Waves of El Niño-Southern Oscillation and Influenza Pandemics

Oluwole, Oluleke

doi:10.3389/fenvs.2016.00025

Cited by 2 publications

(6 citation statements)

References 67 publications

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“…Occurrence of influenza pandemics is, therefore, deterministic rather than random. El Niños that were lagged by influenza pandemics have been shown to have similar waveforms ( 2 ). The significantly lower degree centrality of sub-networks of El Niños that were lagged by influenza pandemics compared with other El Niños, and with El Niños of different strengths, indicate that influenza pandemics lag El Niños of distinct state space geometry (Figures 7 C,D).…”

Section: Discussionmentioning

confidence: 99%

“…Influenza epidemics occur annually during the winter of northern and southern hemispheres ( 1 ), but only five influenza pandemics occurred between 1899 and 2016 ( 2 ). Putative risk factors for influenza pandemics, which include school calendar, demography, geography, changes in virulence of influenza A viruses, and waning immunity ( 3 ), are, however, the same for seasonal influenza epidemics in these regions.…”

Section: Introductionmentioning

confidence: 99%

“…Analysis of historical data from 1580 to 2013 showed that influenza pandemics lagged peaks of El Ninos by 0–2 years ( 12 ). Analysis of monthly ENSO time series, however, showed that influenza pandemics lagged El Ninos by 0–2 months ( 2 ). Influenza epidemics and pandemics, therefore, appear coupled to El Niños.…”

Section: Introductionmentioning

confidence: 99%

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Dynamic Regimes of El Niño Southern Oscillation and Influenza Pandemic Timing

Oluwole

2017

Front. Public Health

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El Niño southern oscillation (ENSO) dynamics has been shown to drive seasonal influenza dynamics. Severe seasonal influenza epidemics and the 2009–2010 pandemic were coincident with chaotic regime of ENSO dynamics. ENSO dynamics from 1876 to 2016 were characterized to determine if influenza pandemics are coupled to chaotic regimes. Time-varying spectra of southern oscillation index (SOI) and sea surface temperature (SST) were compared. SOI and SST were decomposed to components using the algorithm of noise-assisted multivariate empirical mode decomposition. The components were Hilbert transformed to generate instantaneous amplitudes and phases. The trajectories and attractors of components were characterized in polar coordinates and state space. Influenza pandemics were mapped to dynamic regimes of SOI and SST joint recurrence of annual components. State space geometry of El Niños lagged by influenza pandemics were characterized and compared with other El Niños. Timescales of SOI and SST components ranged from sub-annual to multidecadal. The trajectories of SOI and SST components and the joint recurrence of annual components were dissipative toward chaotic attractors. Periodic, quasi-periodic, and chaotic regimes were present in the recurrence of trajectories, but chaos–chaos transitions dominated. Influenza pandemics occurred during chaotic regimes of significantly low transitivity dimension (p < 0.0001). El Niños lagged by influenza pandemics had distinct state space geometry (p < 0.0001). Chaotic dynamics explains the aperiodic timing, and varying duration and strength of El Niños. Coupling of all influenza pandemics of the past 140 years to chaotic regimes of low transitivity indicate that ENSO dynamics drives influenza pandemic dynamics. Forecasts models from ENSO dynamics should compliment surveillance for novel influenza viruses.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dynamic Regimes of El Niño Southern Oscillation and Influenza Pandemic Timing

Oluwole

2017

Front. Public Health

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“…Multiple peaks which occur during (Figures 2A-E). Multiple seasonal peaks of influenza occurrence, which correlated with the waveforms of ENSO, have been observed during all influenza pandemics since 1918 (Oluwole, 2016). El Niño typically starts in spring (Philander, 1985) and peaks in winter (Sheinbaum, 2003;Caviedes, 2007).…”

Section: Discussionmentioning

confidence: 99%

“…Scale invariance of multivariate El Niño Index (MEI) between 1950 and 2008 (Mazzarella and Giuliacci, 2009), and detrended fluctuation analysis of southern oscillation index (SOI) between 1866 and 2000 also showed that ENSO is fractal (Ausloos and Ivanova, 2001). Similarity of ENSO waveforms during five influenza pandemics from 1876 to 2015, which suggests scale invariance (Oluwole, 2016), is indicative of fractal time series (van Rooij et al, 2013). While chaotic trajectories have fractal geometry, not all fractals are self-similar under magnification (Mandelbroit, 1989).…”

Section: Phase Spaces Of El Niño Southern Oscillation and Influenzamentioning

confidence: 99%

Deterministic Chaos, El Niño Southern Oscillation, and Seasonal Influenza Epidemics

Oluwole

2017

Front. Environ. Sci.

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Low precipitation enhances transmission of influenza viruses, which cause seasonal epidemics during the winter in northern and southern hemispheres. El Niño southern oscillation (ENSO) which modulates global precipitation is a multicomponent signal that is composed of sub-annual to multi-decadal oscillations. The dynamics of oscillatory components of ENSO and influenza are characterized, and causal relationship of annual oscillatory components is determined. Seasonality of influenza was determined in five geographical areas of north and south hemispheres. Monthly influenza time series of these regions and of ENSO were decomposed to oscillatory components. The oscillatory components were characterized in time-frequency and phase space domains. Periodicities of the oscillatory components of ENSO and influenza range from sub-annual to multidecadal. Time-dependent intrinsic correlations of instantaneous amplitude and frequencies of annual oscillatory components of ENSO and influenza are > 0.9. The dynamics of ENSO and influenza, which are dissipative with multifractal chaotic attractors, transit from quasi-periodic to chaotic regimes. Five most severe peaks of epidemic, which include 2009-2010 pandemic, occur during chaos. ENSO and influenza dynamics are phase coherent, but there is unidirectional causal effect of ENSO on influenza. Amplitude and frequency modulations of annual oscillatory components of ENSO and influenza are strongly coupled. Chaotic dynamics of ENSO determines the timing and severity of influenza epidemics. Monitoring of ENSO dynamics will aid public health surveillance of influenza epidemics.

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Waves of El Niño-Southern Oscillation and Influenza Pandemics

Cited by 2 publications

References 67 publications

Dynamic Regimes of El Niño Southern Oscillation and Influenza Pandemic Timing

Dynamic Regimes of El Niño Southern Oscillation and Influenza Pandemic Timing

Deterministic Chaos, El Niño Southern Oscillation, and Seasonal Influenza Epidemics

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