De Proprietatibus Rerum
Table of contents:
he terminology in the microbiology (= theory of the small organisms) is frequently so inconsistent that a definition of certain termini technici appears to be absolutely necessary for the time being. One can speak only about something, which one designated with a name before - a thought, which is found in the Old Testament at the creation of the world and which is worked out by Platon more exactly.
Microbes: derives as word from ancient Greek meening micro- (small) and bios (life) and covers as idea small organisms, that are in the medicine viruses, bacteria, single-celled organisms, and "small fungi", but not "animals". However, the Medical Microbiology as the theory of the microorganisms being significant in human and veterinary medicine, incorpores also the types formerly designated as animals, thus e.g. also partially very large tapeworms and ticks.
Definition of a Parasites, definition: Parasites in the broad sense are all ways of life, or each organic reproductable mass, which find their ecological niche in another way of life. Another definition is that Leuckarts (1879): Organisms, which find their habitat and their source of food in other organisms. Whereas parasitoides are parasites which program the host`s death coercively. No parasitoides are known from man or other mammals, probably not even from any vertebrate.
Definition of an opportunistic parasite: Opportunistic microorganisms are microorganisms that may or may not cause disease in the host. They generally colonize but do not infect (= invasion, multiplication and/or causing of an immune reaction) the host. When usually found associated with a host they may be seen as normal microbiota, but they can cause severe, even lethal disease if they are inadvertently introduced into a site where they do not usually reside, especially inside host tissue and/or if the immune system of the host is damaged. Because of the decreased immune answer, immunosuppressed persons are highly endangered by opportunistic infections, however, dependent on the type of the immunosuppression, the degree is different. Opportunistic microorganisms do not appear in healthy adults, or, if they nevertheless arise, adults recover from infections very quickly or do not get sick at all.
Some biological characteristics of microbes: Microbes constantly change. This development may also include changes in virulence (this is the microorganism-induced reduction of the fitness of the host; differentiate: pathogenicity) and in production of poison. The most prominent example are the strains of pathogenic Escherichia coli, which may have taken over genes of virulence by some horizontal gene transmission. The result is a very potent new pathogen, the enterohaemorrhagic E. coli (EHEC). In addition, the development of drug-resistant protozoa has become frequent. This is propelled mainly by the widespread and usually not too appropiate use of antimicrobial drugs in a multiplicity of countries of the earth. Too, one hasn`t to underestimate the influence of changes in animal breeding methods towards intensive husbandry for the emerging of new and/or resistant pathogens, this applies also to the small area of the husbandry of exotic pet animals.
infectious diseases are a frequent health problem, not seldom fatal for the host in each pushed way of life, thus finally a space problem. The manifestations of such diseases are just as various as the fauna of the causers, the microorganism. The spectrum of microorganisms comprises tiny small, dead forms such as viruses and prions (?), the not visible single-celled organisms and bacteria, up to partially large forms such as round worms (filarial: see picture left), tapeworms, which may partially reach meter-length, and large arthropods, like ticks. The general symptoms of an infectious disease is characterized by the effects of the preventive measures of the host against the microorganism, the immune reaction. Nearly all ill-making infections - there are not ill-making infections also, these are even the majority - lead to partially violent defense reactions of the host, which manifest themselves in so called general symptoms: temperature increase even in poikilotherms (fever), loss of appetite, mass loss, frequently diarrhea, and decrease in activity. In the terraristic the infective agents can be divided into two groups according to their place of infestation. One calls the outward ectoparasites, that inside the host endoparasites.
Infectivity: Genetic, biochemical or physiological characteristics of the pathogen that determine its ability to infect the host. High infectivity does not necessarily mean that symptoms of disease (pathology) appear more quickly, nor that the illness is more severe (= virulence).
Resistance Genetic, biochemical or physiological characteristics of the host that inhibit pathogen establishment, survival or development. Resistance may be quantitatively, so that hosts may be infected but resistant ones are harmed less, or qualitative, so that host infection is prevented. The majority of studies of host-pathogen co-evolution regard resistance as the latter.
Virulence The direct or indirect reduction in host fitness attributable to pathogen infection, often measured as pathogen-induced host mortality. (Conflicting definitions exist, such as that of the infective capacity of pathogens (here termed "infectivity")).
Compatibility The ability of a given pathogen to infect a given host as a consequence of the combined genetic, biochemical or physiological characteristics that determine infectivity and resistance of the host.
last four definitions acccording to: Woolhouse, M. E. J.; Webster, J. P.; Domingo, E.; Charlesworth, B.; Levin, B. R.: Biological and biomedical implications of the co-evolution of pathogens and their hosts. Nature Genetics 32 (2002) 569-577.
ctoparasites usually derive from the enormous circle of the arthropods. Within amphibians and reptiles they cause serious illnesses only in very rare cases, but they are usually clear signs for a bad keeping (i.e. they act as marker organisms). From the ectoparasites different kinds of mites such as blood mites (e.g. Ophionyssus natricis) and ticks (in Central Europe usually Ixodes-species) most frequently lead to problems in the keeping, rarer one finds leeches, mosquitoes and others blood-sucking insects.
Microbiological marker: Hygienic evaluation of terraria by cryptosporidia, free living-amebas, salmonella. Amphibians and reptiles are popular pet animals in about 90.000 Austrian households despite their again and again disputed capacity to transmit some diseases associated with animal keeping. We studied the epidemiological significance of the triangle animal keeper, exotic pet animal, and feeding mice by means of investigating the frequency of three intestinal infestations, caused by cyryptosporida, opportunistic free living-ameba and salmonella, in amphibians and reptiles living in a public vivarium. Besides the first record of the occurrence of Naegleria australiensis in Austria, and of this species and of Acanthamoeba polyphaga in the feces of reptiles worldwide, we could detect a strong association between Salmonella subspecies I and captured reptiles and between S. subspecies III and free living lizards. Thus, animal keeper, the exotic animals kept, and the feeding mice may constitute an epidemiological pool for such infectious agents being able to interchange. This new epidemiological situation may support the further uprising of some opportunistic and exotic diseases like reptile borne salmonellosis. Despite the benefits of keeping exotic animals in a household especially immundeficient persons must be aware of the danger of infectious diseases possibly spread by their pets.
Exotic pets as hazard source for man
xotic pets as hazard source for a transmission of parasites to humans: It is almost a typical characteristic from animals that they present themselves the base of life of others parasitisch from them to nourishing kinds. Reptiles and amphibians make thereby no exception naturally. Since parasites live by definition by energy robbery and damage their hosts, the necessity results with them to sit down apart from the objectives of the Vivaristik. Usually the problem of the parasitosis in the Terraristik from view the veterinary medicine is concerned, humans are hardly ever considered in this connection as vector or as a host. That does not happen completely groundlessly, because parasites are nearly always bound to a close host spectrum and therefore not in a the position, of the reptile or of the Amphibium on a mammal to change over in the special case on humans. The physiology of these animal classes and thus the environmental condition are for usually the closely eingenischten parasites too different. There are nevertheless some frequently parasites arising with amphibians and reptiles, which represent a source of danger also for humans. A transmission effected from parasites mostly through close contact of humans and animal or the admission of infectious stages of a parasite from the habitat inhabited by animals. Interestingly enough this seems to the human culture most intensively at two Gegenpolen. On the one hand reptiles and amphibians are roughly eaten or used for medical treatments, held on the other hand in terraria. While first might be understood in the decrease, home animal husbandry develops of nations industrialized by "Exoten", in particular from amphibians and reptiles, to ever more popular leisure activities of the urban population. If one surrounds microorganisman estimations on Austria, then in approximately 90,000 Austrian households reptiles are held. This means that more than 200,000 humans in close contact with many thousands reptiles live. There is world-wide some millions humans their habitat in such way with reptiles or amphibians probably divides. From this large number the phenomenon of a transmission of parasites of Terrarientieren on humans at meaning, actually arising with small probability, wins. Due to their rarity illnesses of humans are through diagnosable by exotic pets transferred parasite in addition with difficulty and remain frequently aetiologisch unsettled.
Increasingly begins in science circles to awake in the public and the national authorities competent for health a consciousness for the fact that inappropriately operated Terraristik is connected with health risks. It is to be stressed expressly that errors are committed or special circumstances to be present to have, so that the infection risk achieves a substantial extent. With the problem to set apart in time critically and carry out, helps itself clearing-up work however reliably to estimate the risk correctly and avoid factors of risk. Research work in this area serves also for it legislator and authorities basic knowledge for the order to place, due to whose the extent of an action need can be measured. That such is recognized also by national side shows itself by the 1975 in the USA to issued sales ban for turtles of less than 10.2 cm.
Newer research results point out that it comes again and again for a change of the originally species-characteristic Keimflora between all at the Terraristik organism taken part. Of it can be equally concerned Terrarientieren, care persons and fodder animals. This way microorganisms new habitats also pathogenen can be opened. Particularly parasites with a primarily already broad landlord spectrum can change, favoured by inappropriate being busy, injuries and frequent exposition, between the Herpetotaxa and humans. " neuen" Landlords turn out usually as false landlords, i.e. they prove as unsuitable for the further ontogenetische development of the parasite. This is however usually connected with a high Pathogenität of the exciter in the inadäquaten landlord (= maladjusted parasitism). The frequency of such an microorganism exchange is positively correlated with the number of persons concerned, the number held of Exoten, the width of the pallet of kinds concerned, the tightness of the living situation and of the adherence to the necessary hygiene. At present the rapidly changing life circumstances in centers of dense development, particularly the substantial rise of the portion of immunsupprimierter persons of the population and the increase in spare time and leisure activities possibilities, lead to rapidly changing epidemiological conditions for infections. These new conditions can be reconstructed both on the basis the parasitologischen situation and on the basis the reptile-associated Salmonellosefälle, which culminated with the first description of a Salmonellose outgoing from a house queue in Austria in the year 1999.
Some Herpetotaxa associated Parasitosen are very exotic and for different reasons usually only in the theory humans endangering. In addition e.g. pay those potentially humanpathogenen parasites, which cannot develop themselves further or increase in usual Terrarien due to the absence of compellingly necessary intermediate landlords. These exciters represent usually no hygiene problem, since they disappear some to time after a new trimming from the landlord population automatically. In addition Gnathostoma e.g. belongs spinigerum, to one the exciter of the Larva migrans visceralis (= an atypical migration of worm larvae in humans as a false landlord). Another group are those parasites, which can change only by a behavior uncommon in Europe to humans. Larva stages of the tapeworm Spirometra frame penetrate during a Wundbehandlungen with raw frog meat actively by the skin into humans and can arrange spacious Gewebszerstörungen (sparganoses). Some few cases of such Sparganosen in connection with the Vivaristik were reported over Internet publication from the USA. The infection of humans with reptile-associated Pentastomidenarten, in particular with Armillifer armillatus, is usually brought with the preparation from queue meat to the human consumption in connection, although also dirt and lubrication infections with reptile excrement are possible. Human Pentastomideninfektionen is perhaps more underestimated the classical example there only coincidentally found infections, therefore also no data to the frequency and humanmedical meaning in purchase are present to the Vivaristik. The collection of such epidemiological data over two important, fakultativ humanpathogene, opportunistische reptiles and groups of amphibian parasites is the goal of a common study of the Micro-Biology Consult Dr. Andreas Hassl and nature-historical museum Vienna (NHMW). In the last years among other things the frequency of the intestine settlement was examined of Terrarientieren with that potentially pathogenen, free-living amoebas of the kinds Acanthamoeba and Naegleria, held in the NHMW. These amoebas are ubiquitous organisms, which can unfold occasionally gewebszerstörende effects from so far unknown causes. Since a high number (42 - 93%) at free-living reptiles as Ausscheider of such amoebas was described, it could be present to an endanmicroorganisment of humans by the admission of these resistant and mobile Protozoen. In the collective of the Terrarientiere of the NHMW we determined however only 2% of the animals as Ausscheider of these amoebas. The landlords did not show any clinical symptomatology, their role as reservoir or pure tractors are still unclear.
In opinion of some specialists low vertebrate animals could have however substantial meaning as reservoir of potentially humanpathogenen Kryptosporidien (Cryptosporidium spp.). Kryptosporidien are single-cell, mandatory intestine parasites of many vertebrate animals, with immunsupprimierten landlords the unstillbare and to today untherapierbare (!) Durchfälle with lethal exit cause. Immune-competent vertebrate animals can be clinically quiet Ausscheider of these parasites. The infection effected in connection with water, Kryptosporidien examinations of the drinking water everywhere in the industrial nations are probably usually initialized at present. Although in Austria Terrarientiere 1991 as Kryptosporidien Ausscheider were already recognized, the humanmedical relevance of this find is only recently clearly nascently as it possible became to differentiate the individual Kryptosporidien kinds. In a study broadly put on these parasites were not proven quite often with Terrarientiere however free-living lizards. It let this and the kind cluster assume that the Kryptosporidien infections of the exotic home animals of anthropogenen origin are and have a cause in the changed life situation of the Terrarientiere. A further realization of the study is also that immunsupprimierten persons the care Exoten, in particular queues, must be advised against.
Some Arachnids (Ixodes ricinus, Amblyomma variegatum, Haemaphysalis concinna, Ophionyssus natricis among other mites) can suck blood not only at reptiles, but may also change on humans. At least unpleasant skin excursions can be the result. However the phase of the unimpaired blood sucking at humans is usually only short, so that no serious symptomatology arises.
The mentioned parasitic infections are not only a danger for the animal keeper, but represent in connection with the commercial marketing of animals in the context of live stock exchanges a substantial public health problem. The strict observance of hygiene regulations and - recommendations is to be demanded particularly in this contact-intensive form of the animal trade, is it not from health-political considerations in the future to legal prohibition of such meetings to come. After our view over the risks of the Terraristik with clearing-up, knowledge transfer and a rating examination of all pro and cons Rechung should be carried for the rising consciousness of the public.
© Andreas Hassl opus vindobonensis fabricavit AD MMI