Wind: a neglected factor in the spread of infectious diseases
Authors: Joel H Ellwanger, José A B Chies
Journal: The Lancet Planetary Health (2018)

Emerging and reemerging infectious diseases can result from unbalanced human, animal, and environmental factors. This concept belongs to the One Health perspective and has a growing role in discussions on global health. In addition to affecting the emergence of new or neglected infectious diseases or even the maintenance of a given condition at a population level, different factors of the One Health triad (humans, non-human animals, and environment) also have an effect on human-to-human transmission of pathogens. For example, host genetic traits might increase or decrease individual susceptibility to viral diseases,1Ellwanger JH Zambra FMB Guimarães RL Chies JAB MicroRNA-related polymorphisms in infectious diseases—tiny changes with a huge impact on viral infections and potential clinical applications.Front Immunol. 2018; 9: 1316Crossref Scopus (17) Google Scholar zoonoses can be transmitted from wild animals to humans due to the sharing of habitats or deforestation and hunting,2Wolfe ND Daszak P Kilpatrick AM Burke DS Bushmeat hunting, deforestation, and prediction of zoonoses emergence.Emerg Infect Dis. 2005; 11: 1822-1827Crossref PubMed Scopus (391) Google Scholar and unregulated urbanisation and bad sanitation could increase the occurrence of mosquito breeding sites, favouring the transmission of arthropod-borne diseases.3Zahouli JBZ Koudou BG Müller P Malone D Tano Y Utzinger J Urbanization is a main driver for the larval ecology of Aedes mosquitoes in arbovirus-endemic settings in south-eastern Côte d'Ivoire.PLoS Negl Trop Dis. 2017; 11: e0005751Crossref Scopus (56) Google Scholar The aforementioned examples are classic and even considered commonplace when analysing the factors involved in the dynamics of the spread of infectious diseases, although often they are unable to provide us with a complete understanding of the complex behaviour of certain outbreaks. In this sense, the identification of neglected factors within the One Health components is urgently needed. In our view, the study by Noriko Endo and Elfatih Eltahir4Endo N Eltahir EA Prevention of malaria transmission around reservoirs: an observational and modelling study on the effect of wind direction and village location.Lancet Planet Health. 2018; 2: e406-e413Summary Full Text Full Text PDF PubMed Scopus (9) Google Scholar published in The Lancet Planetary Health (Sep 1, p e406–13) is an important contribution, because it shows that the wind speed and direction affect malaria transmission. The simplicity and the beauty of the proposed model, relies on the fact that such factors naturally affect the behavior of Anopheles mosquitoes. The main points of this study that we would like to highlight is that no extreme environmental alterations, including degradation of the natural environment, were needed to identify and explain potential differences in the dynamics of mosquito populations. Instead, the authors considered naturally occurring components. Although the study's conclusions were obtained from the analysis of a single scenario and pathogen, they have broader implications. They indicate that wind should be taken into account as a crucial factor in the transmission of various diseases, not just those that are air-borne, because it could modulate the dynamics of different vectors and pathogens. In other words, despite being relatively neglected and mainly considered in terms of its direct effects on pathogen dispersion, wind's capacity to carry and disperse signal molecules (eg, CO2), or other as yet unidentified features, make it a more important factor in the environmental component of the One Health concept. The consequences of our associations and contact with other species, and of the human activity on natural or modified environments, are issues that are continuously raised and discussed. Practical recommendations on preservation of biodiversity and prevention of disease emergence from the close contact between humans and the natural world have recently been published in Brazil.5Fundação Oswaldo CruzPlataforma Institucional Biodiversidade e Saúde SilvestreBiodiversidade faz bem à saúde: guia prático. Plataforma Institucional Biodiversidade e Saúde Silvestre, Rio de Janeiro2017https://www.biodiversidade.ciss.fiocruz.br/sites/www.biodiversidade.ciss.fiocruz.br/files/Guia_Biodiversidade_Saude.pdfDate accessed: September 3, 2018Google Scholar In line with this initiative, Endo and Eltahir4Endo N Eltahir EA Prevention of malaria transmission around reservoirs: an observational and modelling study on the effect of wind direction and village location.Lancet Planet Health. 2018; 2: e406-e413Summary Full Text Full Text PDF PubMed Scopus (9) Google Scholar suggest actions focused on counteracting some of the unwanted effects of wind on malaria transmission, including that "villages should be located downwind of reservoirs to reduce the incidence of malaria". Turning the results of scientific studies into functionally applicable recommendations is not always possible, but such attempts should be encouraged. Taken together, the findings discussed here point to the urgent need for inclusion of the effects of wind in the One Health approach focused on understanding and control of arthropod-borne diseases. The potential effects of wind on the behaviour of other vectors must also be investigated. JHE reports funding from Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, outside the submitted work. JABC reports funding from Conselho Nacional de Desenvolvimento Científico e Technológico, outside the submitted work. Prevention of malaria transmission around reservoirs: an observational and modelling study on the effect of wind direction and village locationThe effect of wind on malaria transmission around reservoirs can be substantial. The transmission of malaria can be minimised if the location of villages situated near a reservoir is carefully considered. For areas in which the environmental conditions surrounding a resevoir are equal, villages should be located downwind of reservoirs to reduce the incidence of malaria, although further research will be required in locations where wind direction changes in different seasons. Full-Text PDF Open AccessWind: a neglected factor in the spread of infectious diseases – Authors' replyWe thank Joel Ellwanger and José Chies for their Correspondence regarding our Article.3 This Correspondence resonates with theirs and highlights a neglected approach in One Health from a larger perspective. Full-Text PDF Open Access