Related Experiment Video
Updated: Nov 21, 2025

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
Mathematical modeling of COVID-19 in 14.8 million individuals in Bahia, Brazil
Juliane F Oliveira1,2, Daniel C P Jorge3, Rafael V Veiga4
1Center of Data and Knowledge Integration for Health (CIDACS), Instituto Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, Bahia, Brazil. julianlanzin@gmail.com.
Insights
Mathematical modeling of COVID-19 in Brazil shows that reducing transmission is key to preventing healthcare collapse. Periodic interventions are needed, as current efforts are insufficient, and undetected cases significantly increase the R0 value.
Area of Science:
- Epidemiology
- Mathematical Modeling
- Public Health
Background:
- COVID-19 strains global healthcare, especially in lower and middle-income countries.
- Challenges include insufficient hospital beds, ventilators, and medical supplies.
- Asymptomatic and non-detected cases complicate disease dynamics.
Purpose of the Study:
- To model COVID-19 dynamics in Bahia, Brazil.
- To assess the impact of policies on transmission rates.
- To understand the role of undetected cases and inform public health strategies.
Main Methods:
- Utilized mathematical modeling to simulate COVID-19 transmission.
- Incorporated factors like asymptomatic cases, hospitalizations, and mortality.
- Examined the effect of varying transmission rates and intervention policies.
Main Results:
- Current efforts to decrease transmission by 36% are insufficient to prevent healthcare system collapse.
- Periodic interventions are necessary to manage peak demand.
- Non-detected COVID-19 cases increase the basic reproduction number (R0) by approximately 55%.
Conclusions:
- Maintaining healthcare infrastructure during the pandemic is challenging.
- Lowering the transmission rate is critical, requiring more than current reduction levels.
- Undetected cases significantly amplify disease spread, necessitating targeted public health interventions.
Abstract:
COVID-19 is affecting healthcare resources worldwide, with lower and middle-income countries being particularly disadvantaged to mitigate the challenges imposed by the disease, including the availability of a sufficient number of infirmary/ICU hospital beds, ventilators, and medical supplies. Here, we use mathematical modelling to study the dynamics of COVID-19 in Bahia, a state in northeastern Brazil, considering the influences of asymptomatic/non-detected cases, hospitalizations, and mortality. The impacts of policies on the transmission rate were also examined. Our results underscore the difficulties in maintaining a fully operational health infrastructure amidst the pandemic. Lowering the transmission rate is paramount to this objective, but current local efforts, leading to a 36% decrease, remain insufficient to prevent systemic collapse at peak demand, which could be accomplished using periodic interventions. Non-detected cases contribute to a ∽55% increase in R0. Finally, we discuss our results in light of epidemiological data that became available after the initial analyses.
Related Concept Videos
Statistical Methods for Analyzing Epidemiological Data
Exponential Equations for Modeling Growth
Steps in Outbreak Investigation
Mathematical Modeling: Problem Solving
Estimating Population Standard Deviation
Causality in Epidemiology

