Microvertebrates preserved in mammal burrows from the Holocene of the Argentine Pampas: a taphonomic and paleoecological approach

Microvertebrates are a major component of many assemblages recovered from the Quaternary of the Argentine Pampas. The main goal of this paper is to analyse the taphonomic history of a Holocene microfossil bonebed, recovered from the infilling of a burrow. Evidences suggest the plains vizcacha Lagostomus maximus as the putative producer of the burrow. The assemblage includes individuals belonging to different taxa of mammals (marsupials and rodents) and reptiles (snakes). Taphonomic features suggest that the accumulation inside the burrow was related to flooding processes in the plain. The burrow was a natural trap that favoured the accumulation and preservation of remains corresponding to individuals from different sources. According to the taphonomic evidence, some individuals (Lagostomus maximus, Lestodelphys halli and Serpentes indet.) died inside the burrow, whereas others (Microcavia australis, Reithrodon auritus and Ctenomys sp.) died outside the burrow, and after a time of being exposed on the surface their remains were transported by surface run-offs into the burrow. The record of Lestodelphys halli and Serpentes indet. in the burrow produced by Lagostomus maximus could be related to a circumstantial use. Mammal burrows are a significant taphonomic mode for the late Cenozoic of the Argentine Pampas

Using Geographical Information Systems to Identify Populations in Need of Improved Accessibility to Antivenom Treatment for Snakebite Envenoming in Costa Rica

INTRODUCTION: Snakebite accidents are an important health problem in rural areas of tropical countries worldwide, including Costa Rica, where most bites are caused by the pit-viper Bothrops asper. The treatment of these potentially fatal accidents is based on the timely administration of specific antivenom. In many regions of the world, insufficient health care systems and lack of antivenom in remote and poor areas where snakebites are common, means that efficient treatment is unavailable for many snakebite victims, leading to unnecessary mortality and morbidity. In this study, geographical information systems (GIS) were used to identify populations in Costa Rica with a need of improved access to antivenom treatment: those living in areas with a high risk of snakebites and long time to reach antivenom treatment. METHOD/PRINCIPAL FINDINGS: Populations living in areas with high risk of snakebites were identified using two approaches: one based on the district-level reported incidence, and another based on mapping environmental factors favoring B. asper presence. Time to reach treatment using ambulance was estimated using cost surface analysis, thereby enabling adjustment of transportation speed by road availability and quality, topography and land use. By mapping populations in high risk of snakebites and the estimated time to treatment, populations with need of improved treatment access were identified. CONCLUSION/SIGNIFICANCE: This study demonstrates the usefulness of GIS for improving treatment of snakebites. By mapping reported incidence, risk factors, location of existing treatment resources, and the time estimated to reach these for at-risk populations, rational allocation of treatment resources is facilitated.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP

Snakebite Envenomingin Latin America and the Caribbean

Envenomings induced by snakebites constitute a serious public health problem in Latin America. This condition affects predominantly vulnerable rural populations and has a high impact in regions where the provision of health services is deficient. Most envenomings are provoked by species of the genera Bothrops and Crotalus, classified in the family Viperidae, whereas about 1 % of cases are due to Micrurus species (family Elapidae). There are laboratories in several countries in the region which manufacture antivenoms. Scientific and biotechnological research has generated a significant body of knowledge on snakes and their venoms and on antivenoms. Despite important advances in the control of these envenomings in Latin America, it is necessary to strengthen regional efforts in order to (a) improve the knowledge on snakes and their venoms; (b) acquire information on the incidence and mortality of snakebite envenomings; (c) increase the volume of antivenom produced and, in some cases, the quality of antivenoms; (d) improve the regulatory work of national quality control laboratories; (e) develop knowledge-based strategies of distribution of antivenoms; (f) consolidate continuous education programs for the health staff in charge of the treatment of these envenomings; (g) ensure support to people that suffer physical or psychological sequelae as a consequence of these envenomings; and (h) strengthen community programs aimed at improving the prevention and adequate management of snakebites. The development of inter-programmatic and inter-sectorial projects in this field should be promoted in the region, involving multiple actors and institutions, within a frame of regional cooperation programs.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto Clodomiro Picado (ICP)UCR::Vicerrectoría de Docencia::Salud::Facultad de Microbiologí