Porcine reproductive and respiratory syndrome (PRRS) is the most economically important viral infectious disease in pig populations worldwide. This study was conducted to better understand the epidemic and dynamics of PRRS virus (PRRSV) on each farm and to evaluate the risk of PRRSV infection in Korea. Interviews with pig farmers were carried out to obtain PRRS vaccination programmes in 60 pig farms throughout Korea. Blood samples were also collected from the 59 pig farms to investigate outbreak patterns of each farm. Vaccination against PRRS was performed in 16.7% farms for breeding pigs and 8.3% of farm for nursery pigs. According to the seroepidemiological analysis, 56 (94.9%) out of 59 farms were considered to be affected by PRRSV infection. The results revealed that 68.9% of sows tested were seroconverted and interestingly, gilt herds had the highest seropositive rate (73%), suggesting that gilts may play a key role in PRRSV transmission in sow herds. Among the PRRS-affected piglet herds, 33 (55.9%), 14 (23.7%) and 6 (10.2%) farms were initially infected with PRRSV during the weaning, suckling and nursery period, respectively. It seems likely, therefore, that PRRSV infection predominantly occurs around the weaning period in piglet herds. Based on antibody seroprevalence levels in both sow and piglet groups, we were able to classify patterns of PRRSV infection per farm unit into 4 categories; category 1 (stable sow groups and non-infected piglet groups), category 2 (unstable sow groups and non-infected piglet groups), category 3 (stable sow groups and infected piglet groups), and category 4 (unstable sow groups and infected piglet groups). Our data suggested that 43 (72.9%) farms were analysed to belong to category 4, which is considered to be at high-risk for PRRS outbreak. Taken together, our information from this study will provide insight into the establishment of an effective control strategy for PRRS on the field.

Brucellosis is one of the most important zoonosis in worldwide. As one of the control measures, attempts have been made to develop new diagnostic methods using filed isolates as a national policy in many countries. Currently, bovine brucellosis in Korea have been received attention in both public health and economical aspects due to sudden increase of outbreak. Based on the situation, we compared standard strain (B. abortus 1119-3) with field isolates to reveal the differences among them. Biological and biochemical charateristics, antibiotic resistance profiles, outer membrane proteins (OMPs) and lipopolysaccharide analysis of the strains were included in this study. For the diagnostic purpose, an attempt was made to find out a novel antigen from the Korean isolates by serological analysis. There were differences about 55 kDa, 36-38 kDa and 20 kDa in analysis of OMPs by SDS-PAGE and Western blot with positive sera (greater-than or equal to 1:400 in SAT titer). Also, a serological diagnostic method, ELISA was conducted using OMPs of the strains as novel antigen. Relationships between O.D. and SAT titer were analyzed using field sera showing different SAT titer. High correlation coefficient was observed between SAT titer and ELISA. Results from this study suggested that a new diagnsotic method should be developed using their own field isolates in each country.

There were studied the most effective methods of diagnostics of genital forms of clamidiosis at cows in pregnancy, calving and the postnatal period. The description is resulted and the estimation is given methods of laboratory diagnostics, serological methods, a method of light microscopy, immunofluorescence, enzyme immunoassay, chlamydia allocation method on laboratory models, complement linkage reaction, hemagglutination reaction, a method of polymerase chain reaction. As a result of complex use of reaction of complement linkage reaction, on the basis of the analysis of clinical and histologic research, studying of a condition of immune system and nonspecific resistance of an organism it is possible to carry out successfully diagnostics of genital forms of clamidiosis at cows. | Целью исследований явилось изучение наиболее эффективных методов диагностики генитальной формы хламидиоза у коров в период беременности, ca и послеродового периода. Приведено описание и дана оценка методам лабораторной диагностики, серологическим методам, методу световой микроскопии, иммунофлюоресценции, иммуноферментному анализу, методу выделения хламидии на лабораторных моделях, реакции связывания комплемента, реакции гемагглютинации, методу полимеразной цепной реакции. В результате комплексного использования реакции связывания комплемента (РДСК), на основании анализа клинических и гистологических исследований, изучения состояния иммунной системы и неспецифической резистентности организма можно успешно проводить диагностику генитальной формы хламидиоза у коров.