RESUMO
Life table data of Rhodnius prolixus (Heteroptera: Reduviidae) kept at laboratory conditions were analysed in search for mortality patterns. Gompertz and Weibull mortality models seem adequate to explain the sigmoid shape of the survivorship curve. A significant fit was obtained with both models for females (R(2) = 0.70, P < 0.0005 for the Gompertz model; R(2) = 0.78, P < 0.0005 for the Weibull model) and for males (R(2) = 0.39, P < 0.0005 for the Gompertz model; R(2) = 0.48, P < 0.0005 for the Weibull model). The mortality parameter (b) is higher for females in Gompertz and Weibull models, using smoothed and non-smoothed data (P < 0.05), revealing a significant sex mortality differential. Given the particular life history of this insect, the non-linear relationship between the force of mortality and age may have an important impact in the vectorial capacity of R. prolixus as Chagas disease vector, and its consideration should be included as an important factor in the transmission of Trypanosoma cruzi by triatomines.
Assuntos
Insetos Vetores/crescimento & desenvolvimento , Modelos Biológicos , Rhodnius/crescimento & desenvolvimento , Animais , Doença de Chagas/parasitologia , Doença de Chagas/transmissão , Feminino , Insetos Vetores/parasitologia , Masculino , Rhodnius/parasitologia , Fatores Sexuais , Análise de Sobrevida , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
Screw-worms (Cochliomyia hominivorax Coquerel) constitute a serious plight for livestock in the New World, because they inflict high losses on animals and man. A survey was done by means of an epizootic surveillance system with geographic squares to check for the presence of the insects in Cuba. Screw-worms were detected in 54.8% of myiasis cases all over the island, affecting various animals species, cattle first, followed by swine, sheep and others. Small injuries appeared to be the main enabling factor for screw-worm development. The reasons for the presence of screw-worms without serious consequences on the Cuban livestock are discussed.
Assuntos
Animais Domésticos/parasitologia , Infecção por Mosca da Bicheira/veterinária , Animais , Cuba/epidemiologia , Infecção por Mosca da Bicheira/epidemiologia , Infecção por Mosca da Bicheira/parasitologiaRESUMO
An immunoperoxidase assay for the serological diagnosis of Babesia bigemina was developed. The antigen slides were prepared from B. bigemina-infected blood and stored at -20 degrees C. One hundred and sixty five sera were tested, comparing the immunoperoxidase assay to the indirect fluorescent antibody test. A coincidence of 95% was observed between both tests. For the immunoperoxidase assay, a relative sensitivity of 94.8%, a relative specificity of 95.5%, and a positive predictive value of 96.8% were calculated. The results demonstrated the efficacy of this technique for detecting antibodies to B. bigemina.
Assuntos
Babesiose/diagnóstico , Doenças dos Bovinos/diagnóstico , Técnicas Imunoenzimáticas , Animais , Babesiose/parasitologia , Bovinos , Doenças dos Bovinos/parasitologia , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The attenuation of a Babesia bovis strain depends on its protease content. The present work evaluates this parameter on a virulent strain, before and after attenuation by quick passages on splenectomized calves. The protease activity at different pH values was determined in protein fractions from the blood of calves. The enzymatic test showed marked differences between the protease content of both substrains.
Assuntos
Babesia bovis/enzimologia , Peptídeo Hidrolases/metabolismo , Animais , Babesia bovis/patogenicidade , Bovinos , VirulênciaRESUMO
A serological survey using indirect immunofluorescence (IFAT) for bovine babesiosis (Babesia bovis and B. bigemina) and card test for anaplasmosis, indicates that these haemoparasites are widespread in Martinique. The high prevalences (62% for B. bovis, 52% for B. bigemina and 43% for Anaplasma marginale) lead to the hypothesis of an unstable epizootic situation for these three haemoparasitic diseases. However, the number of smears examined was too low to evaluate their clinical incidence. Both the American and Cuban card tests gave similar results in the detection of antibodies to A. marginale. Theileria mutans is described for the first time in Martinique. Trypanosomosis (Trypanosoma vivax) has disappeared from Martinique, on clinical and serological evidence.