Abstract
Dengue is one of the most prominent tropical epidemic diseases present in the Rio de Janeiro city and Southeast part of Brazil, due to the widespread conditions of occurrence of the dengue vector, the mosquito Aedesaegypti, such as high-temperature days interlaced with afternoon or nocturnal rainstorms in summer. This work has the objective of investigating the relationships between variabilities of the El Ni?o-South Oscillation (ENSO) and greater epidemics of dengue in Rio de Janeiro city. To accomplish this goal, the analysis and signal decomposition by cross-wavelet transform (WT) was applied to obtain the cross variability associated with variations of power and phase of both signals by characteristic periods and along with the time series. Data considered in the analysis are (the decimal logarithm of normalized value) of the monthly available notifications of dengue worsening, provided by the public health system of Brazil, and the Southern Oscillation Index (SOI) Ni?o 3.4 data, provided by the National Oceanic and Atmospheric Administration (NOAA), in the period 2000-2017. A maximum cross-wavelet power close to 0.45 was obtained for the representative period of 1 year and also to periods between 3 and 4 years, associated with the positive phase of the SOI index (i.e. , La Ni?a) or with a transition to the positive phase. The evolution of the combined variability of SOI and dengue can be expressed by progressive differences in phase along the time, eventually resulting in yielding phases (i.e., La Niña-Dengue epidemic).
Highlights
Dengue is a viral disease transmitted mainly by the mosquito vector Aedesaegypti, being of great importance for the society, mainly in the countries of the tropical region, where there is a high number in case records
Dengue is one of the most prominent tropical epidemic diseases present in the Rio de Janeiro city and Southeast part of Brazil, due to the widespread conditions of occurrence of the dengue vector, the mosquito Aedesaegypti, such as high-temperature days interlaced with afternoon or nocturnal rainstorms in summer
Data considered in the analysis are of the monthly available notifications of dengue worsening, provided by the public health system of Brazil, and the Southern Oscillation Index (SOI) Niño 3.4 data, provided by the National Oceanic and Atmospheric Administration (NOAA), in the period 2000-2017
Summary
Dengue is a viral disease transmitted mainly by the mosquito vector Aedesaegypti, being of great importance for the society, mainly in the countries of the tropical region, where there is a high number in case records. Dengue infections occur in more than 100 countries in Asia, the Americas, the Middle East, and Africa, and infection rates continue to rise worldwide, with an estimated 50 million infections occurring each year [1]. Dengue infectious disease in the Americas has an endemic-epidemic pattern with outbreaks every 3 to 5 years [2]. The change to a highly endemic pattern is observed with the increase in the number of cases over the years, especially in the first decade of the 21st century with two Pan American outbreaks registered in 2002 and 2010. The wavelet transform (WT) has been shown over the years as a useful tool in the study of the transmission of epidemic diseases such as dengue because it allows the decomposition of non-stationary signals, having among its advantages the frequency variations and the detection of structures temporal and/or spatially localized [5]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
