Rabies surveillance in the United States during 2007

SUMMARY: During 2007, 49 states and Puerto Rico reported 7,258 cases of rabies in animals and 1 case in a human to the CDC, representing a 4.6% increase from the 6,940 cases in animals and 3 cases in humans reported in 2006. Approximately 93% of the cases were in wildlife, and 7% were in domestic animals. Relative contributions by the major animal groups were as follows: 2,659 raccoons (36.6%), 1,973 bats (27.2%), 1,478 skunks (20.4%), 489 foxes (6.7%), 274 cats (3.8%), 93 dogs (1.3%), and 57 cattle (0.8%). Compared with numbers of reported cases in 2006, cases in 2007 increased among dogs, bats, foxes, and skunks while decreases were reported among cattle, cats, and skunks. Increases in numbers of rabid raccoons during 2007 were reported by 11 of the 20 eastern states where raccoon rabies was enzootic, and reported cases increased by 1.7% overall, compared with 2006. On a national level, the number of rabies cases in skunks during 2007 decreased by 1.1% from the number reported in 2006. Texas reported the greatest number (n = 362) of rabid skunks and the greatest overall state total of animal rabies cases (969). No cases of rabies associated with the dog/coyote rabies virus variant were reported. The United States remains free of dog-to-dog transmission of canine rabies virus variants. The total number of cases of rabies reported nationally in foxes increased 14.5%, compared with 2006. Increases in the number of reported rabid foxes were attributable to greater numbers of foxes reported with the Arctic fox rabies virus variant in Alaska, the Texas gray fox rabies virus variant in Texas, and the raccoon rabies virus variant in Virginia. The 1,973 cases of rabies reported in bats represented a 16.6% increase over numbers reported in 2006. Cases of rabies in dogs and in sheep and goats increased 17.7% and 18.2%, respectively, whereas cases reported in cattle, cats, and horses and mules decreased 30.5%, 13.8%, and 20.8%, respectively. In Puerto Rico, reported cases of rabies in mongooses decreased 51.5%, and rabies in domestic animals, presumably attributable to spillover infection from mongooses, increased 25%. One human rabies case was reported from Minnesota during 2007. Although typing of the rabies virus variant in this case was not possible, an investigation of this case indicated a bat as the most likely source of exposure.     

Rabies surveillance in the United States during 2005

During 2005, 49 states and Puerto Rico reported 6,417 cases of rabies in nonhuman animals and 1 case in a human being to the CDC, representing a 6.2% decrease from the 6,836 cases in nonhuman animals and 8 cases in human beings reported in 2004. Approximately 92% of the cases were in wildlife, and 8% were in domestic animals. Relative contributions by the major animal groups were as follows: 2,534 raccoons (39.5%), 1,478 skunks (23%), 1,408 bats (21.9%), 376 foxes (5.9%), 269 cats (4.2%), 93 cattle (1.5%), and 76 dogs (1.2%). Compared with numbers of reported cases in 2004, cases in 2005 decreased among all groups, except bats, horses, and other wild animals. Decreases in numbers of rabid raccoons during 2005 were reported by 10 of the 20 eastern states in which raccoon rabies was enzootic and decreased overall by 1.2%, compared with 2004. On a national level, the number of rabies cases in skunks during 2005 decreased 20.4% from the number reported in 2004. Once again, Texas reported the greatest number (n = 392) of rabid skunks and the greatest overall state total of rabies cases (741). Texas reported no cases of rabies associated with the dog/coyote rabies virus variant and only 8 cases associated with the Texas gray fox rabies virus variant (compared with 22 cases in 2004). The total number of cases of rabies reported nationally in foxes decreased 3.3%, compared with those reported in 2004. The 1,408 cases of rabies reported in bats represented a 3.5% increase over numbers reported in 2005. Cases of rabies in cats, dogs, cattle, and sheep and goats decreased 4.3%, 19.2%, 19.1%, and 10%, respectively, whereas cases reported in horses and mules increased 9.3%. In Puerto Rico, reported cases of rabies in mongooses increased 29.8%, and rabies in domestic animals decreased 37.5%. One case of human rabies was reported from Mississippi during 2005. This case was submitted by the state to the CDC's unexplained deaths project and diagnosed as rabies retrospectively.     

Rabies surveillance in the United States during 2002

During 2002, 49 states and Puerto Rico reported 7,967 cases of rabies in nonhuman animals and 3 cases in human beings to the Centers for Disease Control and Prevention, an increase of 7.2% from the 7,436 cases in non-human animals and 1 case in a human being reported in 2001. More than 92% (7,375 cases) were in wild animals, whereas 7.4% (592) were in domestic species (compared with 93.3% in wild animals and 6.7% in domestic species in 2001). Compared with cases reported in 2001, the numbers of cases reported in 2002 increased among all major reporting groups with the exception of swine and rodents and lagomorphs. The relative contributions of the major groups of animals were as follows: raccoons (36.3%; 2,891 cases), skunks (30.5%; 2,433), bats (17.2%; 1,373), foxes (6.4%; 508), cats (3.8%; 299), dogs (1.2%; 99), and cattle (1.5%; 116). Thirteen of the 19 states in which the raccoon-associated variant of the rabies virus has been enzootic reported increases in the numbers of rabid raccoons during 2002. Among those states that have engaged in wildlife rabies control programs, Ohio reported 1 case of raccoon rabies associated with the epizootic of rabies in raccoons and 1 case in an equid that was infected with a bat variant of the rabies virus, compared with 2 cases reported in terrestrial animals during 2001. Texas reported no cases of rabies associated with the dog/coyote variant of the rabies virus (compared with 1 case in 2001) and 65 cases associated with the gray fox variant of the virus (an increase of 225% from 20 cases reported in 2001). In Massachusetts and Rhode Island, states with enzootic raccoon rabies, reports of rabid skunks again exceeded those of rabid raccoons (the sixth consecutive year, although in Rhode Island, this difference decreased to only 7 more skunks than raccoons [38/31]). Tennessee reported a single case of raccoon rabies in a pet raccoon from the central part of the state; the captive animal had been transported toTennessee from northern Georgia. Nationally, the number of rabies cases in skunks during 2002 increased by 6.6% over those reported in 2001. Texas reported the greatest number (740) of rabid skunks and the greatest overall state total of rabies cases (1,049) during 2002. The 1,373 cases of rabies reported in bats during 2002 surpassed the previous year's record (1,281 cases) as the largest number of reported cases ever recorded for this group of mammals. Cases of rabies reported in cats (299), cattle (116), and dogs (99) increased by 10.7%, 41.5%, and 11.24%, respectively, from 2001 to 2002. Rabies among sheep and goats increased 400% from 3 cases in 2001 to 15 in 2002, and cases among horses and mules increased 13.7% (51 cases in 2001 to 58 in 2002). Reported cases of rabies in mongooses in Puerto Rico decreased 4.3% from the previous year (70 cases in 2001 to 67 cases in 2002), while cases of rabies in dogs increased 77% (13 to 14). California, Tennessee, and Iowa each reported a case of rabies in a human being during 2002. All cases of rabies in humans were the result of infection with bat variants of the rabies virus.     

Rabies surveillance in the United States during 2011

Summary-During 2011, 49 states and Puerto Rico reported 6,031 rabid animals and 6 human rabies cases to the CDC, representing a 1.9% decrease from the 6,153 rabid animals and 2 human cases reported in 2010. Approximately 92% of reported rabid animals were wildlife. Relative contributions by the major animal groups were as follows: 1,981 raccoons (32.8%), 1,627 skunks (27.0%), 1,380 bats (22.9%), 427 foxes (7.1%), 303 cats (5.0%), 65 cattle (1.1%), and 70 dogs (1.2%). Compared with 2010, there was a substantial increase in the number of rabid skunks reported. Six cases of rabies involving humans were reported from California, Massachusetts, New Jersey, New York, and South Carolina. Three cases reported from Massachusetts, New Jersey, and New York were determined to be a result of canine rabies virus variants acquired outside the United States.     

Rabies surveillance in the United States during 1999

During 1999, 49 states, the District of Columbia, and Puerto Rico reported 7,067 cases of rabies in nonhuman animals to the Centers for Disease Control and Prevention, a decrease of 11.2% from 7,961 cases in nonhuman animals and 1 case in a human being reported in 1998. More than 91% (6,466 cases) were in wild animals, whereas 8.5% (601 cases) were in domestic species (compared with 92.4% in wild animals and 7.6% in domestic species in 1998). No cases of rabies were reported in human beings in 1999. Decreases were evident in all major species groups, with the exception of cattle, sheep/goats, and swine. The relative contributions of the major groups to the total reported were as follows: raccoons (41.0%; 2,872 cases), skunks (29.4%; 2,076), bats (14.0%; 989), foxes (5.4%; 384), cats (3.9%; 278), cattle (1.9%; 135), and dogs (1.6%; 111). Reported cases (6) associated with the epizootic of rabies in raccoons in Ohio declined from the 26 cases reported in 1998. Fifteen of the 19 states where the raccoon variant of the rabies virus is enzootic reported fewer cases of rabies during 1999. Massachusetts and Rhode Island, states with enzootic rabies in raccoons, each reported more rabid skunks than rabid raccoons for the third consecutive year. In Texas, cases associated with the enzootic canine variants of the rabies virus remained low (10 cases), whereas cases associated with the gray fox variant of the virus increased (66). Cases of rabies in skunks decreased by 8.6%, compared with those reported in 1998. Michigan reported the largest percentage increase in rabid skunks (950.0%; 2 cases in 1998 to 21 in 1999). Cases of rabies in horses and mules declined 21%, from 82 cases in 1998 to 65 in 1999. Cases of rabies reported in bats (989) were similar in number to those reported in 1998 (992) and represented almost 14.0% of the total number of rabid animals reported during 1999. Reported cases of rabies in cats (278) and dogs (111) decreased by 1.4% and 1.8%, respectively, whereas cases in cattle (135) increased by 16.4%, compared with those reported in 1998.     

Rabies surveillance in the United States during 1998

During 1998, 49 states, the District of Columbia, and Puerto Rico reported 7,961 cases of rabies in nonhuman animals and 1 case in a human being to the Centers for Disease Control and Prevention, a decrease of 6.5% from 8,509 cases in nonhuman animals and 4 cases in human beings reported in 1997. More than 92% (7,358 cases) were in wild animals, whereas > 7.5% (603 cases) were in domestic species (compared with 93% in wild animals and 7% in domestic species in 1997). Decreases were evident in all of the major contributing species groups, with the exception of skunks and bats. The relative contributions of the major groups to the total reported for 1998 were reccoons (44.0%; 3,502 cases), skunks (28.5%; 2,272), bats (12.5%; 992), foxes (5.5%; 435), cats (3.5%; 282), cattle (1.5%; 116), and dogs (11.5%; 113). No further discernable westward extension of the epizootic of rabies in raccoons in Ohio was reported. Twelve of the 19 states enzootic for the raccoon variant of the rabies virus and the District of Columbia reported decreased numbers of cases of rabies during 1998, compared with 13 states and the District of Columbia that reported increases during 1997. Three states, Rhode Island (143.2%), Massachusetts (77.2%), and New Hampshire (69.4%), reported increases of > 50% during 1998, compared with totals reported for 1997. In Texas, the number of cases of rabies associated with enzootic canine variants of the rabies virus remained greatly diminished; however, overall totals of reported cases of rabies increased in Texas and 12 other states where skunks are the major terrestrial reservoir of rabies. At the national level, the total of 82 reported cases of rabies among horses and mules was greater than that reported for any year since 1981 (88 cases) and represented a 74.5% increase, compared with the total for 1997. The 992 cases of rabies reported in bats during 1998 were the greatest proportionate contribution by bats since 1990. Reported cases of rabies in cats (282), dogs (113), and cattle (116) decreased 6.0%, 10.3%, and 4.9%, respectively. One indigenously acquired case of rabies reported in a human being during 1998 was the result of infection with a rabies virus variant associated with silver-haired and eastern pipistrelle bats.     

Rabies surveillance in the United States during 1989

In 1989, 4,808 cases of rabies in animals other than human beings were reported to the Centers for Disease Control, 1.8% more (4,724 to 4,808) than in 1988. Eighty-eight percent (4,224/4,808) of those affected were wild animals and 12% (584/4,808) were domestic animals. Cases were reported from 49 states, the District of Columbia, and Puerto Rico; Hawaii remained rabies-free. Skunks (1,657) continued to be the most commonly reported rabid wild animal. For the second consecutive year, more cats (212) were reported to be infected with rabies virus than any other domestic species. Compared with their 1988 reports, 5 states reported increases of greater than 100% (Alaska, 109%; New Jersey, 233%; Ohio, 133%; Oklahoma, 168%; and Washington, 125%), and 5 states reported decreases of greater than 50% (Connecticut, 63%; Mississippi, 56%; Montana, 67%; Nevada, 55%; and West Virginia, 53%) in 1989.     

Rabies surveillance in the United States during 2003

During 2003, 49 states and Puerto Rico reported 7,170 cases of rabies in nonhuman animals and 3 cases in human beings to the CDC. This represents a 10% decrease from the 7,967 cases in nonhuman animals and 3 cases in human beings reported in 2002. More than 91 (n = 6,556) were in wild animals, and 8.6% (614) were in domestic species (compared with 92.5% in wild animals and 74% in domestic species in 2002). The relative contributions of the major groups of animals were as follows: 2,635 raccoons (36.7%), 2,112 skunks (29.4%), 1,212 bats (16.9%), 456 foxes (6.4%), 321 cats (4.5%), 117 dogs (1.6%), and 98 cattle (1.4%). Compared with cases reported in 2002, the number of cases reported in 2003 decreased among all reporting groups with the exception of cats, dogs, equids, and swine. Ten of the 19 states with enzootic rabies in raccoons, the District of Columbia, and New York City reported decreases in the numbers of rabid raccoons during 2003. Tennessee reported 4 cases of indigenous rabies in raccoons during 2003, becoming the 20th state where rabies in raccoons is known to be enzootic. On a national level, the number of rabies cases in skunks during 2003 decreased by 13.2% from those reported in 2002. Texas again reported the greatest number (n = 620) of rabid skunks during 2003, as well as the greatest overall state total of rabies cases (909). As in 2002, Texas did not report any cases of rabies associated with the dog/coyote variant of the rabies virus, but did report 61 cases associated with the gray fox variant of the virus (compared with 65 cases in 2002).The 1,212 cases of rabies reported in bats during 2003 represented a decline of nearly 12% from the previous year's record high of 1,373 cases for this group of mammals. Cases of rabies reported in foxes.and raccoons declined 10.2% and 8.9%, respectively, during 2003. Rabies among sheep and goats decreased from 15 cases in 2002 to 12 cases in 2003, whereas cases reported in cats, dogs, and equids increased 74%, 18.2%, and 8.6%, respectively. In Puerto Rico, reported cases of rabies in mongooses and dogs decreased 26.9% and 35.7%, respectively, from those reported in 2002. Three cases of rabies in human beings were reported in California, Virginia, and Puerto Rico during 2003. The Virginia case was the first reported occurrence of rabies in a human being infected with the raccoon rabies virus variant; however, the exposure history was unknown. The California and Puerto Rico cases were the result of infections with bat and dog/mongoose rabies virus variants, respectively, and each patient had a history of a bite.     

Rabies surveillance in the United States during 2004

During 2004, 49 states and Puerto Rico reported 6,836 cases of rabies in nonhuman animals and 8 cases in human beings to the CDC, representing a 4.6% decrease from the 7,170 cases in nonhuman animals and 3 cases in human beings reported in 2003. Approximately 92% of the cases were in wildlife, and 8% were in domestic animals (compared with 91% and 9%, respectively, in 2003). Relative contributions by the major animal groups were as follows: 2,564 raccoons (37.5%), 1,856 skunks (27.1%), 1,361 bats (19.9%), 389 foxes (5.7%), 281 cats (4.1%), 115 cattle (1.7%), and 94 dogs (1.4%). Compared with the numbers of reported cases in 2003, cases in 2004 decreased among all groups, except bats, cattle, human beings, and "other domestics" (1 llama). Decreases in numbers of rabid raccoons during 2004 were reported by 12 of the 20 eastern states in which raccoon rabies was enzootic. In the East, Massachusetts reported the first cases of raccoon rabies detected beyond the Cape Cod oral rabies vaccine barrier. Along the western edge of the raccoon rabies epizootic (Ohio in the north and Tennessee in the south), cases of rabies were reported from unexpected new foci beyond oral rabies vaccine zones. On a national level, the number of rabies cases in skunks during 2004 decreased by 12.1% from the number reported in 2003. Once again, Texas reported the greatest number (n = 534) of rabid skunks and the greatest overall state total of rabies cases (913). Texas reported only 1 case of rabies in a dog that was infected with the dog/coyote rabies virus variant and only 22 cases associated with theTexas gray fox rabies virus variant (compared with 61 cases in 2003). The total number of cases of rabies reported nationally in foxes and raccoons declined 14.7% and 2.7%, respectively, during 2004. The 1,361 cases of rabies reported in bats during 2004 represented a 12.3% increase over the previous year's total of 1,212 cases for this group of mammals. Cases of rabies reported in cats, dogs, horses and mules, and sheep and goats decreased 12.5%, 19.7%, 31.8%, and 16.7%, respectively, whereas cases reported in cattle increased 174%. In Puerto Rico, reported cases of rabies in mongooses decreased 4.1% and rabies in dogs (9 cases) remained unchanged from those reported in 2003. Among the 8 cases of rabies in human beings, 1 person from Oklahoma and 3 from Texas died following receipt of infected organs and tissues from an Arkansas donor. In California, a person originally from El Salvador and, in Florida, a person originally from Haiti both died of canine rabies infections acquired outside the United States. In Wisconsin, a teenager contracted rabies from a bat bite and became the first known person to survive rabies despite not having received rabies vaccine prior to symptom onset.     

Rabies surveillance in the United States during 2006

During 2006, 49 states and Puerto Rico reported 6,940 cases of rabies in animals and 3 cases in humans to the CDC, representing an 8.2% increase from the 6,417 cases in animals and 1 case in a human reported in 2005. Approximately 92% of the cases were in wildlife, and 8% were in domestic animals. Relative contributions by the major animal groups were as follows: 2,615 raccoons (37.7%), 1,692 bats (24.4%), 1,494 skunks (21.5%), 427 foxes (6.2%), 318 cats (4.6%), 82 cattle (1.2%), and 79 dogs (1.1%). Compared with numbers of reported cases in 2005, cases in 2006 increased among all groups except cattle. Increases in numbers of rabid raccoons during 2006 were reported by 11 of the 20 eastern states where raccoon rabies was enzootic, and reported cases increased by 3.2% overall, compared with 2005. On a national level, the number of rabies cases in skunks during 2006 increased by 6.1% from the number reported in 2005. Once again, Texas reported the greatest number (n = 351) of rabid skunks and the greatest overall state total of animal rabies cases (889). No cases of rabies associated with the dog/coyote rabies virus variant were reported. The last identified case of this canine rabies virus variant was identified in March 2004, along the US/Mexico border. With 2006 marking the second year of no apparent transmission of the dog/coyote variant, these findings from surveillance data support the contention that the canine rabies virus variant is no longer in circulation in the United States. Total number of cases of rabies reported nationally in foxes increased 13.6%, compared with 2005. Increases in the number of reported rabid foxes were attributable to greater numbers of foxes reported with the Arctic fox rabies virus variant in Alaska, the Texas gray fox rabies virus variant in Texas, and the raccoon rabies virus variant in Virginia. The 1,692 cases of rabies reported in bats represented a 14.5% increase, compared with numbers reported in 2005, making bats the second most reported rabid animal behind raccoons. Cases of rabies in cats, dogs, horses and mules, and sheep and goats increased 18.2%, 3.9%, 12.8%, and 22.2%, respectively, whereas cases reported in cattle decreased 11.8%. In Puerto Rico, reported cases of rabies in mongooses increased 9.2%, and rabies in domestic animals, presumably attributable to spillover infection from mongooses, increased 20%. Three cases of human rabies were reported from Texas, Indiana, and California during 2006. The cases in Indiana and Texas were attributed to bat rabies virus variants, whereas the case in California was attributed to an exposure to a dog in the Philippines.     

Rabies surveillance in the United States during 1991.

In 1991, 49 states, the District of Columbia, and Puerto Rico reported 6,972 cases of rabies in nonhuman animals and 3 cases in human beings to the Centers for Disease Control. Ninety-one percent (6,354 cases) were wild animals, whereas 8.9% (618 cases) were domestic species. The total number of reported cases of rabies increased 42.9% over that of 1990 (4,881 cases), with most of the increase resulting from continued spread of the epizootic of rabies in raccoons in the mid-Atlantic and northeastern states. Large increases in cases of rabies in animals were reported from Connecticut (200 cases in 1991, compared with 3 in 1990, an increase of 6,567%), Delaware (197 cases in 1991, compared with 44 in 1990, an increase of 348%), New York (1,303 cases in 1991, compared with 242 in 1990, an increase of 326%), and New Jersey (994 cases in 1991, compared with 469 in 1990, an increase of 112%). Other noteworthy increases were reported by Wyoming (96.4%), Texas (69.7%), California (41.3%), Oklahoma (33.1%), Minnesota (31.4%), Georgia (26.7%), and Maryland (23.7%). Hawaii reported 1 imported case of rabies in a bat. Only 16 states reported decreases in rabies in animals in 1991, compared with 30 in 1990. Pennsylvania and Iowa reported decreases of 40.6% and 27.4%, respectively. Rhode Island was the only state that did not report a case of rabies in 1991.     

Rabies surveillance in the United States during 1990.

In 1990, the United States and its territories reported 4,881 cases of rabies in animals to the Centers for Disease Control, a 1.5% increase from 1989. Of these, 553 were domestic animals, 4,327 were wild animals, and one was a human being. Pennsylvania reported the highest number (611) of rabies cases in animals in 1990. For the first time since surveillance of rabies in wild animals was begun in the 1950s, the number of cases of rabies in raccoons exceeded that in skunks. Particularly large increases of cases of rabies in wild and domestic animals were reported in New Jersey (469 cases in 1990 compared with 50 cases in 1989, an increase of 838% from 1989) and New York (242 cases in 1990 compared with 54 cases in 1989, an increase of 348%). The 1,821 cases of rabies in raccoons represented a 17.9% increase over those reported in 1989 and 24.5% over those in 1988. This increase was largely attributable to the larger number of rabid raccoons in New Jersey and New York. Other states that reported an increased number of rabies cases in animals in 1990 included Utah (77.8%), Louisiana (64.7%), North Dakota (60.3%), Arizona (28.6%), Oklahoma (27.5%), Delaware (22.2%), and Maryland (20.6%). Thirty states reported a decrease in the number of cases of rabies in animals.     

Rabies surveillance in the United States during 2000.

During 2000, 49 states, the District of Columbia, and Puerto Rico reported 7,364 cases of rabies in nonhuman animals and 5 cases in human beings to the Centers for Disease Control and Prevention, an increase of 4.3% from 7,067 cases in nonhuman animals reported in 1999. Ninety-three percent (6,855 cases) were in wild animals, whereas 6.9% (509 cases) were in domestic species (compared wth 91.5% in wild animals and 8.5% in domestic species in 1999). Compared with cases reported in 1999, the number of cases reported in 2000 increased among bats, dogs, foxes, skunks, and sheep/goats and decreased among cats, cattle, horses/mules, raccoons, and swine. The relative contributions of the major groups of animals were as follows: raccoons (37.7%; 2,778 cases), skunks (30.2%; 2,223), bats (16.8%; 1,240), foxes (6.2%; 453), cats (3.4%; 249), dogs (1.6%; 114), and cattle (1.1%; 83). Ten of the 19 states where the raccoon-associated variant of the rabies virus has been enzootic reported increases in the numbers of cases of rabies during 2000. Among those states that have engaged in extensive wildlife rabies control programs, no cases of rabies associated with the epizootic of rabies in raccoons (or in any other terrestrial species) were reported in Ohio, compared with 6 cases reported in 1999. No rabies cases associated with the dog/coyote variant (compared with 10 cases in 1999, including 5 in dogs) were reported in Texas, and cases associated with the gray fox variant of the virus decreased (58 cases in 2000, including 38 among foxes). Reports of rabid skunks exceeded those of rabid raccoons in Massachusetts and Rhode Island, states with enzootic raccoon rabies, for the fourth consecutive year. Nationally, the number of rabies cases in skunks increased by 7.1% from that reported in 1999. The greatest numerical increase in rabid skunks (550 cases in 2000, compared with 192 in 1999) was reported in Texas. The number of cases of rabies reported in bats (1,240) during 2000 increased 25.4% over the number reported during 1999 (989) and represented the greatest contribution (16.8% of the total number of rabid animals) ever recorded for this group of mammals. Cases of rabies reported in cattle (83) and cats (249) decreased by 38.5% and 10.4%, respectively, whereas cases in dogs (114) increased by 2.7% over those reported in 1999. Reported cases of rabies among horses and mules declined 20% from 65 cases in 1999 to 52 cases in 2000. Four indigenously acquired cases of rabies reported in human beings were caused by variants of the rabies virus associated with bats. One case of human rabies acquired outside the United States that resulted from a dog bite was caused by the canine variant of the rabies virus.     

State-level zoonotic disease surveillance in the United States

Most emerging infectious diseases are zoonotic, yet recent commissions have highlighted deficiencies in their surveillance. We conducted a survey to understand the needs of state agencies for zoonotic disease surveillance. The findings will hopefully support the development of biomedical informatics applications that can link animal and human data for surveillance.     

An evaluation of scrapie surveillance in the United States

Animal health surveillance systems should reflect national disease control priorities and promote the best use of public resources by maximizing effectiveness and efficiency. A surveillance system should be routinely evaluated to assess the degree to which the system accomplishes these goals, fulfills its stated objectives, and meets accepted surveillance standards. In the United States, there are a number of disparate endemic disease surveillance and eradication programs. The National Animal Health Surveillance System is a federal initiative designed to combine animal health surveillance and monitoring activities into a comprehensive and coordinated system. A protocol has been developed to facilitate the evaluation of animal health surveillance systems and investigate opportunities for coordination between the different surveillance and eradication programs. The evaluation protocol was based largely on protocols developed for public health but adapted for the specific needs and goals of animal health surveillance. The evaluation process was designed to identify program strengths and areas for improvement and facilitate the system's adaptability to changing situations. The evaluation protocol was applied to the scrapie surveillance system in the United States; scrapie surveillance was found to be an important part of surveillance for transmissible spongiform encephalopathies. Results from the evaluation of sensitivity, sampling methods and representativeness are presented.     

Trends in national surveillance for rabies among bats in the United States (1993-2000)

OBJECTIVE: To describe surveillance trends and epidemiologic features of rabies in bats in the United States, focusing on 3 bat species primarily associated with variants of the rabies virus that affect humans. DESIGN: Retrospective study. ANIMALS: 31,380 bats. PROCEDURE: Data on rabies for bats identified to species and reported by state laboratories from 1993 to 2000 were analyzed, focusing on silver-haired, eastern pipistrelle, and Brazilian free-tailed bats. Categoric variables were derived from other provided information. RESULTS: Data were reported from 37 states during the study interval; complete species-specific data were not reported by any state for the entire interval. Bats primarily associated with rabies virus variants affecting humans were more likely to yield positive test results for rabies (22.7%), compared with all other bats (5.5%) in most seasons and from most regions of the United States. However, certain other bat species had higher percentages of positive results. Risk of positive results was highest in the fall and highest among bats originating in the southwestern United States. CONCLUSIONS AND CLINICAL RELEVANCE: Increased risk of rabies among certain groups of bat species was consistently found across seasons and most geographic regions of the United States. Results were in general agreement with those of previous studies conducted within smaller geographic regions. There are ongoing efforts to improve surveillance of rabies in bats, although surveillance is incomplete in some regions.