Abundance of impacted forest patches less than 5 km2 is a key driver of the incidence of malaria in Amazonian Brazil

• Published in: Scientific reports Vol. 8; no. 1; pp. 1 - 11
• Main Authors: Chaves, Leonardo Suveges Moreira, Conn, Jan E., López, Rossana Verónica Mendoza, Sallum, Maria Anice Mureb
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04.05.2018; Nature Publishing Group; Nature Portfolio
• Subjects: 692/499; 704/158/1469; 704/172/4081; Deforestation; Environmental conditions; Forest degradation; Forest products; Humanities and Social Sciences; Logging; Malaria; multidisciplinary; Science; Science (multidisciplinary); Vector-borne diseases; Brazil
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-018-25344-5

The precise role that deforestation for agricultural settlements and commercial forest products plays in promoting or inhibiting malaria incidence in Amazonian Brazil is controversial. Using publically available databases, we analyzed temporal malaria incidence (2009–2015) in municipalities of nine Amazonian states in relation to ecologically defined variables: (i) deforestation (rate of forest clearing over time); (ii) degraded forest (degree of human disturbance and openness of forest canopy for logging) and (iii) impacted forest (sum of deforested and degraded forest patches). We found that areas affected by one kilometer square of deforestation produced 27 new malaria cases (r² = 0.78; F1,10 = 35.81; P < 0.001). Unexpectedly, we found both a highly significant positive correlation between number of impacted forest patches less than 5 km 2 and malaria cases, and that these patch sizes accounted for greater than ~95% of all patches in the study area. There was a significantly negative correlation between extraction forestry economic indices and malaria cases. Our results emphasize not only that deforestation promotes malaria incidence, but also that it directly or indirectly results in a low Human Development Index, and favors environmental conditions that promote malaria vector proliferation.