Soil Dust Aerosols and Wind as Predictors of Seasonal Meningitis Incidence in Niger

Abstract

Background: Epidemics of meningococcal meningitis are concentrated in sub-Saharan Africa during the dry season, a period when the region is affected by the Harmattan, a dry and dusty northeasterly trade wind blowing from the Sahara into the Gulf of Guinea.Objectives: We examined the potential of climate-based statistical forecasting models to predict seasonal incidence of meningitis in Niger at both the national and district levels.Data and methods: We used time series of meningitis incidence from 1986 through 2006 for 38 districts in Niger. We tested models based on data that would be readily available in an operational framework, such as climate and dust, population, and the incidence of early cases before the onset of the meningitis season in January–May. Incidence was used as a proxy for immunological state, susceptibility, and carriage in the population. We compared a range of negative binomial generalized linear models fitted to the meningitis data.Results: At the national level, a model using early incidence in December and averaged November–December zonal wind provided the best fit (pseudo-R2 = 0.57), with zonal wind having the greatest impact. A model with surface dust concentration as a predictive variable performed indistinguishably well. At the district level, the best spatiotemporal model included zonal wind, dust concentration, early incidence in December, and population density (pseudo-R2 = 0.41).Conclusions: We showed that wind and dust information and incidence in the early dry season predict part of the year-to-year variability of the seasonal incidence of meningitis at both national and district levels in Niger. Models of this form could provide an early-season alert that wind, dust, and other conditions are potentially conducive to an epidemic.Citation: Pérez García-Pando C, Stanton MC, Diggle PJ, Trzaska S, Miller RL, Perlwitz JP, Baldasano JM, Cuevas E, Ceccato P, Yaka P, Thomson MC. 2014. Soil dust aerosols and wind as predictors of seasonal meningitis incidence in Niger. Environ Health Perspect 122:679–686; http://dx.doi.org/10.1289/ehp.1306640

Sand and Dust Storms: Impact Mitigation

“…However, the lack of understanding of causal links that characterize our appreciation of most dust-related ailments may still have an impact on appropriate mitigation advice. The incidence of epidemics in the Sahelian zone, the so-called Meningitis Belt, certainly appears to be related to Saharan dust intrusions brought by the Harmattan [114,115], but several possible explanations have been proposed for how dust may be linked causally to the epidemics (Table 4). Should the idea that higher meningitis transmission occurs because people gather together in close proximity during dusty periods, as suggested by Remy [116], prove to be valid, then advice to stay indoors may not be appropriate.…”

Validation of reactive gases and aerosols in the MACC global analysis and forecast system

“…More detailed validation results have been (and will be) described in several scientific papers from the individual partners of VAL Cuevas et al, 2015;Wagner et al, 2015;Langerock et al, 2015;Katragkou et al, 2015) or contributions to papers led by partners from other sub-projects of MACC Flemming et al, 2015;Pérez García-Pando et al, 2014;Stein et al, 2014;Cesnulyte et al, 2014). Several of these papers are submitted to the MACC special issue of the EGU Copernicus journals Atmospheric Chemistry and …”

An empirical equation to estimate mineral dust concentrations from visibility observations in Northern Africa

“…The empirical equation relating PM 10 and horizontal visibility obtained at IZO has been compared with empirical equations derived by other authors within the broad "dust belt" area (Prospero et al 2002;Ginoux et al, 2012) which extends from the west coast of Northern Africa, over the Middle East, Central and South Asia to China.…”

“…Griffin (2007) summarized the current state of knowledge of desert dust microbiology and the health impact that desert dust and its microbial constituents may have on downwind environments, both close and far from their sources. Saharan dust seems to be related with meningitis epidemics in the Sahel region (Thomson et al 2006, Pérez et al 2014) and increased incidence of pediatric asthma crisis in the Caribbean region (Gyan et al 2005). Stefanski and Sivakumar (2009) summarized the negative impacts of sand and dust storms on agriculture.…”

“…There is an increasing interest in quantifying the mineral dust concentration over North Africa, which is the most important dust source of the world (Prospero et al 2002;Washington et al, 2003;Shao et al 2011;Ginoux et al, 2012. However, air quality monitoring stations in rural sites or near dust sources over Northern Africa are almost inexistent.…”