Seroprevalence after vaccination of cattle and sheep against Bluetongue Virus (BTV) serotype 8 in Sweden.

Sweden experienced its first outbreak of bluetongue virus (BTV) infection beginning in September 2008. Mandatory vaccination with an inactivated vaccine (BTVPUR Alsap8; Merial, Lyon, France) began 2 days after bluetongue was confirmed in the country. The aim of this study was to investigate whether the goal of 80% seroconversion by the susceptible population within the vaccination area was met during the initial phase of the Swedish vaccination campaign and whether there were discrepancies between subpopulations. Milk or blood samples were collected from 274 cattle randomly selected from the vaccinated population. Blood samples were also collected from ten ewes on each of 28 randomly selected vaccinated herds. The vaccination campaign in Sweden may be regarded as successful, as measured by apparent seroprevalence in the vaccinated population. The overall apparent seroprevalence was 77%, and in cattle, which constituted the majority of the susceptible population, the apparent seroprevalence was 82%. Factors that influenced the titres after vaccination were as follows: (i) the time span between vaccination and sampling and (ii) the age of the animals.

The acute phase response in calves experimentally infected with bovine viral diarrhoea virus and/or Mannheimia haemolytica.

The aim of this investigation was to study differences and similarities in the acute phase response of calves experimentally infected in the respiratory tract with either bovine viral diarrhoea virus (BVDV) or Mannheima haemolytica (Mh), or with a combination of both (BVDV/Mh). A non-inoculated control group was also included. The acute phase response was measured by serum or plasma concentrations of the acute phase proteins (APPs) haptoglobin, serum amyloid A (SAA) and fibrinogen, and of cortisol, prostaglandin F2alpha-metabolite and interferon-alpha (IFN-alpha) activity. Clinical symptoms were also recorded and were most severe in the BVDV/Mh group. The symptoms were mild to moderate in the BVDV group, while none, or very mild symptoms were observed in the Mh group. In all inoculated groups, a significant acute phase response was observed, with elevated values of haptoglobin, SAA and fibrinogen, while the control group remained unaffected throughout the study. In general, the magnitude of the response was similar, but the duration of elevated concentrations of APPs was significantly longer in the BVDV/Mh group than in the BVDV group, reflecting the duration of the clinical symptoms. However, in the single infection groups, the APP response and the clinical symptoms were not correlated. The IFN-alpha activity increased in all BVDV-inoculated animals, but no response in cortisol and PGF2alpha-metabolite concentrations was observed after infection. Basal levels of serum concentrations of haptoglobin, SAA and fibrinogen were established and may be used for evaluating calf health in herds. The duration of elevated haptoglobin, SAA and fibrinogen values did not differ significantly within groups indicating that their value as indicator of disease is equal.

Interleukin 6, serum amyloid A and haptoglobin as markers of treatment efficacy in pigs experimentally infected with Actinobacillus pleuropneumoniae.

The possibility to use acute phase proteins to monitor the elimination of a bacterial infection in pigs would facilitate an objective assessment of treatment with various antimicrobial substances. To examine this possibility, the acute phase response (IL-6, serum amyloid A (SAA), and haptoglobin) elicited by Actinobacillus pleuropneumoniae and its reduction on treatment with various antibiotics was studied in serum from specific pathogen free (SPF) pigs. Pigs were infected intranasally with A. pleuropneumoniae serotype 2, and either left as non-treated control pigs or treated with different antibiotics intramuscularly at onset of respiratory disease (20h post-infection). Pigs responded to the infection with prominent increases in activity and concentrations of IL-6, SAA, and haptoglobin. These responses were to a certain extent overlapping and covered the time span from a few hours after infection until development of detectable levels of specific antibodies (7-10 days post-infection in untreated pigs). The haptoglobin response lasted until the end of the study on day 17 and thereby partly coincided with the antibody response. Treatment with antimicrobials that effectively reduced establishment of the infection with A. pleuropneumoniae also reduced the duration of all three acute phase responses, and reduced the concentration of serum haptoglobin. In contrast, less efficacious treatments did not reduce these acute phase responses. Thus, acute phase reactants can be applied to monitor therapeutic effects of antimicrobial drugs in the pig and measurements of IL-6, SAA and haptoglobin could add valuable information about the stage of infection during a disease outbreak.

Serum amyloid A (SAA) as an aid in the management of infectious disease in the foal: comparison with total leucocyte count, neutrophil count and fibrinogen.

Differentiation between infectious and noninfectious disease and rapid initiation of accurate treatment are essential in managing diseases in the neonatal and young foal. Identification of useful inflammatory markers for these purposes is, therefore, of great importance. The aim of this study was to compare the responses of the acute phase protein serum amyloid A (SAA) with the responses of fibrinogen and total leucocyte and neutrophil counts in infectious diseases encountered in the young foal, and to assess whether SAA measurements give additional information useful in the management of these diseases. In a prospective study, foals (n = 25) showing clinical signs indicative of infectious disease were blood sampled on admission and then daily or every second day during hospitalisation. The main presenting signs were neonatal weakness (n = 9), pneumonia (n = 6) and diarrhoea (n = 10). SAA and fibrinogen concentrations on admission were higher in foals with bacterial infections (n = 8) than in foals with nonbacterial or uncertain diagnoses (n = 17). On admission, weak foals with negative blood cultures (n = 3) had normal SAA and fibrinogen concentrations and varying total leucocyte and neutrophil counts. Foals with positive blood cultures (n = 2) had markedly increased SAA, decreased or increased fibrinogen concentration and leuco- and neutropenia. Those with ambiguous blood cultures (n = 3) had moderate to markedly increased SAA concentrations and normal fibrinogen concentration, leucocyte and neutrophil counts on admission. All foals with negative or ambiguous blood cultures recovered and had normal or decreasing SAA concentration on discharge. Both foals with a positive blood culture were subjected to euthanasia. One foal born with equine herpesvirus-1 infection had moderately increased SAA and normal fibrinogen concentration and leuco- and neutropenia. Foals with Rhodococcus equi pneumonia had increased concentrations of all parameters on admission. On discharge, recovered foals had normal SAA concentrations, whereas fibrinogen and total white blood cell count and neutrophil counts were still increased. There were no consistent inflammatory changes in the parameters measured in diarrhoeic foals and there was no statistical difference between rotavirus-positive (n = 4) and -negative (n = 6) foals in this respect. The results of this investigation suggest that SAA might be an aid in the differential diagnostic procedure of neonatally weak foals and in foals with diarrhoea as the main presenting clinical sign and that SAA measurements could add information in the monitoring of treatment in Rhodococcus equi pneumonia by responding more rapidly than the markers used to date.

Dynamics in serum of the inflammatory markers serum amyloid A (SAA), haptoglobin, fibrinogen and alpha2-globulins during induced noninfectious arthritis in the horse.

Despite the importance of noninfectious joint diseases in equine medicine, little is known about the acute phase response which may be elicited if the local inflammatory process of noninfectious arthritis is sufficiently strong, Therefore the aim of this study was to monitor the systemic inflammatory response during experimentally-induced noninfectious arthritis by studying the dynamics in serum of the acute phase proteins serum amyloid A (SAA), haptoglobin, fibrinogen and alpha2-globulins. Twenty-four Standardbred horses, age 3-7 years, found healthy on thorough clinical, radiological, haematological and serum biochemical examination, were injected aseptically into the right midcarpal joint with amphotericin B. Blood samples were drawn before induction of arthritis (0 h), and at 8, 16, 24, 36 and 48 h postinduction and then on Days 3, 4, 5 and 15 postinduction. All horses developed lameness with joint effusion and joint heat as well as increased respiratory rate, heart rate and body temperature. The lameness started to decline after 24-36 h and, in most animals, systemic signs disappeared on Day 2 postinjection. The concentration of the acute phase proteins increased following induction of arthritis. The SAA concentrations were higher than baseline concentrations from 16 h postinduction and were maximal at 36-48 h (227 times baseline concentration). The haptoglobin concentrations were higher than baseline concentrations from 24 h and were maximal at 48-96 h (1.14 times baseline concentration). The maximal concentrations of fibrinogen were seen between 36-72 h postinjection and increased on average 0.87 times from baseline concentrations. The fibrinogen concentrations were higher than baseline concentrations from 24 h postinjection. Alpha2-globulins concentrations showed a minor increase and increased 0.55 times from baseline concentrations. The markers had returned to baseline concentrations by Day 15. Our results demonstrate that amphotericin B-induced arthritis in a single joint gives rise to a systemic acute phase response measurable as increased concentrations in serum SAA, haptoglobin, fibrinogen and alpha2-globulins during the first 2 weeks of the condition and, thereby, that such an increase need not be indicative of infectious arthritis. Further research should be aimed at determining whether chronic noninfectious arthritis in the horse gives rise to increased acute phase protein concentrations in serum.

Intestinal cannulation: model for study of the midgut of the pig.

PURPOSE: To develop a pig model that would enable repeated biopsy specimen collection and endoscopic monitoring of the gut. This would increase precision of the experiment and reduce the number of experimental animals required. METHODS: Six 10-week-old Yorkshire pigs underwent surgery, and a cannula was inserted in the cecum. Two pigs served as non-operated controls. The health status of the animals was monitored by clinical, hematologic, and biochemical examinations and by studies of gut motility and microbial flora. The experimental period lasted for eight weeks and approximately 45 biopsy specimens were obtained from each animal. RESULTS: Repeated endoscopy was performed and biopsy specimens were taken. Adverse effects on the animal's health were not apparent, and differences were not evident in transit time of digesta or in diversity of the gut microbial flora. After surgery there was a transient increase in the concentrations of haptoglobin, serum amyloid A, and plasma cortisol, and in body temperature and white blood cell count. CONCLUSIONS: It is possible to use an intestinal cannula in the cecum both for endoscopy and biopsy specimen collection. The procedures did not influence health status of the pigs, nor alter gut function. The method will be useful in experimental infection studies as well as in other physiologic investigations.

A non-competitive chemiluminescence enzyme immunoassay for the equine acute phase protein serum amyloid A (SAA) -- a clinically useful inflammatory marker in the horse.

A non-competitive chemiluminescence enzyme immunoassay for measuring serum amyloid A (SAA) in equine serum was developed. A polyclonal anti-equine-amyloid A antiserum specific for equine SAA was utilized, and the assay was standardized using highly purified equine SAA. An acute phase horse serum was calibrated against the purified SAA and was used as standard when running the assay. Serum SAA concentrations in the range of 3-1210 mg/l could be measured. The reference range of SAA in clinically healthy adult horses was <7 mg/l. The clinical validation of the assay comprised the SAA responses after surgery and experimentally induced aseptic arthritis, and those associated with viral and bacterial infections. The SAA response after surgery (castration) was consistent, with peak concentrations on day 2 and a return to normal SAA concentrations within eight days. The aseptic arthritis produced an SAA response with a pattern similar to that seen after surgery, with peak concentrations of SAA 36-48 h after induction. Seven horses showed a biphasic pattern, with a second rise in SAA concentrations on day 4 and 5. All animals had SAA levels <7 mg/l on day 15. All horses with viral and bacterial infections had SAA concentrations above 7 mg/l. The ranges of SAA concentrations following the different types of inflammation overlap, being consistent with the unspecific nature of the SAA response. This study revealed that SAA is a sensitive and unspecific marker for inflammation, and describes the dynamics of the SAA response after standardized and well defined tissue damage.

The acute phase protein serum amyloid A (SAA) as an inflammatory marker in equine influenza virus infection.

The acute phase protein serum amyloid A (SAA) has proven potentially useful as an inflammatory marker in the horse, but the knowledge of SAA responses in viral diseases is limited. The aim of this study was to evaluate SAA as a marker for acute equine influenza A2 (H3N8) virus infection. This is a highly contagious, serious condition that inflicts suffering on affected horses and predisposes them to secondary bacterial infections and impaired performance. Seventy horses, suffering from equine influenza, as verified by clinical signs and seroconversion, were sampled in the acute (the first 48 h) and convalescent (days 11-22) stages of the disease, and SAA concentrations were determined. Clinical signs and rectal temperature were recorded. Secondary infections, that could have influenced SAA concentrations, were clinically suspected in 4 horses. SAA concentrations were higher in the acute stage than in the convalescent stage, and there was a statistically positive relationship between acute stage SAA concentrations and clinical signs and between acute stage SAA concentrations and maximal rectal temperature. Horses sampled early in the acute stage had lower SAA concentrations than those sampled later, indicating increasing concentrations during the first 48 h. There was a statistically positive relationship between convalescent SAA concentrations and degree of clinical signs during the disease process. The results of this investigation indicate that equine SAA responds to equine influenza infection by increasing in concentration during the first 48 h of clinical signs and returning to baseline within 11-22 days in uncomplicated cases.

Concentrations of total protein, albumin and immunoglobulins in undiluted uterine fluid of gynecologically healthy mares.

Undiluted uterine fluid from 20 Warmblood/Standardbred mares (5 to 14 yr old) was recovered by absorption to an intrauterine tampon. The mares were considered gynecologically healthy based on a clinical examination including uterine swabs for cytology and bacteriology as well as endometrial biopsy examinations. The protein profiles (SDS-PAGE) and concentrations of total protein, albumin, and immunoglobulins (Ig) A and G in the uterine fluid were examined and compared with the same proteins in serum. Major peaks were identified on the obtained protein profiles, and there was a clear similarity between the serum profiles and uterine fluid profiles. Variability in protein concentrations among mares was considerably larger in uterine fluid than in serum. Concentrations of the various proteins in uterine fluid were 44 to 56% of those in serum, except for IgA, which had a similar concentration in both serum and uterine fluid. Concentration of the proteins corresponding to peak No. 3 (molecular weight 60 to 71 kDa) in uterine fluid was higher (P < 0.05) in younger mares than in older ones. Parity had no effect on the recorded protein concentrations. The present study of gynecologically healthy mares showed that there is a large individual variation in the protein composition of uterine fluid. The results suggest that age, but not parity, may affect this composition, and indicate further that there is considerable transudation to the uterine cavity.

The acute phase serum amyloid A protein (SAA) in the horse: isolation and characterization of three isoforms.

Serum amyloid A (SAA) from acute phase horse serum was isolated using hydrophobic interaction chromatography, gel filtration and ion exchange chromatography. Three SAA isoforms with different isoelectric points, i.e. SAA pI 8.0, SAA pI 9.0 and SAA pI 9.7, were identified by two-dimensional electrophoresis and further characterized with amino acid sequence analysis. These isoforms were found in similar concentrations in all animals investigated, with SAA pI 9.7 constituting about half of the total SAA content. Partial amino acid sequence analysis verified the previously published heterogeneous SAA sequence. SAA pI 8.0 was found to have isoleucine in Position 16, glutamine in Position 44 and glycine in Position 59. SAA pI 9.0 had leucine, glutamine and alanine in the corresponding positions. In SAA pI 9.7 leucine, lysine and alanine were detected. The three isoforms characterized in this study are all acute phase SAAs. SAA pI 9.0 and 9.7 correspond to amyloid A protein variants previously isolated from amyloid deposits of equine liver, while there are no reports on an amyloid A variant corresponding to SAA pI 8.0.

Serum concentrations of thyroid hormones in calves with a transient or persistent infection with bovine viral diarrhoea virus.

Calves persistently infected with bovine viral diarrhoea virus (BVDV) often appear small for their age and it is possible that the virus interferes with their body metabolism by affecting the production of hormones. In this study, the serum concentrations of thyroxine (T4) and triiodothyronine (T3) were measured in calves with transient or persistent BVDV infections. The mean (SD) concentrations of T3 and T4 were lower (P < 0.001) in the persistently infected calves (1.79 [0.67] and 69.2 [23.8] nmol litre-1, respectively) from three dairy herds than in age-matched control calves (2.39 [0.72] and 93.4 [22.1] nmol litre-1, respectively). In each herd, the thyroid hormone levels were also lower in the persistently infected calves than in the controls, the differences being significant (P < 0.05) with the exception of the T3 level in one herd. The girth of the infected calves over the heart was less (P < 0.001) than that of the controls, and, among the infected calves but not among the controls, there was a significant correlation between heart girth and the levels of T3 (r = 0.72, P < 0.001) and T4 (r = 0.60, P < 0.01). Six calves not previously exposed to BVDV were infected through nose-to-nose contact with a persistently infected calf. Their T3 and T4 levels were decreased seven days (P < 0.05 and not significant, respectively) and nine days (P < 0.001 and P < 0.01, respectively) after the infection, when the clinical signs of the disease appeared.