ABSTRACT
SUMMARY: Two outbreaks of Leptospira borgpetersenii serovar Hardjo infection in dairy cattle herds were managed through the application of enhanced biosecurity measures, whole-herd antibiotic treatment and vaccination. Micro-agglutination test antibody titres were determined in paired serum samples at 3 weeks (T1: n = 125, 97% seropositivity, median 800, range 100-12 800) and 24 weeks (T2: n = 110, 88% seropositivity, median 200, range 100-6400) after vaccination and studied in relation to cows' age, herd of origin and sampling time. From T1 to T2, vaccine-elicited antibody titres decreased by 84·7% (95% CI 76·2-90·1). Consistent with increasing immunocompetence in calves (aged <12 months) and immunosenescence in adult cows (aged >36 months) associated with ageing, antibody titres correlated positively with calves' age and negatively with adult cows' age. No cow had cultivable, (histo)pathologically detectable and/or PCR-detectable leptospires in urine or kidney samples after treatment and vaccination. Vaccination together with proper biosecurity measures and chemoprophylaxis are an affordable insurance to control bovine leptospirosis.
Subject(s)
Cattle Diseases/prevention & control , Dairying , Disease Outbreaks/veterinary , Leptospirosis/veterinary , Abortion, Veterinary/epidemiology , Abortion, Veterinary/microbiology , Abortion, Veterinary/prevention & control , Animals , Anti-Bacterial Agents/therapeutic use , Bacterial Vaccines/immunology , Cattle , Cattle Diseases/drug therapy , Cattle Diseases/epidemiology , Disease Outbreaks/prevention & control , Italy/epidemiology , Kidney/microbiology , Leptospira/isolation & purification , Leptospirosis/drug therapy , Leptospirosis/epidemiology , Leptospirosis/prevention & control , Seroepidemiologic Studies , Urine/microbiology , VaccinationABSTRACT
The immunological abnormalities of polytransfused patients affected by beta-thalassaemia major have been investigated in relation to B cell function. The spontaneous in vitro production of Ig by patient peripheral mononuclear cells was not modified, while the pokeweed mitogen induced IgM synthesis was significantly reduced. However, by comparing the splenectomized and non-splenectomized patients, this alteration proved to be present only in the splenectomized group. The proliferation of patient peripheral B cells in vitro stimulated with B cell growth factor alone was not significantly enhanced in respect to the controls. These results indicate that in vivo activation state of patient B cells is not different from that of the controls. The stimulation of peripheral B cell with anti-mu or anti-alpha antibodies and anti-mu and anti-alpha antibodies plus B cells growth factor induced a significant increase in proliferative responses of B cells from the splenectomized patients. Taken together, these findings suggest that circulating B cells of thalassaemic polytransfused patients are not hyperactivated. The splenectomy can account for the immunological changes observed in our thalassaemic sample as compared to control group.
Subject(s)
B-Lymphocytes/immunology , Blood Transfusion , Lymphocyte Activation , Thalassemia/immunology , Thalassemia/therapy , Adolescent , Adult , Child , Humans , Immunoglobulins/metabolism , SplenectomyABSTRACT
Aspects of the humoral and cellular immune response have been studied in polytransfused patients with beta-thalassaemia major. Serum immunoglobulins (G, A, M) levels were significantly higher than in controls; reduced C4 serum level and high incidence of circulating immune complexes and anti-nuclear autoantibodies were found in the majority of patients. Marked increases were also observed in absolute and relative numbers of lymphocytes and their subpopulations. Such results suggested that the allogenic stimulation, by frequent transfusion, is the mainly responsible of the immunological alterations observed in these patients.
