Medical Sterilization Research Articles

PEDOT:PSS/PEDOT Film Chemiresistive Sensors for Hydrogen Peroxide Vapor Detection under Ambient Conditions

Hydrogen peroxide (aqueous solution of H2O2) is one of the most used reagents i n medical sterilization, environmental disinfection, food storage, and other fields. However, hydrogen peroxide has the potential to cause serious harm to biological health and environmental safety. There are many methods (especially electrochemistry) for H2O2 detection in liquid phase systems, but a lack of methods for vapor detection. This is due to its colorless and tasteless nature, as well as the oxidative activity of the molecule and its coexistence with humidity. In this study, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), one of the most commercially successful and widely used conductive polymers, was employed to fabricate an all-organic chemiresistive sensor for simple, real-time, and on-site sensing of hydrogen peroxide vapor (HPV) at room temperature. In comparison with pristine PEDOT:PSS film, the PEDOT:PSS/PEDOT film was prepared by in situ electrochemical polymerization. Upon exposure to different concentrations of HPV, it was found that the hydrophobic and porous PEDOT layer could weaken the interference of humidity in HPV sensing, resulting in a more sensitive and accurate response. At 1.0 ppm HPV concentration, the resistance signal response was increased by nearly 89% compared with the pristine PEDOT:PSS film. This PEDOT-film-based chemiresistive sensor showcases the possibility for further development of nonenzymatic HPV monitoring technology.

Pathogenic Drug Resistant Fungi: A Review of Mitigation Strategies.

Fungal pathogens cause significant human morbidity and mortality globally, where there is a propensity to infect vulnerable people such as the immunocompromised ones. There is increasing evidence of resistance to antifungal drugs, which has significant implications for cutaneous, invasive and bloodstream infections. The World Health Organization (WHO) published a priority list of fungal pathogens in October 2022, thus, highlighting that a crisis point has been reached where there is a pressing need to address the solutions. This review provides a timely insight into the challenges and implications on the topic of antifungal drug resistance along with discussing the effectiveness of established disease mitigation modalities and approaches. There is also a need to elucidate the cellular and molecular mechanisms of fungal resistance to inform effective solutions. The established fungal decontamination approaches are effective for medical device processing and sterilization, but the presence of pathogenic fungi in recalcitrant biofilms can lead to challenges, particularly during cleaning. Future design ideas for implantable and reusable medical devices should consider antifungal materials and appropriates for disinfection, and where it is relevant, sterilization. Preventing the growth of mycotoxin-producing fungi on foods through the use of appropriate end-to-end processes is advisable, as mycotoxins are recalcitrant and challenging to eliminate once they have formed.

A SIMPLE STUDY OF JOULE HEATING EFFECT IN ARGON DBD REACTOR

Study of the gas heating phenomenon due to the heat joule effect in plasma created by an argon dielectric barrier discharge (DBD) reactor operating under treatment surface and medical sterilization conditions is essential to find the optimum of DBD discharge functioning. The present investigation of the influence of gas heating on argon discharge characteristics was executed by a one-dimensional fluid model. The gas temperature development in the DBD discharge was determined by the heat conduction equation. To consider the joule heating effect, the heat transport equation was solved along the gap distance of discharge. The results obtained from the coupling of a 1D fluid model with the heat conduction equation allowed us to calculate the gas temperature profile of argon in the DBD and plasma physical characteristics such as the densities of charged particles, the voltages, the electric field, and the coefficient rate of the ionization, attachment, and recombination in order to analyze the gas temperature development in argon DBD.

The impact of electron beam irradiation on some novel borate glasses doped V2O5; Optical, physical and spectral investigation

New borate glass systems with composition of 56B2O3 + 25Li2O + 10Na2O + 5CaO + 2SrO + 2Al2O3 + 0.5 TeO2 + x V2O5, where × = 0.2 or 0.3 (wt. %), were fabricated via the traditional melting-annealing method at low temperature (650–750 °C). Some of the glasses optical, physical, chemical and spectral measurements were investigated within the impact of electron beam (EB) irradiation up to 8 kGy. UV–visible spectra revealed peaks at ∼ 290 and ∼ 300 nm for 0.2 and 0.3 V2O5 glasses, respectively. In addition to broad visible band at ∼ 580 nm owing to the participation of vanadium ions as V5+ with possible conversion to V3+/V4+ under the effect of EB irradiation. FTIR spectra revealed the main trigonal BO3 and tetrahedral BO4 units with an increase in N4 values by the progressive EB irradiation. ESR spectra revealed a gradual increase in intensity with irradiation doses. While, testing chemical durability in distilled H2O at 100 °C reveals a good manner before and after irradiation process. Some physical parameters e.g. optical energy gap (Eoptdirect and Eoptindirect), Urbach energy (EUrbach), refractive index (n) and spectral distribution (k) showed also a gradual decrease with continual irradiation owing to the gradual generating of non-bridging oxygens NBOs and progressive transformation of BO3 to BO4 units. The overall data displayed some dosimetric properties of the two studied glasses with a useful dose range 3–8 kGy of EB radiation. The study recommends usage of glasses as glass dosimeters in medical sterilization, industry and food irradiation processing.

Application of 3D-Woven Fabrics for Packaging Materials for Terminally Sterilized Medical Devices.

This research aimed to test a newly developed 3D fabric for use in a hospital sterilization unit as a packaging material. Two basic properties were tested: the efficiency of the microbial barrier, and the bursting strength of the woven fabric, determined with a steel ball. Material deformations caused by bursting are common in medical sterilization, as a consequence of the packaging of the medical tools needed in surgery. Six 3D-fabric samples were woven from the same warp, with three weft densities and in two different weaves. The weaving conditions and other construction characteristics of the fabrics were the same. To determine the effectiveness of the microbial barrier, bacterial endospores of an apathogenic species of the genus Bacillus, Geobacillus stearothermophilus and Bacillus atrophaeus, were used. Mechanical testing of the 3D-woven fabric, i.e., the bursting strength of the fabric using a steel ball, was carried out according to the standard method. The results showed the exceptional puncture strength of the woven fabrics and their formation of an effective microbial barrier, i.e., complete impermeability to microorganisms in five samples, which is the main condition for possible use as a packaging material in medical sterilization. Sample 3tp did not provide an effective microbial barrier and did not meet the basic requirements for use in medical sterilization.

Optimization of X-Ray Spectra in Medical Sterilization Accelerator through MCNP

A Bremsstrahlung converter for medical apparatuses sterilization has been designed using tantalum and stainless-steel frame for a high energy electron accelerator operating at an incident electron energy of 7.5 MeV. Optimization of the x-ray spectra of the converter is investigated in this paper by adding a beam hardening filter from copper, aluminum, and stainless steel. The MCNP code is used to simulate the particle transport through the converter design. To survey the effect of each filtered spectra, angular dose distribution in the air is measured at radial distances of 50, 75, and 100 cm from the tantalum for the angle of 0° to 90°. A comparison between the unfiltered and the filtered spectra shows a marked decrease in low energy photon intensity up to the energy of 100 keV by all three filter materials with a greater reduction and hardening when combining the filter materials. These findings result in the angular dose distribution of the produced x-ray having a lower intensity at closer radial distances to the target due to the decreased intensity of x-rays with low energy, denoting a better dose homogeneity over the irradiated material.

Nonthermal Atmospheric Pressure Plasma Technology in Dermatology

Nonthermal atmospheric plasma (NTAP), also known as cold atmospheric plasma (CAP), is an emerging tool with important effects on biological systems. NTAP harnesses physical plasma, generating a low energy ion environment in which reactive oxygen and nitrogen species are formed. These ionic species can modify proteins and cell membranes in a non-invasive manner. The use of NTAP therapy, a technology once used for medical sterilization, is rapidly expanding, particularly in the field of dermatology. In addition to potent anti-microbial properties, NTAP has demonstrated promise in skin regeneration and cancer-related indications. NTAP affords a unique advantage to pharmacological therapies in that there is no risk of drug-drug interactions. A preliminary safety profile for NTAP has been established, with no adverse effects such as pain, inflammation, blistering, bruising, and pruritus noted to date. In this review, we discuss the clinical application of NTAP in the treatment of onychomycosis, warts, actinic keratosis, and wound healing.

THE POSSIBILITY OF APPLICATION OF PYROMETRIC METHOD IN INDUSTRIAL DOSIMETRY OF ELECTRON BEAM RADIATION

Validation of process of medical product sterilization includes absorbed dose mapping in a phantom made of material representative of the object to be processed. Commonly, such measurements are carried out using the disposable chemical dosimeters placed in the phantom at the nodes of the 3D grid. Such a procedure is very laborious and costly in terms of the consumption of dosimeters. In the work, we investigated the possibility of using pyrometric method for prompt mapping of the absorbed dose. The studies were carried out using a rectangular phantom in the form of a set of expanded polystyrene plates, which is exposed to a scanned electron beam. The temperature and absorbed dose distributions in the phantom were measured. A linear dependence between them has been established. The calculation of the absorbed dose profile was also performed by MC simulations. Satisfactory agreement of the calculated dose distribution with the measured one is shown. The limitations of applicability of the proposed method are determined.

Application Effect of the 6S Care Model in Sterilization in the Department of Stomatology and Its Impact on the Incidence of Nosocomial Infection.

Objective The study aimed to explore the effectiveness of the 6S care model in sterilization in department of stomatology and its impact on the incidence of nosocomial infections. Methods The infection surveillance indicators of the department of stomatology implementing the routine sterilization care model in 2019 were selected as the general group (including 140 patients and 140 cases of oral instrument kits for unpacking), and the infection surveillance indicators of the department of stomatology implementing the 6S care model in 2020 were selected as the 6S group (including 140 patients and 140 cases of oral instrument kits for unpacking). Analysis of the air culture qualification rate of the consultation room + operating room, medical equipment sterilization qualification rate, medical equipment damage rate, incidence of nosocomial infections, satisfaction of medical and nursing staff with instrument sterilization, and patient satisfaction with medical and nursing staff care services under different care models was carried out. Result The air culture pass rate of the consultation room + operating room in the 6S group was 96.43% (135/140), which was higher than 90.00% (126/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). The sterilization pass rate of medical devices in the 6S group was 100% (140/140), which was higher than 95.71% (134/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). The medical device damage rate in the 6S group was 0.71% (1/140), which was lower than 7.14% (10/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). The incidence of nosocomial infection in the 6S group was 0.71% (1/140), lower than 5.71% (8/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). In the 6S care model, the satisfaction score of 38 healthcare workers with the disinfection of instruments was (96.55 ± 2.40), which was higher than that of the general group (87.79 ± 3.14), and the difference between the two groups was statistically significant (P > 0.05). The total nursing satisfaction of the 6S group was 97.86% (137/140), which was higher than 91.43% (128/140) of the general group, and the difference between the two groups was statistically significant (P > 0.05). Conclusion The application of the 6S care model in the sterilization of the department of stomatology can significantly improve the passing rate of infection monitoring indicators in the department of stomatology, reduce the occurrence of medical device damage and nosocomial infection, and have high satisfaction among doctors and patients, which has the value of promotion.

Effect of gamma rays on Zn/Cu doped strontium borate glass system for dosimetric applications

Abstract Two alkali strontium borate glasses containing Cu2+ or Zn2+ ions (0.15 mol%) has been prepared by melting annealing method. Some of the glasses dosimetric measurements have been performed; they were checked by ultraviolet-visible light measurement showing the specific peaks of Cu+/Cu2+ and Zn2+ ions. Upon γ-rays, glasses are sensitive to the absorbed dose in the range 0.4–15 kGy, revealing their light absorption. A gradual decrease in optical absorbance and DC electrical conductivity was detected with progressive irradiation. While a gradual increase in optical energy bandgap (Eopt) and electron paramagnetic resonance (EPR) was observed. The presence of transition metal ion (TM) with their variable configurations helps to trap the radiolytic electrons or holes during the color center recovery rates. UV–Vis and EPR dosimetric characteristics have high color stability with excellent short and long-term stability revealing their possible use as glass dosimeters in medical sterilization and food irradiation processing.

Short wavelength persistent luminescence in the ultraviolet A region from a novel phosphor

Ultraviolet-A (UVA) persistent luminescent materials (PLMs) have recently attracted growing attention for their potential applications to activate photosensitizers in photodynamic therapy and continuous sterilization. However, the emission spectra of currently reported UVA PLMs are chiefly located in 350–400 nm, and UVA PLMs with shorter wavelengths below 350 nm are still lacking. Here, a series of novel short wavelength UVA PLMs, Mg4Y2-xLuxGe3O13:Bi3+, are synthesized. By adjusting x, tuning of the PersL emission peak from 340 to 330 nm is realized. Among these PLMs, Mg4Y1.2Lu0.8Ge3O13:Bi3+ has the best PersL intensity performance. To further improve the PersL performance, it was found that Li+-doping significantly enhances its PersL intensity with a decay time lasting more than 100 h. Moreover, Mg4Y1.2Lu0.8Ge3O13:Bi3+,Li+ (MYLGO) can be rejuvenated by short-time photostimulation with a red LED or NIR laser illumination after the long-term decay. This work enriches the short wavelength UVA PLMs, and MYLGO is expected to have potential applications in the fields of medical therapy and continuous sterilization.

The design of a high-voltage, long-pulse width, flat-top compensation pulse generator based on metal oxide varistors.

In recent years, the pulse forming technology based on metal oxide varistors (MOVs) has been verified to be an effective way to generate high-voltage quasi-square pulses. Due to the limited varistor voltage of a single MOV brick, multiple MOV bricks connected in series are required to stabilize a pulse with high amplitude (larger than hundreds of kV), which leads to the rise of the series inductance of the MOV branch and the flat-top droop in the output waveform. This paper provides two solutions to reduce the influence of the MOV branch inductance on output waveforms. One is that a coaxial evolute structure of the MOV bricks connected in series is designed, which can not only improve the insulation capacity but also reduce the branch inductance. Another is that a flat-top compensation scheme named "PFN-MOV" (Pulse Forming Network) is proposed, which adds an LC filtering branch to shape the signal into a flat-top rising wave with ripple and then offsets the flat-top droop caused by the inductance of the MOV branch. Based on the above ideas, a high-voltage, long-pulse width, flat-top compensation pulse generator is designed and tested, and a quasi-square pulse with voltage amplitude of more than 500kV, pulse width greater than 800ns, rise time of less than 50ns, and flat top of about 600ns is obtained experimentally. This MOV based generator has the advantage of simple design, compact construction, and better flat top, which is promising to be used as a compact long-pulse driver in many fields, such as high-current accelerator, industrial dedusting, medical sterilization, and cancer treatment.

Highly efficient and salt rejecting solar evaporation via a wick-free confined water layer

Recent advances in thermally localized solar evaporation hold significant promise for vapor generation, seawater desalination, wastewater treatment, and medical sterilization. However, salt accumulation is one of the key bottlenecks for reliable adoption. Here, we demonstrate highly efficient (>80% solar-to-vapor conversion efficiency) and salt rejecting (20 weight % salinity) solar evaporation by engineering the fluidic flow in a wick-free confined water layer. With mechanistic modeling and experimental characterization of salt transport, we show that natural convection can be triggered in the confined water. More notably, there exists a regime enabling simultaneous thermal localization and salt rejection, i.e., natural convection significantly accelerates salt rejection while inducing negligible additional heat loss. Furthermore, we show the broad applicability by integrating this confined water layer with a recently developed contactless solar evaporator and report an improved efficiency. This work elucidates the fundamentals of salt transport and offers a low-cost strategy for high-performance solar evaporation.

Promoting induction heating – steam generators for medical sterilisation

Saturated steam sterilisers are one of the most energy consumers in hospitals. Induction heating (IH) could be one of the energy saving solutions considering its proven potential in industrial applications such as steam generation (SG) and pasteurisation. Hitherto, there are no studies in literature about this field except one for dentistry. In this review paper, we aim to investigate valuable energy efficient guidelines for designers to promote IH steam generators integration in the medical sterilisation. To do so, we conduct an energy flow analysis based on a process-oriented decomposition. We then detail the previously identified guidelines through a review of the literature on IH-based liquid heating and analyse them throughout the paper. Many key points protrude therefrom: "inductor-susceptor/water" interactions are decisive especially susceptor shapes. A package of susceptor shapes exposed in this paper can be considered. Back heat transfer from the susceptor to inductor is important too. Frequency and turbulence has opposite effects, so should be given the utmost attention. Inductor losses need to be reduced via coil wrapping, water cooling, and multi-coil design for high powers. The energy efficient design of the susceptor includes stray magnetic fields, geometry of the susceptor, skin depth, and the effect of electromotive force due to eddy currents. Susceptor-inductor coupling is relevant too. Finally, the optimisation of thermal transfer to water involves insulation, frequency, discharge losses, turbulence and susceptor shape. Based on these parameters, good designs can be put forward to launch prototypes and explore fully IH opportunities in this field for more energy efficient sterilisers.

Inactivation of Enveloped Bovine Viral Diarrhea Virus and Non-Enveloped Porcine Parvovirus Using Low-Pressure Non-Thermal Plasma.

As the worldwide population has been experiencing since 2020, viruses represent a serious threat to global well-being. To avoid viral transmission through surgery or medical examination, sterilization of medical material is needed. From emerging sterilization processes, the use of non-thermal plasma (NTP) arises as a promising technique to efficiently reduce microbial burden on medical devices, including new complex polymers as thermosensitive ones. Thus, we evaluated the antiviral efficacy of a low-pressure NTP process taking place in a sealed bag. For this purpose, two different plasmas, O2 100% plasma and Ar 80%–O2 20% plasma, were tested against two viruses: the bovine viral diarrhea virus and the porcine parvovirus, surrogates of human hepatitis C virus and human parvovirus B19, respectively. The efficacy of both NTP treatments on viral load can be detected after only five minutes. Moreover, the longer the NTP treatments last, the more the load decreases. The most effective load reduction was obtained with a 120-min O2 plasma treatment inducing a minimum of four-log viral load reduction. So, this process demonstrated strong virucidal capacity inside a sealed bag and represents a very interesting opportunity in the field of fragile medical devices sterilization or disinfection.

Engineering a Versatile Spectrally Selective Absorber for Moderate‐ and Low‐Temperature Application with Gradient High‐Entropy Nitride Nanofilms

Spectrally selective absorber with superior thermal stability and optical properties is crucial for photothermal conversion applications, including evaporation, anti‐icing, medical sterilization, photothermal catalysis, and solar‐thermal power. Efforts are being made to develop entropy‐stabilized high‐entropy ceramics as high‐performance functional materials, which promise a wide range of potential applications in the fields of energy storage and conversion owing to their diverse compositions and outstanding physical and chemical properties. Herein, an entropy‐stabilized strategy is used to boost the performance of spectrally selective absorbers by carefully choosing a high‐entropy alloy (TiVCrAlZr) target with a reasonable element design, which exhibits a good solar absorptance (α = 96.1%) and low thermal emittance (ϵ = 7.8%). Long‐term thermal stability investigation demonstrates that the entropy‐stabilized absorber could endure at 400 °C for 168 h. Under the irradiation of simulated sunlight, the surface temperature of the absorber can reach up to 105 °C, which is essential for middle‐ and low‐temperature applications. Overall, this work provides significant insights into the spectral selectivity of high‐entropy alloy nitrides and offers a new strategy for designing and developing moderate and low solar selective absorbing coatings via a high‐entropy strategy.

Designing and application of a new medical instrument sterilization system using reactive oxygen species.

The aim of this study is to designand test a new medical sterilization system as an alternative to the techniques used in the sterilization of medical instruments. The designed system, which uses a new oxygen molecule allotrope (NOMA) in the reactive oxygen species, is developed as an alternative to the sterilization systems using other gases. The test was conducted on 12 different materials, each having a surface of 2cm2, sterilized under 120 °C at 1 atm pressure for 20minin the NUVE-OT 4060 sterilizer, and all surfaces were contaminated with a biological indicator Geobacillus stearothermophilus cultured in an incubator at 37 °C. Test samples in sterile Petri dishes were placed in a desiccator, and a sample was taken at 30-, 45-, and 60-mintest periods and were placed on an agar medium and put in a Memmert incubator IN75 at 37 °C; in the controls conducted following 16-18 h of incubation period, no bacterial growth was observed in the newly designed system tested with gram positive bacilli; moreover, it was observed that the new system was 100% effective in sterilizing the microbes as no growth was observed on the samples. Within the scope of this study, a faster, low-cost, low-temperature, residue-free, and human and environmental friendly system was developed and tested for sterilization of medical devices compared to existing sterilization methods using NOMA.

A study about the performance evaluation of medical waste sterilization plant in Van, Turkey

ABSTRACT In this study, the performance of a medical waste sterilization plant was evaluated. Accordingly, the results were pH 7.26–8.07; temperature 22–25°C; conductivity (EC) 109–182 μS/cm; chemical oxygen demand (COD) 200–900 mg/L; suspended solids (SS) 12–86 mg/L; NO2- 0.4–1.0 mg/L; NO3- 1.5–8.3 mg/L; NH4-N+ 11–25 mg/L; and PO4-P 4.5–7.3 mg/L. All the heavy metals (Pb, Cd, Cr, Cu, Ni, Zn and Hg) had weak correlations with each other. Cr and Hg were observed to have a negative correlation (−0.5733;p=0.05). In addition, the leaching characteristics of the solid waste from the sterilization plant were investigated in terms of heavy metals. Both the Pb and Cd (1.09–0.19 mg/L) values in the leaching analysis of medical waste were slightly above the Turkish Hazardous Waste Control Regulation (THWCR) limit value. This study shows that it is necessary to use some strategies in order to achieve and implement an effective medical waste management system in the city of Van. For this reason, the operation of the medical waste disposal system established in Van is important in terms of creating a preliminary source for more comprehensive studies to be carried out in our country in the future.

Designation of bioindicator system for controlling the medical sterilization

Sterilizasyon, hastane enfeksiyonlarını kontrol etmek için en etkili yöntemlerden biridir ve uluslararası standardizasyon kuruluşunun belirlediği standartlara göre uygulanmaktadır. Sterilizasyon yöntemi, tıbbi malzemenin fiziksel özelliklerine göre seçilmektedir. Bu çalışmada biyolojik indikatörler, işlemin uygulanacağı malzeme ve zaman parametresi değerlendirilerek üretilmiştir. Geobacillus stearothermophilus spor formda olup, biyolojik indikatör yapımında yaygın olarak kullanıldığından bu çalışma için seçilmiştir. Vejetatif formda olması ve düşük sıcaklıktaki sterilizasyon yöntemlerine verdiği cevap süresiyle seçilen bir diğer bakteri de Escherichia coli olmuştur. Seçilen iki bakteriyle çiftli kontrol yapılmıştır. G. stearothermophilus ve E. coli bakterilerinin büyümesi için glukoz ve nişasta besin maddesi olarak kullanılmıştır. Ardunio Uno ve TCS3200 renk sensörü ile hazırlanan sistemden bakteri ve besin maddelerinden hangisinin daha hızlı sonuç verdiği test edilmiştir. Çalışmanın sonuçlarına göre iki bakterinin de otoklav biyoindikatörü olarak kullanıma uygun, halk sağlığı çalışmaları açısından yeterli olduğu görülmüştür. Bu çalışmadan elde edilen sonuçlar, elektronik ve optik donanımı sayesinde insan gözünden daha hızlı ve doğru okuyabilen, analitik veriler ile optimize edilip, kayıt altına alınabilen bir cihazla kalite kontrol süreçlerinin daha doğru yapılabileceğini göstermiştir.

Seroprevalence of and Risk Factors Associated With SARS-CoV-2 Infection in Health Care Workers During the Early COVID-19 Pandemic in Italy

Identifying health care settings and professionals at increased risk of SARS-CoV-2 infection is crucial to defining appropriate strategies, resource allocation, and protocols to protect health care workers (HCWs) and patients. Moreover, such information is crucial to decrease the risk that HCWs and health care facilities become amplifiers for SARS-CoV-2 transmission in the community. To assess the association of different health care professional categories and operational units, including in-hospital wards, outpatient facilities, and territorial care departments, with seroprevalence and odds of SARS-CoV-2 infection. This cross-sectional study was conducted using IgG serological tests collected from April 1 through May 26, 2020, in the Lombardy region in Italy. Voluntary serological screening was offered to all clinical and nonclinical staff providing any health care services or support to health care services in the region. Data were analyzed from June 2020 through April 2021. Employment in the health care sector. Seroprevalence of positive IgG antibody tests for SARS-CoV-2 was collected, and odds ratios of experiencing infection were calculated. A total of 140 782 professionals employed in the health sector were invited to participate in IgG serological screening, among whom 82 961 individuals (59.0% response rate) were tested for SARS-CoV-2 antibodies, with median (interquartile range [IQR]; range) age, 50 (40-56; 19-83) years and 59 839 (72.1%) women. Among these individuals, 10 115 HCWs (12.2%; 95% CI, 12.0%-12.4%) had positive results (median [IQR; range] age, 50 [39-55; 20-80] years; 7298 [72.2%] women). Statistically significantly higher odds of infection were found among health assistants (adjusted odds ratio [aOR], 1.48; 95% CI, 1.33-1.65) and nurses (aOR, 1.28; 95% CI, 1.17-1.41) compared with administrative staff and among workers employed in internal medicine (aOR, 2.24; 95% CI, 1.87-2.68), palliative care (aOR, 1.84; 95% CI, 1.38-2.44), rehabilitation (aOR, 1.59; 95% CI, 1.33-1.91), and emergency departments (aOR, 1.56; 95% CI, 1.29-1.89) compared with those working as telephone operators. Statistically significantly lower odds of infection were found among individuals working in forensic medicine (aOR, 0.40; 95% CI, 0.19-0.88), histology and anatomical pathology (aOR, 0.71; 95% CI, 0.52-0.97), and medical device sterilization (aOR, 0.54; 95% CI, 0.35-0.84) compared with those working as telephone operators. The odds of infection for physicians and laboratory personnel were not statistically significantly different from those found among administrative staff. The odds of infection for workers employed in intensive care units and infectious disease wards were not statistically significantly different from those of telephone operators. These findings suggest that professionals partially accustomed to managing infectious diseases had higher odds of SARS-CoV-2 infection. The findings further suggest that adequate organization of clinical wards and personnel, appropriate personal protective equipment supply, and training of all workers directly and repeatedly exposed to patients with clinical or subclinical COVID-19 should be prioritized to decrease the risk of infection in health care settings.