**1. Introduction**

#### **1.1 The SARS-CoV-2 outbreak**

A cluster of cases of pneumonia with unknown etiology was first reported in Wuhan, Hubei Province, China in December 2019. Subsequent analysis identified a novel coronavirus, later named severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The disease caused by the virus was eventually called coronavirus disease 2019 (COVID-19) [1, 2]. On January 30, 2020, the World Health Organization (WHO) declared the outbreak a Public Health Emergency of International Concern; on March 11, a pandemic was declared [3].

Coronaviruses are widely distributed globally [2]. Most human coronavirus infections are mild; however, two previous outbreaks led to many illnesses and deaths. The epidemics of severe acute respiratory syndrome coronavirus (SARS-CoV) in 2002–2003 and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012 resulted in many people developing severe pneumonia, with mortality rates of 10% and 36%, respectively [4].

According to the WHO, a patient with suspected COVID-19 infection is anyone meeting the clinical criteria with respect to signs and symptoms associated with the disease, including fever, dry cough, and fatigue. Other less common symptoms include myalgia, nasal congestion, headache, conjunctivitis, sore throat, diarrhea, and smell or taste disorders (anosmia and dysgeusia). Epidemiologic criteria include exposure to an area with a high risk of viral transmission or community transmission owing to work, residence, or travel [5].

COVID-19 infection exhibits different effects in different groups and individuals. Most infected people have mild- or moderate-intensity symptoms and approximately 80% recover without the need for hospitalization. One in five people develop severe illness and experience breathing difficulties, among other serious symptoms. Importantly, it is possible that transmission can occur from someone who either has mild symptoms, remains asymptomatic, or is in the incubation period [6].

According to the United States Centers for Disease Control and Prevention (CDC), the incubation period (time from infection to illness onset) is from 2 to 14 days after exposure, and symptoms develop in 97.5% of infected individuals within 12 days [7]. Adopting a 14-day period of quarantine has become the standard procedure for individuals who have been in contact with someone with a confirmed COVID-19 diagnosis or who have traveled to high-risk areas [8].

SARS-CoV-2 is transmitted through droplets produced when an infected person coughs, sneezes or talks, which are ingested or inhaled by an individual nearby (within a distance of approximately 2 meters). A person can also become infected by touching a contaminated surface or object that has been contaminated with the virus and subsequently touching the mouth, nose, or eyes [9]. The diagnosis of COVID-19 is confirmed via a positive nucleic acid test result using sputum, a throat swab, or lower respiratory tract secretion sample [10].

The Lancet COVID-19 Commission has offered a list of practical solutions to the challenges during the current pandemic. One set of solutions is focused on nonpharmaceutical interventions in which governments, non-governmental organizations (NGOs), and the private sector collaborate to mitigate negative consequences of the pandemic [11]. In line with this, the WHO has recommended the use of face masks, proper hand hygiene, physical distancing and mobility restrictions, among other measures [12–14]. In Mexico, the federal government announced the National Social Distancing Period Intervention, which included closure of nonessential public and private activities with the objective of reducing population mobility to limit community transmission, especially among those with a high risk of developing complications (age 60 years and older; people with hypertension, type 2 diabetes, obesity, respiratory diseases, or immunosuppression [15–17]; and pregnant women) [18].

*The MONITOR Ecosystem: A Digital Health Intervention for the Early Detection, Control… DOI: http://dx.doi.org/10.5772/intechopen.95260*
