Subclinical mastitis in dairy camels in Algeria: Comparison of screening tests | Subklinični mastitis pri mlečnih kamelah v Alžiriji: primerjava presejalnih testov

Inglés. The aim of the present study was to determine a threshold values and to assess the effectiveness of four indirect tests for the diagnosis of subclinical mastitis in dairy camels comparing with bacteriological culture. One hundred fifty three milk samples from 17 lactating camels were subjected to bacteriological culture, where 84 milk samples were positive, 47 were negative and 22 samples were considered as contaminated. A total of 131 milk samples were screened by pH, electrical conductivity (EC), California mastitis test (CMT) and somatic cell count (SCC). The good combination of sensitivity and specificity were obtained with a threshold of 6.55, 7.2 mS/cm, score trace was considered as CMT (+) and 240 000 cells/ml for the four tests, respectively. The sensitivity of the SCC, pH, EC and CMT was 72.61, 66.66, 47.61 and 39.28 %; the specificity 70.21, 38.02, 59.57 and 72.34 %; percentage accuracy 71.75, 51.14, 51.90 and 51.14 %; and positive predictive value 81.33, 47.61, 67.79 and 71.73 %, respectively. The SCC was significantly correlated with bacteriological culture (r = 0.415, p < 0.05). Kappa value of SCC was higher than that of other tests (SCC > CMT > EC > pH). In conclusion, the results suggest that the SCC was the most accurate, reliable, diagnostic method compared to other tests used in this study after cultural isolation for the detection of subclinical mastitis in dairy camel under field conditions.

Esloveno. Namen te študije je bil določiti mejne vrednosti in preveriti učinkovitost štirih posrednih testov za diagnozo subkliničnega mastitisa pri kamelah v primerjavi z bakteriološko kulturo. Sto triinpetdeset vzorcev mleka 17 kamel v laktaciji smo analizirali s kultivacijsko metodo, kjer je bilo 84 vzorcev mleka pozitivnih, 47 je bilo negativnih, 22 vzorcev pa je bilo okuženih. Na skupno 131 vzorcih mleka smo izmerili pH vrednost, električno prevodnost (EC) in število somatskih celic (SCC) ter opravili Kalifornijski test za mastitis (CMT). Dobro kombinacijo občutljivosti in specifičnosti smo dobili pri mejnih vrednostih: za pH 6,55, električno prevodnost 7,2 mS/cm, pozitivnim izidom CMT (+) in 240.000 somatskimi celicami na ml mleka. Občutljivost testa za SCC je bila 72,61, za pH 66,66, za EC 47,61 in za CMT 39,28 %. Specifičnost testov se je gibala med 38,02 in 72,34 %; natančnost med 51,14 in 71,75 % in pozitivna napovedna vrednost med 47,61 in 81,33 %. SCC je bilo statistično značilno povezano z bakteriološko kulturo (r = 0,415, p < 0,05). Kapa vrednost za SCC je bila višja kot pri drugih testih (SCC > CMT > ES > pH). Rezultati kažejo, da je v praktičnih pogojih reje SCC med primerjanimi metodami najnatančnejša in najbolj zanesljiva metoda za določanje subkliničnega mastitisa pri kamelah v primerjavi z bakteriološko metodo osamitve povzročiteljev mastitisa.