Wound Infection of Snakebite from Venomous Protobothrops mucrosquamatus, Viridovipera stejnegeri and Naja atra in Taiwan: Validation of BITE and Cobra BITE Scoring Systems and their Bacteriological Differences in Wound Cultures

Abstract

Patients bitten by Protobothrops mucrosquamatus, Viridovipera stejnegeri, and Naja atra develop different degrees of wound infection. This study validated BITE and Cobra BITE scoring systems that we established previously. Bacteriological studies of patients with wound infection were conducted. The operating characteristic curves and area under the curve (AUC) and wound infection rates were compared between the derivation set (our previous study patient population) and the validation set (new patient cohorts enrolled between June 2017 and May 2021). No significant differences in the AUC for both the BITE (0.84 vs. 0.78, p = 0.27) and Cobra BITE (0.88 vs. 0.75, p = 0.21) scoring systems were observed between the derivation and validation sets. Morganella morganii and Enterococcus faecalis were the two most commonly detected bacteria in the microbiological study. More bacterial species were cultured from N. atra-infected wounds. Antibiotics such as amoxicillin with clavulanic acid, oxacillin, and ampicillin may not be suitable for treating patients with P. mucrosquamatus, V. stejnegeri, and N. atra bites in Taiwan. Carbapenem, third-generation cephalosporins, and fluoroquinolone may be superior alternatives.

Keywords: Naja atra; Protobothrops mucrosquamatus; Viridovipera stejnegeri; snakebites; wound infections.

Figure 1

(a) Wound infection rates determined using the BITE scores, and the X axe meant the BITE score points (b) Receiver operator characteristic curves for derivation and validation sets. The derivation set was the previous BITE study, and the area under the curve (AUC) was 0.8391. The AUC of the validation cohort was 0.7814. Both the derivation and validation AUC were >0.5. We suggest the administration of antibiotics to patients with a BITE score of 4 or 5 points.

Figure 1

(a) Wound infection rates determined using the BITE scores, and the X axe meant the BITE score points (b) Receiver operator characteristic curves for derivation and validation sets. The derivation set was the previous BITE study, and the area under the curve (AUC) was 0.8391. The AUC of the validation cohort was 0.7814. Both the derivation and validation AUC were >0.5. We suggest the administration of antibiotics to patients with a BITE score of 4 or 5 points.

Figure 2

(a) Wound infection rates determined using the Cobra BITE scoring system and the X axe meant the Cobra BITE score points (b) Receiver operator characteristic curves for derivation and validation sets. The derivation set was the previous Cobra BITE study, and the area under the curve (AUC) was 0.8780. The AUC of the validation cohort was 0.7500. Both the derivation and validation AUC were >0.5. Antibiotics should be given if the Cobra BITE score is ≥5.

Figure 3

The Cobra BITE score and the suggested antibiotics for patients bitten by Naja atra.

Figure 4

The BITE score and suggested antibiotics for patients bitten by Protobothrops mucrosquamatus and Viridovipera stejnegeri.