Sensibilidade e especificidade do "California Mastitis Test" como recurso diagnóstico da mastite subclínica em relação à contagem de células somáticas

• Published in: Pesquisa Veterinária Brasileira 1997, Vol.17 (2), p.49-53
• Main Authors: Brito, José Renaldi Feitosa(Embrapa), Caldeira, George Afonso Vitor, Verneque, Rui da Silva(Embrapa), Brito, Maria Aparecida Vasconcelos Paiva e(Embrapa)
• Format: Article
• Language: eng ; por
• Subjects: contagem de células somáticas; Dairy cows; glândula mamária; leite; mammary gland; milk; somatic cell count; Vacas leiteiras; VETERINARY SCIENCES
• ISSN: 0100-736X; 1678-5150; 1678-5150
• DOI: 10.1590/s0100-736x1997000200002

The California Mastitis Test (CMT) is a simple and widely used diagnostic tool for subclinical mastitis. It is used even in areas where laboratory facilities are available for diagnosis and monitoring program purposes. CMT usually score 1-5, where 1 indicates a completely negative reaction and 2-5 increasing degrees of inflammatory reaction of the udder. The reactions 2-5, 3-5 or 4-5 may be considered as indicative of subclinical mastitis, bever, may produce either false-positive or false-negative results. The aim of this study waecause they are related to an increase of the somatic cell count (SCC) in the milk. This variation, hows to assess the sensitivity and specificity of the CMT in comparison with SCC. A total of 3,012 quarter milk samples from 760 lactating cows were examined. CMT was evaluated at the moment of sampling at cow side and SCC in the laboratory, with a fluoro-opto-electronic method (Fossomatic 90). The average CCS (x 1,000 cells/ml) for CMT scores were: 1 (79.9), 2 (333.5), 3 (670.3), 4 (1,354.0) and 5 (4,455.6). Three options for CMT interpretation were evaluated in relation to a range of CCS, starting from 100,000 cells/ml: (a) 1 versus 2, 3, 4, and 5; (b) 1 and 2 versus 3, 4 and 5; and (c) 1, 2 and 3 versus 4 and 5. The sensitivities of CMT scoring to detect quarters with SCC >200,000/ml were 79%, 61% e 34% for options a, b and c, respectively. The sensitivities of CMT scores for SCC >500,000/ml for options a, b and c, were, respectively, 93%, 82% e 54%. The sensitivity of CMT scores to identify subclinical mastitis was satisfactory (above 80%) when options b and c were used. The interpretation of CMT score 3 as negative for subclinical mastitis was considered as adequate (sensitivity around 80%) only when CCS ranged between 1,200,000 and 1,400,000 cells/ml. The specificities of CMT scoring for CCS of 200,000 and 500,000 were, respectively, 90% and 80% (option a), 97% and 90% (option b) and 99% and 97% (option c). O "California Mastitis Test" (CMT) estima o conteúdo de células somáticas no leite e é interpretado subjetivamente, estabelecendo-se escores que, na maioria dos casos, variam de 1 a 5. O escore 1 indica uma reação completamente negativa e os de 2-5 indicam graus crescentes de resposta inflamatória do úbere, sendo normalmente considerados como indicativos de mastite subclínica. Dependendo da interpretação dos escores, o CMT pode produzir resultados falso-positivos ou falso-negativos. Esse trabalho teve o objetivo de av