Reemergence of Yellow Fever in Brazil: The Role of Distinct Landscape Fragmentation Thresholds.

Roberto C Ilacqua,Gabriel Z Laporta,Marcos T Obara,Mauro T Marrelli,Daniel G Ramos,Walter Ceretti-Junior,Luis F Mucci,Antônio R Medeiros-Sousa,Mohamed A El-Khateeb

doi:10.1155/2021/8230789

Abstract

Yellow Fever Virus (YFV) reemergence in Brazil was followed by human suffering and the loss of biodiversity of neotropical simians on the Atlantic coast. The underlying mechanisms were investigated with special focus on distinct landscape fragmentation thresholds in the affected municipalities. An ecological study in epidemiology is employed to assess the statistical relationship between events of YFV and forest fragmentation in municipal landscapes. Negative binomial regression model showed that highly fragmented forest cover was associated with an 85% increase of events of YFV in humans and simians (RR = 1.85, CI 95% = 1.24–2.75, p=0.003) adjusted by vaccine coverage, population size, and municipality area. Intermediate levels of forest cover combined with higher levels of forest edge densities contribute to the YFV dispersion and the exponential growth of YF cases. Strategies for forest conservation are necessary for the control and prevention of YF and other zoonotic diseases that can spillover from the fragmented forest remains to populated cities of the Brazilian Atlantic coast.

Highlights

Reemergence of Yellow Fever Virus (YFV) has been reported in the extra-Amazonian region of Brazil since the 2000s [1,2,3,4]
The ongoing YFV reemergence which started in 2014 has been resulting in widespread virus dissemination and an extended transmission period [5,6,7]. e transmission zone has expanded from the endemic hub of the disease in the Amazon to the Brazilian Atlantic coast where the virus had not been recorded for more than 60 years [8, 9]. e expansion of the transmission zone has been driving the increase of YFV vaccine coverage to nonendemic territories [4]. ousands of cases and deaths are occurring, causing impacts on public health and on the biodiversity of neotropical primates [10]. e most affected nonhuman primate species are New World Monkeys of the genera Callithrix and Alouatta [10,11,12]
In 2020, 881 suspected human cases occurred in southern Brazilian states, from which 18 nonvaccinated men between 18 and 59 years old have been confirmed as YF cases [14]. e dispersion of YFV in the landscape of cities on the Atlantic coast follow ecological corridors through the fragmented forest remains [15]

Summary

Introduction

Reemergence of Yellow Fever Virus (YFV) has been reported in the extra-Amazonian region of Brazil since the 2000s [1,2,3,4]. Land use land cover approaches are often applied to studies of zoonotic diseases in Atlantic Forest [21, 22], they are rarely applied to understand the mechanisms underlying the reemergence of YFV in Brazil (but see [23, 24]).

Results

Conclusion