ICBs had no adverse effect on FS of both composites’ upper layers. Pinnacle sleeve significantly reduced FS of both composites’ lower layers. X-tra fil showed higher DC and FS compared to Tetric N-Ceram for all experimental conditions. Regarding WVP; the wrapping film showed higher WVP compared to the curing sleeve.ConclusionsSanita wrapping film can be used as a successful ICB, without jeopardizing the concept of bulk-fill composites. Pinnacle cure sleeve can be considered an effective ICB, however its influence on properties and serviceability of bulk-fill composites remains questionable.

Front-Tracking and Gelation in Sessile Droplet Suspensions: What Can They Tell Us about Human Blood?

Recently developed imaging techniques have been used to examine the redistribution of human red blood cells and comparator particles dispersed in carrier fluids within evaporating droplets. We demonstrate that progressive gelation initiates along an annular front, isolating a central pool that briefly remains open to particulate advection before gelation completes across the droplet center. Transition to an elastic solid is evidenced by cracking initiating proximal to front locations. The arrested flow of cellular components, termed a "halted front", has been investigated using a time-lapse analysis "signature". The presence of a deformable biocellular component is seen to be essential for front-halting. We show a dependence of front-halt radius on cell volume-fraction, potentially offering a low-cost means of measuring hematocrit. A simple model yields an estimate of the gel zero-shear yield-stress. This approach to understanding the drying dynamics of blood droplets may lead to a new generation of point-of-care diagnostics.

Deposit of Red Blood Cells at low concentrations in evaporating droplets is dominated by a central edge growth

Evaporation of blood droplets and diluted blood samples is a topic of intensive research, as it is considered a potential low-cost diagnostic tool. So far, samples with a volume fraction down to a few percent of red blood cells have been studied, and these were reportedly dominated by a “coffee-ring” deposit. In this study, samples with lower volume fractions were used to investigate the growth of the evaporative deposit from sessile droplets in more detail. We observed that blood samples and salt solutions with less than 1% volume fraction of red blood cells are dominated by a central deposit. We characterized the growth process of this central deposit by evaporating elongated drops and determined that it is consistent with the Kardar-Parisi-Zhang process in the presence of quenched disorder. Our results showed a sensitivity of the deposit size to fibrinogen concentration and the shape of red blood cells, suggesting that this parameter could be developed into a new and cost-effective clinical marker for inflammation and red blood cell deformation.

Yield-stress effects on spontaneous imbibition in paper-based kits

The classic Richards equation is a good model for predicting imbibition of viscous fluids in porous materials such as dry soils or filter papers. It cannot, in principle, be used for physiological fluids such as blood simply because such fluids often exhibit a variety of non-Newtonian behavior such as a yield stress. In the present work, we have theoretically extended the classic Richards equation to viscoplastic fluids obeying the Bingham model using the concept of the effective viscosity together with the bundle-of-tube model. The new imbibition model could partly resolve the discrepancy reported in the literature between the predictions of the classic Richards equation for the stain growth of sessile blood droplets in a typical filter paper. A better fit, however, requires considering other non-Newtonian effects of the blood such as its viscoelasticity. Using the Bingham-modified Richards equation, it is demonstrated that yield stress in a test fluid has a retarding effect on the imbibition phenomenon, so that such fluids may not necessarily reach the test line of a paper-based diagnostic kit. But yield stress is predicted to extend the duration of the quasi-steady regime on the test line of diagnostic kits, which is a desirable effect. The results suggest that inducing (or elevating) the level of yield stress in a test liquid such as blood can be used as a passive means to control imbibition characteristics in paper-based systems.

Three-dimensional morphological characterization of blood droplets during the dynamic coagulation process.

In this study, we employed a method integrating optical coherence tomography (OCT) with the U-Net and Visual Geometry Group (VGG)-Net frameworks within a convolutional neural network for quantitative characterization of the three dimensional whole blood during the dynamic coagulation process. VGG-Net architecture for the identification of blood droplets across three distinct coagulation stages including drop, gelation, and coagulation achieves an accuracy of up to 99%. In addition, the U-Net architecture demonstrated proficiency in effectively segmenting uncoagulated and coagulated portions of whole blood, as well as the background. Notably, parameters such as volume of uncoagulated and coagulated segments of the whole blood were successfully employed for the precise quantification of the coagulation process, which indicates well for the potential of future clinical diagnostics and analyses.

Expansion of highly interferon-responsive T cells in early-onset Alzheimer's disease.

Altered immune signatures are emerging as a central theme in neurodegenerative disease, yet little is known about immune responses in early-onset Alzheimer's disease (EOAD). We examined single-cell RNA-sequencing (scRNA-seq) data from peripheral blood mononuclear cells (PBMCs) and droplet digital polymerase chain reaction (ddPCR) data from CD4 T cells from participants with EOAD and clinically normal controls. We analyzed PBMCs from 16 individuals by scRNA-seq and discovered increased interferon signaling-associated gene (ISAG) expression and striking expansion of antiviral-like ISAGhi T cells in EOAD. Isolating CD4 T cells from 19 individuals, including four cases analyzed by scRNA-seq, we confirmed increased expression of ISAGhi marker genes. Publicly available cerebrospinal fluid leukocyte scRNA-seq data from late-onset mild cognitive impairment and AD also revealed increased expression of interferon-response genes. Antiviral-like ISAGhi T cells are expanded in EOAD. Additional research into these cells and the role of heightened peripheral IFN signaling in neurodegeneration is warranted. Interferon-responsive T cells expanded in early-onset Alzheimer's disease (AD). Increased interferon-associated gene expression present in early- and late-onset AD. Peripheral immune changes in T and NK cells driven by females with early-onset AD.

A digital microscope for the diagnosis of Plasmodium falciparum and Plasmodium vivax, including P. falciparum with hrp2/hrp3 deletion.

Sensitive and accurate malaria diagnosis is required for case management to accelerate control efforts. Diagnosis is particularly challenging where multiple Plasmodium species are endemic, and where P. falciparum hrp2/3 deletions are frequent. The Noul miLab is a fully automated portable digital microscope that prepares a blood film from a droplet of blood, followed by staining and detection of parasites by an algorithm. Infected red blood cells are displayed on the screen of the instrument. Time-to-result is approximately 20 minutes, with less than two minutes hands-on time. We evaluated the miLab among 659 suspected malaria patients in Gondar, Ethiopia, where P. falciparum and P. vivax are endemic, and the frequency of hrp2/3 deletions is high, and 991 patients in Ghana, where P. falciparum transmission is intense. Across both countries combined, the sensitivity of the miLab for P. falciparum was 94.3% at densities >200 parasites/μL by qPCR, and 83% at densities >20 parasites/μL. The miLab was more sensitive than local microscopy, and comparable to RDT. In Ethiopia, the miLab diagnosed 51/52 (98.1%) of P. falciparum infections with hrp2 deletion at densities >20 parasites/μL. Specificity of the miLab was 94.0%. For P. vivax diagnosis in Ethiopia, the sensitivity of the miLab was 97.0% at densities >200 parasites/μL (RDT: 76.8%, microscopy: 67.0%), 93.9% at densities >20 parasites/μL, and specificity was 97.6%. In Ethiopia, where P. falciparum and P. vivax were frequent, the miLab assigned the wrong species to 15/195 mono-infections at densities >20 parasites/μL by qPCR, and identified only 5/18 mixed-species infections correctly. In conclusion, the miLab was more sensitive than microscopy and thus is a valuable addition to the toolkit for malaria diagnosis, particularly for areas with high frequencies of hrp2/3 deletions.

Concern about the risk of aerosol contamination from ultrasonic scaler: a systematic review and meta-analysis

BackgroundMany instruments used in dentistry are rotary, such as handpieces, water syringes, and ultrasonic scalers that produce aerosols. The spray created by these instruments can carry, in addition to water, droplets of saliva, blood, and microorganisms, which can pose a risk of infections for healthcare professionals and patients. Due to the COVID-19 pandemic, this gained attention.ObjectiveThe aim was to carry out a systematic review of the evidence of the scope of the aerosol produced by ultrasonic scaler in environmental contamination and the influence of the use of intraoral suction reduction devices.DesignScientific literature was searched until June 19, 2021 in 6 databases: Pubmed, EMBASE, Web of science, Scopus, Virtual Health Library and Cochrane Library, without restrictions on language or publication date. Studies that evaluated the range of the aerosol produced by ultrasonic scaler during scaling/prophylaxis and the control of environmental contamination generated by it with the use of low (LVE) and high (HVE) volume evacuation systems were included.ResultsOf the 1893 potentially relevant articles, 5 of which were randomized controlled trials (RCTs). The meta-analysis of 3 RCTs showed that, even at different distances from the patient’s oral cavity, there was a significant increase in airborne bacteria in the dental environment with the use of ultrasonic scaler. In contrast, when meta-analysis compared the use of HVE with LVE, there was no significant difference (P = 0.40/CI -0.71[-2.37, 0.95]) for aerosol produced in the environment.ConclusionsThere is an increase in the concentration of bioaerosol in the dental environment during the use of ultrasonic scaler in scaling/prophylaxis, reaching up to 2 m away from the patient’s mouth and the use of LVE, HVE or a combination of different devices, can be effective in reducing air contamination in the dental environment, with no important difference between different types of suction devices.

Infection Control Practices in Dental Clinics and Dental Care Settings during COVID - 19's Spread: A Comprehensive Review

Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus, known as severe acute respiratory syndrome. Dental care units and settings face various problems relating to the transmission of disease during treatment and dental operations. The degree to which the healthcare system is ready affects how well coronavirus illness is managed. Blood, saliva, and mixed water droplets possessing the virus cause contamination of equipment used for dental treatment. Both patients and workers may become transmitters and infectors of COVID-19 through direct contact during dental operations. It is possible for dental professionals and patients to contract COVID-19 and spread it to others. The dental care routine is very effective as we discussed below the prevention steps are very effective. All healthcare workers at the dentistry clinics should collaborate to prevent the spread of the COVID-19 virus among patients. The primary aim is to make dental health care providers aware of the pathophysiology of COVID-19 and to increase their preparedness and understanding of this challenge, which will aid in controlling transmission. The information and data that collected will be useful for the dental community in providing effective patient management through evidence-based recommendations for infection control and disinfection protocols.

Artificial intelligence assisted patient blood and urine droplet pattern analysis for non-invasive and accurate diagnosis of bladder cancer

Bladder cancer is one of the most common cancer types in the urinary system. Yet, current bladder cancer diagnosis and follow-up techniques are time-consuming, expensive, and invasive. In the clinical practice, the gold standard for diagnosis remains invasive biopsy followed by histopathological analysis. In recent years, costly diagnostic tests involving the use of bladder cancer biomarkers have been developed, however these tests have high false-positive and false-negative rates limiting their reliability. Hence, there is an urgent need for the development of cost-effective, and non-invasive novel diagnosis methods. To address this gap, here we propose a quick, cheap, and reliable diagnostic method. Our approach relies on an artificial intelligence (AI) model to analyze droplet patterns of blood and urine samples obtained from patients and comparing them to cancer-free control subjects. The AI-assisted model in this study uses a deep neural network, a ResNet network, pre-trained on ImageNet datasets. Recognition and classification of complex patterns formed by dried urine or blood droplets under different conditions resulted in cancer diagnosis with a high specificity and sensitivity. Our approach can be systematically applied across droplets, enabling comparisons to reveal shared spatial behaviors and underlying morphological patterns. Our results support the fact that AI-based models have a great potential for non-invasive and accurate diagnosis of malignancies, including bladder cancer.

Impact of anti-coagulant choice on blood elongational behavior.

Blood is a highly complex fluid with rheological properties that have a significant impact on various flow phenomena. In particular, it exhibits a non-Newtonian elongational viscosity that is comparable to polymer solutions. In this study, we investigate the effect of three different anticoagulants, namely EDTA (ethylene diamine tetraacetic acid), heparin, and citrate, on the elongational properties of both human and swine blood. We observe a unique two stage thinning process and a strong dependency of the characteristic relaxation time on the chosen anticoagulant, with the longest relaxation time and thus the highest elongational viscosity being found for the case of citrate. Our findings for the latter are consistent with the physiological values obtained from a dripping droplet of human blood without any anticoagulant. Furthermore, our study resolves the discrepancy found in the literature regarding the reported range of characteristic relaxation times, confirming that the elongational viscosity must be taken into account for a full rheological characterization of blood. These results have important implications for understanding blood flow in various physiological, pathological and technological conditions.

Dried blood drops on vertical surfaces

The analysis of structures in dried droplets has made it possible to detect the presence and conformational state of macromolecules in relevant biofluids. Therefore, the implementation of novel drying strategies for pattern formation could facilitate the identification of biomarkers for the diagnosis of pathologies. We present an experimental study of patterns formed by evaporating water-diluted blood droplets on a vertical surface. Three significant morphological features were observed in vertical droplet deposits: (1) The highest concentration of non-volatile molecules is consistently deposited in the lower part of the droplet, regardless of erythrocyte concentration. (2) The central region of deposits decreases rapidly with hematocrit; (3) At high erythrocyte concentrations (36–40% HCT), a broad coating of blood serum is produced in the upper part of the deposit. These findings are supported by the radial intensity profile, the relative thickness of the crown, the aspect ratio of the deformation, the relative area of the central region, and the Entropy of the Gray Level Co-occurrence Matrix Entropy (GLCM). Moreover, we explore the pattern formation during the drying of vertical blood drops. We found that hematocrit concentration has a significant impact on droplet drying dynamics. Finally, we conducted a proof-of-concept test to investigate the impact of vertical droplet evaporation on blood droplets with varying lipid concentrations. The results revealed that it is possible to differentiate between deposits with normal, slightly elevated, and moderately elevated lipid levels using only the naked eye.

Prevention of the spread of infection during highly infectious autopsy using acraniotomy box.

In cranial autopsies, the post-mortem examination requires the use of a saw for the removal of the skull cap. In these procedures, sawing of bone becomes a critical source of infectious aerosols which spread instantaneously in the immediate environment, generating liquid aerosols including droplets of cerebrospinal fluid and blood, and leading to exposure of all autopsy personnel. In high-risk cases like prion disease, tuberculosis, severe acute respiratory syndrome (SARS), COVID-19, etc. where the skull would require sawing, the prime concern is the saw operator's exposure to these pathogens. Therefore, the author suggests the use of an ingenious ergonomic semi-circular craniotomy box during skull cap and brain removal in the autopsy procedure to successfully prevent the contamination of the entire autopsy hall. A transparent acrylic plastic box has been customized, which is semi-circular in shape having three walls, one semi-circular dome without a floor, a front wall with adjustable zipper closure, and a hind wall with circular holes with sleeves made of 5-layer fabrics. The dome contains one outlet for a vacuum suction pipe on the side, two holes on each side of the dome with non-woven fabric arms for the saw operator, and assistants' arms for performing skull opening procedures. The use of this box allowed the author to prevent and limit the spread of the generation of infectious aerosols in the autopsy hall as the bone dust collected in the vacuum ensures the safety of autopsy surgeons.

Plasma microrna quantification protocol.

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate translation and are involved in many pathological processes. They have emerged as promising biomarkers for diagnosis of conditions such as aortic aneurysm disease. Quantifying miRNAs in plasma is uniquely challenging because of the lack of standardized reproducible protocols. To facilitate the independent verification of conclusions, it is necessary to provide a thorough disclosure of all pertinent experimental details. In this technical note, we present a comprehensive protocol for quantifying plasma miRNAs using droplet digital PCR. We detail the entire workflow, including blood collection, plasma processing, cryo-storage, miRNA isolation, reverse transcription, droplet generation, PCR amplification, fluorescence reading, and data analysis. We offer comprehensive guidance regarding optimization, assay conditions, expected results, and insight into the troubleshooting of common issues. The stepwise normalization and detailed methodological guide enhance reproducibility. Moreover, multiple portions of this protocol may be automated. The data provided in this technical note is demonstrative of the values typically obtained when following its steps. To facilitate standardization in data reporting, we include a table of expected aortic aneurysm-related miRNA levels in healthy human plasma. This versatile protocol can be easily adapted to quantify most circulating miRNAs in plasma, making it a valuable resource for diagnostic development.

Bloodstain tails: Asymmetry aids reconstruction of oblique impact

In the field of forensic science, elongated bloodstains formed from oblique impact of droplets are sometimes used to reconstruct aspects of a bloodletting event. For low impact angles, these stains can include an asymmetric tail that bloodstain analysts can use qualitatively to establish directionality. Quantitative analysis of these bloodstain tails, and any insight that they can provide into the impact dynamics, is lacking due to experimental challenges. Previous studies of bloodstain shapes have predominantly focused on relatively large drip drops that fall vertically on flat and inclined surfaces; yet, for inclinations that produce low impact angles, gravitational effects can reshape and obscure tails, preventing insight into how tails develop on horizontal surfaces. Here, we carry out systematic experiments in which human blood droplets with diameters less than a millimeter impact a horizontal surface at impact angles ranging from 16° to 65°. High-speed imagery confirms that the tail is not part of a prompt splashing event, but rather forms at the last moments of spreading, maintaining its shape as it dries. For each stain, we link the tail length and elliptical geometry to the blood drop size and impact velocity vector that created it. Additionally, we report a power-law correlation of the dimensionless tail length with the angle and Weber and Reynolds numbers, and we describe how this correlation in conjunction with other existing correlations can improve reconstruction of the droplet size and impact velocity.

Blood and bacterium repellent superhydrophobic coating based on assembly of nanoparticles

A new superhydrophobic coating with low surface roughness is prepared by facile spray-coating method for robust blood and bacterium repellent application. The superhydrophobic coating does not only display good water repellency with a large contact angle of 171.4°, but also shows a satisfactory mechanical stability (a contact angle of 151.8° after 100 abrasion cycles). Furthermore, the superhydrophobic coating is evaluated to apply in blood and bacterium repellency. It is observed that the blood droplet can roll off the surface within 0.5 s, and the bacteria count is reduced from 120 cfu/cm2 to 5.0 cfu/cm2. The good comprehensive performance is attributed to good superhydrophobicity and low surface roughness. This work thus provides a facile method to improve blood and bacterium repellent performance of superhydrophobic coating for biomedical application.

Crime Light Imaging (CLI): A Novel Sensor for Stand-Off Detection and Localization of Forensic Traces.

Stand-off detection of latent traces avoids the scene alteration that might occur during close inspection by handheld forensic lights. Here, we describe a novel sensor, named Crime Light Imaging (CLI), designed to perform high-resolution photography of targets at a distance of 2-10 m and to visualize some common latent traces. CLI is based on four high-power illumination LEDs and one color CMOS camera with a motorized objective plus frontal filters; the LEDs and camera could be synchronized to obtain short-exposure images weakly dependent on the ambient light. The sensor is integrated into a motorized platform, providing the target scanning and necessary information for 3D scene reconstruction. The whole system is portable and equipped with a user-friendly interface. The preliminary tests of CLI on fingerprints at distance of 7 m showed an excellent image resolution and drastic contrast enhancement under green LED light. At the same distance, a small (1 µL) blood droplet on black tissue was captured by CLI under NIR LED, while a trace from 15 µL semen on white cotton became visible under UV LED illumination. These results represent the first demonstration of true stand-off photography of latent traces, thus opening the way for a completely new approach in crime scene forensic examination.

Prevalence of COVID-19 infection among dental and nursing students in Alappuzha

Background: The Corona Virus (SARS-COV2) is one of the major pathogens that affect the human respiratory system. As it spreads via droplets, healthcare workers are at increased risk of acquiring the infection. Nursing students who are exposed to the hospital setting during their clinical postings are prone to infection because they may provide care to patients who are suspected of or diagnosed with COVID-19 infection. In dentistry, the use of hand pieces and ultrasonic instruments during dental procedures unavoidably result in generation of blood and saliva droplets. Objective was to estimate the prevalence of COVID-19 infection among Dental and Nursing students of Government dental college and nursing college, Alappuzha. Methods: A cross sectional study was conducted in Dental and Nursing students of Government TD Dental College and Nursing College, Alappuzha in November 2021. Convenient sampling was done and persons who were willing to take part in the study were distributed with a pretested questionnaire via Google Form and data was collected and analysed. Results: Out of the 174 study participants, 77 were Dental students and 97 were Nursing students, 33% of Dental students and 36% of Nursing students reported of being infected with COVID-19 virus. Significant association was obtained between COVID-19 infection and contact with Covid positive case. Conclusions: Prevalence of COVID-19 infection among Dental and Nursing students was 35.10%. Prevalence of COVID-19 infection among Dental students and Nursing students were 33% and 36% respectively.