The Importance of Complementary PCR Analysis in Addition to Serological Testing for the Detection of Transmission Sources of Brucella spp. in Greek Ruminants.

The early and accurate diagnosis of brucellosis, a ubiquitous zoonotic infection, is significant in preventing disease transmission. This study aimed to assess the infection rate of Brucella spp. in ruminants and to evaluate the agreement between a serological test and a molecular method for the detection of infected cases. Blood and milk samples of 136 ruminants were analyzed using two laboratory methods: the Rose Bengal plate (RBP) test to detect B. abortus and B. melitensis antibodies and the molecular polymerase chain reaction (PCR) method for the presence of bacterial DNA. The agreement between the methods was assessed using the kappa statistic. Based on the RBP test, there were 12 (8.8%) seropositive animals (10 sheep and 2 cows), while 2 (1.4%) samples were positive on PCR analysis. The positive PCR samples were from seronegative cow samples on RBP testing. There was slight agreement (k = -0.02) between the two methods, which was not statistically significant. Our results indicate that complementary molecular methods are useful to detect the bacteria in infected animals that are seronegative due to an early stage of infection. Therefore, a combination of molecular methods and serological tests can be applied to detect brucellosis in ruminants efficiently.

Sero-epidemiology investigation of Coxiella burnetii in domestic ruminants throughout most Greek regions.

Q fever is not considered as a public health problem in Greece where most regions are considered as Coxiella burnetii free possibly because of the low interest for this agent. Our objective was to conduct a large-scale study to investigate the sero-epidemiology of C. burnetii in domestic ruminants throughout the most of Greek regions. We tested serum samples obtained from goats, sheep and bovines from different regions of Greece. All sera were tested for C. burnetii IgG antibodies by a commercial ELISA according to the manufacturer's recommendations. We tested 1,173 goats and sheep obtained from 177 different herds and totally 194 (17%) animals from 78 (44%) herds were positive for C. burnetii. Positive animals were present in seven (88%) different regions and seropositivity varied widely among these regions. The highest percentage was observed in Peloponnese (44%), where all the tested herds presented animals with C. burnetii antibodies. Ιn all Aegean Islands except the island of Limnos we detected goats and sheep positive for C. burnetii with seroposivity varying between 2% in Kos to 37% in Rhodes. Finally, in 22 (85%) Greek prefectures we found C. burnetii IgG-positive animals whereas in 14 (54%) prefectures more than 50% of tested herds had seropositive animals. We also tested 28 cows from five different herds in Macedonia and Aegean Islands and six (21%) of them, obtained from two (40%) herds were positive. Considering the importance of C. burnetii for public health, our data reflect the lack of awareness by veterinarians, physicians and competent authorities as we provide evidence of C. burnetii seropositivity in productive animals throughout the most of Greek territories. Due to the increased risk of inhalation of the bacterium by people who entered the affected farms we raise the question of Q fever emergence in Greece.