United States Snakebite Data

American farmers are at high risk from animal-associated injuries. Surveys by the National Safety Council found animals accounting for 17% of all nonfatal farm injuries, second only to agricultural machinery. In an epidemiology study from 1979 to 1990, animals were responsible for 3.6% of all farm deaths, and there were 66 deaths from snakebites, accounting for 3.5% of all animal-related deaths (19,20).

About 45,000 snakebites are reported in the United States annually, with approximately 8,000 venomous bites, but only about 6 to 15 persons die each year. There were only two snakebite fatalities reported to poison control centers in 2002 (Table 32.2), and both were related to rattlesnake bites.

Table 32.2. Statistics on snakebites in United States, based on 2002 annual report of the AAPCC toxic exposure surveillance system.

Type of snake

No. of bites

% of venomous bites

Rattlesnake

1150

47%

Copperhead

889

36

Cottonmouth

173

7

Crotaline: unknown

25

1

Coral

88

4

Exotic snake-poisonous

125

5

Total venomous snakebites

2450

100%

Exotic (non-poisonous)

155

Exotic (unknown if poisonous )

7

Nonpoisonous

1976

Unknown snake

2145

Total snakebites reported

6733

Source: Data from Watson WA et al. (29).

Source: Data from Watson WA et al. (29).

Crotalidae accounted for 91% of the reported venomous bites (4,9,10,20-29).

Herpetologists define an exotic snake as one out of its normal geographic range. Emergency physicians may have difficulty with an exotic snakebite because of erroneous reporting by the illicit collector, limited knowledge of the clinical presentation of the envenomation, and lack of locally available antivenin. Most estimates of poisonous snakebites by exotic nonnative species are in the 3% to 5% range (8,29,30).

The highest snakebite rates are found in southern states. Most bites occur from April to October. The optimal temperature range for snakes is 27°C to 32°C (80°C to 90°F), which occurs at night in the southwestern desert and in the evening in southern states. Snakebites are most common in young men who have purposely handled a venomous snake and often have consumed alcohol prior to the encounter. Of intentional exposures 35% occurred in an occupational setting such as professional snake handling and snake hunts (11,24,25,27,28).

0 0

Post a comment