We have experienced many abnormal weather conditions in recent years in Japan. For example, we had abnormally cool summer in 2003, abnormally hot summer in 2004 and 2007, and heavy snowfall in winter of 2005/6. Disasters caused by those abnormal weather conditions are increasing. Such a situation is not only the case in Japan but rather ubiquitous in the world. People are apt to think that it is due to global warming of the anthropogenic origin. However, it is a too simplistic view ; the abnormal weather conditions are consequences of natural climate variations under the global warming trend. Typical examples of those climate variations are El Niño in the Pacific Ocean and the Indian Ocean Dipole Mode. Because of the progress in prediction science, the climate variations can now be predicted to some extent by use of a state-of-the-art ocean-atmosphere coupled model several seasons prior to their occurrences. To achieve this, we need to have ocean-atmosphere data as initial conditions and a high-performance supercomputer. Because of the warming of world oceans, climate variations are modulated in recent years. El Niño is becoming more frequent and stronger. The Indian Ocean Dipole Mode is also becoming more frequent. Global impacts of such climate variations are either canceling or augmenting each other ; they are different from place to place. We are promoting efficient delivery of prediction results for preventing disasters as well as science for predicting climate variations.

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Patterns of the prevalence of important veterinary arthropod-borne (arbo-) viruses, such as Akabane, Aino, Chuzan, Ibaraki and bovine ephemeral fever viruses, in Japan have been changed recently by probable global warming. Although the number of the clinical cases caused by these viruses has been reduced in the south-western region of Japan, not only by promotion of the vaccines, but also by more frequent prevalence of the viruses, the epidemic areas tend to expand to whole country beyond the northern limit. Frequent prevalence of arboviruses after 1995 has led to the emergence of antigenic and/or pathogenic variants by genetic mutations such as reassortment among field isolates. Furthermore, Peaton, Sathuperi and Shamonda viruses were newly detected one after another. These rare arboviruses were initially isolated from cattle, Culicoides biting midges and/or mosquitoes from 1957 to 1976 in India, Nigeria and Australia. Fortunately, large-scale outbreaks of the disease associated with these novel viruses have not been observed yet in Japan.

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A recent IPCC (Intergovernmental Panel on Climate Changes) report clearly showed that the emission of greenhouse gases has already changed world climate, such as severe heat waves, rises in global mean sea level, summer droughts, wild fire, more intense precipitation, and increasing number of large typhoon, cyclones and hurricanes. The average global temperature is expected to rise by 1.4 to 5.8°C by 2100, potentially raising the sea level to rise a maximum 88 centimeters by melting of glacier of the Antarctic. High temperatures may increase survival among arthropod vector in the winter season in Temperate Zone and accelerate the spread of vectors such as Asian Tiger mosquito, Aedes albopictus, in Japan, USA and Europe.
Global warming, extreme climate change, changing physical distribution, and an increase in oversea travel are also expected influence the epidemiology of vector-borne infectious diseases.

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We attempted to determine the carriage rate of Salmonella in pet turtles and the characterization of isolates. One hundred twenty two red-eared sliders, 40 reeve's turtles and 29 turtles and tortoises of other species formed the subject of this study. The Salmonella carriage rates were 79.5% in red-eared sliders, 37.5% in reeve's turtle and 65.5% in other turtles. Salmonella enterica subsp. enterica was dominant among isolates from turtles studied. Salmonella serovars isolated were S. Montevideo, S. Braenderup, S. Litchfield, S. Newport, S. Poona, S. Typhimurium, S. Thompson, S. Sandiego, S. Saintpaul and others. Pulsed-field gel electrophoresis done on S. Montevideo, S. Litchfield and S. Newport resulted in 3, 2 and 3 patterns, respectively. Multiple drug resistant strains of S. Montevideo to gentamycin, kanamycin and tetracyclin were isolated from red-eared sliders.

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To know the mechanism of harboring Salmonella in wild snakes, newborn snakes hatched from 57 eggs obtained from 10 Japanese wild snakes were examined for the prevalence of Salmonella. Of the newborn snakes born from mother snakes that were Salmonella positive, 50 to 100% of newborns carried Salmonella and Random amplified polymorphic DNA profiles were consistent in 50% of the isolates from mother and newborns, while Salmonella were not isolated from any newborn snakes born from mother snakes that were Salmonella negative. Meanwhile Salmonella were not isolated from 8 eggs that were obtained from 3 female snakes by aseptic dissection, although these mother snakes carried Salmonella. Most of the 25 newborn snakes excreted Salmonella in high densities ranging from 10⁴ to 10⁹CFU/g over 310 days after birth. These results indicated that the vertical infection of Salmonella is organized in wild snakes and snakes already carry Salmonella at the time of birth and excreted a high density of organisms over a long period. Consequently, it is suggested that reptiles may carry Salmonella as a part of the normal bacterial flora in their intestinal tract

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Porcine Reproductive and Respiratory Syndrome (PRRS) is a serious problem for swine producers throughout Japan. However, few information is available about the economical losses due to this disease. Therefore, we investigated 3 farms (Farm A, B, C ; sow population of 500-600) with the experience of PRRS outbreaks, utilized past production records and estimated the economical losses using variables such as increased death rates, still births, abortion and reduced body weight gain during PRRS outbreaks.
The outbreak in Farm A occurred between September 2006 and February 2007. The total economical loss was estimated as 36 million yens and they were caused mostly from deaths of suckling , nursing and fattening pigs. The outbreak in Farm B occurred between August 2004 and April 2005. The total economical loss was estimated as 27 million yens and they were caused from deaths of every stages of pigs, stillbirths, abortion and reduced body weight gain. The outbreak in Farm C occurred between November 2004 and December 2005. The total economical loss was estimated as 20 million yens and they were caused from deaths of nursing and fattening pigs and reduced body weight gain. PRRS outbreaks caused losses of at least 20 million yens in these farms and type of losses differed depending on the outbreaks.

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The erosion, crack, swelling of hind heels, the conditions of hind leg and standing of 188 sows in three farms in Chiba prefecture were investigated on May 2007. Four heels with erosion were examined using histopathologic technique. As a result, the prevalence rates of erosion, clack and swelling of hind heel were 73.4%, 48.7% and 78.8%, respectively. The score of heel lesion gradually increased with sow aging. The prevalence rates of the outside heel and inside heel were 60.1% and 8.4%, respectively. The relationship between standing and heel lesion was not found. The lesion was diagnosed as hyperkeratosis by histopathologic examination.

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Bovine spongiform encephalopathy (BSE) is the disease which causes spongiform pathologic change in the brain tissues. It has been concerned that there is the possible link between BSE and variant Creutzfeldt-Jacob disease. Then, BSE is now recognized as a significant zoonotic disease. In Japan, the first BSE case was detected in September 10th, 2001, and as of December 2007, 33 BSE cases were detected. In this study, we estimated the number of the BSE-infected animals by using the BSurvE method.
In the estimation, we used the number of the tested animals and the number of the test-positive animals which both were collected in abbatoirs and farms. In order to reflect the actual conditions of the Japanese BSE testing program, we modified the original BSurvE model into the Japanese specifications. The main modification was the reduction of the number of the surveillance streams from four to three by omitting the stream of the clinical suspects.
The main result was that as of the end of 2006, 7 BSE infected animals were remaining in Japan. These 7 infected animals consisted of : one born in 1999, three born in 2000, one born in 2001 and two born in 2002. The numbers of the total infected animals in each cohort were also estimated. The result showed that the highest exposure had occurred in 1996, and the estimated BSE-infected animals were 288. The estimation also showed that the BSE-infected animals born in 2000 were 69. This was the second highest level of the exposure.

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Evaluation of surveillance results is important to estimate the risk of bovine spongiform encephalopathy (BSE) outbreaks in a country. However, no evaluation method focusing on surveillance from a qualitative perspective has yet been developed. Here, we developed a method to evaluate the qualitative aspects of BSE surveillance based on the Analytic Hierarchy Process. Using the Analytic Hierarchy Process, a qualitative issue can be evaluated through standardised criteria with point values based on the opinions from evaluators. Factors relating to surveillance reliability were selected through expert meetings, and were arranged in a hierarchy. These hierarchic evaluation factors were also weighed, so that a point system could be used for evaluation. When the surveillance in Japan before and after a BSE outbreak was evaluated using this evaluation system, an improvement in the quality of the surveillance was observed after the outbreak. We believe that this method will be applicable to establishing a qualitative evaluation system for other diseases.

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It has been suspected that outbreaks of mass mortality of birds occuring within the Japanese territory are possibly due to West Nile virus (WNV) infection from the Far Eastern Region of Russia. These epidemic events have been considered as one of the major factors responsible for the extinction and endangerment of avian species in Japan. Hence, our co-operative project will assess the risk of infection using screening test with application of a commercial WNV kit (VecTest) for Japanese avian species. Materials derived from 658 individuals of 123 avian species belonging to 20 orders (Yoshino et al., 2008) were examined using this particular kit. Real-time polymerase chain reaction (PCR) was also applied for a definitive diagnosis. In general, the application of the kit for the monitoring of WNV infection in the Japanese avian species was valuable, although some false-positive results were detected. After the confirmation of each negative result, each body was dissected for pathological, toxicological and parasitological examinations, because protozoan, helminth and/or arthropod parasites can become highly pathogenic agents for wild avian species. In this presentation, we will show not only the outline of the WNV infection monitoring project performed by the Wild Animal Medical Center (WAMC) (http : //www.rakuno.ac.jp/dep19/wildanimal/wildanimal.htm), Rakuno Gakuen University, but also most recent parasitological results obtained there. The present survey was supported in part by a Global Environment Research Fund (F-062, 2006-2008) of the Ministry of the Environment and a Grant-in-Aid (No. 18510205) of the Ministry of the Education, Science and Culture, Japan.

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After the large epidemic of foot-and-mouth disease (FMD) hit Europe in 2001, vaccination strategy against FMD has drawn considerable attention as one of disease containment approaches. This is supported by recent technical innovations, such as development of diagnostic methods to distinguish the antibody induced by infection from that by vaccination. However, there are a lot of technical and management issues to be considered for actual application of vaccination strategies upon the outbreak. This article reviews current technical issues related to FMD vaccine and the recent examples where vaccination was used for the disease control. It also discusses recent trends over the FMD vaccination strategies.

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The objectives in this study were to compare salivary progesterone (PRG) concentrations between sows weaned one litter and sows used for nursing piglets after weaning their own piglets (nurse sows), and to investigate the associations between PRG concentrations, backfat thickness (BF), and reproductive performance. A farm with approximately 300 female pigs (females) was visited 13 times from 2005 to 2006 to collect saliva samples at weaning from 138 sows weaned one litter and 42 nurse sows. Reference samples were also collected from 15 gestating females. The reproductive performance was recorded for each sow. The weaned sows were categorized into two groups on the basis of the upper 25 percentile of PRG concentrations : >3.1 (HIGH) and<3.0ng/ml (OTHER). Statistical mixed-effects models were used and statistical power was calculated. Sows weaned one litter and nurse sows had lower PRG concentrations than gestating females (2.1 and 3.0 vs. 4.1ng/ml ; P<0.01). No differences were found in any reproductive performance between sows weaned one litter and nurse sows. HIGH group had 0.7 fewer pigs born alive at subsequent farrowing than OTHER group (P<0.05). Sows with increased BF during lactation tended to have 17.1% higher in the percentages of sows having high PRG concentrations (P=0.068 ; Power=0.373) and 0.8 days longer weaning-to-first-mating interval than those with decreased BF (P<0.05). High PRG concentrations at weaning were associated with few pigs born alive at subsequent farrowing. This association may be partially related to increased BF during lactation.

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The distribution of the adhesive capsular protein (Cp39) gene, the protein antigen, and its genetic variation among avian clinical isolates of Pasteurella multocida in Japan were determined by the gene sequencing, the PCR-restriction fragment length polymorphism (PCR-RFLP) and immunoblot analysis. The results demonstrated that the gene distributed among all the somatic serotype 3 isolates. Adhesive protein gene-based PCR-RFLP categorized the clinical isolates into three patterns by digestion with HindIII or three patterns with EcoRI, respectively. Genetic diversity of the adhesive protein gene was observed among those isolates but it did not influence their virulence to hosts. Whole-cell lysate of all clinical isolates incubated with sample buffer at 37°C were immunostained with chicken antiserum against recombinant Cp39 (rCp39) by immunoblot analysis. Therefore, the rCp39 may be an emerging candidate of effective component for fowl cholera vaccine in Japan.

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