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Complex temporal climate signals drive the emergence of human water-borne disease.

Morris A, Gozlan RE, Hassani H, Andreou D, Couppié P, Guégan JF - Emerg Microbes Infect (2014)

Bottom Line: Predominantly occurring in developing parts of the world, Buruli ulcer is a severely disabling mycobacterium infection which often leads to extensive necrosis of the skin.While the exact route of transmission remains uncertain, like many tropical diseases, associations with climate have been previously observed and could help identify the causative agent's ecological niche.From this, it was possible to postulate for the first time that outbreaks of Buruli ulcer can be triggered by combinations of rainfall patterns occurring on a long (i.e., several years) and short (i.e., seasonal) temporal scale, in addition to stochastic events driven by the El Niño-Southern Oscillation that may disrupt or interact with these patterns.

View Article: PubMed Central - PubMed

Affiliation: Bournemouth University, Dorset BH12 5BB , UK ; UMR MIVEGEC, IRD-CNRS-Universités de Montpellier 1 et 2, Centre IRD de Montpellier, 34394 Montpellier cedex 5 , France.

ABSTRACT
Predominantly occurring in developing parts of the world, Buruli ulcer is a severely disabling mycobacterium infection which often leads to extensive necrosis of the skin. While the exact route of transmission remains uncertain, like many tropical diseases, associations with climate have been previously observed and could help identify the causative agent's ecological niche. In this paper, links between changes in rainfall and outbreaks of Buruli ulcer in French Guiana, an ultraperipheral European territory in the northeast of South America, were identified using a combination of statistical tests based on singular spectrum analysis, empirical mode decomposition and cross-wavelet coherence analysis. From this, it was possible to postulate for the first time that outbreaks of Buruli ulcer can be triggered by combinations of rainfall patterns occurring on a long (i.e., several years) and short (i.e., seasonal) temporal scale, in addition to stochastic events driven by the El Niño-Southern Oscillation that may disrupt or interact with these patterns. Long-term forecasting of rainfall trends further suggests the possibility of an upcoming outbreak of Buruli ulcer in French Guiana.

No MeSH data available.


Related in: MedlinePlus

Wavelet coherence between (A) Buruli ulcer incidences per 100 000 people and the rainfall trend obtained from SSA. (B) Buruli ulcer incidences per 100 000 people and ENSO. The colors are coded from dark blue to dark red with dark blue representing low coherence through to high coherence with dark red. The solid black lines around areas of red show the α=5% significance levels computed based on 2000 Monte Carlo randomizations. The dotted white lines represent the cone of influence; outside this area, coherence is not considered as it may be influenced by edge effects. The black arrows represent the phase analysis and adhere to the following pattern: arrows pointing to the right mean that rainfall and cases are in phase, arrows pointing to the left mean that they are in antiphase, arrows pointing up mean that cases lead rainfall and arrows pointing down mean that rainfall leads cases.
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fig6: Wavelet coherence between (A) Buruli ulcer incidences per 100 000 people and the rainfall trend obtained from SSA. (B) Buruli ulcer incidences per 100 000 people and ENSO. The colors are coded from dark blue to dark red with dark blue representing low coherence through to high coherence with dark red. The solid black lines around areas of red show the α=5% significance levels computed based on 2000 Monte Carlo randomizations. The dotted white lines represent the cone of influence; outside this area, coherence is not considered as it may be influenced by edge effects. The black arrows represent the phase analysis and adhere to the following pattern: arrows pointing to the right mean that rainfall and cases are in phase, arrows pointing to the left mean that they are in antiphase, arrows pointing up mean that cases lead rainfall and arrows pointing down mean that rainfall leads cases.

Mentions: During the period 1969–2012, the series was dominated by four inter-annual peaks in rainfall followed by three inter-annual periods of recessions, with three corresponding peaks and recessions of BU disease cases. The results of the wavelet coherence analyses showed a statistically significant correlation between the two time series for 1979–2000, with cohering peaks and troughs over periods of approximately 8 years (Figure 6A). Phase analysis, indicated by the arrows pointing downwards suggests a preceding relationship of rainfall change occurring before BU cases. In essence, after a peak in rainfall, during a dry period, the number of BU cases increases. Null models showed no significant relationships between rainfall and disease cases. The analysis between cases and SST showed less coherence; however, there were two short periods during the mid-1970s and early 1990s which weakly corresponded (Figure 6B).


Complex temporal climate signals drive the emergence of human water-borne disease.

Morris A, Gozlan RE, Hassani H, Andreou D, Couppié P, Guégan JF - Emerg Microbes Infect (2014)

Wavelet coherence between (A) Buruli ulcer incidences per 100 000 people and the rainfall trend obtained from SSA. (B) Buruli ulcer incidences per 100 000 people and ENSO. The colors are coded from dark blue to dark red with dark blue representing low coherence through to high coherence with dark red. The solid black lines around areas of red show the α=5% significance levels computed based on 2000 Monte Carlo randomizations. The dotted white lines represent the cone of influence; outside this area, coherence is not considered as it may be influenced by edge effects. The black arrows represent the phase analysis and adhere to the following pattern: arrows pointing to the right mean that rainfall and cases are in phase, arrows pointing to the left mean that they are in antiphase, arrows pointing up mean that cases lead rainfall and arrows pointing down mean that rainfall leads cases.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150285&req=5

fig6: Wavelet coherence between (A) Buruli ulcer incidences per 100 000 people and the rainfall trend obtained from SSA. (B) Buruli ulcer incidences per 100 000 people and ENSO. The colors are coded from dark blue to dark red with dark blue representing low coherence through to high coherence with dark red. The solid black lines around areas of red show the α=5% significance levels computed based on 2000 Monte Carlo randomizations. The dotted white lines represent the cone of influence; outside this area, coherence is not considered as it may be influenced by edge effects. The black arrows represent the phase analysis and adhere to the following pattern: arrows pointing to the right mean that rainfall and cases are in phase, arrows pointing to the left mean that they are in antiphase, arrows pointing up mean that cases lead rainfall and arrows pointing down mean that rainfall leads cases.
Mentions: During the period 1969–2012, the series was dominated by four inter-annual peaks in rainfall followed by three inter-annual periods of recessions, with three corresponding peaks and recessions of BU disease cases. The results of the wavelet coherence analyses showed a statistically significant correlation between the two time series for 1979–2000, with cohering peaks and troughs over periods of approximately 8 years (Figure 6A). Phase analysis, indicated by the arrows pointing downwards suggests a preceding relationship of rainfall change occurring before BU cases. In essence, after a peak in rainfall, during a dry period, the number of BU cases increases. Null models showed no significant relationships between rainfall and disease cases. The analysis between cases and SST showed less coherence; however, there were two short periods during the mid-1970s and early 1990s which weakly corresponded (Figure 6B).

Bottom Line: Predominantly occurring in developing parts of the world, Buruli ulcer is a severely disabling mycobacterium infection which often leads to extensive necrosis of the skin.While the exact route of transmission remains uncertain, like many tropical diseases, associations with climate have been previously observed and could help identify the causative agent's ecological niche.From this, it was possible to postulate for the first time that outbreaks of Buruli ulcer can be triggered by combinations of rainfall patterns occurring on a long (i.e., several years) and short (i.e., seasonal) temporal scale, in addition to stochastic events driven by the El Niño-Southern Oscillation that may disrupt or interact with these patterns.

View Article: PubMed Central - PubMed

Affiliation: Bournemouth University, Dorset BH12 5BB , UK ; UMR MIVEGEC, IRD-CNRS-Universités de Montpellier 1 et 2, Centre IRD de Montpellier, 34394 Montpellier cedex 5 , France.

ABSTRACT
Predominantly occurring in developing parts of the world, Buruli ulcer is a severely disabling mycobacterium infection which often leads to extensive necrosis of the skin. While the exact route of transmission remains uncertain, like many tropical diseases, associations with climate have been previously observed and could help identify the causative agent's ecological niche. In this paper, links between changes in rainfall and outbreaks of Buruli ulcer in French Guiana, an ultraperipheral European territory in the northeast of South America, were identified using a combination of statistical tests based on singular spectrum analysis, empirical mode decomposition and cross-wavelet coherence analysis. From this, it was possible to postulate for the first time that outbreaks of Buruli ulcer can be triggered by combinations of rainfall patterns occurring on a long (i.e., several years) and short (i.e., seasonal) temporal scale, in addition to stochastic events driven by the El Niño-Southern Oscillation that may disrupt or interact with these patterns. Long-term forecasting of rainfall trends further suggests the possibility of an upcoming outbreak of Buruli ulcer in French Guiana.

No MeSH data available.


Related in: MedlinePlus