Bacterial diseases of fish associated with human health

As this country continues to increase its food fish output without increasing the water acreage, and environmental wastes continue to plague fish production, we can expect to encounter more zoonotic organisms, especially enteric-like organisms. Since 1972, the number of enteric genera has doubled and the species have tripled. The veterinarian engaged in aquatic animal medicine should be aware that aquatic pets or food fish can be associated with human disease and respond accordingly. In such cases, the veterinarian plays a major role in maintaining human health.     

The prion hypothesis and the human prion diseases

Our understanding of the pathogenesis of the transmissible spongiform encephalopathies (TSE) has made terrific headway over the past 40 years and some scientists are even of the opinion that this group of diseases belongs to the neurodegenerative syndromes best understood. On the other hand, the investigation of TSE has led to a multitude of unexpected and surprising results and consequently has initiated impassioned discussions among scientists. Although the human forms of TSE are very rare, the wildfire-like spread of the bovine spongiform encephalopathy (BSE) raises the pressing question as to whether BSE is communicable to humans. This overview summarizes some current hypotheses about the nature of the infectious agent and about the pathogenesis of the damage of the central nervous system.     

人与鸽相互交叉传染疾病的预防

在鸽子的生长发育过程中，如果饲养人员的管理和预防不当或是鸽子的生活环境异常，就有可能发生各种各样人与鸽交心叉感染的疾病，其中一些传染性的鸽病常会传染给人，这也是养鸽人员最为担心的问题。     

Molecular pathogenesis of bovine paratuberculosis and human inflammatory bowel diseases

Paratuberculosis (Ptb), caused by Mycobacterium avium subsp. paratuberculosis (Map), is a chronic enteritis that affects many ruminants and other wild animals worldwide. Ptb is a great concern in animal health and in etiology of human Crohn's disease (CD). In the present study, we detected Map-specific insertion sequence IS900 of DNA in tissue sections surgically removed from lesions of patients with CD (29 samples), ulcerative colitis (UC) (17 samples), and non-inflammatory bowel disease (IBD) (20 samples). We then compared the histopathological findings of 29 CD and 17 UC cases with those of 35 cases of bovine Ptb, since few comparative pathological studies of human IBD and Ptb have been conducted. The QPCR examination indicated positive results in 13.37% of CD cases, 3.57% of UC cases, and 10% of non-IBD cases. Human CD tissues typically exhibited destructive full thickness enteritis with severe lympho-plasma infiltration and scattered additional granulomas; UC lesions exhibited much less inflammation than CD lesions. Non-IBD control samples did not exhibit pathological changes. Human CD and UC lesions were very different from Ptb lesions that are characterized by predominant granuloma formation. Immunohistochemistry for Map antigen and acid-fast staining were negative in all human IBD cases but were always positive in Ptb cases. Our present comparative study strongly suggests that we reconsider the previous hypothesis that "Map infection" causes CD, even though human intestines were considered to have been exposed to the Map antigen containing the DNA.     

Salmonella infections in swine herds--epidemiology and importance for human diseases]

Based on pertinent literature and research work performed by the authors, a report is presented on the presence of salmonellas in swine herds and the importance of these organisms as agents of disease in swine and source of infection for human salmonellosis. The share among human cases of salmonellosis which are caused by salmonellas originating from swine is estimated at ca. 20%. It has to be assumed that a very large proportion of swine herds is contaminated by Salmonella. Salmonellas may be introduced through infected pigs (parent animals, pigs from other herds added to the herd) or carriers among other animal species (e.g. rodent pests, birds) as well as by feeding stuffs with primary or secondary contamination. So far, the individual importance of the various routes cannot be reliably assessed. It appears that the level of Salmonella prevalence within a herd essentially depends on the hygienic conditions, the mode of keeping and the management of the animals. Serological examinations of meat juice permit conclusions as to the level of Salmonella contamination in slaughtered pigs. The results can thus be used for programmes to reduce the introduction of salmonellas into the food chain.     

The impact of zoonotic diseases transmitted by pets on human health and the economy

In the context of all causes of human morbidity and mortality, or even within the context of all infectious diseases affecting the public health, pet-associated zoonotic infections are of moderate importance. The data documented in Table 1, however, indicate that they do exact significant human health and economic costs. If complete data were available for all of the infections shown in Table 1, the costs would be considerably higher. Moreover, most of these diseases are preventable through educating the public, particularly pet owners, of the zoonotic potential of these diseases, so that they may take precautions to minimize the risks leading to infection. These measures include appropriate health care of pets to eliminate infectious agents, reducing the number of uncontrolled, ownerless pets as well as unwanted or poorly supervised pets, preventing pets from soiling public places with their feces, excluding animals from areas where children play, enforcing leash laws, and promoting responsible pet ownership. Veterinarians, physicians, and public health agencies can aid in these efforts; ultimately, however, the responsibility lies with the pet owner.     

Beyond Lyme: aetiology of tick-borne human diseases with emphasis on the south-eastern United States

Since its emergence in the north-eastern and upper mid-western United States in the 1970s, Lyme disease, caused by Borrelia burgdorferi, has captured the public's attention as the nation's most prevalent vector-borne zoonotic disease. In contrast, recent publications on tick-pathogen systems in the eastern United States, and findings from Department of Defense investigations of ticks found biting military personnel, indicate that residents of the south-eastern United States are primarily at risk from emerging diseases caused by tick-borne pathogens other than B.?burgdorferi. The risk of contracting these diseases varies greatly among states as a consequence of regional variation in the abundance of the key vector tick species. Moreover, this risk is changing, because tick distributions are in flux. To improve health outcomes, health providers need better information and awareness regarding which tick species bite humans in each state and which zoonotic pathogens are prevalent in these ticks. Effective diagnosis, treatment, control and reporting of tick-borne disease in the south-eastern United States require that health providers think 'beyond Lyme' and consider the marked regional differences in the tick species that bite humans and in the pathogens that these ticks carry.     

Comparative aspects of the proliferation marker thymidine kinase 1 in human and canine tumour diseases

As cell proliferation is one of the hallmarks of cancer, various types of proliferation markers are used as important tools in diagnosis, prognosis, treatment decision-making and follow-up in clinical oncology. The S phase-specific protein thymidine kinase 1 (TK1) can be used in immunohistochemistry for RNA/protein expression in tissue specimens and for activity or protein/peptide levels in serum from patients. TK1 has been used mainly in haematologic malignancies in humans, but also found beneficial in canine malignancies. As the protein sequence homology is high between humans and dogs, findings in canine models will have a high comparative value in further human research as well. In the present review, we will focus on the recent results concerning TK1's S phase-correlated expression, increased serum levels of TK1 in patients with malignancies and the relevance for veterinary and comparative oncology. Finally, the benefit of recently developed specific anti-TK1 antibodies suitable for immunologic assay is discussed.     

Immunologic diseases

Selected equine cutaneous diseases for which there is strong evidence of an immunological aetiology are discussed in this section. The reactive disorders of urticaria, Culicoides hypersensitivity, erythema multiforme, drug eruptions and systemic granulomatous disease are included. The autoimmune diseases of the horse with cutaneous manifestations (pemphigus foliaceus, pemphigus vulgaris, bullous pemphigoid and cutaneous lupus erythematosus) are discussed. The clinical signs and diagnostic features of these immunologically induced equine dermatoses are defined, and the challenges in making a definitive diagnosis and managing the clinical signs are confirmed.     

Congenital diseases

In this brief section only three congenital cutaneous diseases are outlined. They include epitheliogenesis imperfecta, epidermolysis bullosa and hyperelastosis cutis. The first is an absence of epidermal structures, the second is a defect at the epidermal–dermal junction and the third is a disease of a component of the dermis. The clinical and histopathologic findings for each are described herein.     

Nodular diseases

The development of a nodule is a fairly common reaction pattern in the skin and subcutaneous tissues of the horse. In many such nodules, the inciting aetiologic agent or antigen is unknown, but in some equine cases there is significant evidence for insect bite origin. The pathogenesis of some equine nodular diseases appears to involve marked collagen degeneration which varies from hyalinization to lysis and can become mineralized. The exact role the lytic collagen has in the pathogenesis of these lesions is still unknown. Vascular changes may be present in some entities. Other nodules may be caused by or complicated by the larva of Habronema spp. The clinical or histological entities outlined in this section include the collagenolytic granuloma, axillary nodular necrosis, unilateral papular dermatosis and cutaneous habronemiasis.     

Neurologic diseases

The responses of apparently healthy newborn foals to neurologic testing differ significantly from those of adult horses. These responses and the diagnostic techniques pertinent to neurologic problems are reviewed as a basis for evaluation of the compromised neonatal foal. The more frequently encountered neurologic diseases are discussed in a problem-oriented format. These clinical problems include behavioral abnormalities, convulsions, changes in consciousness, blindness, ataxia without loss of strength, ataxia with weakness and paralysis, and the floppy foal.