Snakebites in "Invisible Populations": A cross-sectional survey in riverine populations in the remote western Brazilian Amazon

PLoS Negl Trop Dis. 2021 Sep 9;15(9):e0009758. doi: 10.1371/journal.pntd.0009758. eCollection 2021 Sep.


In the Brazilian Amazon, long distances, low healthcare coverage, common use of ineffective or deleterious self-care practices, and resistance to seeking medical assistance have an impact on access to antivenom treatment. This study aimed to estimate snakebite underreporting, and analyze barriers that prevent victims from obtaining healthcare in communities located in 15 municipalities on the banks of the Solimões, Juruá and Purus Rivers, in the remote Western Brazilian Amazon. Information on the participants' demographics, previous snakebites, access to healthcare, time taken to reach medical assistance, use of self-care practices, and the reason for not accessing healthcare were collected through semi-structured interviews. In the case of deaths, information was collected by interviewing parents, relatives or acquaintances. A total of 172 participants who reported having suffered snakebites during their lifetime were interviewed. A total of 73 different treatment procedures was reported by 65.1% of the participants. Participants living in different river basins share few self-care procedures that use traditional medicine, and 91 (52.9%) participants reported that they had access to healthcare. Living in communities along the Juruá River [OR = 12.6 (95% CI = 3.2-49.7; p<0.001)] and the use of traditional medicine [OR = 11.6 (95% CI = 3.4-39.8; p<0.001)] were variables that were independently associated to the lack of access to healthcare. The main reasons for not accessing healthcare were the pprioritization of traditional treatments (70.4%), and the failure to recognize the situation as being potentially severe (50.6%). Four deaths from complications arising from the snakebite were reported, and three of these were from communities on the banks of the Juruá River. Only one of these received medical assistance. We found an unexpectedly high underreporting of snakebite cases and associated deaths. Snakebite victims utilized three main different healing systems: 1) self-care using miscellaneous techniques; 2) official medical healthcare generally combined with traditional practices; and 3) self-care using traditional practices combined with Western medicines. To mitigate snakebite burden in the Brazilian Amazon, an innovative intervention that would optimize timely delivery of care, including antivenom distribution among existing community healthcare centers, is needed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antivenins
  • Brazil / epidemiology
  • Community Health Services / organization & administration
  • Cross-Sectional Studies
  • Demography*
  • Health Services Accessibility*
  • Humans
  • Medicine, Traditional
  • Rivers*
  • Rural Population*
  • Self Care
  • Snake Bites / epidemiology*


  • Antivenins

Grants and funding

This research was funded by Fundação de Amparo à Pesquisa do Estado do Amazonas - FAPEAM (PAREV 007/2019, to JS, and PRÓ-ESTADO and POSGRAD calls, to WM) and by the Ministry of Health, Brazil (proposal no. 733781/19-035, to ML). ML (308748/2017-4), PSB (311509/2020-7)), and WM (309207/2020-7) are research fellows from CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.