Venomous snakes of medical importance in the Brazilian state of Rio de Janeiro: habitat and taxonomy against ophidism.

Snakebite envenoming is a major global health problem that kills or disables half a million people in the world's poorest countries. Identifying the biting snake and its habitat use is key to understanding snakebite eco-epidemiology and optimizing its clinical management. To prevent and combat the neglected snakebite disease, we characterize the morphology, geographic distribution, habitat use, and snakebites of medically important venomous snakes in the state of Rio de Janeiro (Brazil). Despite Philodryas spp. not being considered of medical importance by the Brazilian Ministry of Health, we also explore their data once the bites may require medical intervention, may cause death, and their consequences are underestimated. Methods: We assessed taxonomy and geographic data from specimens housed in scientific collections, the literature, and the Notifiable Diseases Information System. Our data revealed fragility in the morphological characters recommended to distinguish Bothrops jararaca from B. jararacussu, identify the subspecies of Crotalus durissus and distinguish the species of Philodryas. To help identify these species, we present an identification key to the venomous snake species from Rio de Janeiro based on the morphological data collected. We record the genera Bothrops and Micrurus in all mesoregions of the state. Here, we provide the first record of C. durissus in the Serrana region, supporting the hypothesis of geographic expansion of the species in the state. The crotalic antivenom must not be missing in Médio Paraíba, Centro-Sul Fluminense, and Serrana, where the rattlesnake C. durissus occurs. Bothrops bilineatus and Lachesis muta have historical records presented for the first time herein. However, these species are likely endangered or extinct in the state. There were 7,483 snakebites reported between 2001 and 2019, with an annual average of 393.8 cases. The Bothrops genus is responsible for the majority of accidents. The highest number of cases occurred in the Serrana region, the largest pole of family agriculture in Rio de Janeiro. We improve the identification of venomous snake species, better delimit their distribution, and update the number of cases of snakebites, thus providing greater precision in the attention to this problem in Rio de Janeiro. We emphasize the importance of clinical studies to test using bothropic-crotalic antivenom and heparin in all mesoregions to treat B. jararacussu envenomation; and mechanical ventilation, atropine, and anticholinesterases in the emergency health centers in the Metropolitana and Norte Fluminense regions due to the occurrence of the coral M. lemniscatus in these areas.

Pentastomid infection in Philodryas nattereri Steindachner, 1870 and Oxybelis aeneus (Wagler, 1824) (Squamata: Colubridae) in a caatinga of northeastern Brazil.

The relationship between pentastomids and two Colubridae species, Phillodryas nattereri Steindachner, 1870 and Oxybelis aeneus (Wagler, 1824), were investigated in the federal government's reserve Estação Ecológica do Seridó (ESEC, Seridó) situated at lat 6 degrees 35'-40' S and long 37 degrees 15'-20 W in the municipality of Serra Negra do Norte, state of Rio Grande do Norte, Northeast Brazil and run by IBAMA (the Brazilian Institute for the Environment and Natural Resources). Throughout 2005, 26 specimens of snakes, 13 of P. nattereri and 13 of O. aeneus were collected. After anatomical dissection and laboratorial examination of the snakes respiratory tracts, P. nattereri was found to be parasitized by two species of pentastomids: Cephalobaena tetrapoda Heymons, 1922 with a prevalence of 30.8% and a mean intensity of infection of 51.5 +/- 32.7 (range 3-147), and Raillietiella furcocerca (Diesing, 1863) which had a prevalence of 7.7% and a mean intensity of infection of 1.0. Only one female of O. aeneus was found to be infected by C. tetrapoda, with a prevalence of 7.7% and mean intensity of infection of 2.0. There was no significant relationship between size of snout-vent length (SVL) and intensity of infection in the specimens investigated here. The two individuals of P. nattereri infected by more than 40 specimens of pentastomids had their lungs completely infected including the pulmonary peritoneum and trachea. It is noteworthy that the hosts had their lung tissues partially destroyed with apparent haemorrhage, and the trabecular structure of their lungs was also destroyed. The contrasting rates of infection estimated here may be related to differences in foraging strategies, in diet, and habitat selection carried out by individuals of P. nattereri and O. aeneus.

Pentastomid infection in Philodryas nattereri Steindachner, 1870 and Oxybelis aeneus (Wagler, 1824) (Squamata: Colubridae) in a caatinga of northeastern Brazil

The relationship between pentastomids and two Colubridae species, Phillodryas nattereri Steindachner, 1870 and Oxybelis aeneus (Wagler, 1824), were investigated in the federal government’s reserve Estação Ecológica do Seridó (ESEC, Seridó) situated at lat 6° 35’-40’ S and long 37° 15’-20 W in the municipality of Serra Negra do Norte, state of Rio Grande do Norte, Northeast Brazil and run by IBAMA (the Brazilian Institute for the Environment and Natural Resources). Throughout 2005, 26 specimens of snakes, 13 of P. nattereri and 13 of O. aeneus were collected. After anatomical dissection and laboratorial examination of the snakes’ respiratory tracts, P. nattereri was found to be parasitized by two species of pentastomids: Cephalobaena tetrapoda Heymons, 1922 with a prevalence of 30.8 percent and a mean intensity of infection of 51.5 ± 32.7 (range 3-147), and Raillietiella furcocerca (Diesing, 1863) which had a prevalence of 7.7 percent and a mean intensity of infection of 1.0. Only one female of O. aeneus was found to be infected by C. tetrapoda, with a prevalence of 7.7 percent and mean intensity of infection of 2.0. There was no significant relationship between size of snout-vent length (SVL) and intensity of infection in the specimens investigated here. The two individuals of P. nattereri infected by more than 40 specimens of pentastomids had their lungs completely infected including the pulmonary peritoneum and trachea. It is noteworthy that the hosts had their lung tissues partially destroyed with apparent haemorrhage, and the trabecular structure of their lungs was also destroyed. The contrasting rates of infection estimated here may be related to differences in foraging strategies, in diet, and habitat selection carried out by individuals of P. nattereri and O. aeneus.

As relações entre pentastomídeos e duas espécies de Colubridae, Phillodryas nattereri Steindachner, 1870 e Oxybelis aeneus (Wagler, 1824), foram investigadas na Estação Ecológica do Seridó (ESEC-Seridó) situada em 6° 35’ - 40’S e 37°15’ - 20’W no município de Serra Negra do Norte, Estado do Rio Grande do Norte, Nordeste do Brasil, mantida pelo IBAMA (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis). Ao longo de 2005 foram coletados 26 espécimes de serpentes, sendo 13 de P. nattereri e 13 de O. aeneus. Depois da dissecação dos espécimes e exame em laboratório do trato respiratório, foram encontradas duas espécies de pentastomídeos parasitando P. nattereri: Cephalobaena tetrapoda Heymons, 1922 com prevalência 30.8 por cento, intensidade média de infecção 51.5 ± 32.7 (amplitude de 3-147) e Raillietiella furcocerca (Diesing, 1863) com prevalência 7.7 por cento e intensidade média de infecção 1.0. Apenas uma fêmea de O. aeneus estava infectada por C. tetrapoda com prevalência 7.7 por cento e intensidade de infecção 2.0. Não houve relação significativa entre o comprimento rostro-anal (SVL) e a intensidade de infecção nos espécimes coletados. Os dois indivíduos de P. nattereri com infecção por pentastomídeos em número superior a 40 tinham seus pulmões completamente infectados por esses parasitas, incluindo a traquéia e peritônio pulmonar. Esses indivíduos possuíam seus pulmões gradualmente destruídos, hemorragias aparentes e partes da estrutura trabecular dos pulmões destruída. As taxas de infecção contrastantes estimadas aqui podem estar relacionadas com as diferenças de estratégias de forrageamento, dieta e seleção de habitats por P. nattereri e O. aeneus.