The prevalence of leptospiral antibodies in sows was investigated throughout Japan using microscopic agglutination test (MAT). A total of 1,121 sows raised in 140 farms in 20 prefectures between 2001 and 2004 were randomly selected for serological survey. Sows positive for leptospiral antibodies were found in 98 (70.0%) of the 140 farms. Of the 1,121 sows examined, 281 (25.1%) were positive. The positive rate for serovar Bratislava was the highest and was detected in 202 sows (18.0%) in 87 farms (62.1%), followed by Australis in 84 sows (7.5%) in 45 farms (32.1%), Autumnalis in 25 sows (2.2%) in 25 farms (17.9%), and Canicola in 25 sows (2.2%) in 14 farms (10.0%). The wide prevalence of leptospiral antibody in sows in Japan has been confirmed by MAT in this study, and serovar Bratislava was the major serovar detected.

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The traditional small scale pig farmers in Vietnam keep animals in open backyard stalls and usually keep cats to catch rats and mice. Under these conditions, controlling for the exposure of pigs to toxoplasmosis, a significant zoonoses, is difficult. The purpose of this study is to investigate the seroprevalence of Toxoplasma gondii antibodies in domestic cats and pigs in T.T. Hue Province, Vietnam with commercial latex agglutination kits (Eiken-Toxocheck). A total of 155 cat and 260 pig sera samples (110 from a slaughterhouse and 150 from 6 pig farms) were collected in 2007. Among them, 112 (72.3%) cats, 62 (41.3%) live pigs and 76 (69.1%) slaughtered pigs tested positive for T. gondii antibodies (1 : 64 cut-off). The seroprevalence increases as the pig grows ; the seroprevalence of piglets less than 15kg was 16.7% and 71.0% for those over 50kg (OR=12.26, 95%CI=3.31, 45.34). We also have collected sera from the same herds of 6 farmers 2 times with 2 month interval. Of which, the prevalence rate at the first sampling was 28.4% (88 samples) and 2 months later in the 2^nd sampling it was 64.0% (50 samples) (OR=4.48, 95%CI=2.14, 9.39). The results indicate a high prevalence of T. gondii in pigs under the current farming system in T.T. Hue Province, Vietnam.

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From July 2001 to September 2004, 571 fecal samples from cattle and 363 retail food samples including 150 of beef, 50 of chicken meat, 51 of duck meat and 112 of shrimp were examined for the prevalence of Escherichia coli O157 in the Mekong Delta, Southern Vietnam. E. coli O157 was isolated from 2.1% (12/571) of the cattle and from 15% (6/40) of the farms, but was not isolated from foods. E. coli O157 was isolated from 4% (3/75) of calves (≤6 month) and 1.8% (9/496) of cattle (>6 month). Of 15 isolates, 12 (80%) possessed the eae and EHEC-hlyA genes and 13 (86.7%) carried the stx2 gene. No stx1gene was detected from any O157 isolates. Of 15 isolates, 12 (80%) were O157 : H7 and 3 (20%) were O157 : H-. Three of 15 isolates showed antibiotic resistance to one or more antibiotics.
These results indicate that this pathogen is distributed in cattle in the Mekong Delta, Vietnam. This is the first isolation of E. coli O157 in the Mekong Delta, Southern Vietnam.

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The objectives of the present study were to apply leg structure scores (LSS) to examine the leg structures in stalled females, to assess the occurrence of poor leg structures, to investigate any associations between LSS and backfat thickness or behavior, and to compare the survival probabilities between LSS groups. A commercial farm equipped with a computerized recording system was visited six times over two years to record the LSS in the four legs of 709 stalled females. The structures were scored by trained evaluators when a female was standing in a gestation stall. In our scoring method (POOR or OK), the POOR leg structure was defined as buck-kneed front legs, sickle-hocked hind legs or post-legged hind legs. Females having at least one POOR leg were classified into the POOR group and the other females were classified into the OK group. We recorded the relative frequencies (%) of three types of postural behavior (standing, sitting or lying) and vacuum chewing in stalled females by point sampling at 15-minute intervals over a six hour period when the leg evaluators were recording LSS during our farm visits. Linear mixed-effects models and survival analysis were performed. The mean value (±SEM) of observed parity for the 1,560 four-leg observations in 709 females was 1.9±0.04. Relative frequencies in the POOR and OK groups were 6.4% and 93.6%, respectively. LSS was recorded more than twice in 69.8% (495 females) of the 709 females. The LSS in 86.5% (428 females) of these 495 females did not change across parity. Proportions of females having the POOR leg structures in parity 0, 1, 2, 5 and 6 were lower than those in parity 3 and 4 sows (P<0.05). No differences were found between the LSS groups for hazards of culling, backfat measurements or any types of behavior of females (P>0.10). In summary, stalled females having POOR or OK leg scores similarly survived. Furthermore, the LSS of stalled females was not related to backfat thickness or behavior.

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As a result of the outbreaks of pandemic influenza (H1N1/2009) in swine, some questions have been raised about the risks to humans from exposure to infected pigs and pork products. In this paper, the characteristics of swine influenza (SI) virus in pigs and the measures to be taken to prevent the spread of SI virus are reviewed. Possible risks of swine influenza virus from infected human to pig and from infected pig to human are also reviewed. According to the OIE/FAO/WHO recommendations pig meat is safe for human consumption if it is processed according to the international standards and cooked above 70°C.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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[in Japanese]

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