Control of Rabies in Wildlife; Request for Public Involvement

AGENCY:

Animal and Plant Health Inspection Service, USDA.

ACTION:

Notice.

SUMMARY:

The Animal and Plant Health Inspection Service's Wildlife Services program is soliciting public involvement in the planning of a proposed cooperative program to stop the spread of rabies in the States of New York, Ohio, Texas, Vermont, and West Virginia. A small portion of northeastern New Hampshire and the western counties in Pennsylvania that border Ohio could also be included in these control efforts. In addition, Wildlife Services may cooperate in smaller scale oral rabies vaccine projects in the States of Florida, Massachusetts, Maryland, New Jersey, Virginia, and Alabama. The information received in response to this notice will be considered during the planning of the proposed program and development of an environmental assessment that will be prepared in accordance with the National Environmental Policy Act.

DATES:

We invite you to comment on this notice. We will consider all comments that we receive by April 6, 2001.

ADDRESSES:

Please send four copies of your comment (an original and three copies) to: Docket No. 01-009-1, Regulatory Analysis and Development, PPD, APHIS, Suite 3C03, 4700 River Road Unit 118, Riverdale, MD 20737-1238.

Please state that your comment refers to Docket No. 01-009-1.

You may read any comments that we receive on this docket in our reading room. The reading room is located in room 1141 of the USDA South Building, 14th Street and Independence Avenue SW., Washington, DC. Normal reading room hours are 8 a.m. to 4:30 p.m., Monday through Friday, except holidays. To be sure someone is there to help you, please call (202) 690-2817 before coming.

APHIS documents published in the Federal Register, and related information, including the names of organizations and individuals who have commented on APHIS dockets, are available on the Internet at http://www.aphis.usda.gov/ppd/rad/webrepor.html.

FOR FURTHER INFORMATION CONTACT:

Mr. Dennis Slate, Rabies Program Coordinator, Wildlife Services, APHIS, 59 Chennell Drive, Suite 7, Concord, NH 03301-8548; phone (603) 223-6832.

SUPPLEMENTARY INFORMATION:

Rabies is an acute, fatal viral disease of mammals most often transmitted through the bite of a rabid animal. The disease can be effectively prevented in humans and domestic animals, but abundant and widely distributed reservoirs among wild mammals complicate rabies control. The vast majority of rabies cases reported to the Centers for Disease Control and Prevention (CDC) each year occur in raccoons, skunks, bats, foxes, and other wild animals. Domestic animals account for less than 10 percent of the reported rabies cases, with cats, dogs, and cattle among those most often reported.

Public health importance of rabies. Over the last 100 years, the rabies situation in the United States has changed dramatically. About 90 percent or greater of all animal cases reported annually to CDC now occur in wildlife, whereas before 1960 the majority of cases were reported in domestic animals. The principal rabies hosts today are wild carnivores and bats. The number of rabies-related human deaths in the United States has declined from more than 100 annually at the beginning of the 20th century to an average of one or two people per year in the 1990's. Modern prophylaxis, which consists of a series of vaccine injections given to people who have been exposed, has proven nearly 100 percent successful in preventing mortality when administered promptly after exposure. In the United States, human fatalities associated with rabies occur in people who fail to seek timely medical assistance, usually because they were unaware of their exposure.

Although human rabies deaths are rare, the estimated public health costs associated with disease detection, prevention, and control have risen, exceeding $300 million annually. These costs include the vaccination of companion animals, animal control programs, maintenance of rabies laboratories, and medical costs, such as those incurred for exposure case investigations and rabies post-exposure prophylaxis (PEP).

Accurate estimates of these expenditures are not available. Although the number of PEP's given in the United States each year is unknown, it is estimated to be about 40,000. When rabies becomes epizootic (epidemics in animals) or enzootic (i.e., present in an area over time but at low case frequency) in a region, the number of PEP's in that area increases. Although the cost varies, a course of rabies immune globulin and five doses of vaccine given over a 4-week period typically exceeds $1,000 and may be as high as $2,000.

Rabies in raccoons was virtually unknown prior to the 1950's. It was first described in Florida and spread slowly during the next three decades into Georgia, Alabama, and South Carolina. It was unintentionally introduced into the mid-Atlantic States by translocation of infected animals. The first cases appeared in West Virginia and Virginia in 1977 and 1978. Since then, raccoon rabies in the area has expanded to form the most intensive rabies outbreak in the United States.

Two rabies epizootics emerged in Texas in 1988; one involved spillover of canine dog rabies into coyotes in south Texas, and the other involved a rabies variant unique to gray foxes in west-central Texas. The south Texas epizootic alone resulted in 2 human deaths and caused over 3,000 people to receive post-exposure rabies treatment. In 1994, the public health threat created by these two expanding epizootics prompted the Governor of Texas to declare rabies a public health emergency in Texas.

Primary need for action. If the rabies strains transmitted by raccoons, gray foxes, and coyotes are not prevented from spreading to broader areas of the United States, the health threats and costs associated with rabies are expected to increase substantially. In the area that stretches west from the leading edge of the current distribution of raccoon rabies (which stretches from Alabama northeastward along the Appalachian Mountains to Maine) to the Rocky Mountains, and north from the distribution of gray fox and coyote rabies in Texas, there are more than 111 million livestock animals—including cattle, horses, mules, swine, goats, and sheep—valued at $42 billion. If raccoon, gray fox, or coyote rabies were to spread into the above described area, the livestock there would be at risk from these specific rabies variants. More importantly, human health care concerns would be expected to increase substantially as well if raccoon, coyote, and gray fox strains of rabies infect a much broader geographic area.

Development of oral rabies vaccine (ORV) programs. Although the concept of ORV to control rabies in free-ranging wildlife populations originated in the United States, it has a longer history of implementation in Europe and Canada. The emergence of raccoon rabies in the United States during the 1970's heightened interest in the application of ORV to raccoons. Due to biological and ecological differences between the types of animals that transmit rabies, development of specific vaccine and bait combinations was necessary. One of the main difficulties was the development of a safe and effective vaccine for raccoons. In contrast to red foxes, which were the primary subjects of ORV programs in Europe and Canada, raccoons were not readily immunized by the oral route with the modified live rabies virus vaccines that worked well in foxes. In addition, modified “live virus” vaccines pose a small risk of vaccine-induced rabies and resulted in some cases of vaccine-induced rabies associated with oral baiting programs in Europe and Canada. However, a genetically engineered vaccine, vaccinia-rabies glycoprotein (V-RG), has proven to be effective orally in raccoons, coyotes, and foxes. V-RG was extensively evaluated in the laboratory for safety in over 50 vertebrate species with no adverse effects, regardless of route or dose. Following successful field safety testing in the early 1990's, V-RG was licensed in 1995 in the United States for vaccination of free-ranging raccoons. It remains the only effective vaccine licensed for use in the United States for raccoons. It has also been approved for experimental use to vaccinate wild gray foxes and coyotes in Texas.

V-RG is commercially available from Merial, 115 Transtech Drive, Athens, GA 30601, under the registered name Raboral V-RG®. It is currently the only licensed oral vaccine available for rabies control for carnivores in the United States. V-RG is a recombinant vaccine that uses vaccinia, a living pox virus, as the vector (i.e., carrier) for the rabies gene that encodes for the production of rabies antigen in the form of rabies glycoprotein. Rabies glycoprotein is the protective sheath around the bullet-shaped rabies virus. The glycoprotein by itself is noninfective and cannot cause rabies, but, because it serves as the rabies antigen, it elicits an immune antibody response to rabies when the vaccine is swallowed by raccoons, foxes, or coyotes. When raccoons, foxes, or coyotes swallow the V-RG vaccine, it bathes the lymphatic tissue in the throat area and initiates the immunization process.

There is no possibility of vaccine-induced rabies with Raboral V-RG® because the vaccine only contains the noninfective surface protein of the rabies virus; none of the viral nuclear material that would be required for the rabies virus to replicate is present in the vaccine. Over 22 million doses of Raboral V-RG® have been distributed in the United States since 1994, with only one reported case of adverse effects on humans (i.e., a single case of a vaccinia virus infection, which caused localized skin rashes). This vaccine has been tested in 59 wild mammalian and avian species without adverse effects. In addition, a domestic animal's annual rabies vaccination can be safely administered even if it recently ingested a dose of oral rabies vaccine.

The V-RG vaccine is most often encased in baits and distributed by aircraft. The baits are small blocks of fishmeal (for coyotes and raccoons) or dog food (for gray foxes) that are held together with a polymer binding agent. The sachet, a thin plastic packet containing the liquid vaccine, is in the middle of the bait. Efforts to provide for more efficient delivery of vaccine/bait packages to wildlife populations at lower cost have resulted in the development of “baitless” sachets, in which the vaccine is enclosed within a plastic sachet that has been coated with special waxes and attractants, rather than the thick outer package of edible meal. These baitless sachets, which can be prepared without extensive manual labor and for less cost in materials, are smaller and lighter than other oral rabies vaccine baits, allowing for the possibility that more baits can be transported via aircraft, and smaller, less expensive aircraft can be used. Another attribute of the baitless sachet is that it is not possible for the animal to eat the edible material and leave the un-ruptured vaccine container behind. Field trials to date have shown that it performs very well in delivering vaccine to raccoons and coyotes. While the traditional fishmeal/dog food baits are likely to be used in most cases, it is possible that APHIS-WS and the States may employ baitless sachets, depending on their availability, in the course of the proposed cooperative program.

Oral wildlife vaccination for raccoon rabies control has been under field evaluation in the United States since 1990. A limited field release of the recombinant vaccine occurred on Parramore Island, VA, prior to wider use in the United States for control of raccoon rabies. A major objective of that field trial was to evaluate the free-ranging raccoon population for adverse effects after the distribution of V-RG vaccine-laden baits. With the development and field testing of the V-RG vaccine, a potential method of rabies control now exists for some rabies variants to complement methods of control that include public education, domestic animal vaccination, and human post-exposure prophylaxis.

Since the first field release of the V-RG vaccine in 1990, the annual number of vaccine-laden baits distributed to better understand the role of ORV for raccoon rabies control in the United States has risen exponentially. Eleven field projects have been conducted or are in progress in Pennsylvania (1991-1992), New Jersey (1992-1994, with further projects reinitiated in the last couple of years), Massachusetts (1994-present), Florida (1995-present), New York (1994-present), Vermont (1997-present), Ohio (1997-present), Maryland (1998), and Virginia (2000). Since 1995, more than 13.25 million individual doses of ORV have been distributed over 196,000 square miles of southern and west-central Texas for control of rabies strains in coyotes and gray foxes.

Several pilot projects were conducted to evaluate the effect of ORV baiting upon raccoon rabies. Through intensive baiting efforts at the peninsular neck, raccoon rabies was prevented from invading the Cape Cod peninsula. A recently completed project in Albany and Rensselaer Counties in New York demonstrated that raccoon rabies may be virtually eliminated from an area where the disease had been present for a number of years by use of ORV. In Ohio, along the Pennsylvania border from Lake Erie to West Virginia, twice-yearly baiting has been successful to date in preventing the westward spread of raccoon rabies.

Previous rabies control activities by Wildlife Services. The Animal and Plant Health Inspection Service's (APHIS) Wildlife Services (WS) program is authorized to conduct programs to address wildlife-caused disease problems by the Animal Damage Control Act of 1931 and the Rural Development, Agriculture and Related Agencies Act of 1988. WS's previous involvement in rabies prevention and control has been to provide technical and operational assistance to State health departments in experimental and operational distribution of ORV baits; in some of those States, WS has also assisted in the collection of animal specimens for monitoring purposes.

Proposed programs. APHIS-WS is proposing to cooperate in State programs to stop the spread of rabies in the States of New York, Ohio, Texas, Vermont, and West Virginia. A small portion of northeastern New Hampshire and the western counties in Pennsylvania that border Ohio could also be included in these control efforts. In addition, APHIS-WS may cooperate in smaller scale ORV projects in the States of Florida, Massachusetts, Maryland, New Jersey, Virginia, and Alabama. Consequently, we are soliciting public involvement in the planning process. The proposal is to provide Federal funds authorized by Congress to: (1) Purchase ORV baits that would be distributed by air and ground placement; (2) provide other forms of assistance in monitoring rabies and determining the effectiveness of the ORV programs through collection and testing of samples from wild animal specimens; and (3) if the targeted rabies strains advance beyond the barriers created by the ORV zones, participate in implementing contingency plans to restore the integrity of the ORV barrier and prevent further spread of rabies. Such contingency plans may involve increased distribution of ORV baits in and around the ORV zones or, if necessary, the localized reduction of target species populations through lethal means.

The intent of the bait distribution is to orally vaccinate wild raccoons in portions of the above-listed States with the exception of Texas. Similar programs would be directed at gray foxes in west-central Texas and coyotes in southern Texas. The primary goals of the program are to: (1) Stop the forward advance of these strains of rabies from areas where they now occur by immunizing portions of target species populations along the leading edges of the rabies fronts; and (2) reduce the incidence of rabies cases involving wild and domestic animals and rabies exposure to humans in the areas where the ORV programs are conducted.

The areas over which the ORV baits would be distributed and from which animal specimens would be collected could be anywhere in the above-listed States. The ORV zones would be delineated based on the most current distribution of rabies cases and the expected direction of disease spread. Vaccination zones would be determined in cooperation with State health departments and other State agencies with jurisdiction over wildlife and domestic animals. Pending the verification of legal authorities to do so, ORV baits would be distributed over a variety of classes of land ownership, including private, public, tribal, and other State and Federal lands. Each individual bait would have a warning label advising persons not to handle or disturb the bait along with a toll-free telephone number to call for further information.

Wild animal collections for purposes of monitoring would be conducted using a variety of live capture or lethal methods. Information from raccoons would be predominantly collected from cage-trapped individuals that, if apparently healthy, would be released at or near their site of capture. The requisite sample from coyotes would be obtained primarily by aerial or ground-based shooting from sample areas within the ORV zone. Gray fox samples would be obtained by ground shooting and various capture methods including leghold traps, cage traps, foot snares, and wire cable neck snares. Only legally approved methods would be used in all animal sample collection areas to provide critical data for the evaluation of project effectiveness. Project effectiveness would be based in large part on the percentage of ORV baits consumed in populations of target species and by the presence of sufficient levels of serum neutralizing antibodies to produce immunity to rabies as determined from serological analysis of blood samples obtained from target species within ORV zones.

In the event that the targeted rabies strains advance beyond the barriers created by the ORV zones, contingency plans may be implemented by the involved States that could involve local population suppression of the target wildlife species using lethal means. Another type of contingency plan to address such outbreaks might be to distribute higher densities of ORV baits in and around such areas to attempt to arrest the outbreak without resorting to lethal population suppression. If any localized lethal population control efforts were undertaken, those efforts would likely be integrated with hand or aerial placement of ORV baits in and around the population suppression area to restore the integrity of the ORV barrier and prevent further spread of rabies. APHIS-WS may, as part of the proposed action, assist in such efforts by providing funds, personnel, or equipment to capture and kill target species. Should this occur, methods used would involve any of those described above for the collection of wild animal specimens. In Texas, an additional method that could be used to remove gray foxes and coyotes would be sodium cyanide in the M-44 device, which is approved by the U.S. Environmental Protection Agency for this purpose. The need for APHIS-WS involvement in contingency plans that employ localized lethal population suppression is considered to be unlikely.

We are encouraging members of the public and other interested agencies and organizations to assist in the planning of this program by answering the following questions:

• What issues or concerns about the distribution of ORV baits by air and ground should we analyze?
• What other issues or concerns about the proposed action do you think we should address?
• What alternatives to the proposed action should we analyze?
• Do you have any information (i.e., scientific data or studies) that we should consider in the analysis?

Information received will be considered in an environmental assessment (EA) prepared in accordance with the National Environmental Policy Act.

Issues and alternatives identified thus far. Several issues have already been identified as areas of concern for consideration in the EA:

• Potential for adverse effects on people that become exposed to the vaccine or the baits.
• Potential for adverse effects on nontarget wildlife species that might consume the baits.
• Potential for adverse effects on pet dogs or other domestic animals that might consume the baits.
• Potential for aerially dropped baits to strike and injure people or domestic animals.
• Cost of the program in comparison to perceived benefits.
• Humaneness of methods used to collect wild animal specimens critical for timely program evaluation.

Other issues may also be included in the analysis and will be identified based on comments obtained through gathering information from the public and other agencies. Several alternatives that have been identified for consideration are:

• No involvement by APHIS-WS in rabies prevention or control.
• Implement the proposed action.
• Live capture of species being targeted (e.g., raccoon, gray fox, coyotes) followed by administration of rabies vaccines by injection and release back into the wild.
• Provide resources for ORV bait distribution without collection of wild animal specimens by APHIS-WS for monitoring purposes.

Other alternatives may also be included in the analysis based on comments obtained through gathering information from the public and other agencies.

Availability of additional information. Further information on rabies and ORV may be obtained from CDC Internet website (http://www.cdc.gov) and from the vaccine manufacturer, Merial ­(http://www.merial.com,, e-mail: raboral@merial.com). Further information on the status of ORV program planning efforts within the involved individual States may be available by contacting individual State health departments. Links to individual State health department Internet websites are available on the CDC Internet website. Information regarding APHIS-WS rabies control activities may be obtained by calling or writing the person listed under FOR FURTHER INFORMATION CONTACT.