Snakebites as a largely neglected problem in the Brazilian Amazon: highlights of the epidemiological trends in the State of Amazonas

Abstract

34www.scielo.br/rsbmt I www.rsbmt.org.br Revista da Sociedade Brasileira de Medicina Tropical 48(Suppl I):34-41, 2015http://dx.doi. org/10.1590/0037-8682-0105-2013 Review Article ABSTRACT Envenoming snakebites are thought to be a particularly important threat to public health worldwide, especially in rural areas of tropical and subtropical countries. The true magnitude of the public health threat posed by snakebites is unknown, making it diffi cult for public health offi cials to optimize prevention and treatment. The objective of this work was to conduct a systematic review of the literature to gather data on snakebite epidemiology in the Amazon region and describe a case series of snakebites from epidemiological surveillance in the State of Amazonas (1974Amazonas ( -2012. Only 11 articles regarding snakebites were found. In the State of Amazonas, information regarding incidents involving snakes is scarce. Historical trends show an increasing number of cases after the second half of the 1980s. Snakebites predominated among adults (20-39 years old; 38%), in the male gender (78.9%) and in those living in rural areas (85.6%). The predominant snake envenomation type was bothropic. The incidence reported by the epidemiological surveillance in the State of Amazonas, reaching up to 200 cases/100,000 inhabitants in some areas, is among the highest annual snakebite incidence rates of any region in the world. The majority of the cases were reported in the rainy season with a case-fatality rate of 0.6%. Snakebite envenomation is a great disease burden in the State of Amazonas, representing a challenge for future investigations, including approaches to estimating incidence under-notifi cation and casefatality rates as well as the factors related to severity and disabilities.

Stepping into a dangerous quagmire: environmental determinants of human-lancehead pit vipers (Bothropsgenus) contact resulting in injuries, Brazilian Amazon

“…In the Brazilian Amazon, although urban population predominates, most of the snakebites were recorded in adult males living in rural areas. This epidemiological profile was reported previously in the Amazon (35,36), and probably is related to a significant higher exposition of this population group when exerting agricultural or forestry activities, in the habitat mostly selected by lancehead pit vipers. Several studies have reported on habitat use by B. atrox, the easiest snake to find in comparison to other species in Central Amazonia (46), and concluded that the species is mainly found on the ground or climb into understory vegetation, in the case of juveniles (15)(16)(17).…”

“…In the Brazilian Amazon, snakebites are under the influence of precipitation, likely because snakes in the Amazon exhibit increased activity during months with heaviest rainfall. Moreover, in this period, the snakes look for upland areas during flooding, which increases the likelihood of contact between humans and snakes (35,36). The contact between snakes and human populations is often associated with extractive or agricultural activities, which can increase snakebite burden in…”

Epidemiological transition of tropical diseases in the Brazilian Amazon

“…The review by Feitosa et al (11) systematically addresses snake bites as one of the most neglected problems in the Amazon region. This review demonstrates the magnitude of this type of envenoming in a background of lack of information, calling for a more aggressive approach by the authorities and affected communities to implement an appropriate surveillance system and promote the reduction of risk in the affected populations as well as ensuring access to timely treatment.…”

“…This review demonstrates the magnitude of this type of envenoming in a background of lack of information, calling for a more aggressive approach by the authorities and affected communities to implement an appropriate surveillance system and promote the reduction of risk in the affected populations as well as ensuring access to timely treatment. Despite the low mortality registered, the sequelae of severe poisoning are important and timely treatment would reduce both harmful sequelae and mortality (11) .…”

Incidence of snakebites from 2007 to 2014 in the State of São Paulo, Southeast Brazil, using a Bayesian time series model

“…Information systems with a good performance are needed for adequate surveillance of the number of accidents per geographical region, types of venom, and the consequences of the bites (2) . Records of these accidents are useful to reduce the incidence by promoting health education and to decrease their severity, frequency of sequelae, and lethality (4) .…”