Introductory Chapter: Multisystem Inflammation Syndrome

1. Introduction

Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2), which caused Coronavirus Disease 2019 (COVID-19), emerged in late 2019 in Wuhan, China [1, 2], and has spread to virtually the entire world.

The infection has had a higher impact on older populations (over 40 years of age) and men. For example, Padilla et al. [3] reported that in Mexico, 58.48% of confirmed cases were men, and 97% were over 20 years old. Children and adolescents are susceptible to SARS-CoV-2 infection but usually develop COVID-19 at lower rates than adults, and the disease is less severe [4, 5].

In April 2020, the United Kingdom reported an increase in children with hyperinflammatory shock and evidence of infection by SARS-CoV-2. This condition was named Multisystem Inflammatory Syndrome (MIS) [6]. MIS has been described in adults as a complication due to COVID-19 [7].

From there, cases of my children and adults have been reported in many countries [8, 9].

The incidence of MIS in children is estimated to be between 0.05% and 0.1% of those previously infected by SARS-CoV-2. A recent review study has revealed that most of the children with MIS (95.21%) recovered, while only 1–4% died from this syndrome [10, 11].

By January 2021, 6431 cases of MIS in children were reported. Of them, 55 died. 60% were Hispanic or Black [12].

Multiple organizations, including the CDC and the WHO, have proposed MIS case definitions. However, there is no test for the MIS diagnosis [7, 11, 13].

With the emergence of a hyperinflammation state in patients with COVID-19, Kawasaki’s disease, severe macrophage activation syndrome, and systemic vasculitis with cardiomyopathy were considered for diagnosis [14, 15, 16]. Nevertheless, there are differences between MIS and those syndromes [17].

The emergence of SARS-COV-2 and COVID-19 has been a difficult situation for all countries. The emergence of new processes, such as MIS or the post-COVID-19 condition, is a current threat to health personnel and services.

2. Primary care. First level. Sanitary education and health promotion

Some recommendations against SARS-COV-2 infection were to use a facemask, to isolate COVID-19 cases for 10 days, to go out only for indispensable, hand washing, If you cough or sneeze cover mouth and nose with the elbow fold and social distancing (1 m or more) [18]. Nevertheless, many persons did not apply these measures, causing quick COVID-19 dissemination.

Besides, at a social level, schools were closed, and outdoor events were forbidden in most countries.

3. Second level. Specific protection

Due to the vaccination against SARS-COV-2, the frequency and severity of the disease decreased. Even so, there is much more to know about the current vaccines. It is worth noting that they were approved for emergency use.

4. Natural history of disease and prevention levels

The decision to address the natural history of the disease was motivated because it allowed us to review the disease’s evolution and get some insight on how to prevent it. It also lets us compare MIS with previously detected and treated diseases.

The natural history model of the disease was developed in 1953 [19]. It establishes that disease results from a dynamic process that changes with time, space, and the person. There are factors that affect interactions between agents and guests. A preventive attitude should be developed [20].

The prepathogenic period, or ecological triad, is when the disease is absent, when the agent, the susceptible guest, and the environment are in equilibrium. If the balance is lost, the subclinical stage of the pathogenic period comes, where all the pathophysiological changes occurring in the body are described. In this period, the disease begins but does not yet manifest clinically. When signs and symptoms appear, the disease exceeds the clinical horizon. If the disease follows its natural course, complications will be presented or self-limited and return to the susceptible state, or can die. If the complications persist, the sequelae appear [20].

Regarding the levels of prevention, the prepathogenic period would correspond to the primary prevention, which has two levels. The first one is health education and health promotion, which would be all the activities to carry out so that the ecological triad does not break its balance and the disease does not occur. The second level of prevention would be specific protection, such as by applying vaccines to prevent the disease from being presented. In the pathogenic period, secondary prevention corresponds to its third level, an early diagnosis and timely treatment, for example, by applying all the measures to cure the disease in the initial phases. The fourth level would be the damage limitation or complications treatment. Tertiary prevention has the fifth level, the rehabilitation of sequelae (Table 1).

Table 1.

Natural history of disease and prevention level scheme.

5. Conclusion

MIS has been reported in many countries among children and adults. It is crucial to be informed about the characteristics of this disease. The natural history of the disease and its levels of prevention is an agile way to review all aspects of MIS in children and adults. In this book, we also address other aspects of the disease to portray the big picture of the situation.