Health protocol for translocation of free-ranging elk.

When considering an elk (Cervus elaphus) restoration program, wildlife managers must evaluate the positive and negative elements of translocation. We prepared this protocol to give an overview of health considerations associated with translocation of elk, with an emphasis on movement of free-ranging elk from western North America to the southeastern USA. We evaluated infectious agents and ectoparasites reported in elk from two perspectives. First, we made a qualitative estimate of the ability of the agent to be introduced and to become established. This was done using a selected set of epidemiologic factors. Second, if there was a good possibility that the organism could become established in the release area, the potential pathological consequences for elk and other wildlife, domestic animals, and humans were assessed via examination of the literature and consultation with other animal health specialists. The results of these evaluations were used to classify infectious agents and ectoparasites as low risk (n = 174), unknown risk (n = 10), and high risk (n = 9). We classified Anaplasma marginale, Anaplasma ovis, Mycobacterium paratuberculosis, Pasteurella multocida serotype 3, Elaphostrongylus cervi, Dicrocoelium dendriticum, Fascioloides magna, Echinococcus granulosus, Dermacentor albipictus, and Otobius megnini as unknown risks. High risk infectious agents and ectoparasites were the agent of chronic wasting disease, Brucella abortus, Mycobacterium bovis, Dermacentor andersoni, Ixodes pacificus, and Psoroptes sp. Parelaphostrongylus tennis, Elaeophora schneideri, and a Babesia sp. are parasites endemic in the southeastern USA that may present a "reverse risk" and adversely affect elk if released in some parts of the region. We developed a five-component protocol to reduce the risk of introduction of high risk infectious agents and ectoparasites that included: (1) evaluation of the health status of source populations, (2) quarantines, (3) physical examination and diagnostic testing, (4) restrictions on translocation of animals from certain geographic areas or populations, and (5) prophylactic treatment.

Mycoplasma gallisepticum in house finches (Carpodacus mexicanus) and other wild birds associated with poultry production facilities.

Since 1994, an epidemic of conjunctivitis caused by Mycoplasma gallisepticum (MG) has spread throughout the eastern population of house finches (Carpodacus mexicanus). The adaptation of MG to a free-flying avian species presents potential problems for the control of mycoplasmosis in commercial poultry. To evaluate risks associated with this emerging problem, a field survey was conducted to assess prevalence of MG infection in house finches and other passerine birds associated with poultry farms. Between November 1997 and March 1999, 1058 birds were captured by mist net or trap at 17 farms and at 10 feeder stations in northeast Georgia. Birds were bled and screened by serum plate agglutination (SPA) for antibodies to MG. Birds with negative or weak positive SPA results were released at capture sites, and those with strong positive SPA reactions were kept for further evaluation. Necropsies were performed on selected house finches and individuals of 11 other passerine species, and samples were collected for MG testing by culture, polymerase chain reaction (PCR), hemagglutination inhibition, and histopathology. Testing revealed 19.1% of 671 birds caught at farms and 11.6% of 387 birds caught at feeder sites were SPA positive for MG. Three house finches captured on farms were positive for MG by culture and PCR, whereas three from feeder sites were positive only by PCR. No MG isolates were made from tufted titmice (Baeolophus bicolor), but 40% were positive by PCR. Individuals from 10 additional species were SPA positive only. Results suggest that MG persists at low levels in house finches in northeast Georgia and that tufted titmice may be nonclinical carriers of MG or a related mycoplasma. Positive SPA reactions in other species may be caused by nonspecific reactions or contact exposure. Current biosecurity recommendations should be sufficient to minimize risks of transmission between wild and domestic birds.

Epidemiological study of Campylobacter spp. in broilers: source, time of colonization, and prevalence.

From October 1993 to August 1994, broiler chickens in four grow-out houses, two previously used (houses 1 and 2) and two newly constructed (houses 3 and 4), were used in a study to determine the source, time of infection, and prevalence of Campylobacter spp. Cecal droppings and cecal samples were obtained from the broilers. Samples were also obtained from water, feed, litter, soil, fans, and workers' boots. Samples were obtained from domestic animals and wildlife species (rectal swabs), including insects, on or near the premises. Broilers in houses 2, 3, and 4 became infected in the second or third week and were fully colonized by day 42. Campylobacter appeared in house 1 during week 2 in a low percentage of the birds, disappearing by the fourth week. Isolates were also recovered from domestic pigs and water on this farm. In house 3, the organism was isolated from workers' boots and a wild bird prior to isolation from the broilers. Following isolation from cecal droppings, the organism was isolated from water, feed, litter, feathers, flies, cattle, feces, and wild animals. In house 2, Campylobacter was isolated from cattle feces and wild birds prior to week 5, when the broilers first became infected, and thereafter from water, feed, insect, and wildlife, and cecal droppings. It was subsequently isolated from workers' boots, cattle feces, feathers, insects, and other wildlife. All ceca taken from 20 birds each from houses 2 and 3 were positive at time of slaughter (day 49). All ceca from house 1 were negative. No ceca were collected from birds originating in house 4. No specific source could be identified from the samples obtained, although apparently the organism permeates the environment and several potential sources are discussed in this paper.

Potential impact of wildlife on the tropical bont tick eradication program in the Caribbean.

Wildlife are hosts for A. variegatum throughout its range in Africa, and have been demonstrated to serve as hosts for larvae and nymphs on several islands in the Caribbean. Studies conducted in the Caribbean have indicated that most larvae and nymphs and all adults of the tick feed on livestock; therefore, eradication can be approached through the treatment of livestock. However, since small numbers of animals such as the mongoose are infested with larvae and nymphs, these animals may represent a short-term alternative host system. Such infestations potentially could result in a presence of small numbers of ticks for up to 46 months after the onset of a treatment program and could serve as a source to reinfest livestock during the eradication process. Wildlife surveys have been conducted in St. Croix, Puerto Rico, Guadeloupe, and Antigua; but the host status of species present on other islands such as the white-tailed deer on St. Kitts has not been evaluated. As part of the eradication program, the species of wildlife present on each island and the association of these species with infested pastures should be determined. Surveys of wildlife can be used during the eradication to determine if wildlife are serving as an alternative host system. Cattle egrets may serve to disseminate the tick among islands in the region, and to areas outside the region. Cattle egrets have been shown to serve as hosts for the tick, and to move throughout the eastern Caribbean and to North America. The potential for interisland dissemination of ticks by cattle egrets, as well as by other means, substantiates the need for a region-wide eradication program.

Disinfection and wildlife.

Capture, handling or transport of wildlife for purposes such as research, disease monitoring, wildlife damage control, relocation, and collection of zoological specimens can create risks of disease spread. Cleaning and disinfection procedures for equipment used in these activities must be routine and designed to eliminate the spread of pathogens to either animals or humans. General methods and materials for cleaning and disinfection apply to wildlife studies. Concepts involved in preparing a protocol specific to a wildlife investigation are discussed. The control of the spread of livestock and poultry pathogens via free-ranging mammals and birds prior to disinfection of contaminated premises is approached through an accurate assessment of the problem and, where necessary, the selection of appropriate wildlife control measures. The authors discuss the development of a problem assessment, and review potential methods for use in the control of wildlife. For an accurate problem assessment, information is needed on the presence of wild mammals and birds at the site, exposure of wild mammals and birds to the pathogen, and the potential for further transmission. When wildlife control is deemed necessary, techniques may be selected to disperse or exclude animals from premises or to depopulate the site. Dispersal or exclusion from premises is appropriate when movement of animals within or away from the contaminated premises would not result in further transmission of the pathogen. Depopulation is necessary when the continued presence or dispersal of wild mammals or birds would potentially result in further spread of the disease.

Population dynamics of Lutzomyia shannoni (Diptera: Psychodidae) in relation to the epizootiology of vesicular stomatitis virus on Ossabaw Island, Georgia.

Population dynamics of Lutzomyia shannoni Dyar were studied on Ossabaw Island, GA, to define further the role of this species in the epizootiology of the New Jersey serotype of vesicular stomatitis (VSNJ) virus. Bimonthly collections of sand flies egressing from hollow trees from April to November 1991 indicated that there were three generations of sand flies. Data from light trap collections from 1986 through 1989 indicated that similar seasonal cycles occurred during previous years. At this site, we hypothesize that L. shannoni undergoes facultative diapause. Two isolates of VSNJ virus were obtained from female sand flies collected in May and June of 1991. We believe that the virus overwinters in immature L. shannoni and that transovarially infected sand flies emerging each spring initiate a summer amplification cycle in swine on Ossabaw Island.

Field evaluation of baits and baiting strategies for delivering oral vaccine to mongooses in Antigua, West Indies.

A field study was conducted on Antigua, West Indies, to determine the feasibility of delivering an oral rabies vaccine or population control agent to free-ranging mongooses (Herpestes javanicus). Two biomarkers (tetracycline hydrochloride [THCL] and DuPont Oil Blue A dye) and two bait types (DuPont polymer fish meal and polyurethane foam) were used to bait three study sites. Four hundred polymer baits containing both biomarkers were distributed at 36 central point bait stations (11 baits/station) on an 80 ha study site (5 baits/ha); 69% of the mongoose population consumed one or more baits. Two thousand baits containing THCL and 400 baits containing DuPont dye were distributed on two additional 100 ha study sites (24 baits/ha). Polymer fish meal baits were used on the first site and polyurethane baits on the second site. Based on the presence of biomarkers in bone or soft tissue, 96 to 97% of the mongooses at both sites consumed at least one bait. We conclude that oral baiting of mongooses is a feasible method for delivery of vaccines for the control of rabies in this species.

Field evaluation of baits and baiting strategies for delivering oral vaccine to mongooses in Antigua, West Indies

A field of study was conducted on Antigua, West Indies to determine the feasibility of delivering an oral rabies vaccine or population control agent to free-ranging mongooses (Herpestes javanicua). Two biomarkers (tetracycline hydrochloride [THCL] and Dupoint Oil Blue A dye) and two bait types (Dupont polymer fish meal and polyurethane foam) were used to bait three study sites. Four hundred polymer baits containing both biomarkers were distributed at 36 central point bait stations (11 baits/station) on an 80 ha study site (5 baits/ha); 69 percent of the mongoose population consumed one or more baits. Two thousand baits containing THCL and 400 baits containing DuPont dye were distributed on two additional 100 ha study sites (24 baits/ha). Polymer fish meal baits were used on the first site and polyurethane baits on the second site. Based on the presence of biomarkers in bone or soft tissue, 96 to 97 percent of the mongooses at both sites consumed at least one bait. We conclude that oral baiting of mongooses is a feasible method for delivery of vaccines for the control of rabies in this species (AU)

Effect of acaricide treatment of cattle on Amblyomma variegatum (Acari: Ixodidae) infestation of mongooses (Carnivora: Viverridae: Herpestes auropunctatus) in Guadeloupe, French West Indies.

The effect of acaricide treatment of cattle on the infestation of the small Indian mongoose (Herpestes auropunctatus Hodgson) by Amblyomma variegatum (F.) was determined during a field evaluation of selected acaricides in Guadeloupe, French West Indies. From April 1990 to April 1991, cattle at one site were treated every 14 d with pour-on formulations of deltamethrin, flumethrin, or permethrin; and cattle at a second site were treated as per a local standard treatment using a spray formulation of coumaphos every 30 d. The protocol was then reversed, and from April to July 1991 cattle at the original standard treatment site were treated using the pour-on treatment. Mongooses were examined for ticks during February-March and July 1990 and 1991. The mean prevalence of infestation of mongooses by A. variegatum larvae was reduced from 41 to 27% during the February-March to July periods at the pour-on treatment sites but increased from 29 to 43% during the same periods at the standard treatment sites. The mean relative density of infestation by larvae decreased from 2.15 to 0.65 at the pour-on treatment sites and increased from 0.7 to 1.95 at the standard treatment sites during the same periods. Data on nymphal infestations were inconclusive, and mongooses were not infested by adult ticks. The infestation of mongooses by A. variegatum may be of importance as a short-term alternative host system for immature stages of this tick during an eradication program.

Wildlife as hosts for ticks (Acari) in Antigua, West Indies.

A survey was conducted to determine the status of wild mammals and birds as hosts for Amblyomma variegatum (F.) and other tick species in Antigua. Surveys of wild mammals and birds were conducted periodically from September 1988 through May 1991. Wild mammals surveyed included the small Indian mongoose (Herpestes auropunctatus Hodgson), Norway rat (Rattus norvegicus Berkenhout), and house mouse (Mus musculus L.), but only mongooses were surveyed intensively. Larvae and nymphs of A. variegatum, larvae of Boophilus microplus (Canestrini), and larvae of Ornithodoros puertoricensis (Fox) were recovered. The mean prevalences of infestation of mongooses by A. variegatum larvae and nymphs were 4.7 and 1.3%, respectively; maximums were 16.1 and 5.0%, respectively. The mean prevalence of infestation of mongooses by B. microplus was 3.2%. O. puertoricensis is reported from Antigua for the first time. The mean prevalence of infestation of mongooses by O. puertoricensis larvae was 41.2%, but seasonal prevalences ranged from 27.8 to 55.0%. Of 610 birds representing 16 species, three Carib grackles (Quiscalus lugubris Swainson) were each infested with one larva of A. variegatum.

Potential role of cattle egrets, Bubulcus ibis (Ciconiformes: Ardeidae), in the dissemination of Amblyomma variegatum (Acari: Ixodidae) in the eastern Caribbean.

The potential role of cattle egrets, Bubulcus ibis (L.), in the dissemination of Amblyomma variegatum (F.) in the eastern Caribbean was evaluated. The status of cattle egrets as hosts for A. variegatum in Antigua was determined during seven survey periods between September 1988 and May 1991. The mean prevalences of infestation by larvae and nymphs were 2.3 and 0.5%, respectively. The mean intensity and relative density of infestation by larvae were 8.8 (SD = 9.80) and 0.2 (SD = 0.28), respectively. Cattle egrets examined in Guadeloupe during February-March 1991 were not infested but 5.9% were infested by larvae during June-July 1991. Interisland movement of cattle egrets was evaluated relative to emigration of birds captured and marked in Antigua and Guadeloupe. During this aspect of the study, 1,129 cattle egrets were captured, marked, and released. Of 195 sighting reports received, 56 were determined to be independent sightings. Emigration of cattle egrets included movement of birds marked in Antigua or Guadeloupe to 14 Caribbean islands and the Florida Keys. Interisland movement occurred in each of the discrete observation periods during the 3-yr study period. The rate of emigration per period ranged from 1.2 to 12.9%. That cattle egrets served as hosts for immature A. variegatum in the eastern Caribbean and moved between islands in the region demonstrates that these birds could serve as disseminators of the tick. Estimates of the numbers of infested cattle egrets emigrating from Antigua and Guadeloupe ranged from 0 to 0.24% of the current populations.

Feral swine as a potential amplifying host for vesicular stomatitis virus New Jersey serotype on Ossabaw Island, Georgia.

Sentinel feral swine (Sus scrofa) on Ossabaw Island, Georgia (USA), were serologically monitored for antibodies to vesicular stomatitis New Jersey serotype (VSNJ) virus from 17 April to 27 August 1990. Seroconversions to VSNJ virus were detected in 24% of swine island-wide. Differences in the incidence of seroconversion were detected between swine sampled in the Pleistocene and Holocene formations of the island suggesting that the presence of virus is forest type dependent. Based on the consistency in onset and spatial distribution of seroconversions with data from 1981 to 1985, this is a very stable host-parasite system. Sequential virus isolation attempts from nasal swabs, tonsil swabs, and blood were made on a subsample of 54 sentinel swine from 9 May to 4 July 1990. The VSNJ virus was isolated from five swine from 16 May to 20 June. Vesicular lesions were detected on only two of these animals. Although infections in these feral swine were short-lived (< 7 days) and were followed by a strong neutralizing antibody response, VSNJ virus was detected in a single group of swine for a period exceeding 1 month. From these data, it appears that feral swine could provide a source of virus to feeding arthropods for extended periods of time. The failure to detect a viremia in these animals, however, indicates that a source other than blood may be required for transmission to occur.

Effect of forest type on the distribution of Lutzomyia shannoni (Diptera: Psychodidae) and vesicular stomatitis virus on Ossabaw Island, Georgia.

We studied the effects of three forest types on multiple factors that are believed to influence the transmission of the New Jersey serotype of vesicular stomatitis (VSNJ) virus on Ossabaw Island, GA. These factors included availability of tree hole diurnal resting habitat for the presumed sand fly vector, Lutzomyia shannoni Dyar; relative abundance of L. shannoni; prevalence of VSNJ virus infection in sand flies; and prevalence of VSNJ virus antibodies in wild swine. Tree hole availability, sand fly abundance, and antibody prevalence in swine were significantly greater in maritime live oak forest than in other forest types. A single isolate of VSNJ virus was obtained from sand flies collected in maritime live oak forest. These data indicate that the relative abundance of adult L. shannoni is influenced significantly by the availability of tree holes and that VSNJ virus infection in wild swine is linked to forest type and is greatest in areas capable of supporting abundant populations of L. shannoni.

Evaluation of baits for oral rabies vaccination of mongooses: pilot field trials in Antigua, West Indies.

A field study was conducted on the island of Antigua, West Indies, to evaluate baits for delivering an oral rabies vaccine to the small Indian mongoose (Herpestes auropunctatus). Tracking tiles were used to determine that mongooses were nonselective and took both egg-flavored polyurethane baits and fish-flavored polymer baits containing several different food materials. A high proportion of baits were taken the day of placement with minimal disturbance by nontarget species. DuPont Oil Blue A dye was an effective short-term biomarker for use in baits; based on its subsequent detection in mongooses, some of the population had consumed and not cached or discarded baits. Central point baiting stations showed promise as an alternative delivery technique.

Evaluation of baits for oral rabies vaccination of mongooses: pilot field trials in Antigua, West Indies

A field study was conducted on the island of Antigua, West Indies, to evaluated baits for delivering an oral rabies vaccine to the small mongoose (Herpestes auropunctatus). Tracking tiles were used to determine that mongooses were nonselective and took both egg-flavored polyurethane baits and fish-flavored polymer baits containing several different food materials. A high proportion of baits were taken the day of placement with minimal disturbance by nontarget species. DuPont Oil Blue A dye was an effective short-term biomarker for use in baits;based on its subsequent detection in mongooses, some of the population had consumed and not cached or discarded baits. Central point baiting stations showed promise as an alternative delivery technique (AU)

Ectoparasites of the blackbuck antelope (Antilope cervicapra).

Fifty-two free-ranging blackbuck antelope (Antilope cervicapra) from Texas were examined for ectoparasites. Two species of sucking lice (Anoplura), one species of chewing louse (Mallophaga), one species of louse fly (Diptera), and three species of ticks (Acari) were found. This is the first report of the anoplurans Linognathus cervicaprae and L. pithodes from the Western Hemisphere. The southern deer ked (Lipoptena mazamae), the winter tick (Dermacentor albipictus), and the rabbit tick (Haemaphysalis leporispalustris) are reported from blackbuck for the first time. The lone star tick (Amblyomma americanum) and the mallophagan (Damalinia cornuta cornuta) were reported previously from blackbuck in Texas, the latter species under the name Tricholipeurus balanicus balanicus.

Titers of vesicular stomatitis virus, New Jersey serotype, in naturally infected male and female Lutzomyia shannoni (Diptera: Psychodidae) in Georgia.

Seven isolates of the New Jersey serotype of vesicular stomatitis (VSNJ) virus were obtained from pooled specimens of phlebotomine sand flies, Lutzomyia shannoni Dyar, collected on Ossabaw Island, Chatham County, Ga., in 1989 and 1990. Three isolates, including two from males, were obtained from light-trapped sand flies in 1989. Four isolates were obtained from pools of sand flies collected from hollow trees in 1990. Three of the latter pools contained from 4.0 to 4.7 log10 of plaque-forming units of virus per ml, suggesting that the positive flies in these pools had supported VSNJ virus replication. One of these high-titered isolates was obtained from a pool of male sand flies. These data provide further support for the hypotheses that L. shannoni is a biological vector of VSNJ virus at this enzootic focus and that transovarial transmission of the virus occurs in nature.

Lutzomyia shannoni (Diptera: Psychodidae): a biological vector of the New Jersey serotype of vesicular stomatitis virus on Ossabaw Island, Georgia.

The New Jersey serotype of vesicular stomatitis virus (VSNJ) is enzootic on Ossabaw Island, Georgia. Lutzomyia shannoni is the only phlebotomine sand fly present on the island and there is strong evidence that it is a vector of the virus at this site. This overview summarizes the studies that have been done on the island, reviews the evidence which confirms that L. shannoni is a biological vector of VSNJ, and discusses remaining unknown aspects of the epizootiology of VSNJ.

Funnel trap for the capture of phlebotomine sand flies (Diptera: Psychodidae) from tree holes.

A funnel trap that fitted over holes leading into hollow trees was used to capture adult phlebotomine sand flies, Lutzomyia shannoni Dyar, on Ossabaw Island, Chatham County, Ga. These insects rested in hollow trees during the day and were collected by funnel traps as they egressed from the tree holes at night. The trap is lightweight, durable, inexpensive, waterproof, and selective. Using this trap, greater than 100 healthy L. shannoni ++were captured per night by a single investigator during July and August 1988 when adult flies were abundant on the island.

Isolation of vesicular stomatitis virus New Jersey serotype from phlebotomine sand flies in Georgia.

Vesicular stomatitis virus New Jersey serotype (VSNJ virus) was isolated from 6 of 610 pools of phlebotomine sand flies (Lutzomyia shannoni) collected on Ossabaw Island, GA. All isolates were from non-blooded females. Infected sand flies were collected at 6 sites at 5 separate times from 3 June through 25 July 1988. Thirty-five pools of Culicoides ssp. and 48 pools of mosquitoes obtained in conjunction with the infected sand flies also were evaluated for VSNJ virus; all were negative. Concomitant serologic monitoring of sentinel swine indicated that VSNJ virus transmission began in late April and continued through the completion of this study in August. The incidence of seroconversion among the sentinel wild swine was 50%. Domestic sentinel swine did not seroconvert at 2 sentinel sites, 1 of 2 seroconverted at 1 site, and 2 of 2 seroconverted at the fourth site. Vesicular lesions were seen on 10 sentinel wild swine during the summer. Vesicular stomatitis virus (NJ) was isolated from 4 of these swine and was diagnosed in 1 additional swine by direct complement-fixation assay. The time period within which VSNJ virus was isolated from sand flies preceded detection of vesicular lesions but corresponded with the period of seroconversion in sentinel swine. Site specific data indicated that VSNJ virus activity was widespread within the study area.