Relationships between climate and year-to-year variability in meningitis outbreaks: A case study in Burkina Faso and Niger

<p>Abstract</p> <p>Background</p> <p>Every year, West Africa is afflicted with Meningococcal Meningitis (MCM) disease outbreaks. Although the seasonal and spatial patterns of disease cases have been shown to be linked to climate, the mechanisms responsible for these patterns are still not well identified.</p> <p>Results</p> <p>A statistical analysis of annual incidence of MCM and climatic variables has been performed to highlight the relationships between climate and MCM for two highly afflicted countries: Niger and Burkina Faso. We found that disease resurgence in Niger and in Burkina Faso is likely to be partly controlled by the winter climate through enhanced Harmattan winds. Statistical models based only on climate indexes work well in Niger showing that 25% of the disease variance from year-to-year in this country can be explained by the winter climate but fail to represent accurately the disease dynamics in Burkina Faso.</p> <p>Conclusion</p> <p>This study is an exploratory attempt to predict meningitis incidence by using only climate information. Although it points out significant statistical results it also stresses the difficulty of relating climate to interannual variability in meningitis outbreaks.</p

Comparative study of meningitis dynamics across nine African countries: a global perspective

<p>Abstract</p> <p>Background</p> <p>Meningococcal meningitis (MM) represents an important public health problem especially in the "meningitis belt" in Africa. Although seasonality of epidemics is well known with outbreaks usually starting in the dry season, pluri-annual cycles are still less understood and even studied. In this context, we aimed at study MM cases time series across 9 sahelo-sudanian countries to detect pluri-annual periodicity and determine or not synchrony between dynamics. This global and comparative approach allows a better understanding of MM evolution in time and space in the long-term.</p> <p>Results</p> <p>We used the most adapted mathematical tool to time series analyses, the wavelet method. We showed that, despite a strong consensus on the existence of a global pluri-annual cycle of MM epidemics, it is not the case. Indeed, even if a clear cycle is detected in all countries, these cycles are not as permanent and regular as generally admitted since many years. Moreover, no global synchrony was detected although many countries seemed correlated.</p> <p>Conclusion</p> <p>These results of the first large-scale study of MM dynamics highlight the strong interest and the necessity of a global survey of MM in order to be able to predict and prevent large epidemics by adapted vaccination strategy. International cooperation in Public Health and cross-disciplines studies are highly recommended to hope controlling this infectious disease.</p

Relationships between climate and year-to-year variability in meningitis outbreaks: A case study in Burkina Faso and Niger-0

Ur clusters characterizing the intensity of the epidemic) of the contingency table (Tab.2) are projected.<p><b>Copyright information:</b></p><p>Taken from "Relationships between climate and year-to-year variability in meningitis outbreaks: A case study in Burkina Faso and Niger"</p><p>http://www.ij-healthgeographics.com/content/7/1/34</p><p>International Journal of Health Geographics 2008;7():34-34.</p><p>Published online 2 Jul 2008</p><p>PMCID:PMC2504476.</p><p></p

Meningococcal meningitis in Mali : long-term study of persistence and spread

International audienc

Wavelet coherence and phase analyses of meningitis time series between countries

<p><b>Copyright information:</b></p><p>Taken from "Comparative study of meningitis dynamics across nine African countries: a global perspective"</p><p>http://www.ij-healthgeographics.com/content/6/1/29</p><p>International Journal of Health Geographics 2007;6():29-29.</p><p>Published online 10 Jul 2007</p><p>PMCID:PMC1939699.</p><p></p> The left or top panel represents the wavelet coherence (x-axis: year, y-axis: period, in years). Blue, low coherence; red, high coherence. The dotted lines show the α = 5% and α = 10% significance levels based on 500 bootstrapped series. The cone of influence (black curve) indicates the region not influenced by edge effects. The right or bottom panels represent the phase analyse between two countries (in blue and red), based on wavelets for a given periodic band (white band). Green boxes represents the period of time where coherency is significant, i.e. when the interpretation of analyse is possible. Blue lines: first country (name in blue); red lines: second country (name in red); dashed lines: time delay between the two oscillating components (ΔT)

Conceptual design of the AGATA 2<math display="inline" id="d1e396" altimg="si24.svg"><mi>π</mi></math> array at LNL

International audienceThe Advanced GAmma Tracking Array (AGATA) has been installed at Laboratori Nazionali di Legnaro (LNL), Italy. In this installation, AGATA will consist, at the beginning, of 13 AGATA triple clusters (ATCs) with an angular coverage of 1π, and progressively the number of ATCs will increase up to a 2π angular coverage. This setup will exploit both stable and radioactive ion beams delivered by the Tandem–PIAVE-ALPI accelerator complex and the SPES facility. The new implementation of AGATA at LNL will be used in two different configurations, firstly one coupled to the PRISMA large-acceptance magnetic spectrometer and lately a second one at Zero Degrees, along the beam line. These two configurations will allow us to cover a broad physics program, using different reaction mechanisms, such as Coulomb excitation, fusion-evaporation, transfer and fission at energies close to the Coulomb barrier. These setups have been designed to be coupled with a large variety of complementary detectors such as charged particle detectors, neutron detectors, heavy-ion detectors, high-energy γ-ray arrays, cryogenic and gasjet targets and the plunger device for lifetime measurements. We present in this paper the conceptual design, characteristics and performance figures of this implementation of AGATA at LNL

Conceptual design of the AGATA 2<math display="inline" id="d1e396" altimg="si24.svg"><mi>π</mi></math> array at LNL

International audienceThe Advanced GAmma Tracking Array (AGATA) has been installed at Laboratori Nazionali di Legnaro (LNL), Italy. In this installation, AGATA will consist, at the beginning, of 13 AGATA triple clusters (ATCs) with an angular coverage of 1π, and progressively the number of ATCs will increase up to a 2π angular coverage. This setup will exploit both stable and radioactive ion beams delivered by the Tandem–PIAVE-ALPI accelerator complex and the SPES facility. The new implementation of AGATA at LNL will be used in two different configurations, firstly one coupled to the PRISMA large-acceptance magnetic spectrometer and lately a second one at Zero Degrees, along the beam line. These two configurations will allow us to cover a broad physics program, using different reaction mechanisms, such as Coulomb excitation, fusion-evaporation, transfer and fission at energies close to the Coulomb barrier. These setups have been designed to be coupled with a large variety of complementary detectors such as charged particle detectors, neutron detectors, heavy-ion detectors, high-energy γ-ray arrays, cryogenic and gasjet targets and the plunger device for lifetime measurements. We present in this paper the conceptual design, characteristics and performance figures of this implementation of AGATA at LNL