Injuries Due to Venomous Insects and Plants
among Arizona Residents, 2010

Resources for the development of this report were provided through funding to the
Arizona Department of Health Services from the Centers for Disease and Control and
Prevention, Cooperative Agreement 1U17CE002023-01, Core Violence and Injury
Prevention Program
Permission to quote from or reproduce materials from this publication is granted when
acknowledgment is made.

Prepared by: Alana Shacter, MPH
th
150 North 18 Avenue, Suite 320
Phoenix, AZ 85007
Injury Prevention Program
Bureau of Women’s and Children’s Health
Arizona Department of Health Services
September 2011

This brief includes mortality data with an underlying cause of death coded to ICD-10 codes X20X29, and hospital discharge data coded to ICD-9 codes 905.0-905.9. The hospital discharge
data only include information from private, acute-care facilities. Data from urgent care centers or
federal facilities, including Indian Health Services or Veteran’s Administration facilities, are not
available.
In 2010, there were 2 fatalities among Arizona residents due to envenomations by insects or
reptiles. In the five year period from 2006 through 2010, 11 Arizona residents died from
envenomations by insects or reptiles; 45 percent of deaths resulted from bee stings (n=5).
Six thousand four hundred Arizona residents were hospitalized or treated in emergency
departments in 2010 for non-fatal insect or reptile envenomations. While males have higher
rates of injury than females for most types of injury, males and females had nearly identical ageadjusted rates of non-fatal insect or reptile envenomations. In 2010, there were 100.5 injuries
per 100,000 males (n=3,201) and 100.9 injuries per 100,000 females (n=3,198). There was one
injury to an individual of unknown sex.
The highest number of hospitalizations and emergency department visits due to envenomations
by insects or reptiles occurred during the hot summer months. There were not significant
differences in the distribution of cases by type of envenomation. Figure 1 shows the distribution
of cases by month.

Figure 1. Percentage of Non-Fatal Venomous Creature
Hospitalizations and Emergency Department Visits
by Month, Arizona, 2010 (n=6,400)
Percentage of Cases

16%
14%

14%

14%

14%
11%

12%
9%

10%
7%

8%

5%

6%
4%

4%
2%

14%

4%

3%
2%

0%
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
(n=154) (n=179) (n=255) (n=417) (n=578) (n=884) (n=927) (n=887) (n=872) (n=712) (n=297) (n=238)

Rural counties had the highest age-adjusted rates of hospitalizations and emergency
department visits for non-fatal injuries due to insect or reptile envenomations in 2010. While
there were 100.7 cases per 100,000 residents across Arizona, La Paz and Graham Counties
had rates three times that high (302.2 cases per 100,000 residents). Counties located at higher
elevations had lower rates of injuries related to venomous creatures; this is most likely
attributable to the fact that venomous invertebrates cannot survive in colder climates. There is
not a definitive reason regarding why Yuma County residents sought medical care at such a low
rate. It is possible that residents sought care on the local military base, resulting in an artificially
low rate. Figure 2 shows the age-adjusted rates of hospitalizations and emergency department
visits due to venomous creature injuries by county of residence.

1

Figure 2.

2

In 2010, there were 284 non-fatal inpatient hospitalizations among Arizona residents for
treatment of insect or reptile envenomations. Scorpion stings accounted for 18 percent of nonfatal inpatient hospitalizations (n=51). Bites by venomous snakes and lizards accounted for the
highest percentage of non-fatal inpatient hospitalizations (51 percent, n=145). Figure 3 shows
non-fatal inpatient hospitalizations by type of bite/sting.

Figure 3. Non-Fatal Inpatient Hospitalizations due to
Venomous Animals or Plants, Arizona 2010 (n=284)
Venomous spiders
5% (n=14)

Scorpions
18% (n=51)

Hornets, wasps,
bees
22% (n=63)

Venomous
snakes/lizards
51% (n=145)

Ants, caterpillars
3% (n=7)
Other or unspecified
venomous animal or
plant
1% (n=4)

Hospital charges for non-fatal inpatient hospitalizations due to venomous animals or plants
totaled more than $11.3 million, with an average hospital stay lasting 2 days and resulting in
$40,010 in hospital charges. The median hospital charge was $16,515. Arizona residents spent
a total of 503 days hospitalized, with the longest stay lasting 11 days. While scorpion stings
resulted in 18 percent of inpatient hospitalizations, they only accounted for 12 percent of the
hospital days, and 5 percent of the total charges.
Between 2004 and 2010, the age-adjusted rates of non-fatal inpatient hospitalizations increased
15 percent from 2.0 to 2.3 hospitalizations per 100,000 residents for injuries from venomous
snakes and lizards, though the rate declined between 2004 and 2008, with a sharp increase in
2009. The rate of hospitalizations due to scorpions decreased 53 percent from 1.7 to 0.8
hospitalizations per 100,000 residents. Figure 4 shows the age-adjusted rates of non-fatal
inpatient hospitalizations due to venomous reptiles and scorpions between 2004 and 2010.

3

Figure 4. Age-Adjusted Rate of Non-Fatal Inpatient
Hospitalizations Due to Selected Venomous Creatures
by Year, Arizona, 2004-2010
Age-Adjusted Rate per 100,000 Residents

3.0
2.7
2.5

2.3

2.0
2.0
1.5

2.3

2.2
1.8
1.5

1.7

1.5

1.2

1.0
0.5

0.9

0.9

0.8

2007

2008

2009

0.8

Venomous snakes and lizards
Scorpion

0.0
2004

2005

2006

2010

In 2010, there were 6,116 non-fatal emergency department visits by Arizona residents for
treatment of insect or reptile envenomations. Scorpion stings accounted for a majority of these
visits (57 percent, n=3,498). The second highest number of visits resulted from stings by
hornets, bees, and wasps (26 percent, n=1,606). Figure 5 shows non-fatal emergency
department visits by type of bite/sting.

Figure 5. Non-Fatal Emergency Department Visits due to
Venomous Animals or Plants, Arizona 2010 (n=6,116)
Hornets, wasps, bees
26% (n=1,606)
Centipede or tropical
millipede
1% (n=25)
Ants, caterpillars
6% (n=372)
Venomous marine
animal/plant
0% (n=18)
Scorpions
57% (n=3,498)

Other/Unspecified
venomous animal or
plant
2% (n=100)
Venomous
snakes/lizards
2% (n=135)
Venomous spiders
6% (n=362)

4

Among the 3,498 non-fatal emergency department visits due to scorpion stings in 2010, the
highest rate of events was among children ages 1 to 4 (136.4 ED visits per 100,000 residents).
Children ages 1 to 4 also had the highest age-specific rate of emergency department visits due
to hornet, wasp, and bee stings, the second leading cause of emergency department visits due
to venomous creatures (56.0 ED visits per 100,000 residents). Figure 6 shows the rate of nonfatal emergency department visits due to scorpion stings by age group, and Figure 7 shows the
rate of non-fatal emergency department visits due to hornets, wasps, and bee stings by age
group.

Figure 6. Rate of Non-Fatal Emergency Department Visits due to
Scorpion Stings per 100,000 Residents, Arizona 2010 (n=3,498)
Rate per 100,000 residents

160.0
136.4

140.0
120.0
100.0

71.5

80.0

58.4

60.0
40.0

51.5
45.7

42.3

44.2

34.8

39.8

42.8
25.1

20.0
0.0
Under 1
Year

1-4
Years

5-14
Years

15-24
Years

25-34
Years

35-44
Years

45-54
Years

55-64
Years

65-74
Years

75-84
Years

85 Years
and Older

Figure 7. Rate of Non-Fatal Emergency Department Visits due to
Hornet, Wasp, or Bee Stings per 100,000 Residents,
Arizona 2010 (n=1,606)
Rate per 100,000 residents

60.0

56.0

50.0
40.0

35.8
27.4

30.0

25.2

22.8

22.2

20.0

19.2

16.5
16.2

13.9
8.7

10.0
0.0
Under 1
Year

1-4
Years

5-14
Years

15-24
Years

25-34
Years

35-44
Years

45-54
Years

55-64
Years

65-74
Years

75-84
Years

85 Years
and Older

Hospital charges for non-fatal emergency department visits due to venomous animals or plants
totaled more than $8.5 million. Visits to treat scorpion stings totaled more than $3.8 million in

5

hospital charges. While scorpion stings resulted in 57 percent of the total non-fatal emergency
department visits for venomous animals or plants, they only accounted for 45 percent of the
total hospital charges. While the 2010 hospital charges are relatively low, charges for visits
related to scorpion envenomations are likely to increase in the future, due to the introduction of
a new antivenin to treat serious reactions, such as those occurring in young children and older
adults.
While the age-adjusted rate of non-fatal emergency department visits declined 41 percent
between 2004 and 2010 for bites from venomous spiders, the age-adjusted rates increased for
stings from scorpions and flying insects (73 percent and 46 percent, respectively). Figure 8
shows the age-adjusted rates of non-fatal emergency department visits due to selected
venomous creatures between 2004 and 2010 by year.

Figure 8. Age-Adjusted Rate of Non-Fatal Emergency
Department Visits Due to Selected Venomous Creatures
by Year, Arizona, 2004-2010

Age-Adjusted Rate per 100,000 Residents

60.0
Venomous snakes and lizards
Scorpion
Venomous spiders
Hornets, wasps, bees

50.0

55.0
49.8
41.0

40.0

40.9

36.3
31.8

31.7

30.0
22.4
20.0

25.3

4.6

5.8

20.4

19.2

17.3

25.1
16.5
9.9
10.0
2.0
0.0
2004

8.9

7.1
6.8

5.4

2.3

1.7

2.1

1.8

2005

2006

2007

2008

1.9
2009

2.1
2010

6

Figure 9. An Arizona Bark Scorpion

Figure 10. A Striped Scorpion

Source: http://phoenix.about.com/od/arizonapicturesandphotos/ig/Arizona-Bark-Scorpions/Scorpion-01.htm;
http://phoenix.about.com/od/arizonapicturesandphotos/ig/Arizona-Bark-Scorpions/Scorpion-06.htm

Hospital discharge data do not specify the species of scorpion, so it is not possible to further
classify injuries. Bark scorpions, as shown in Figure 9, are the most venomous scorpions in
North America, and extreme reactions to their stings can cause paralysis and convulsions,
though fatalities are rare. Medical attention is recommended for stings to pets, young children,
older adults, and people with compromised immune systems.
Visit the following websites for more information on Arizona’s venomous creatures:
The University of Arizona’s Cooperative Extension:
o Venomous Wildlife: http://cals.arizona.edu/pubs/natresources/az1481g
o Scorpions: http://ag.arizona.edu/pubs/insects/az1223.pdf
The Arizona Game and Fish Department:
http://www.azgfd.gov/w_c/nongameandendangeredwildlifeprogram/reptiles.shtml
Arizona’s Poison Control Centers:
o Banner Good Samaritan Poison & Drug Information Center:
http://www.bannerhealth.com/Locations/Arizona/Banner+Good+Samaritan+Poiso
n+and+Drug+Information+Center/_Banner+Poison+Control+Center.htm
o The University of Arizona College of Pharmacy Poison and Drug Information
Center: http://www.pharmacy.arizona.edu/outreach/poison/scorpions.php
The Arizona-Sonora Desert Museum:
http://www.desertmuseum.org/books/nhsd_inverts.php

7