Detection of rabies virus antibodies in Brazilian free-ranging wild carnivores

Rabies virus is a pathogen of major concern in free-ranging wild carnivores in several regions of the world, but little is known about its circulation in Brazilian wild carnivores. Sera from 211 free-ranging wild carnivores, captured from 2000 to 2006 in four locations of two Brazilian biomes (Pantanal and Cerrado), were tested for rabies antibodies. Twenty-six individuals (12.3%) had neutralizing antibody titers ≥0.10 IU/ml. The four sampled locations had antibody-positive animals, suggesting that Rabies virus circulates in all of these regions. Results underscore the risk posed by rabies for conservation of Brazilian carnivores and the possibility of the animals acting as reservoirs for the Rabies virus.     

Bluetongue epidemiology in wild ruminants from Southern Spain

Serum samples from 210 wild ruminants collected between 2006 and 2007 in southern Spain were tested for antibodies against bluetongue virus (BTV) by means of a competitive ELISA assay. Eighty-seven of the 210 wild ruminants analysed (41%) showed antibodies against BTV. Statistically significant differences were found in the seroprevalence among species: 66% (65 of 98) for red deer (Cervus elaphus), 50% (ten of 20) for fallow deer (Dama dama), 33% (three of nine) for mouflon (Ovis aries musimon) and 11% (nine of 83) for Spanish ibex (Capra pyrenaica). Overall, the sites where seropositive wild ruminants were found coincide with the areas where BTV had been detected in livestock, but in eastern Sierra Morena, the virus circulated in wild ruminants, although it had not been detected in domestic ruminants in the same areas. Wild ruminants over 1-year of age (sub-adults and adults) had significantly higher seroprevalences than juvenile animals. Statistically significant differences were also observed between BTV seroprevalence and management (free-ranging vs. captivity) with higher prevalence in free-ranging animals. The high seroprevalences obtained suggest that BTV is widespread in wild ruminants in southern Spain. This factor could have an important influence on the evolution of the infection in domestic livestock and indicates the need to include wild ruminant species in BTV surveillance or control programs. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Seroepidemiology of chlamydial infections of wild ruminants in Spain

Chlamydial infections were determined serologically among wild ruminants in the Nature Park of the Sierras de Cazorla, Segura y Las Villas (CNP; Spain). Sampling was done during the period from 1990-95. There were 1,244 blood samples collected, consisting of 490 from fallow deer (Dama dama), 343 from mouflon (Ovis mussimon), 283 from red deer (Cervus elaphus) and 128 from Spanish ibex (Capra pyrenaica). Specific complement-fixing antibodies of Chlamydia spp. were detected by means of microtechnique, using lipopolysaccharide antigen. The relationship of biological (species, sex, age), temporal (year) and territorial (central and peripheral areas) factors to seropositive prevalence was examined, and preliminary data were collected on whether or not sheep and goat herds grazing in the peripheral areas of the park also were infected with Chlamydia spp. Chlamydiosis was common in the four species of wild ruminants in the CNP in all the years studied. The prevalence of Chlamydia sp. in mouflon (37%) was significantly greater than in fallow deer (30%), and both had a significantly higher prevalence rate than Spanish ibex and red deer (both 24%). The four species of wild ruminants were similar in that they act as reservoirs of Chlamydia spp., although their receptivity may be different, and the infection can certainly be maintained among these animals by intra-group transmission. The differences in prevalences and geometric mean titers (GMT), both between the sexes (male versus female) and between different ages (adult versus juvenile), were insignificant in all four species. For all species of wild ruminants both prevalence rates and GMTs were greater in populations occupying the peripheral areas of the park than in those inhabiting the central area. Herds of sheep and goats had a high prevalence of chlamydiosis. Intertransmission of Chlamydia sp. between wild and domestic ruminants occurred through grazing on the same pastures. The highest mean prevalence (44%) of patent infections (CFT titers of > or =1:80) was detected in red deer, although this frequency was not significantly different from those observed in mouflon (39%), Spanish ibex (38%), and fallow deer (37%). The proportion of patent infection was higher in females than in males, and none of the juveniles (<2-yr-old) showed patent infections. The prevalence of predicted patent chlamydial infections was always higher in the peripheral areas of the park, although only among mouflon and fallow deer were the differences statistically significant.     

Inter-laboratory trial to evaluate the reproducibility of a new ELISA to detect rabies antibodies in vaccinated domestic and wild carnivores.

Validation of new diagnostic assays requires the establishment of their performance characteristics such as diagnostic sensitivity and specificity, precision, repeatability, accuracy and reproducibility. These different stages of validation are described in the recent Standard Operating Procedure for OIE Validation and Certification of Diagnostic Assays. This report describes a reproducibility study of a new ELISA to titrate rabies antibodies in vaccinated wild and domestic carnivores. The study was modelled on the proficiency tests which are annually organised by the Community Reference Institute (Afssa Nancy, France) in the frame of international movements of pets. Analyses demonstrated that the five participants provided satisfactory repeatability estimates (variation coefficients generally below 15% for the 20 coded sera of the panel), and concordant status for all serums. A regression analysis performed on standard curves revealed that two different positive standards used in two dilution ranges were titrated similarly by all participants, and that no significant differences were observed by using these two standards. Titres obtained on a dilution range included in the panel demonstrated that all laboratories were consistent with themselves (significant correlation between experimental and theoretical results), and consistent with other laboratories (significant correlation between results of laboratory under test and mean results of all other laboratories).     

Prevalence of Neospora caninum and Toxoplasma gondii antibodies in wild ruminants from the countryside or captivity in the Czech Republic

In the Czech Republic, sera from 720 wild ruminants were examined for antibodies to Neospora caninum by screening competitive-inhibition enzyme-linked immunosorbent assay and confirmed by indirect fluorescence antibody test (IFAT); the same sera were also examined for antibodies to Toxoplasma gondii by IFAT. Neospora caninum antibodies were found in 14% (11 positive/79 tested) roe deer (Capreolus capreolus), 14% (2/14) sika deer (Cervus nippon), 6% (24/ 377) red deer (Cervus elaphus), 1% (2/143) fallow deer (Dama dama), 3% (3/105) mouflon (Ovis musimon), and none of 2 reindeer (Rangifer tarandus). Toxoplasma gondii antibodies were found in 50% (7/14) sika deer, 45% (169/377) red deer, 24% (19/79) roe deer, 17% (24/143) fallow deer, 9% (9/105) mouflon, and 1 of 2 reindeer. In 42 samples of wild ruminants that tested positive for N. caninum antibodies, 28 (67% of the positive N. caninum samples) reacted solely to N. caninum. This is the first evidence of N. caninum infection in mouflon, the first N. caninum seroprevalence study in farmed red deer, and the first survey of N. caninum in wild ruminants from the Czech Republic.     

Survey of parasite control programs used in captive wild ruminants

The purpose of this study was to document, through a mailed questionnaire survey, the methods of parasite control currently used in captive wild ruminants. There was a 69% overall response to the survey. The majority of respondents indicated that they used parasite surveillance and identification techniques similar to those used for domestic ruminants. Of the four major anthelmintic drug classes, the benzimidazoles and ivermectin were used most commonly. Many of the parasite control programs had high treatment frequencies which were similar to dosing frequencies reported to result in anthelmintic resistance in domestic animals. Lack of effectiveness by benzimidazoles was perceived to be a problem by many respondents.     

Prevalence of antibodies to Neospora caninum in wild animals

Antibodies to Neospora caninum were determined in several species of wild animals in the United States by the Neospora agglutination test (NAT). Antibodies (NAT 1:40 or higher) were found in 5 of 249 bison (Bison bison), 5 of 160 caribou (Rangifer tarandus), 4 of 162 moose (Alces alces), 4 of 122 wolves (Canis lupus), and 1 of 224 musk ox (Ovibos moschatus) but not in 197 black bears (Ursus americanus). To our knowledge, this is the first report of antibodies to N. caninum in bison and caribou. The total absence of N. caninum antibodies in black bears indicates that bears are not a host for N. caninum and that there is no cross-reactivity between the NAT and the modified agglutination test (MAT) for Toxoplasma gondii, because more than 80% of black bears in eastern United States have MAT antibodies at a 1:25 serum solution.     

Monitoring exposure to avian influenza viruses in wild mammals

• 1 Avian influenza (AI) viruses primarily circulate in wild waterfowl populations and are occasionally transmitted to domestic poultry flocks. However, the possible roles of other wildlife species, such as wild mammals, in AI virus ecology have not been adequately addressed.
• 2 Due to their habitat and behaviour, many wild mammals may be capable of transmitting pathogens among wild and domestic populations. Exposure to AI viruses has been reported in an array of wild and domestic animals. The presence of wild mammals on farms has been identified as a risk factor for at least one poultry AI outbreak in North America. These reports suggest the need for seroprevalence studies examining the exposure of wild mammals to AI viruses.
• 3 Serological tests are routinely used to assess domestic poultry, domestic swine and human exposure to influenza A viruses, but these tests have not been validated for use in wild mammals. As such, some of these protocols may require adjustments or may be inappropriate for use in serology testing of wild mammals. Herein, we review these serological techniques and evaluate their potential usefulness in AI surveillance of wild mammals. We call for care to be taken when applying serological tests outside their original area of validation, and for continued assay verification for multiple species and virus strains.

     

Detection of autoreactive antibodies to serum IgG and IgA in amoebic liver abscess cases.

Assessment of autoreactive antibodies in response to healthy human serum IgA and IgG was performed by indirect haemagglutination assay on serum samples from 81 amoebic liver abscess cases for IgA and 70 for IgG. Appropriate controls were taken simultaneously. IgA, IgG were isolated and purified from a healthy human serum through Sephadex G-200 and protein A CL 4B sepharose chromatography. These immunoglobulins were used for the detection of its own antibodies in amoebic liver abscess cases. This revealed that 43.20% and 48.50% of the cases were positive for IgA and IgG respectively, where as only 19.35% and 28.30% of the controls were in positive category (IgA and IgG respectively). The mean titres with standard deviation of the autoreactive antibodies to serum IgA both in ALA cases and controls shows a highly significant difference between tests and controls (P less than 0.001). Similarly the mean titres with standard deviation both in ALA and controls for the serum IgG differed significantly (P less than 0.001). This suggests the presence of autoreactive antibodies against serum IgA and IgG in amoebic liver abscess cases.     

Staphylococci associated with the rumen of young and wild ruminants

Staphylococcus warneri, Staph, xylosus, Staph. saprophyticus, Staph. epidermidis, Staph. sciuri subsp. lentus, Staph. sciuri subsp. sciuri and Staph. cohnii subsp. urealyticum were the most frequently occurring staphylococci in the rumen content and wall of young and wild ruminants. Staphylococcus warneri formed a high percentage mainly among 2–9-week-old ruminants. Staphylococcus hominis was found only in mouflons. Staphylococcus gallinarum was detected only in calves. Staphylococcus aureus was the predominant representative of coagulase-positive staphylococci in the rumen of wild ruminants. Most of the strains examined could not be identified as known species.     

Serological survey of herpesvirus infections in wild ruminants of France and Belgium

The presence of antibodies against bovine herpesvirus 1 (BHV-1), bovid herpesvirus 6 (BHV-6), herpesvirus of Cervidae type 1 (HVC-1), reindeer herpesvirus, bovine herpesvirus 2 (BHV-2) and bovid herpesvirus 4 (BHV-4) was investigated in wild ruminants of France and Belgium between 1981 and 1986. There were no animals serologically positive for BHV-4. Antibodies against BHV-2 were demonstrated in roe deer (Cervus capreolus) (less than 1%) and chamois (Rupicapra rupicapra) (1%) in France. Animals seropositive to the four related viruses (BHV-1, BHV-6, HVC-1, reindeer herpesvirus) were detected in red deer (Cervus elaphus) in France and Belgium (1% and 11%, respectively), in roe deer (less than 1%) from France, in chamois (4%) in France and in ibex (Capra ibex) (4%) from France. The presence of antibodies against HVC-1, especially in red deer from Belgium, may suggest that wild ruminants in continental Europe are now infected with this virus, which previously has been isolated only in Scotland.     

Viruses isolated from captive and free-ranging wild ruminants in Alberta.

Nasal secretions, leukocytes and preputial or vaginal swabs from a group of 15 captive wild ruminants, comprising six pronghorn antelope (Antilocapra americana), seven fallow deer (Dama dama) and two mule deer (Odocoileus hemionus), and from 50 free-ranging pronghorns in southern Alberta, were examined for viral agents. Captive animals were given injections of dexamethasone daily for 6 days in attempts to reactivate latent infections. Specimens were collected at 2-3 day intervals from days 0 to 18. Free-ranging pronghorns were sampled only once, at the time of capture. Fifteen viral isolates were obtained from the animals: six isolates of parainfluenza 3 (PI3) from nasal swabs from one fallow deer and one mule deer; five isolates of herpesvirus from leukocytes, vaginal, preputial and nasal swabs from three fallow deer; and four isolates of PI3 from nasal secretions of the 50 free-ranging pronghorns.     

Gastrointestinal nematode infections in wild ruminants Rupicapra rupicapra and Dama dama: influence of density and cohabitation with domestic ruminants

The distribution of gastrointestinal nematodes in different populations of wild ruminants has been studied with regard to density of the animals and the presence of domestic ruminants in the habitat. The degree of parasite overdispersion among the hosts has been examined in the hypothesis of a negative binomial model of distribution. The results show that the density has a greater weight than cohabitation with domestic ruminants, in destabilizing the host-parasite relationship.     

Composition of adrenal lipids from some domestic and wild ruminants.

1. Lipids from the whole adrenal glands of the ox and the African buffalo (Syncerus caffer) were extracted and fractionated into neutral and phospholipids. Both species revealed the presence of considerable quantities of cholesterol but only very small quantities of cholesteryl esters. 2. Fatty acids from various fractions of bovine and buffalo adrenal glands were investigated by gas-chromatography. They showed a remarkably low content of higher unsaturated fatty acids and a very high content of stearic acid. 3. Mitochondrial and microsomal fractions were isolated from the adrenal glands of the impala antelope (Aepyceros melampus), their lipids extracted, analyzed and compared with the composition of the mitochondrial lipids from bovine adrenal glands. 4. Subcellular fractions of the bovine and impala adrenal glands contain only very small quantities of esterified cholesterol. Most of the lipid fractions were characterized by the absence of adrenic acid (C22:4 omega 6) and a low content of arachidonic acid.     

Rabies antibodies in sera of wild birds

Three hundred forty-three birds representing six orders and 22 species were examined serologically for antibodies against rabies. Low passive hemagglutination titers were observed in 23 samples. Fifteen of 65 (23.1%) predatory birds and 8 of 278 (2.9%) non-predatory birds were positive. Rabies antibody positive sera from non-predatory species were from species commonly thought to be scavengers suggesting the importance of the oral route for the presentation of rabies virus to birds.     

Dynamics of parasite communities and interactions between wild and domestic ruminants

Dynamics of parasite communities and host-parasite-environment interactions can be influenced by different factors. The present note, by discussing some field experiences in wild and domestic ruminant populations, approaches eco-epidemiology of abomasal nematodes in relation with host health and dynamics. Factors possibly playing a role in the host-parasite relationship are discussed, as well as possible use of macroparasites as ecological and sanitary indicators. The above topics are approached in a management perspective, in particular regarding interactions between domestic and wild ruminant populations.