Drought, desertification and poverty: A geospatial analysis of snakebite envenoming in the Caatinga biome of Brazil

• Published in: The International journal of health planning and management Vol. 36; no. 5; pp. 1685 - 1696
• Main Authors: Jucá, Thiago L., Oliveira Normando, Leonardo R., Ibrahim, Abdulrazak B., Chapeaurouge, Alex, Cristina de Oliveira Monteiro‐Moreira, Ana, Mackessy, Stephen P.
• Format: Journal Article
• Language: English
• Published: Chichester Wiley Subscription Services, Inc 01.09.2021
• Subjects: climate change; Desertification; Drought; Environmental changes; Epidemiology; Human development; Pasture; Poverty; Principal components analysis; Public health; Rain; Rainfall; Risk analysis; Risk factors; Scarcity; Snake bites; Snakes; Social factors; Socioeconomic factors; Spatial analysis; spearman correlation; state of Ceará; Surveillance systems; Venom; Water scarcity; Brazil
• ISSN: 0749-6753; 1099-1751; 1099-1751
• DOI: 10.1002/hpm.3180

Epidemiological data on snakebite in the Brazilian state of Ceará are scarce, as the only report on this subject was last published in 1997. However, according to the Brazilian system of recording disease incidents (Sistema de Informação de Agravos de Notificação [SINAN]), more than 13,000 snakebites have been registered since 2001 in the state of Ceará, making this disease an important public health issue. In the present study, we evaluate the influence of environmental changes, including drought and desertification, on the risk of snakebite envenoming in the Brazilian northeastern state of Ceará. We compare public data on snakebites from Brazilian Epidemiological Surveillance System (DATASUS), rainfall records, advanced desertification maps, pastures and socioeconomic information of the 184 municipals in Ceará between 2001 and 2017. During the period of investigation, 8,945 snakebites were recorded, the majority (93.8%) of which involved venomous snakes. Almost half of the municipals (48%) had 100 incidences or more per 100,000 inhabitants. Data collected also highlight month‐to‐month occurrences of snakebites, with trends to rise shortly after the onset of precipitation, peaking in July and then trending downward as rainfall decreases, reaching the lowest level in December. We deduce an inverse relationship between Human Development Index (HDI) and snakebites per area. Spearman correlation and principal component analysis support the hypothesis that water scarcity and desertification are linked to increased risk of snakebite envenoming. Our study indicates that besides poverty, dry and desertified areas represent risk factors associated with increased incidence of snakebite envenoming in the state of Ceará.