A survey of perfluorooctane sulfonate and related perfluorinated organic compounds in water, fish, birds, and humans from Japan

Occurrence of perfluorooctane sulfonate (PFOS) in the tissues of humans and wildlife is well documented. In this study, concentrations and distribution of PFOS, perfluorohexane sulfonate (PFHS), and perfluorobutane sulfonate (PFBS) were determined in samples of surface water, fish and bird blood and livers, and human blood collected in Japan. Notable concentrations of PFOS were found in surface water and fish from Tokyo Bay. PFOS was found in all of the 78 samples of fish blood and liver analyzed. Based on the concentrations of PFOS in water and in fish livers, bioconcentration factors were calculated to range from 274 to 41 600. Concentrations of PFOS in the blood of Japanese human volunteers ranged from 2.4 to 14 ng/mL. PFHS was detected in 33% of the fishes analyzed, at concentrations severalfold less than those of PFOS.

Risk to human health from a plethora of simian immunodeficiency viruses in primate bushmeat

To assess human exposure to Simian immunodeficiency virus (SIV) in west central Africa, we looked for SIV infection in 788 monkeys that were hunted in the rainforests of Cameroon for bushmeat or kept as pets. Serologic reactivity suggesting SIV infection was found in 13 of 16 primate species, including 4 not previously known to harbor SIV. Overall, 131 sera (16.6%) reacted strongly and an additional 34 (4.3%) reacted weakly with HIV antigens. Molecular analysis identified five new phylogenetic SIV lineages. These data document for the first time that a substantial proportion of wild monkeys in Cameroon are SIV infected and that humans who hunt and handle bushmeat are exposed to a plethora of genetically highly divergent viruses.

Serologic and molecular characterization of Anaplasma species infection in farm animals and ticks from Sicily

Although Anaplasma marginale was known to be endemic in Italy, the diversity of Anaplasma spp. from this area have not been characterized. In this study, the prevalence of Anaplasma spp. antibodies in randomly selected farm animals collected on the island of Sicily was determined by use of a MSP5 cELISA for Anaplasma spp. and an immunofluorescence test specific for Anaplasma phagocytophilum. Genetic variation among strains of Anaplasma spp. from animals and ticks was characterized using the A. marginale msp1alpha and the Anaplasma spp. msp4 genes. Eight species of ticks were collected and tested by PCR. Seropositivity for Anaplasma spp. and A. phagocytophilum was detected in bovine and ovine samples. All the donkeys were seropositive for A. phagocytophilum but not for Anaplasma spp. Four A. marginale genotypes were identified by msp4 sequences from bovine and tick samples. Two new genotypes of Anaplasma ovis were characterized in sheep. The sequences of A. phagocytophilum from three donkeys proved to be identical to the sequence of the MRK equine isolate from California. Six A. marginale genotypes were found in cattle and one tick using the A. marginale msp1alpha sequences. All genotypes had four repeated sequences in the N-terminal portion of the MSP1a, except for one that had five repeats. The Italian strains of A. marginale contained three repeat sequences that were not reported previously. Definition of the diversity of Anaplasma spp. in Sicily reported, herein is fundamental to development of control strategies for A. marginale, A. ovis and A. phagocytophilum in Sicily.

Serosurvey of Roe Deer, Chamois and Domestic Sheep in the Central Italian Alps

Roe deer (Capreolus capreolus), chamois (Rupicapra rupricapra rupicapra), and domestic sheep in the Orobie Alps, Italy, were serologically tested for antibodies to selected pathogens that may be transmitted across species. Antibodies against Brucella spp. and bovine herpesvirus 1 (roe deer and chamois only) were not detected in any species. In roe deer, antibodies were detected against Toxoplasma gondii (13%) and Neospora caninum (3%). Chamois tested positive for antibodies to T. gondii (5%), N. caninum (21%), bovine respiratory syncytial virus (BRSV) (41%), bovine parainfluenza type-3 virus (17%), pestiviruses (18%), and Mycoplasma conjunctivae (17%). In the sheep, particularly high antibody prevalence rates were found for T. gondii (78%), Chlamydophila spp. (20%), pestiviruses (90%), BRSV (82%), and M. conjunctivae (81%).

An inhibition enzyme-linked immunosorbent assay for the detection of antibody to Rift Valley fever virus in humans, domestic and wild ruminants

This paper describes the development and validation of an inhibition ELISA based on gamma-irradiated tissue culture-derived antigen for the detection of antibody to Rift Valley fever virus (RVFV) in humans, domestic and wild ruminants. Validation data sets derived from field-collected sera in Africa (humans=1367, cattle=649, goats=806, sheep=493, buffalo=258, camels=156) were categorized according to the results of a virus neutralisation test. In addition, individual sera from 93 laboratory workers immunized with inactivated RVF vaccine, 136 serial bleeds from eight sheep experimentally infected with wild-type of RVFV, and 200 serial bleeds from 10 sheep vaccinated with the live-attenuated strain of the virus, were used to study the kinetics of RVFV antibody production under controlled conditions. At cut-off values selected at 95% accuracy level by the two-graph receiver operating characteristic analysis the ELISA sensitivity ranged from 99.47% (humans) to 100% (sheep, buffalo, camels). The specificity ranged from 99.29% (sheep) to 100% (camels). Compared to virus neutralisation and haemagglutination-inhibition tests, the ELISA was more sensitive in detection of the earliest immunological responses in experimentally infected and vaccinated sheep. Our results demonstrate that the ELISA format reported here can be used as a safe, robust and highly accurate diagnostic tool in disease-surveillance and control programmes, import/export veterinary certification, and for monitoring of the immune response in vaccinees.

Clinical assessment of selenium status of livestock

Assessment of the selenium status of livestock is an important aspect of production medicine, but variations in reported values between laboratories and between methods may be > 30%. Reliable interpretations require considerable experience with an assay and an extensive database from field and research case samples of a variety of species. The Michigan State University Animal Health Diagnostic Laboratory (MSU-ADHL) has offered Se analyses by acid-digestion and fluorometric detection since 1982. This laboratory expects serum Se values (nanograms per milliliter) of livestock to increase gradually with age from starting ranges for neonates of 50 to 80 for calves and sheep and 70 to 90 for foals and pigs. Expected or "normal" values for the adults are in the ranges of 70 to 100 for cattle, 120 to 150 for sheep, 130 to 160 for horses, and 180 to 220 for swine. Normal liver Se concentrations are considered to range between 1.2 and 2.0 micrograms/g on a dry weight basis, regardless of the species or age. Based on samples submitted to MSU-AHDL between September 1990 and August 1991, contemporary feeding practices in the Michigan area resulted in mean serum Se values (nanograms per milliliter) of 75 +/- 19 for adult Holsteins, 170 +/- 27 for adult swine (mixed breeds), and 137 +/- 30 for adult race horses. Within that period of time, two field cases of Se toxicity were diagnosed. One involved feeder pigs with a recorded high serum Se value of 1,525 ng/mL due to a commercial premix manufacturing error.(ABSTRACT TRUNCATED AT 250 WORDS)

Species-specific concentrations of perfluoroalkyl contaminants in farm and pet animals in Japan

The persistent metabolites of perfluorinated compounds (PFCs) which have been detected in the tissues of both humans and wildlife, and human contamination by PFCs suggest differences in the exposure patterns to these compounds. However, studies focused on identifying human exposure pathways to PFCs are scarce. To provide a preliminary assessment of PFCs in farm animals such as chicken, cattle, pigs, goats and horses, blood and liver samples were collected from various regions in Japan. Additionally, dog sera samples representing pet animals were also employed for analysis. Perfluorooctane sulfonate (PFOS) was the most prominent contaminant found in farm and pet animals, with mean sera PFOS concentrations (in decreasing order) of: chicken (5.8 ng/ml)>cattle (3.0 ng/ml)>goat (2.4 ng/ml)>horse (0.71 ng/ml)>pig (0.37 ng/ml). Chicken livers (67 ng/g) contained the highest mean PFOS concentration among the farm animals, followed by those of pigs (54 ng/g) and cattle (34 ng/g). In comparison to PFOS levels in farm animals, the detected levels of other PFCs were not significant. The high levels of PFOS found in cattle fetal livers suggest that PFOS crosses the placental barrier to enter fetal circulation. The consumption of chicken by humans might produce higher PFOS exposure in humans compared to that in farm animals; however, the current levels of PFOS in farm animals in Japan were lower than those reported in fish and wild animals. Elevated concentrations of both PFOS (25 ng/ml) and perfluorohexane sulfonate (PFHxS; 10 ng/ml) were found in dog sera, indicating that further studies are needed to identify PFC sources in the human environment.

Spillover of Peste des Petits Ruminants Virus from Domestic to Wild Ruminants in the Serengeti Ecosystem, Tanzania

We tested wildlife inhabiting areas near domestic livestock, pastures, and water sources in the Ngorongoro district in the Serengeti ecosystem of northern Tanzania and found 63% seropositivity for peste des petits ruminants virus. Sequencing of the viral genome from sick sheep in the area confirmed lineage II virus circulation.

Technical note: time-resolved fluoro-immunometric assay for intact insulin in livestock species

Insulin levels in ruminants are often very low and hence are difficult to measure with commercially available RIA kits designed for use with human serum or plasma samples. Those assays may also have high cross-reactivity with nonintact insulin. An assay originally invented for human insulin and based on a pair of monoclonal antibodies binding to specific parts of the insulin molecule was further developed and validated for use with bovine or porcine plasma or serum. The assay is of the sandwich type, with the catching antibody coated to the solid phase of microtiter plate wells and with the detecting antibody labeled with europium, and measured as time-delayed fluorescence. The assay protocol includes an incubation step in which plasma samples of 50 microL are incubated with buffer and detecting antibody for 3 h in coated wells, followed by an enhancement step in which the fluorescence from the europium label is stabilized before measurement. This gives a sensitivity of 3 pmol/L and a possible working range up 16,700 pmol/L. There is no cross-reactivity with pro-insulin or IGF-I. Calibrators are prepared in heat-inactivated serum from the relevant species. Porcine and bovine insulin have different calibration curves; porcine insulin is more reactive and has a higher background than bovine insulin. Validation results show low CV values, parallel dilution of samples, and a recovery ratio close to unity. Comparison with a commercial RIA shows good agreement, except at low concentrations, at which the RIA determinations are inaccurate. Plasma samples from other domestic species (horse, sheep, goat, and mink) have also been assayed, but it is emphasized that calibrators should be prepared in heat-inactivated serum from the appropriate species, and preferably insulin from that species should be used for calibration.

The biological selenium status of livestock in Britain as indicated by sheep erythrocyte glutathione peroxidase activity

The reliability of erythrocyte glutathione peroxidase activity as an indicator of selenium status in livestock is discussed. Based on this measurement, a survey is described of the biological selenium status of sheep on each of 329 farms in Britain. Results showed that 47 per cent of these farms were probably unable to provide grazing livestock with sufficient selenium to maintain blood levels greater than 0.075 microgram per ml. Increased selenium deficiency from the increasing use of home grown feeds as a major constituent of livestock rations may be causally related to the increase of white muscle disease and other selenium responsive diseases in Britain.

Hepatitis E Virus in Domestic Pigs, Wild Boars, Pig Farm Workers, and Hunters in Estonia

While hepatitis E is a growing health concern in Europe, epidemiological data on hepatitis E virus (HEV) in Estonia are scarce. Along with imported HEV infections, autochthonous cases are reported from European countries. Both domestic and wild animals can be a source of human cases of this zoonosis. Here, we investigated the presence of anti-HEV antibodies and HEV RNA in domestic pigs and wild boars, as well as in pig farm workers and hunters in Estonia. Anti-HEV antibodies were detected in 234/380 (61.6%) of sera from domestic pigs and in all investigated herds, and in 81/471 (17.2%) of meat juice samples from wild boars. HEV RNA was detected by real-time PCR in 103/449 (22.9%) of fecal samples from younger domestic pigs and 13/81 (16.0%) of anti-HEV-positive wild boar samples. Analysis of sera from 67 pig farm workers and 144 hunters revealed the presence of HEV-specific IgG in 13.4 and 4.2% of the samples, respectively. No HEV RNA was detected in the human serum samples. Phylogenetic analyses of HEV sequences from domestic pigs and wild boars, based on a 245 bp fragment from the open reading frame 2 showed that all of them belonged to genotype 3. The present study demonstrates the presence of HEV in Estonian domestic pig and wild boar populations, as well as in humans who have direct regular contact with these animals. Our results suggest that HEV infections are present in Estonia and require attention.

Comparison of plasma concentrations of vitamin D and its metabolites in young and aged domestic animals

1. Vitamin D and its metabolites were measured in the plasma of five species of rural domestic animals. 2. Concentration of 1,25-dihydroxyvitamin D was higher (P less than 0.01) in young animals (range 24-118 pg/ml, means +/- SD = 72.0 +/- 30.0) than in adult animals (range 14-67 pg/ml, means +/- SD = 40.2 +/- 22.6). 3. 25-Hydroxyvitamin D3-26,23 lactone was present only in the chick and the pig. 4. Unsheared sheep appeared to be inefficient utilizers of the photochemical conversion of 7-dehydrocholesterol to vitamin D3. 5. Conversion of 25-hydroxyvitamin D to 24,25-dihydroxyvitamin D was most efficient in species with high plasma phosphorus concentrations (pig, sheep).

Role of Leptin in Farm Animals: a Review

The discovery of hormone leptin has led to better understanding of the energy balance control. In addition to its effects on food intake and energy expenditure, leptin has now been implicated as a mediator of diverse physiological functions. Recently, leptin has been cloned in several domestic species. The sequence similarity suggests a common function or mechanism of this peptide hormone across species. Leptin receptors are expressed in most of tissues, which is consistent with the multiplicity of leptin functions. The main goal of this review was to summarize knowledge about effect of leptin on physiology of farm animals. Experiments point to a stimulatory action of leptin on growth hormone (GH) secretion, normal growth and development of the brain. Surprisingly, leptin is synthesized at a high rate in placenta and may function as a growth factor for fetus, signalling the nutritional status from the mother to her offspring. Maturation of reproductive system can be stimulated by leptin administration. Morphological and hormonal changes, consistent with a major role of leptin in the reproductive system, have also been described, including the stimulation of the release of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin. Leptin has a substantial effect on food intake and feeding behaviour in animals. Administration of leptin reduces food intake. Its level decrease within hours after initiation of fasting. Leptin also serves as a mediator of the adaptation to fasting, and this role may be the primary function for which was the molecule evolved.

Adhesive properties of platelets from different animal species

The use of large animals (e.g., pig and sheep) in human medicine, and the need to develop new therapeutic strategies for domestic animal diseases related to platelet disorders, require better characterization of the physiology of animal platelets. In this study, the ability of platelets from buffaloes, horses, pigs and sheep to adhere to immobilized autologous fibrinogen was compared with that of human platelets. Blood samples were collected from the jugular vein of six healthy subjects of each species and platelet-rich plasma (PRP) was obtained by centrifugation. Platelets, isolated by further centrifugation of PRP, were washed by gel-filtration on Sepharose-2B, counted and added to the wells of 96-well plates pre-coated with autologous fibrinogen. After different times of incubation, non-adherent platelets were removed, and the number of adherent platelets was assessed by measuring endogenous acid phosphatase activity. Horse platelets showed the strongest ability to adhere to autologous immobilized fibrinogen, being 1.7-, 3.1- and 2.3-fold more active than human, buffalo and porcine platelets, respectively. Sheep platelets were unable to adhere to autologous immobilized fibrinogen. Platelet activation by adenosine 5-diphosphate (ADP) increased both human and animal platelet adhesive response. ADP-stimulated sheep platelets were able to adhere to autologous immobilized fibrinogen, albeit to a lesser extent than platelets from the other animal species. The observed interspecies variability in adhesive properties of platelets may reflect structural differences, or differences in the availability of the fibrinogen receptor (glycoprotein IIb/IIIa) on the platelet surface.

Comparison of the serum pharmacokinetics of a long acting and a conventional oxytetracycline injection

A crossover study was carried out in cattle to determine the serum pharmacokinetics of a standard dose (20 mg/kg bodyweight) of oxytetracycline given either as a conventional injectable formulation or as a long acting formulation. For reference purposes, an intravenous treatment (also given at 20 mg/kg) was included in the trial protocol. A comparison of the two treatment regimes showed that the long acting formulation gave a significantly lower peak oxytetracycline serum concentration, with a significant extension of drug serum concentration. The long acting formulation also showed a longer serum half life and a significantly greater area under the curve value, calculated from 36 hours onwards, together with serum oxytetracycline concentrations which exceeded 0.5 microgram/ml for 86.8 as opposed to 51.5 hours for the conventional formulation. It is concluded that the use of the long acting formulation in cattle leads to a more sustained serum oxytetracycline concentration than does the same dose of conventional formulation.

The use of blood analyses to evaluate mineral status in livestock

Animal responses are useful means of evaluating and assessing nutritional status. Blood mineral concentrations can be useful nutritional responses, although there are important limitations. The nutritional value in monitoring blood mineral concentrations varies with the specific mineral, being generally most valuable for those minerals in which homeostasis is regulated primarily by renal excretion, as opposed to regulation by variable absorptive efficiency. Examples of minerals for which blood concentrations are good measures of nutritional intake are selenium and magnesium. Blood mineral concentrations are affected by multiple variability factors. The strategy for use in mineral status assessment is to minimize non-nutritional variation by grouping animals for testing based on physiologic factors that affect, or are likely to affect, the concentration of the mineral or minerals being tested. Care should be taken to use the proper sampling protocol, so as not to cause artifactual variation. Removal of the serum from the clot within 2 hours of sample collection is an important step, among others. Sampling adequate numbers of animals and evaluating the herd mean and SD can minimize the effect of random variation on interpretation.

Tuberculosis in domesticated deer (Cervus elaphus): a large animal model for human tuberculosis

Since the recent extensive domestication and farming of deer in New Zealand, tuberculosis (Tb) has presented a major health issue in farmed herds. The spectrum of disease pathology and immune reactivity in this naturally infected species represents a potentially valuable large animal model for the study of the underlying immunological and pathological mechanisms involved in Mycobacterium bovis infection and its spread. A combination of laboratory assays for the detection of tuberculosis in deer is described. Domesticated deer are genetically diverse and their exposure to natural variations in environmental conditions results in a spectrum of immune responses and pathology of Tb, similar to that found in man. The model has special relevance to the study of host responses to tuberculosis in immunocompromised individuals, particularly those in the third world. Elucidation of the mechanisms involved in immune responses to Tb in deer will facilitate the development of vaccines and improved diagnostic assays for Tb in man.

Seasonal changes in adrenocortical responses to acute stress in Eurasian tree sparrow (Passer montanus) on the Tibetan Plateau: comparison with house sparrow (P. domesticus) in North America and with the migratory P. domesticus in Qinghai Province

Seasonal modulation of the adrenocortical response to stress appears to be ubiquitous in arctic-breeding and temperate-zone-breeding birds, but has not been well investigated in alpine-breeding species at mid-latitude. We examined the adrenocortical response to acute stress (capture, handling and restraint) in populations of Eurasian tree sparrow (Passer montanus) among seasons and migratory house sparrow (P. domesticus bactrianus) in pre-breeding on the Qinghai-Xizang Plateau (the Tibetan Plateau). A population of house sparrow (Passer domesticus domesticus) was also sampled in lowland Phoenix, Arizona during breeding and wintering stages. In Eurasian tree sparrows, baseline corticosterone (CORT) does not differ among life history stages, but stress-induced CORT level (maximal CORT, total and corrected integrated CORT) is significantly higher in late breeding stage than those in early breeding and prebasic molt stages. In house sparrows, stress-induced CORT level does not differ between sites and life history stages, but baseline CORT is significantly lower in pre-breeding from Qinghai compared with those in breeding and wintering stages from Phoenix. Interestingly, both baseline CORT and maximal CORT do not differ between the populations of Eurasian tree sparrow and house sparrow in early/pre-breeding stage although tree sparrow is resident species whereas house sparrow is migratory in Qinghai. Our results suggest that the extreme environment of the Tibetan Plateau does not have significant effects on adrenocortical responses to acute stress in Eurasian tree sparrows and house sparrows, which may be a result of masking by human activities. These invasive human commensals may have a unique HPA axis response to different environments because they can take advantage of human food sources and shelter (i.e. buildings).

Serum Biochemical Phenotypes in the Domestic Dog

The serum or plasma biochemical profile is essential in the diagnosis and monitoring of systemic disease in veterinary medicine, but current reference intervals typically take no account of breed-specific differences. Breed-specific hematological phenotypes have been documented in the domestic dog, but little has been published on serum biochemical phenotypes in this species. Serum biochemical profiles of dogs in which all measurements fell within the existing reference intervals were retrieved from a large veterinary database. Serum biochemical profiles from 3045 dogs were retrieved, of which 1495 had an accompanying normal glucose concentration. Sixty pure breeds plus a mixed breed control group were represented by at least 10 individuals. All analytes, except for sodium, chloride and glucose, showed variation with age. Total protein, globulin, potassium, chloride, creatinine, cholesterol, total bilirubin, ALT, CK, amylase, and lipase varied between sexes. Neutering status significantly impacted all analytes except albumin, sodium, calcium, urea, and glucose. Principal component analysis of serum biochemical data revealed 36 pure breeds with distinctive phenotypes. Furthermore, comparative analysis identified 23 breeds with significant differences from the mixed breed group in all biochemical analytes except urea and glucose. Eighteen breeds were identified by both principal component and comparative analysis. Tentative reference intervals were generated for breeds with a distinctive phenotype identified by comparative analysis and represented by at least 120 individuals. This is the first large-scale analysis of breed-specific serum biochemical phenotypes in the domestic dog and highlights potential genetic components of biochemical traits in this species.

Collaborative study to evaluate a new ELISA test to monitor the effectiveness of rabies vaccination in domestic carnivores

To prevent any introduction of rabies, many rabies-free countries have adopted a scheme requiring the rabies vaccination of pets associated with a serological test. FAVN test and RFFIT are the current OIE prescribed techniques to perform this assay. A qualitative indirect ELISA (Serelisa) test has been recently described as a screening test to monitor the effectiveness of rabies vaccination of pets. A lack of sensitivity requires ELISA negative samples to be retested using an OIE confirmatory test. This raised the question whether this new test could be reasonably proposed as an alternative tool in the context of international trades of pets. The Community Reference Institute of Nancy organized a short trial to answer this question. In this study, 16 laboratories tested a panel of their own samples with FAVN test/RFFIT and the Serelisa. The comparison of results revealed that the performance of the Serelisa is highly heterogeneous. A lack of sensitivity was detected in 50% of participants, when 25% of laboratories obtained a significant rate of false positive results. This last point questions the pertinence of using the Serelisa in the context of international trades by preventing any movements of insufficiently or non-protected animals.

Fasting plasma hormones and metabolites in feral and domestic newborn pigs

Newborn Yorkshire and Ossabaw (feral) pigs were examined under thermoneutral conditions to determine whether survival rate during fasting differs between these breeds and whether any blood-borne factors are associated with improved survival. Newborn pigs were removed from the sow before suckling. Body composition was determined on 10 newborn Ossabaw and 12 newborn Yorkshire pigs. Another group of animals (eight Ossabaw, 12 Yorkshire) was fasted for 72 hr, with blood samples drawn at birth and 12 and 24 hr into fasting. Glucose, free fatty acid (FFA), growth hormone (GH), insulin, thyroxine (T4), triiodothyronine (T3), cortisol and glucagon concentrations were measured in plasma of fasted pigs. Concentrations of carcass lipid, dry matter and ash were higher in newborn Ossabaw pigs than in newborn Yorkshire pigs. Survival through 72 hr of fasting was lower among Yorkshire pigs. Yorkshire and Ossabaw pigs had similar concentrations of metabolites and hormones at birth, with the exceptions of lower plasma GH and higher T3 concentrations in Ossabaw pigs. Higher plasma T3 concentrations would indicate a greater potential for fatty acid oxidation. During fasting, Ossabaw pigs had lower plasma GH and T4 concentrations and higher glucagon and FFA concentrations. Increased survival among newborn Ossabaw pigs may have been due to increased availability of FFA during fasting, and to a greater potential for gluconeogenesis through increased oxidation of fatty acids and higher plasma glucagon concentrations. This would suggest that maternal treatments that would increase storage of fat and(or) increase the capacity for oxidation of fat in utero would improve survival of newborn pigs.

Species characteristics of serum proteins demonstrated after agarose gel electrophoresis

Serum samples from five species of domestic animals were subjected to protein electrophoresis on commercially prepared agarose gel films. After processing, the strained electrophoretic patterns and densitometric traces exhibited certain characteristics for each species. The features which were considered distinctive of each species are illustrated.

Screening of Trypanosoma brucei gambiense in domestic livestock and tsetse flies from an insular endemic focus (Luba, Equatorial Guinea)

BACKGROUND

Sleeping sickness is spread over 36 Sub-Saharan African countries. In West and Central Africa, the disease is caused by Trypanosoma brucei gambiense, which produces a chronic clinical manifestation. The Luba focus (Bioko Island, Equatorial Guinea) has not reported autochthonous sleeping sickness cases since 1995, but given the complexity of the epidemiological cycle, the elimination of the parasite in the environment is difficult to categorically ensure.

METHODOLOGY/PRINCIPAL FINDINGS

The aim of this work is to assess, by a molecular approach (Polymerase Chain Reaction, PCR), the possible permanence of T. b. gambiense in the vector (Glossina spp.) and domestic fauna in order to improve our understanding of the epidemiological situation of the disease in an isolated focus considered to be under control. The results obtained show the absence of the parasite in peridomestic livestock but its presence, although at very low rate, in the vector. On the other hand, interesting entomological data highlight that an elevated concentration of tsetse flies was observed in two out of the ten villages considered to be in the focus.

CONCLUSIONS

These findings demonstrate that even in conditions of apparent control, a complete parasite clearance is difficult to achieve. Further investigations must be focused on animal reservoirs which could allow the parasites to persist without leading to human cases. In Luba, where domestic livestock are scarcer than other foci in mainland Equatorial Guinea, the epidemiological significance of wild fauna should be assessed to establish their role in the maintenance of the infection.

Physiological and proteomic evidences that domestication process differentially modulates the immune status of juvenile Eurasian perch (Perca fluviatilis) under chronic confinement stress

The current study aimed to evaluate the influence of domestication process on the stress response and subsequent immune modulation in Eurasian perch juveniles (Perca fluviatilis) submitted to chronic confinement. Briefly, F1 and F4 generations were confined into small-size tanks and sampled 7 and 55 days after stocking. Cortisol and glucose levels as well as lysozyme activity and immunoglobulin level were evaluated in the serum. Spleen Somatic Index and spleen ROS production were also measured. A proteomic analysis was performed on serum sampled on day 7. Finally, both generations were genetically characterized using a microsatellite approach. Globally, results revealed that chronic confinement did not elicit a typical stress response but resulted in a prolonged immune stimulation. Proteomic results suggested that domestication process influenced the immune status of perch submitted to chronic confinement as the F1 confined fish displayed lower abundance of C3 complement component, transferrin and Apolipoprotein E. Microsatellite data showed a strong genetic drift as well as reduced genetic diversity, allelic number and heterozygosity along with domestication process. The present work is the first to report that fish under domestication can develop an immune response, assessed by a combined approach, following recurrent challenges imposed by captive environment despite a reduced genetic variation.