Bites by Xenodon merremii (Wagler, 1824) and Xenodon neuwiedii (Günther, 1863) (Dipsadidae: Xenodontini) in São Paulo, Brazil: a retrospective observational study of 163 cases.
Toxicon
; 198: 24-31, 2021 Jul 30.
Article
in En
| MEDLINE
| ID: mdl-33932473
Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about their medical significance. Here, we describe the clinical, epidemiological, and biological aspects of bites by two colubroid species. We retrospectively analyzed cases of Xenodon merremii and Xenodon neuwiedii bites in which the offending snake was clearly identified. Analyses included variables related to the snake and the patient, including demographic data, clinical findings, and treatments. Of the 163 cases, 123 were bites by X. merremii and 40 by X. neuwiedii. Most bites occurred in spring and summer, predominantly during the daytime. Most offending snakes were female. Bites by X. merremii juveniles were more frequent in autumn than in other seasons, whereas those by X. neuwiedii adults were in the summer. Hands and feet were the most frequently affected regions, with no significant difference between upper and lower limbs bitten by either X. merremii or X. neuwiedii. The main clinical findings were pain, transitory bleeding, erythema, and local edema. Local edema was proportionally more frequent with X. neuwiedii bites than with X. merremii bites. No patient had extensive edema or systemic envenomation. A significant association between the snout-vent-length and transitory bleeding in bites by X. merremii, but not in those by X. neuwiedii, was identified. Whole blood clotting tests were normal in all tested patients (62 cases). Sixteen patients were incorrectly treated with anti-Bothrops antivenom. In conclusion, most accidents caused by X. merremii and X. neuwiedii present mild local symptomatology. These snakes can be mistaken for lance-headed vipers, and some bites present symptoms that resemble mild bites by Bothrops sp. Physicians should be aware of X. merremii and X. neuwiedii bites to avoid unnecessary patient distress and overprescription of antivenom.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Snake Bites
Type of study:
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Animals
/
Female
/
Humans
Country/Region as subject:
America do sul
/
Brasil
Language:
En
Journal:
Toxicon
Year:
2021
Document type:
Article
Affiliation country:
Brazil
Country of publication:
United kingdom