Factors associated with infection and hospitalization due to COVID-19 in Nursing professionals: a cross-sectional study

Abstract Objective: to identify factors associated with infection and hospitalization due to COVID-19 in nursing professionals. Method: a cross-sectional study carried out with 415 nursing professionals in a hospital specialized in cardiology. The sociodemographic variables, comorbidities, working conditions and issues related to illness due to COVID-19 were evaluated. Chi-Square, Fisher’s, Wilcoxon, Mann-Whitney and Brunner Munzel tests were used in data analysis, as well as Odds Ratio for hospitalization, in addition to binary logistic regression. Results: the rate of nursing professionals affected by COVID-19 was 44.3% and the factors associated with infection were the number of people living in the same household infected by COVID-19 (OR 36.18; p<0.001) and use of public transportation (OR 2.70; p=0.044). Having severe symptoms (OR 29.75), belonging to the risk group (OR 3.00), having tachypnea (OR 6.48), shortness of breath (OR 5.83), tiredness (OR 4.64), fever (OR 4.41) and/or myalgia (OR 3.00) increased the chances of hospitalization in professionals with COVID-19. Conclusion: living in the same household as other people with the disease and using public transportation increased the risk of infection by the new coronavirus. The factors associated with the hospitalization of contaminated professionals were presence of risk factors for the disease, severity and type of the symptoms presented.


Introduction
Acute respiratory syndrome 2019 (COVID-19) is caused by a new coronavirus, SARS-CoV-2, from the family of coronaviruses (CoV), responsible for infectious manifestations ranging from a common cold to Severe Acute Respiratory Syndrome (SARS) (1)(2) . The disease had its first cases identified in China at the end of 2019 and, in a few months, spread across the world (1) .
A research study pointed out that, at the beginning of the pandemic, nearly 14% of the infected cases were serious and required hospitalization; in addition to that, 1.7% underwent treatment by invasive mechanical ventilation and 2.6% died (3) . Data (4) .

Prevention of transmission during care and treatment
of the patients depends on the effective use of Personal Protective Equipment (PPE) items, which must include a mask, goggles or face shield, gloves and apron, exclusive to the care environment (5)(6) . The complexity of donning, associated with the fear of infection and, often, PPE scarcity, increases tension and stress in healthcare professionals who work against coronavirus (5)(6) .
In 2020, the scarcity of testing resources, uncertainty about the prognostic factors, the unavailability of vaccines, the imposition of unknown public health measures, significant financial losses and conflicting messages from the authorities were reasons for anguish and stress in the healthcare professionals (6) .
Nurses and midwives represent nearly 50% of the healthcare workforce. Of the 43.5 million healthcare workers in the world, an estimated 20.7 million are nurses and midwives (7) . In Brazil, data obtained from the Federal Nursing Council website indicate that there are 2,305,946 registered and active nursing professionals, of which 565,458 are nurses, 1,320,239 nursing technicians, 419,959 nursing assistants and 290 midwives (8) .
Thus, nursing is at the forefront of the care provided to patients with COVID-19 and plays a central role in clinical care, education, prevention and control of the disease (9) , facing the fear of contagion, dying or infecting their family members.
A research study that analyzed cases and deaths due to COVID-19 in nursing professionals in Brazil showed a higher number of cases in the Southeast region, with higher lethality for the age group between 41 and 50 years old and males (10) .
A cross-sectional study, conducted with Iranian healthcare professionals, described the highest rate of COVID-19 infection among nurses (51.3%). Nearly one third of the professionals were asymptomatic and, for the symptomatic ones, the most frequent clinical features were myalgia (46%) and cough (45.5%) (11) .
Due to the sudden outbreak of the disease, nurses had only brief training to care for COVID-19 patients and many professionals were distanced from work due to flu-like symptoms and suspected or even confirmed infection (9,11) . The absence of healthcare professionals generates an overload in the services and this factor, added to PPE shortage, raises healthcare professionals' tension (6,12) . This study hypothesized that lack of PPE and presence of comorbidities among nursing professionals can be associated with COVID-19 infection. Thus, the research aimed to identify factors associated with infection and hospitalization due to COVID-19 in nursing professionals.

Type of study
This is an analytical, cross-sectional and observational study based on the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines (13) . Cross-sectional studies are characterized as those that evaluate the outcome and exposure of the participants at the same time, with selection of individuals based only on the study inclusion and exclusion criteria (14) .

Study locus, population and sample
The study was carried out in a teaching hospital specialized in cardiopneumology in the city of São Paulo-SP, Brazil. The institution is a reference center for the care www.eerp.usp.br/rlae

Inclusion and exclusion criteria
Nursing professionals who have worked at the institution for at least one month in the Intensive Care Units, Inpatient Units, Surgical Center, Hemodynamics, Emergency Room, Diagnostic Imaging Service and Outpatient Clinic were included. Professionals who were on vacation or on sick leave (not related to  during the data collection period were excluded.

Study variables
The dependent variables were as follows: infection by COVID-19 and need for the professionals to be hospitalized due to COVID-19. The independent variables included sociodemographic data (gender, age, race, marital status, religion, place of residence, number of people in the

Data collection instrument
For data collection, a checklist-type instrument was developed, consisting of two parts. The first included sociodemographic variables, aspects related to housing, comorbidities, working conditions and information about the institution's work. The second part consisted of questions related to infection by COVID-19 and the need for the professionals to be hospitalized due to COVID-19. The instrument was built using as a reference guidelines that instruct about the good practices related to observational studies (13) , risk factors (15) and the professionals' biosafety (16)(17) , as there were still no validated instruments that could be used.

Data collection and period
The data collection instrument was prepared in a survey format in Research Electronic Data Capture (RedCap), a system that guarantees the security of the information recorded and it was forwarded to all nursing professionals via messaging apps, in addition to providing the link to the instrument on the computers of all units where the data were collected.
The researchers were present in all units and periods, providing the link and guiding the professionals. In addition to that, a QR Code was created to facilitate the professionals' access to the instrument.
The data were collected in November and December 2020.

Data treatment and analysis
The data were analyzed in the R statistical program, To identify the factors associated with illness due to COVID-19, binary multiple logistic regression was applied and all the independent variables described above were simultaneously inserted into the model, whose value below 5 was interpreted as absence of collinearity.
For hospital admission, the Odds Ratio was calculated for the variables that were significant in the bivariate analyses. The significance level adopted was 5%.

Ethical aspects
The research was approved by the institution's Ethics

Discussion
Throughout the COVID-19 pandemic, hundreds of professionals were contaminated and many died as a result of the disease. Although it is not always possible to establish the care provided as the source of infection, even when the professionals directly care for patients infected with SARS-CoV-2, a number of research studies indicate a higher risk for healthcare workers when compared to the general population (11)(12)(13)(14)(15)(16)(17)(18) .
It is estimated that before mass vaccination, nearly 14% of the world's cases were in healthcare professionals, from different areas of activity (19) .  (20) .
During the most critical phase of the pandemic or pre-vaccination period, there was a reduction in the healthcare workforce due to infection and illness, which exerted a significant social and economic impact on the health system (19,21) . In this context, this research explored factors associated with the illness of nursing professionals due to COVID-19 in the period before vaccination in the country.
The current study allowed identifying that the use of public transportation increased the chances of the professionals being contaminated by SARS-CoV-2, similarly to other studies that investigated the relationship between public transportation and the risk of infection by  .
A Chinese study that assessed the transmission risk of the new coronavirus in train passengers concluded that contagion on these trips is high, although the risk is influenced by the passenger's exposure time and location and can be minimized by increasing the distance between seats, reducing passenger density and applying personal hygiene measures (23) . Other possibilities would be granting of free transportation by the private sector and implementation of exclusive transportation means for healthcare professionals (25)(26) .
Another variable that significantly increased the chance of contracting the disease was living in the same household as other people diagnosed with COVID-19.
It is noteworthy that, in this study, as in others, it was not possible to identify whether infection went from the professionals to the residents of the same environment or vice versa.
Although rapid identification of cases through surveillance and diagnostic testing makes rapid isolation possible, isolation often needs to be done at home with family members and other close people. Providing accommodations for the quarantine of infected front-line professionals is an example of a measure that can help reduce possible infection in the community (27) .
The need for the contaminated professionals to be hospitalized was associated with belonging to the risk group and to the presence of severe symptoms of the disease, factors that were also observed in other studies that indicated the presence of comorbidities and respiratory symptoms as predictors for the hospitalization of patients affected by COVID-19 (28)(29)(30)(31) . an attempt to prevent worsening of the pandemic. Thus, collecting and managing the teams' healthcare data is an important measure to be considered.
In this study, the low incidence of professionals who needed to be admitted to the ICU (2.2%) corroborates already known data that report rates between 10% and 20% requiring intensive care, with only 3% to 10% of them requiring intubation (32) .
A cohort study developed in Spain compared the outcomes of healthcare workers and of the general population hospitalized due to COVID-19. The results showed that comorbidities and severe radiological findings were more frequent in the general population, and no significant difference was found between the need for ventilatory support and ICU admission between the two groups. However, the incidence of sepsis and mortality was significantly higher in the general population than among the healthcare professionals (33) .
Given the characteristic of the current study, in which the professionals themselves answered about their health conditions, death was not a variable under evaluation, although it is known that there is high mortality for patients who need ICU admission (34)(35) .
In the current study, a relationship was established between infection and lack of PPE. It is believed that the occupational risk imposed by the lack of such equipment should be avoided, and the availability of adequate PPE should receive special attention in local management of the pandemic (36) .
The current study has strengths and limitations that Among the limitations, the sample size established for convenience and in a non-probabilistic way stands out.
In addition to that, data collection took place in only one institution, through self-report, which may incur in some degree of subjective bias.

Conclusion
The study made it possible to identify factors associated with the infection of nursing professionals by COVID-19. Living in the same household as other people with the disease and using public transportation increased the professionals' risk of infection. In addition to that, lack of PPE was related to infection of the nursing team, identifying the need to manage material resources in the healthcare services to guarantee the supply of adequate human resources during the pandemic.
The need for hospital admission among professionals who got infected with COVID-19 was low and was associated with belonging to the risk group, having severe symptoms of the disease and having fever, shortness of breath, fatigue, tachypnea and/or myalgia. Thus, the presence of comorbidities stands out as a significant factor for the infection of nursing professionals and reflects the need for occupational health actions that assist in the management of these health problems.
It is recommended to conduct new studies that comparatively analyze healthcare institutions and systematic reviews that synthesize the factors associated with infection of nursing professionals by COVID-19 and the measures adopted.