It is known that salmonellosis is the most complex and economically the most significant foodborne zoonosis. We have witnessed the emergence of new serovars; and phage types and concomitant increase of cases in several countries as well as in Hungary. Based on the zoonotic nature, protection of animals from Salmonella (primarily from S. Enteritidis and S. Typhimurium) should have a top priority. The authors summarize the initiatives made in this direction during the last decade in Hungary and they point out their experiences with some of the methods applied. Furthermore the authors confirm their earlier (1997) proposals for establishment of a National Salmonella Reduction Plan, partly organized by the government, based on its significance to human health. This Hungarian plan should aim to establish a program for Salmonella monitoring and for Salmonella reduction, primarily for poultry, but later also for swine. In support of such a program, the authors present international and some Hungarian data on the area of diagnostic and epidemiology for supporting a monitoring program. Results and observations regarding vaccinations (serovar specificity and on cross protection) are also discussed. Furthermore the newly recognized quorum sensing" signal mechanism of Salmonella is pointed out as one possible area to improve the efficiency of live oral vaccines.

Within the frame of the program "Scientific support for agricultural production" of the Hungarian Academy of Sciences, a study Nas made to survey the international and the Hungarian situation related to salmonellosis. Based on the last years' data it can be repeatedly stated that in Hungary - just like in many other European countries - salmonellosis continues to have a prime significance. According to the Hungarian enteric surveillance data, the human salmonellosis is mostly due to S. enteritidis infection. Beta een 1992-1996 it was responsible for 69-88% of the total human Salmonella infections investigated, followed by S. typhimurium (3-5%) and S. hadar (1-2%). The overwhelming majority (76-99%) of these infections was related to food, in which the food of poultry origin has strongly dominated (66-96%). Besides, data from the Salmonella serotyping of poultry isolates indicated that this serovar was dominant (62% of meat isolates and 74% of those from egg products), in contrast to years 1990-1992 when S.hadar was the dominant (30-48%) serovar from poultry carcasses. In frame of this study data were collected about the number and size distribution of poultry breeding and production units. The number of breeding units were: 22 of egg type breeders and 28 of meat type breeders (ranging in site 5000 to > 100 000). The number of production units were: 41 of table egg producers and 324 of broiler producers, ranging In the same size as above. The number of hatcheries - based on a 1994 study - can be estimated to be above 300 (3/4 of them with size 10 000-100 000). This size distribution of poultry units has been judged - with respect to potential Salmonella eradication programs - as favourable regarding breeder flocks but very unfavourable regarding the relative large number of small and medium size hatcheries. Regarding Salmonella infection I ate ol prevailing Salmonella serovar of live domestic poultry, turkey, waterfowl and pigs or cattle, there were very few (much less than expected) data available. The study reviewes the most important elements of fight against salmonellosis. It deals with improved hygiene in the slaughtering process (live bird care, microbiological control, avoiding cross contamination, special attention to and application of HACCP rules, new techniques of scalding, evisceration, chilling and drying, to continuous monitoring and cleaning systems). It also discusses new opportunities of chemical and physical decontamination. Further attention is given to activities and techniques aiming to protect live animals from Salmonella. Data from the international literature and from Hungary are listed and analysed on cleaning, disinfection and rodent control (biosecurity), on use of probiotics, CE floras, live oral and killed parenteral Salmonella vaccines, as well as on the controversial issue of using antibiotics. The appropriate and many times simultaneous use of these techniques can essentially help reducing the Salmonella contamination of flocks but can not completely eliminate infection. The most essential area of protection being biosecurity. Based on this study it has been concluded that Hungarian data on Salmonella isolations from live animals and of food of animal origin, are only partially in harmony with data from human epidemics. It is emphasized that more reliable data and mole complete epidemiologic tracing are needed in ol det to obtain a more exact epidemiologic picture and in order to be able to make decisions for a Salmonella reduction plan. Such reliable data are also essential for the professionally sound partnership with public health authorities. It is suggeted that there is an immediate need for establishment of a Salmonella monitoring program, and for elaboration of a Salmonella reduction plan in Hungary. The knowledge and theoretical basis for such programs has been described in the "Integrated Quality System for Salmonella Control" that has been worked out within the PHARE (HU-9304-05-02) project for the Hungarian poultry sector in 1995.

A short review of the salmonellosis of domestic fowl, caused by non host-specific salmonellae (called paratyphoid) has been given, based on the international literature and experiences obtained in Hungary. In both respect, it can be stated that the overwhelming majority of the strains, causing poultry salmonellosis, is limited to a few serotypes, among which the most frequent ones are, as follows: S. typhimurium, S. infantis and S. enteritidis. During the last 5 to 10 years, the prevalence of S. enteritidis has increased in Europe (and thus in Hungary) almost in a pandemic manner: this serotype became the most prevalent contaminant of eggs, egg products and of poultry meat. Its public health significance became remarkable at about the same period. Beyond the epidemiologic, pathologic and diagnostic considerations of poultry salmonellosis, the opportunities of control have also been discussed. Regarding the prevention, it is important to increase the level of general hygiene and of disinfection at certain critical points (i. e.: preparation of poultry houses for newly hatched poultry, collection of eggs, hatching, feedstuff production). The laboratory control of the efficacy of this work is also important. Besides, efficient support in protection against poultry salmonellosis can be gained by creating the intestinal flora early in life through competitive exclusions (CE), furthermore by feed acidification and - on experimental level - by immunization. Regarding the increasing rate of poultry meat and egg production and consumption, it is a more and more urgent task to eradicate salmonella (at least S. typhimurium and S. enteritidis) infections, to observe the present rules of egg and meat production, and to elaborate guidelines for control.

SummaryA disease associated with central nervous system signs was observed in two duck flocks, each consisting of 6000 three‐week‐old ducklings, a week after their arrival at the receiving farms.The clinical signs included leg weakness, dyspnoea, diarrhoea, and in many cases disturbance of equilibrium, retrograde movement, torticollis and twisting of the neck. Pathological and histopathological examinations revealed lympho‐histiocytic meningitis and cerebroventriculitis, airsacculitis with moderate amounts of fibrinous exudate, bronchitis associated with formation of lymphoid follicles, focal or interstitial pneumonia, in some cases with fibrinous serositis, interstitial catarrh and splenomegaly. Large numbers of mycoplasmas were seen by electron microscopy and were isolated from the affected meninges and pericardium.Other diseases were excluded by laboratory examinations. The isolates were identified as Mycoplasma anatis. The pathogenicity and immunogenicity of the strain were investigated in an infection experiment in ducks. Although during this experiment no disease associated with clinical signs or deaths occurred, birds infected into the airsacs or intracranially exhibited pathological lesions similar to, but milder than, those seen in the field outbreak. No immune response was detectable by the serological and cellular tests applied. The pathological significance of M. anatis infection in ducks merits further study.ZusammenfassungAusbruch einer Mycoplasma anatis‐Infektion in Verbindung mit nervösen Symptomen bei Entenbeständen in MassenhaltungIn zwei Beständen mit je 6000 drei Wochen alten Entenküken wurde eine Erkrankung verbunden mit zentralnervösen Symptomen beobachtet. Zum Symptomenbild gehörten Beinschwäche, Atemnot, Durchfall, in vielen Fällen Gleichgewichtsstörung, retrogarde Bewegung, Torticollis und Verdrehung des Halses. Bei der pathologischen und histopathologischen Untersuchung wurden eine lymphohistiozytäre Meningitis und Cerebroventriculitis, eine Entzündung der Luftsäcke mit geringen Mengen fibrinösen Exsudates, eine fokale oder interstitielle Pneumonie (teilweise mit fibrinöser Serositis), ein interstitieller Katarrh und eine Splenomegalie diagnostiziert. Eine große Anzahl von Mycoplasmen wurde elektronenmikroskopisch nachgewiesen und aus den affektierten Meningen und dem Perikardium isoliert. Die Isolate wurden als Mycoplasma anatis identifiziert und andere Krankheitsursachen durch Laboruntersuchungen ausgeschlossen.Die Pathogenität und die immunogenen Eigenschaften des isolierten Stammes wurden in einem Infektionsversuch an gesunden Tieren geprüft. Während des Versuchszeitraumes konnten weder Erkrankungen mit sichtbaren klinischen Anzeichen noch Todesfälle beobachtet werden. Allerdings wurden bei den über die Luftsäcke oder intrakranial infizierten Tieren pathologische Veränderungen festgestellt, die den Befunden der Feldausbrüche ähnelten, jedoch milder in der Ausprägung waren. Sowohl mit den serologischen als auch den zellulären Testmethoden konnte eine Immunantwort nicht nachgewiesen werden.

Small viral particles of 19 to 24 nm in diameter with a buoyant density in CsCl of 1.43 g/ml were detected electron microscopically in samples taken from the gut of 10-day-old chickens suffering from a stunting syndrome. The viral particles are suggested to belong to the Parvoviridae and their possible role in the stunting syndrome is discussed.