Newborn epidemiology in the COVID-19 context - Brazil

Coronaviruses (CoVs) are enveloped, crown-like viruses [1], composed of a single-stranded ribonucleic acid (RNA) genome, able to infect vertebrates. In December 2019, a new coronavirus, namedSARS-CoV2, emerged in Wuhan, Hubei, China, and caused the COVID-19 disease, which has affected millions of lives worldwide. The infection sensitizes the upper and lower respiratory tract [2], thus, the contagion occurs through sneezing and saliva droplets [3,4]. Infected individuals show the first symptoms, approximately, five days after the incubation period [7-9], and the transmission lasts an average of seven days after the onset of symptoms [5,6]. As the virus spreads through the air, the best methods of prevention are hand disinfection with ethanol 70% or soap, use of masks and social distancing, and vaccination [5]. The rapid spread of COVID-19 interferes in the daily lives of billions of people on the planet, from the social, economic, scientific and medical aspects. The pandemic showed, approximately, 214,468,601 confirmed cases and 4,470,969 deaths as of August 2021; in South America: 34,633,766 confirmed cases and 1,065,582 deaths. Brazil is currently considered one of the most important epicenters of the COVID-19 disease, since from the beginning of the pandemic the country has recorded 20,741,815 confirmed cases and 579,308deaths [10]. So far, the SARS-CoV-2 lethality has been mostly associated with elderly or immunocompromised patients [11]. Nonetheless, pregnant women and postpartum women were considered groups of greater clinical vulnerability for COVID-19, due to changes in the immunity mechanism and greater sensitivity to hypoxia [12-14]. This condition is associated with negative outcomes, such as hospitalizations and deaths, and represents a high risk of transmission to the newborn (NB) [15-17]. In Brazil, care for infected pregnant women and postpartum women is associated with the low availability of respirators and intensive care, resulting in high numbers of maternal deaths and poor prognosis for the NB [18]. Postnatal or horizontal transmission of the virus to the NB is more frequent and worsens when the mother is symptomatic [19]. However, evidence of vertical transmission was observed in a study carried out in China. Therefore, it is notorious the need for control measures and prevention procedures during childbirth and puerperium [20]. The wide diversity of socioeconomic, climatic and geographic characteristics of Brazil are critical to define the profile of the vulnerable population to infection. Moreover, the association of great economic inequalities, the migratory process to big cities and the environmental disorder negatively influences the fight against the disease. Thus, this study aimed to investigate the main epidemiological variables affecting a population of NB tested for COVID-19 in Brazil and notified for severe acute respiratory syndrome (SARS), from May 2020 to June 2021. In addition, to evaluate the frequencies of comorbidities associated with the population studied, as well as the relationship between symptoms, chronic diseases and COVID-19, and to correlate the data on the presence of chronic diseases and death with D O I: 1 0 .5 4 4 4 8 / m d n t2 1 6 1 8