The COVID-19 pandemic caused by the novel coronavirus (SARS-CoV-2) is an important public health crisis currently threatening humanity. The World Health Organization (WHO) reported more than 4,307,000 cases and 295,000 deaths worldwide up to mid-March 2020, and these numbers keep rising (1) . Up to the same period, Brazil recorded more than 202,000 cases with a lethality rate of 6.9%, ranking 6 th in the world in terms of the number of deaths (2) , higher than all developing nations.
Even though less vulnerable, children are not spared in this pandemic context. A systematic review reports that this group represents from 1% to 5% of the diagnostic cases and is more frequently associated with milder conditions when compared to adults, deaths being rare (3) . Children may be asymptomatic, though the elimination of the virus through respiratory secretion and feces seems to last longer than in adults, which may contribute to the spread of COVID-19 (4) (5) .
Children exhibit certain particularities and are unable to clearly describe their health conditions or report their history of contacts, which makes it a considerable challenge to protect, diagnose, treat and provide care to this population (6) . A review prior to the pandemic highlights that respiratory conditions such as pneumonia and asthma are important causes of hospitalization among Brazilian children (7) . The humoral and cellular immunity of children is not fully developed though, being unable to present an exacerbated inflammatory response. This may explain the peculiarity of children presenting relatively mild symptoms of COVID-19. It is also known that pediatric patients mainly belong to clustered cases, with one family contact confirmed with the disease, usually manifesting symptoms before the children (8) .
The most common symptoms among children include fever, dry cough, and fatigue in addition to nasal congestion, running nose, and sore throat.
Severe pediatric cases present acute dyspnea and may rapidly progress to Acute Respiratory Distress Syndrome (ARDS), myocarditis, septic shock, refractory metabolic acidosis, coagulation dysfunction, and multiple organ failure (4, 8) .
The largest pediatric series found was 2,143 children in China, with 34% of the cases confirmed through laboratory tests and 66% suspected cases. The median age was seven years old and 57% were boys. The proportion of asymptomatic, mild, moderate, and severe infections among the cases confirmed in the laboratory was 12.9%, 43.1%, 41%, 2.5%, and 0.4%, respectively (9) . Mild cases shall be monitored in primary health care centers and precaution measures implemented at home. Severe cases, however, shall be sent to a referral hospital for timely isolation and treatment (10) .
Children with a history of contacts with the severe form of COVID-19, with long-term use of immunosuppressant drugs, or younger than three months of age are the most vulnerable. Children with congenital malformations of heart, lungs, and airways, presenting chronic heart or kidney diseases, malnutrition, hereditary metabolic diseases, immunodeficiency, or cancer are likely to present the severe form of the disease and require hospitalization (8) . Hence, all hospitalized children with acute respiratory disease (fever, dry cough and/or shortness of breath), or asymptomatic children with direct contacts and those highly vulnerable with confirmed contact should be treated as suspected of being infected with COVID-19 in a hospital setting (4) .
Because the symptoms among children may not manifest as expressively as in adults, hospitalizations with respiratory symptoms may be confounded with other diseases and the measures necessary to prevent the spread of the virus may not be adopted. The consequences of a delayed verification of a patient with COVID-19 are considerable, especially for their contacts. Hence, health workers providing care to these children should be considered as highly vulnerable to exposure (11) . For this reason, pediatric facilities face unique challenges during this pandemic because, in addition to the fact that children with the infection present milder symptoms, they live with adults who may be infected, and usually are those who accompany or visit them during hospitalizations (12) .
The Brazilian Society of Pediatrics reinforces the need to implement measures to prevent the spread of COVID-19 among health workers in the services providing care to pediatric patients, which include: restricted visitation and/or accompaniment restricted to the primary caregiver, who should receive specific guidance on protective measures; all equipment necessary for protection has to be planned and provided, and a specific area needs to be designated for the provision of care to suspected or confirmed children (13) .
The nursing staff is in the front line dealing with 
This descriptive and exploratory study with a qualitative approach was conducted using a semi- Data were collected in the last half of April 2020 until theoretical saturation was achieved (14) , respecting the minimum necessary for analysis to be performed in the software, which recommends between 20 and 30 texts (15) . The workers were invited to participate in the study by two electronic media (e-mail or Whatsapp), and five days were established for the workers to return the completed instrument.
The snowball technique (16) was used. It is a nonprobabilistic, convenient sampling method, using reference chains to locate and recruit participants, and is mainly used for exploratory purposes and survey groups with difficult access given the pandemic, which restricts travels and contact among people. Hence, the first worker invited was nominated by the primary author and, later, the other co-authors, and the participants themselves provided the names of other potential participants at the end of the form. The completed forms were the primary source of data submitted to the lexicographic analysis using the
Textes et de Questionnaires (IRAMUTEQ) (15) , the Word Cloud technique and Similitude Analysis.
(CONEP) approved the study. All the participants were ensured that their identities and information provided would remain confidential, read an online free and informed consent form, and checked the option "I declare to have been informed and agree to participate as in this project a volunteer" to be included in the study.
An alphanumerical code was used according to the order of participation. The care provided to patients suspected or confirmed to be infected with COVID-19 is by itself considered a challenge. If, on the one hand, it requires the delivery of integral and quality care, on the other hand, it implies a great concern with one's protection (health workers) and others' protection (co-workers, the workers' family members, children, companions, and other patients) to avoid the spread of the disease. Therefore, the terms "patient", "assistance" and "contaminate" were frequently reported in the same excerpts. Another challenge nursing workers reported is related to the term "lack", which also becomes evident in the word cloud, especially in terms of restricted personal protective equipment ("PPEs" was also a recurrent term and appear linked to the word "lack") and other supplies necessary to work in the front line to combat this pandemic in pediatric units. Note that despite individuals' concern regarding protection against the disease, the workers, especially the nurses, highlighted challenges concerning team management, whether reporting an insufficient number of workers or the need to provide COVID-19-related guidance and training to workers. Note that the words "difficult" (6), "exhausting" (5), "tense" (4), "weary" (4) and "stressful" (3) were also www.eerp.usp.br/rlae 5 Góes FGB, Silva ACSS, Santos AST, Pereira-Ávila FMV, Silva LJ, Silva LF, Goulart MCL. present in the workers' answers when they reported the main challenges nursing workers experienced at this time.
The synthesis of these challenges reported by the pediatric nursing workers may be better understood through the graphic analysis of similitude (Figure 2) , which shows the connectivity between words with the most recurrent ones. The most frequent ones appear larger to aid the identification of the structure of the corpus content. For instance, the word "fear" and its proximity with "assistance" is highlighted, as well as the connection between the terms "lack" and "PPEs", reinforcing the findings presented thus far. The health sector is facing a pandemic of a highly transmissible and mortal disease in real time and, at the same time, has to deal with the fragility of the health system in the provision of sufficient equipment and basic protection supplies. Thus, the concern the participants report is legit as workers are very likely to develop the disease in addition to facing other problems of a psychological nature that accrue from facing challenges imposed by the COVID-19 pandemic (17) . It is important to reinforce that, even though children seem to present milder forms of COVID-19, they are not immune to contamination (18) . Note that approximately 20% of the cases among children are asymptomatic, which brings up the potential transmissibility of the novel coronavirus, considering the close contact between children with the virus and health workers and their families (20) .
Being in a constant state of alertness, fear, and tension, and having the responsibility to provide harmfree and quality care despite limited resources, in a context of continuous exposure and uncertainty of whether one has been contaminated or not, configure elements that contribute to both physical and mental burnout (21) . In this sense, we reinforce the need for managers to be proactive in terms of promoting the wellbeing of workers (17) .
Another study highlights that the workers' fear of becoming a carrier of the virus and transmit it to coworkers and their own families has led to high levels of psychological stress (22) . Such a fear is justified due to cases of asymptomatic transmission of COVID-19 (11) , as it happens among children.
The scientific literature reinforces that experiences of pain, suffering, and death, associated with intense work rhythms, long working hours without rest, low salaries, complex human relationships, and a lack of supplies and human resources, are stressful factors that may lead not only to illness but mainly to fear (23) , which is in line with the findings of the lexicographic analysis For these professionals to work while dealing with fear due to the high likelihood of being contaminated, continuous training addressing standard precautions is essential as well as to provide supplies, so that workers recognize the dangers and adopt a safe behavior.
Additionally, the inclusion of topics such as the planning of protective measures at home and with family members, such as taking the shoes off, removing and washing clothes, and taking a shower immediately after arriving home, among other measures, can alleviate stress and anxiety (11) .
Emotional issues are enhanced by difficulties in managing the crisis which the pandemic imposes on governments, public policymakers, local managers, and teams in health units. The health needs this pandemic creates surpass the capacity of hospitals and health systems, leading to a stressful scenario for health workers who are in front line services. The reason is that care involves the emergency management of processes as well as material and human resources, which, as reported by the literature, has been an important challenge faced worldwide (26) .
In this sense, the work context of these professionals is marked by a scarcity of PPEs, lack of training, and reduced human resources, which increases workers are not required to make isolated decisions that may be traumatic emotional terms (28) .
This study's participants reported challenges closely related to the management of material resources, that is, related to human resources, especially in terms of a decreased number of nursing workers. This situation may be related to an insufficient number of workers even before the pandemic and that was aggravated by the recent leave of workers.
The need to immediately remove asymptomatic health workers who have contact at home with individuals suspected or confirmed of being infected and workers suspected of having the flu syndrome (fever accompanied of cough or sore throat or difficulty breathing), coupled with the leave of more vulnerable workers, considerably decrease the number of teams and overload those who remain working (29) . Hence, it is a challenge to balance the equation between seven to 14-day sick leaves with the increased demand in health services.
Other challenging situations in human resources that were highlighted in this study concerned a lack of knowledge/information regarding the disease, the urgent www.eerp.usp.br/rlae Góes FGB, Silva ACSS, Santos AST, Pereira-Ávila FMV, Silva LJ, Silva LF, Goulart MCL. need for specific guidance and training, and a perception of a lack of appreciation of the profession; the latter is a recurrent complaint of those who constitute the largest profession in the health field (30) .
Similar challenges faced in a tertiary hospital in Wuhan, China triggered emergency responses, especially related to the work of nurses. Thus, strategies were implemented to manage the nursing workforce, involving significant hospital mobilization promoted by the leadership to provide training, supervision, and adjust priorities in the local context. Interesting measures were adopted to encourage, value, and motivate workers and support those in the front line, including messages sent through mobile phones and the dissemination of achievements on an official website (31) .
Thus, the COVID-19 pandemic presents a great opportunity to assess the health systems. From this perspective, considering that 2020 is the "Year of the Nurse", being amidst this pandemic does not exclude the importance of establishing a political discussion of nursing. On the contrary, this is a time to show the capacity of work and the real needs of these workers to outline appropriate strategies to face this and other pandemics in the future (32) .
This study's limitations are related to the need to offer the participants an electronic form, resulting in the participants providing more objective answers when compared to a face-to-face interview, which was unfeasible during the period of data collection due to social isolation measures.
Despite these limitations, this study presents 