Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L.) colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD) because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels), no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor) were higher in control colonies than CCD-affected colonies. This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted.

Antimicrobial resistant zoonotic pathogens present on food constitute a direct risk to public health. Antimicrobial resistance genes in commensal or pathogenic strains form an indirect risk to public health, as they increase the gene pool from which pathogenic bacteria can pick up resistance traits. Food can be contaminated with antimicrobial resistant bacteria and/or antimicrobial resistance genes in several ways. A first way is the presence of antibiotic resistant bacteria on food selected by the use of antibiotics during agricultural production. A second route is the possible presence of resistance genes in bacteria that are intentionally added during the processing of food (starter cultures, probiotics, bioconserving microorganisms and bacteriophages). A last way is through cross-contamination with antimicrobial resistant bacteria during food processing. Raw food products can be consumed without having undergone prior processing or preservation and therefore hold a substantial risk for transfer of antimicrobial resistance to humans, as the eventually present resistant bacteria are not killed. As a consequence, transfer of antimicrobial resistance genes between bacteria after ingestion by humans may occur. Under minimal processing or preservation treatment conditions, sublethally damaged or stressed cells can be maintained in the food, inducing antimicrobial resistance build-up and enhancing the risk of resistance transfer. Food processes that kill bacteria in food products, decrease the risk of transmission of antimicrobial resistance.

Bluetongue (BT) is a reportable disease of considerable socioeconomic concern and of major importance in the international trade of animals and animal products. Before 1998, BT was considered an exotic disease in Europe. From 1998 through 2005, at least 6 BT virus strains belonging to 5 serotypes (BTV-1, BTV-2, BTV-4, BTV-9, and BTV-16) were continuously present in the Mediterranean Basin. Since August 2006, BTV-8 has caused a severe epizootic of BT in northern Europe. The widespread recrudescence and extension of BTV-8 infections in northern Europe during 2007 suggest that requirements for BTV establishment may now be fulfilled in this area. In addition, the radial extension of BTV-8 across Europe increases the risk for an encounter between this serotype and others, particularly those that occur in the Mediterranean Basin, where vector activity continues for more of the year. This condition increases the risk for reassortment of individual BTV gene segments.

Veterinary Research, a journal on Animal Infection

To describe and discuss the merits of various direct and indirect methods applied in vitro (mainly on blood or milk) or in vivo (allergic test) for the diagnosis of brucellosis in animals. The recent literature on brucellosis diagnostic tests was reviewed. These diagnostic tests are applied with different goals, such as national screening, confirmatory diagnosis, certification, and international trade. The validation of such diagnostic tests is still an issue, particularly in wildlife. The choice of the testing strategy depends on the prevailing brucellosis epidemiological situation and the goal of testing. Measuring the kinetics of antibody production after Brucella spp. infection is essential for analyzing serological results correctly and may help to predict abortion. Indirect ELISAs help to discriminate 1) between false positive serological reactions and true brucellosis and 2) between vaccination and infection. Biotyping of Brucella spp. provides valuable epidemiological information that allows tracing an infection back to the sources in instances where several biotypes of a given Brucella species are circulating. Polymerase chain reaction and new molecular methods are likely to be used as routine typing and fingerprinting methods in the coming years. The diagnosis of brucellosis in livestock and wildlife is complex and serological results need to be carefully analyzed. The B. abortus S19 and B. melitensis Rev. 1 vaccines are the cornerstones of control programs in cattle and small ruminants, respectively. There is no vaccine available for pigs or for wildlife. In the absence of a human brucellosis vaccine, prevention of human brucellosis depends on the control of the disease in animals.