Expected impact of COVID-19 outbreak in a major metropolitan area in Brazil

Abstract

In January 2020 China reported to the World Health Organization an outbreak of pneumonia of undetermined origin in the city of Wuhan, Hubei. In January 30, 2020, the World Health Organization declared the outbreak of COVID-19 as a Public Health Emergency of International Interest (PHEI). Objectives: The aim of this study is to assess the impact of a COVID-19 epidemic in the metropolitan region of Sao Paulo, Brazil. Methods: We used a generalized SEIR (Susceptibles, Exposed, Infectious, Recovered) model, with additional Hospitalized variables (SEIHR model) and age-stratified structure to analyze the expected time evolution during the onset of the epidemic in the metropolitan area of Sao Paulo. The model allows to determine the evolution of the number of cases, the number of patients admitted to hospitals and deaths caused by COVID-19. In order to investigate the sensibility of our results with respect to parameter estimation errors we performed Monte Carlo analysis with 100 000 simulations by sampling parameter values from an uniform distribution in the confidence interval. Results: We estimate 1 368 (IQR: 880, 2 407) cases, 301 (22%) in older people (more than 60 years), 81 (50, 143) hospitalizations, and 14 (9, 26) deaths in the first 30 days, and 38 583 (IQR: 16 698, 113, 163) cases, 8 427 (21.8%) in older people (more than 60 years), 2181 (914, 6392) hospitalizations, and 397(166, 1205) deaths in the first 60 days. Limitations: We supposed a constant transmission probability Pc among different age-groups, and that every severe and critic case will be hospitalized, as well as that the detection capacity in all the primary healthcare services does not change during the outbreak. Conclusion: Supposing the reported parameters in the literature apply in the city of Sao Paulo, our study shows that it is expected that the impact of a COVID-19 outbreak will be important, requiring special planning from the authorities. This is the first study for a major metropolitan center in the south hemisphere, and we believe it can provide policymakers with a prognosis of the burden of the pandemic not only in Brazil, but also in other tropical zones, allowing to estimate total cases, hospitalization, and deaths, in support to the management of the public health emergence caused by COVID-19.

Estimative of real number of infections by COVID-19 on Brazil and possible scenarios

“…We then, divided the population into age groups to better describe how these rates vary from group to group. With that, we suggest the following changes already proposed by [8]:…”

“…The result is the following modification on equations (3) to (5) On the simulation for the whole country, we considered N as 5% of the total population based on an international behavior for the total number of infections on other countries [9]. We also selected P inf = 14% according to [8].…”

Mathematical Modelling For Decision Making of Lockdown during COVID-19

“…The current situation of China, mainly six provinces having most of the cases has been analysed in [12] [13] [14] whereas the same for Germany [15], Portugal [16], United States [17], Italy [18], Brazil [19] has been discussed in the recent literature. Although the spread of COVID-19 has been exponentially increased all over the world, still the fatality rate is not so alarming which gives residents of every country to re-establish the confidence to overcome and fight this pandemic together.…”

“…Finite impulse response filter can be used to forecast the amount of affected and recovered population by previously discussed time dependent SIR model. After calculating the transmission rate and recovery rate according to (14) and (15), the ridge regression is used to solve the optimization problems of (18) and (19) keeping the constraints of (16), (17) to learn the pattern of coefficients of finite impulse response filter.…”

Taming Covid-19 Epidemic in São Paulo With a Logistic Model and Non-Pharmaceutical Measures

“…[13], Rocha Filho T.M. et al [5] just to mention a few. The last one does a nice specific study of the situation in São Paulo city.…”