[Role of the poultry red mite (Dermanyssus gallinae) in the transmission of avian influenza A virus]. / Rolle der Roten Vogelmilbe (Dermanyssus gallinae) bei der Übertragung von aviärem Influenza-A-Virus.

OBJECTIVE: The aim of this study was to investigate the role of the poultry red mite (Dermanyssus [D.] gallinae) in the horizontal transmission of avian influenza A virus (AIV) to chickens. This mite is the most common ectoparasite in poultry worldwide, and may play a role in the spread of infectious agents including AIV. Currently, the control of mites is difficult due to frequently developed resistance to many acaricides, their nocturnality and their ability to survive hidden without feeding for months. MATERIALS AND METHODS: D. gallinae were collected in a commercial layer farm and housed in self-made fibreboard boxes. SPF chickens were intravenously infected with AIV strain A/turkey/Ontario/7732/1966 (H5N9). The viraemia in chickens was monitored and at an appropriate time point about 1000 mites were allowed to suck on the AIV infected chickens. Re-isolation of the virus from blood-filled mites was tried daily for 14 days using chicken embryo fibroblast cultures and embryonated chicken eggs. Subsequently, the virus containing mites were placed into boxes that contained naïve SPF chickens to enable virus transmission from mites to chickens. Possible transmission to the chickens was examined using clinical signs, serology, gross lesions, histopathology and immunohistochemistry. RESULTS: Chickens developed a dose-dependent viraemia one day after infection, therefore this day was chosen for the bloodmeal of the mites. AIV was detected in mites after bloodsucking on AIV-infected chickens over a 10-day period. Naïve SPF chickens were infected during bloodsucking of AIV carrying mites. AIV isolates in mites and in chickens were undistinguishable from the original AIV inoculum by RT-PCR. CONCLUSIONS: D. gallinae ingested AIV during bloodmeals on AIV infected chickens and are able to transmit AIV to SPF chickens. Therefore, mites serve as mechanical vector of AIV and may play a major role in the circulation of AIV within a facility or area although the life span of infectious virus in the mite is limited. CLINICAL RELEVANCE: The proven transmission requires more than ever a systematic control of this ectoparasite in order to maintain poultry health and productivity. The demonstrated vector function of this mite is of great significance for poultry flocks all over the world.

[Fowl plague and avian influenza A viruses of poultry and birds. Diagnosis, control measures and practical experiences]. / Die klassische Geflügelpest und die Influenza-A-Viren des Hausgeflügels und der Vögel. Diagnose, Bekämpfungsmaßnahmen und praktische Erfahrungen.

The causes of the notifiable fowl plague are high and low pathogenic avian influenza A viruses of the haemagglutinin subtypes H5 and H7 but also other haemagglutinin subtypes If the intravenous pathogenicity index is greater than 1.2. The German fowl plague order (Geflügelpest-Verordnung) differentiates between highly pathogenic influenza A viruses of the subtypes H5 and H7, if multiple basic amino acids at the cleavage site of the haemagglutinin molecules are detected by virus isolation, antigen or genome determination and low pathogenic avian influenza A viruses of the subtypes H5 and H7 if either the intravenous pathogenicity index is lower than 1.2 or no basic amino acids are present at the cleavage site of the haemagglutinin molecule. Aspects of diagnosis, control including culling, therapy and vaccination are reviewed. The currently available means and their limitations of a therapy of fowl plague by oral administration of neuraminidase inhibitors (e. g. oseltamivir) are described. Following granted permission, individually marked valuable zoo and pet birds may be vaccinated using licensed inactivated vaccines. Vector vaccines have not been used in Germany so far. Avian influenza A viruses of other haemagglutinin subtypes (H1-H4, H6, H8-H18) may also cause infections and severe disease. These subtypes are not subject to governmental interventions and disease can be prevented by timely use of inactivated vaccines.

Soft plastron, soft carapace with skeletal abnormality in juvenile tortoises. Histopathology and isolation of a novel picornavirus from Testudo graeca and Geochelone elegans.

OBJECTIVE: A disease is described in juvenile tortoises (Testudo graeca and Geochelone elegans) consisting mainly of a soft carapace, soft plastron and deformed skeleton. The aim of this study was to determine histopathological lesions and the biological properties of the isolated viruses. MATERIALS AND METHODS: Clinical signs and gross pathology were determined on diseased and healthy appearing tortoises. Paraffin sections were stained with HE, PAS and Prussian Blue and histologically examined. Terrapene heart (TH-1) cell cultures served for virus isolations from 64 tissues and 104 swabs. One isolate (isolate 1243/37 tongue) was used in neutralization tests on 19 sera. RESULTS: Retarded growth and increasingly soft plastron and carapace were the prominent signs in diseased tortoises. Pathological lesions consisted of dilated urinary sac, enlarged kidneys and livers. Histopathologically, hepatic hemosiderosis, hypoplastic anaemia, congestive glomerulonephrosis and osteodystrophy were seen. A novel vi- rus ("virus X") was isolated from 64 organs and 79 of 104 swabs. The isolated viruses were identified as a novel chelonid picornavirus based on cytopathic effect, resistance to chloroform and stability at low pH. Co-cultivation with 5-iodo-2'-deoxyuridine and actinomycin D did not reduce virus titres. Electron microscopically, round, non-enveloped particles (25-30 nm) were detected. Neutralizing antibodies to the isolate 1243/37tongue were present in 17 of 19 sera from seven species of tortoises. CONCLUSION AND CLINICAL RELEVANCE: Nephropathy, osteodystrophy and virus isolations suggest a viral aetiology. Metabolic bone disease is the major differential diagnosis. Further investigations in vivo are needed to evaluate the likely effects of the picornavirus on tortoises.

Semen collection and artificial inseminationin cockatiels (Nymphicus hollandicus)--a potential model for psittacines.

STUDY: Since many psittacine species are endangered and also rare in captivity, the number of offspring produced from breeding is crucial. Many potential breeding birds in species conservation programs are force-paired, and the eggs of many clutches are frequently infertile. Furthermore, male infertility is a common problem. The use of artificial insemination may increase the number of fertile eggs. MATERIAL AND METHODS: In this study, 32 cockatiels (Nymphicus hollandicus) were divided into two groups. In one group, the males were endoscopically sterilised. The males of the other group were used as semen donors. After collection using a novel massage technique, semen samples were examined microscopically to assess contamination and quality. Samples with medium to high sperm concentrations, medium to high motility and no contaminants were used for intracloacal artificial insemination of hens in the group with sterile males. RESULTS: In total, 74.2% of all attempts to collect semen were successful. Insemination resulted in fertilisation of 17 of 23 eggs (73.9%), which was slightly lower than the natural fertilisation rate (88.4%). No negative effects were observed on the oviposition interval of the inseminated hens throughout the entire study. CLINICAL RELEVANCE: Easily applicable in veterinary practice, this study demonstrates that the use of artificial insemination may be a valuable tool to address reproductive failure of psittacines in breeding projects.

Chlamydial infections in feral pigeons in Europe: Review of data and focus on public health implications.

Feral pigeons (Columba livia domestica), which thrive in most European towns and cities, are commonly infected with the zoonotic bacterium Chlamydophila psittaci, the agent of psittacosis (also known as ornithosis) in humans. A number of surveys carried out over the last thirty years across Europe have detected high seropositivity values and high percentages of infection in feral pigeon populations. Overall, when considering data from 11 European countries, seropositivity values to C. psittaci in the sampled populations ranged from 19.4% to 95.6%. In most surveys, the complement fixation test was used, and antibodies were detected in 19.4-66.3% of the samples, with a median of 46.1%. Indirect immunofluorescence and ELISA tests were employed less frequently, but led to the detection of higher percentages of seropositivity (23.7-67.7% and 35.9-95.6%, respectively). Attempts to grow C. psittaci in cell culture or embryonated chicken eggs were successful in 2-42.3% and 0-57.1% of samples, respectively, antigen detection methods were positive in 2.3-40% of samples, while conventional PCR and real-time PCR using different genomic targets detected the organism in 3.4-50% of samples. Twenty-five C. psittaci isolates from pigeons were typed as ompA genotype B (n=14), E (n=10) and E/B (n=1). The huge increase of feral pigeon populations in Europe is a major cause of concern for the detrimental effect of pigeon droppings on environmental hygiene, in addition to the extensive damage due to the fouling of buildings and monuments. The most important pathogenic organism transmissible from feral pigeons to humans is C. psittaci, with 101 cases of disease reported in the literature. Exposure to C. psittaci-contaminated dust, direct contact with pigeons through handling and, to a lesser extent, through pigeon feeding have been identified as hazardous exposures in more than half of the human cases, while loose or transient contacts with feral pigeons have been mentioned in about 40% of the cases. Education initiatives as to the communication of a health risk resulting from contact with pigeons and pigeon excreta should primarily be targeted at individuals who may be exposed to C. psittaci-contaminated dust, such as demolition/construction workers. Recommendations to this category of workers include wearing protective clothes with hoods, boots, gloves and air filter face masks when removing pigeon faeces from roofs, garrets and buildings, especially if working indoors. Monitoring for C. psittaci infections in these workers over time should also be considered. Children should be warned not to handle sick or dead pigeons, and immunocompromised individuals should be advised to carefully limit their contact to feral pigeons. Culling of pigeons by shooting or poisoning is both unethical and ineffective as the place of the killed birds in the population is quickly filled by new juveniles or immigrating birds from neighbouring areas. Pigeon-deterring systems, such as nets and plastic or metal spikes applied to buildings and monuments will prevent their fouling, and the administration of contraceptive drugs may allow size regulation of the pigeon populations. Nevertheless, the measure that will ultimately lead to permanent reduction and will establish healthy sustainable populations is the restriction of indiscriminate feeding by pigeon lovers. The erection of dovecotes and artificial breeding facilities should be considered for providing shelter and a balanced diet to the birds, as well as a chance of interaction for pigeon lovers in a hygienically controlled environment.

Pacheco's parrot disease in macaws of the Lisbon's Zoological Garden. Description of an outbreak, diagnosis and management, including vaccination.

The Lisbon's Zoological Garden, Portugal, has maintained for many years a large collection of psittacine birds without any serious health problems. Unexpectedly, in April 1999, a total of nine macaws died after a short period of illness. Clinical signs consisted mainly of anorexia, ruffled feathers and yellowish droppings. A herpesvirus was isolated from brain, trachea, lung, liver, spleen, kidney and intestine of each of the examined dead birds, confirming that all animals succumbed during viraemia. Serotyping of the isolate in cross neutralization tests with reference sera prove that the outbreak was caused by serotype 3 of Pacheco's parrot disease herpesviruses. An autogenous, formalin-inactivated vaccine with adjuvant (aluminium hydroxid gel) was prepared from one of the isolates and injected intramuscularly 14 days and six weeks after the onset of mortality in an attempt to protect the remaining psittacine birds in the zoo from the disease. The autogenous vaccine was well tolerated and was able to rapidly stop virus spread and morbidity and mortality among the psittacine birds. Follow-up studies demonstrate that all nine blood samples from vaccinated birds obtained nine month' after the second vaccination contain neutralizing antibodies. Twenty five month' after vaccination two out of four serum samples were still antibody positive. No herpesvirus was isolated from faecal samples nine and twenty five months after the onset of the outbreak. These data prove that the autogenous vaccine played a major role in containing a severe outbreak of Pacheco's parrot disease in a large collection of psittacine birds.

Avian influenza A viruses in birds of the order Psittaciformes: reports on virus isolations, transmission experiments and vaccinations and initial studies on innocuity and efficacy of oseltamivir in ovo.

Birds of the order Psittaciformes are - besides chickens, turkeys and other birds - also susceptible to infection with avian influenza A viruses (AIV) and succumb following severe disease within one week. Published data prove that various parakeets, amazons, cockatoos, African grey parrots and budgerigars (genera Barnardius, Psittacula, Cacatua, Eolophus, Amazona, Myiopsitta, Psittacus and Melopsittacus) were found dead following natural infections. Natural infections of highly pathogenic avian influenza viruses (HPAIV) of the haemagglutinin subtypes H5 and H7 cause severe disease and high rates of mortality. Experimental transmission studies with AlVs of the subtypes H5 and H7 confirm these data. Viruses of the subtypes H3N8, H4N6, H4N8, H11N6 and H11N8 may cause also clinical signs and occasionally losses in naturally infected psittacine birds. Clinical signs and losses were also noted following experimental infection of budgerigars with a H4N6 virus. In the EU and in other countries, vaccination of exposed exotic and rare birds and poultry is a possible and an acceptable measure to provide protection. Currently, the EU Commission accepts inactivated adjuvanted vaccines whereas in some other countries recently developed vector vaccines are applied. However, birds remain susceptible during the time interval between application of any vaccine and the development of immunity. This critical period can be bridged with antiviral drugs. Our in ovo studies demonstrate that the neuraminidase inhibitor oseltamivir is non-toxic for chicken embryos at concentrations of 0.1, 1.0 and 10.0 mg/kg body weight. These dosages prevented entirely the replication of a HPAIV of the subtype H7N1 when this drug is given shortly prior to, simultaneously or soon after inoculation of chicken embryos with this AIV. Thus, we speculate that exposed valuable birds such as psittacines at risk can be successfully treated.

Outbreak of duck plague (duck herpesvirus enteritis) in numerous species of captive ducks and geese in temporal conjunction with enforced biosecurity (in-house keeping) due to the threat of avian influenza A virus of the subtype Asia H5N1.

The continuing westward spread of avian influenza A virus of the subtype H5N1 in free-living and domestic birds forced the European Union and the German federal government to enhance all biosecurity measures including in-house keeping of all captive birds from October 20 to December 15, 2005. Movement of captive ducks and geese of many different species from a free-range system to tight enclosures and maintenance for prolonged times in such overcrowded sheds resulted in pronounced disturbance of natural behaviour, interruption of mating and breeding activities and possibly additional stress. Under these conditions the birds developed signs of severe disease and enhanced mortality twentyfour days later. A total of 17 out of 124 (14%) adult birds and 149 out of 184 year-old birds (81 %) died during the outbreak. A herpesvirus was isolated from many organs of succumbed ducks and geese that was identified as a duck plague herpesvirus by cross neutralization test using known antisera against duck plague virus. The published host range of duck plague comprises 34 species within the order Anseriformes. We report here on additional 14 species of this order that were found to be susceptible to duck plague virus. The exact source of the herpesvirus could not identified. However, low antibody titres in some ducks at day of vaccination indicate that at least some of the birds were latently infected with a duck plague herpesvirus. The remaining healthy appearing birds were subcutaneously vaccinated with a modified live duck plague vaccine (Intervet, Boxmeer, NL) that stopped losses and resulted in seroconversion in most of the vaccinated birds.

Determination of the inhibitory concentration 50% (IC50) of four selected drugs (chlortetracycline, doxycycline, enrofloxacin and difloxacin) that reduce in vitro the multiplication of Chlamydophila psittaci.

A total of 18 chlamydial isolates from various psittacine birds, one isolate from a domestic pigeon and one isolate from a Pekin duck were isolated in continuous Buffalo Green Monkey (BGM) kidney cell cultures. All 20 isolates were identified by nested multiplex polymerase chain reaction as Chlamydophila psittaci. These isolates were multiplied to high titres and subsequently tested for in vitro sensitivity against two tetracyclines (chlortetracycline and doxycycline) and two quinolones (enrofloxacin and difloxacin) at concentrations of 0.0, 0.25, 0.50, 1.00, and 10.00 microg/ml. Replication of chlamydia in BGM cell cultures is assayed on the basis of formation of intracytoplasmic inclusions that are visualized by Giménez staining. All isolates, although to variable degrees, are sensitive to all four drugs. The number of chlamydial inclusions decreases gradually over a broad range of increasing concentrations of the drugs. The variation in the number of inclusions between isolates is remarkably high for chlortetracycline less for doxycycline and minimal for both fluoroquinolones, the enrofloxacin and difloxacin. The decline in numbers of inclusions is highly dose-dependend and the observed reduction stretches over a wide range of drug dilutions. Therefore, it is proposed to calculate drug sensitivity values in terms of inhibitory concentration 50%, (IC5). Its calculation includes all tested drug dilutions instead of the hitherto more common minimal inhibitory concentration, MIC, which is based on results of serial dilution tests for cell-free growing bacteria. Using a logistic regression model for the calculation of the inhibitory concentration 50% of all 20 chlamydial isolates, the IC50 is 0.807 microg/ml for tetracycline, 0.497 microg/ml for doxycycline, 0.180 microg/ml for enrofloxacin and 0.168 microg/ml for difloxacin. Complete prevention of inclusion formation was already seen for enrofloxacin at a concentration of 1.0 microg/ml in 12 out of 20 and for difloxacin in 5 out of 20 isolates whereas more than 10 microg/mI chlortetracycline is needed in 15 out of 20 isolates and for doxycycline 9 out of 20 isolates yielded inclusions at 10 microg/ml.

Mycological examinations on the fungal flora of the chicken comb.

A total of 500 combs of adult chickens from two different locations in Germany (Hessen and Schleswig-Holstein) were clinically and mycologically examined. The chickens came from three battery cages (n = 79), one voliere system (n=32), six flocks maintained on deep litter (n = 69) and 12 flocks kept on free outdoor range (n=320). Twenty-two of the 500 chicken combs (4.4%) were found to have clinical signs: only non-specific lesions neither typical of mycosis nor of avian pox such as desquamation with crust formation, yellow to brown or black dyschromic changes, alopecia in the surrounding area and moist inflammation. Only seven of the 22 clinically altered combs showed a positive mycological result; the non-pathogenic and geophilic Trichophyton terrestre in one case and non-pathogenic yeast in six cases. The following fungi were seen in the different housing systems: 13 dermatophytes (2.6% of 500 samples): 12 x T. terrestre, 1 x Trichophyton mentagrophytes, 11 isolates of Chrysosporium georgiae (2.2% of 500 samples) and 149 isolates of yeasts (29.8%): Malassezia sympodialis: n = 52, Kloeckera apiculata: n = 33, Trichosporon capitatum (syn. Geotrichum capitatum): n = 23, Trichosporon cutaneum/Trichosporon mucoides: n = 12, Trichosporon inkin (syn. Sarcinosporon inkin): n = 8 and Candida spp.: n = 21, including pathogenic or possibly pathogenic species: Candida albicans: n = 3, Candida famata: n = 4, Candida guilliermondii: n = 3, Candida lipolytica: n = 3, Candida dattila: n = 2 and one isolate each of Candida glabrata, Candida parapsilosis, Candida aaseri, Candida catenulata sive brumpti, Candida fructus and Candida kefyr sive pseudotropicalis. There is no stringent correlation between the clinical symptoms diagnosed on the chicken combs and the species of yeasts isolated. The causative agent of favus in chickens, Trichophyton gallinae, and the saprophytic yeast in pigeons, Cr. neoformans were not isolated. The most frequently isolated yeasts M. sympodialis and Kloeckera apiculata are suggested to be classified as members of the resident flora of the chicken comb.

PCR-based detection of genes encoding virulence determinants in Staphylococcus aureus from birds.

The present study was designed to comparatively investigate 19 Staphylococcus aureus strains isolated from specimens of 19 different birds during routine microbiological diagnostics. The S. aureus strains were characterized genotypically by polymerase chain reaction (PCR) amplification using 62 different oligonucleotide primers amplifying genes encoding staphylococcal cell surface proteins, exoproteins and two classes of the accessory gene regulator agr. All 19 investigated S. aureus were positive for the gene segment encoding a S. aureus-specific part of the 23S rRNA, the genes encoding thermostable nuclease (nuc), clumping factor (clfA) and coagulase (coa) and the gene segments encoding the Xr-repetitive region and the immunoglobulin G (IgG)-binding region of protein A (spa). In addition, all tested strains were positive for the genes hla and fnbA and negative for the genes seb, sec, sed, see, sej, tst, eta and etb. The remaining genes, including sbi, hlb, fnbB, ebpS, cna (domains A and B), cap5, cap8, set1, agr class I, agr class II, sea, seg, seh and sei were detected in a variable number of isolates. The presented data give an overview on the distribution of virulence determinants of S. aureus strains isolated from birds. This might be useful to understand the role of these virulence determinants in bird infections.

A retrospective description of a highly pathogenic avian influenza A virus (H7N1/Carduelis/Germany/72) in a free-living siskin (Carduelis spinus Linnaeus, 1758) and its accidental transmission to yellow canaries (Serinus canaria Linnaeus, 1758).

A haemagglutinating virus was isolated in summer 1972 from a single free-living siskin (Carduelis spinus Linnaeus, 1758) in embryonated chicken eggs. Additional cases of morbidity or mortality were not observed in the area were the sick siskin was found. The virus was characterized as an avian influenza A virus of the subtype H7N1 and designated H7N1/Carduelis/Germany/72. The virus induced following experimental inoculation of chicken embryos a high rate mortality (mean death time approximately 24 hours), formed plaques in chicken embryo fibroblast cultures without addition of trypsin and has an intracerebral pathogenicity index (ICPI) of 1.80. Therefore, this virus is considered as a highly pathogenic avian influenza A virus. Canaries (Serinus canarius Linnaeus, 1758), that were housed in the same room with the siskin were accidentially exposed by contact to the sick siskin which resulted in virus transmission followed by conjunctivitis, apathy, anorexia and a high rate mortality.

Avian influenza A viruses in birds --an ecological, ornithological and virological view.

Avian influenza A viruses (AIV) are the causative agents of the presently most important poultry disease. Ten countries in Asia and several other countries in Eastern Europe suffer high losses from the lethal effects of these viruses of the H5N1 subtype. AIV of other subtypes cause in additional countries severe losses. The threat to health and well-being of the avifauna, domestic poultry and possibly mammals including humans are worldwide of major concern. The European Union reacted with a complete import ban on untreated meat, eggs, poultry products as well as free-living and pet birds. Extensive surveillance of free-living birds and domestic poultry that is maintained in free-range and close to open waters were initiated in an attempt to gather information on the current status of infection with these viruses and to target appropriate countermeasures for the protection of domestic poultry (in-house keeping) and to safeguard food production for humans. Since the monitoring of free-living birds is labour-intensive, costly, and time-consuming, only birds should be included in the monitoring programme that harboured in the past most if not all influenza A viruses. The birds of the order Anatiformes, family Anatidae, subfamilies Anserinae and Anatinae, provided 65.9 % of all avian AIV isolates. The cosmopolitan Common Mallard (Anas platyrhynchos) is the dominant species with the highest rate of isolations among all bird species. Second in frequency is the North-American Blue-winged Teal (Spatula discors). Consequently, free-living anatiform birds of the genera Anas and Spatula should comprise the main focus for the collection of cloacal and pharyngeal swabs. With the likely exception of the most recent H5N1 viruses, signs of disease were not recorded in AIV infected anatiform birds. AIV isolations were definitely less frequently obtained from birds of the orders Phasianiformes (including domestic chickens and turkeys), Charadriiformes (plovers and lapwings), Lariformes (gulls), Columbiformes (pigeons) and Psittaciformes (psittacines) and need less attention in sampling efforts. This review presents also data on taxonomy and most suitable means for isolation and typing of haemagglutinating viruses. The different frequencies of the detection of 16 haemagglutinin (HA) subtypes and 9 subtypes of neuraminidase (NA) surface antigens are composed on the basis of extensive literature retrievals. Both antigens occure in isolates at different frequencies. Only 103 of all 144 possible HA x NA combinations were described so far. The AIV that contain the HA subtypes H3, H4, H6 are most frequently isolated whereas the AIV of the subtypes H5 and H7 were less frequently encountered. All other HAs are rather rare. AIV that possess the NA of the subtypes N2, N1, N8 and N3 are frequent and all other NAs are rarely detected.

[Disinfectant tests at 20 and 10 degrees C to determine the virucidal activity against circoviruses]. / Desinfektionsmittelprüfungen bei 20 und 10 Degrees C zur Bestimmung der viruziden Wirksamkeit gegen Circoviren.

To evaluate virucidal activity against porcine circovirus type 2 (PCV2), four disinfectants were tested under laboratory conditions. As basis to perform the testing the "Guidelines for testing chemical disinfectants" of the German Veterinary Association (DVG-guidelines) were applied. For simulation of field conditions, the tests were carried out in virus carrier tests, at 20 and 10 degrees C, and under protein load (40% foetal calf serum (FCS) in virus suspension). For disinfection of PCV2 at 20 degrees C an exposure time of 120 min in 2% Disinfectant 1 (20% glutaraldehyde, 12% 2-propenal, polymer with formaldehyde) or Disinfectant 2 (55% formic acid, 7% glyoxylic acid) was necessary. 1% of Disinfectant 3 (Component 1: Potassium peroxomonosulphate. Component 2: Active detergents) disinfected PCV2 on carriers within 180 min. After a reaction time of 120 min with 1% and 60 min with 2% Disinfectant 4 (21% glutaraldehyde, 17% formaldehyde) there could not be detected any virus. Reduction on effectivity through temperature reduction to 10 degrees C were more significant for aldehyde containing preparations Disinfectant 1 and Disinfectant 4 than for Disinfectant 2 and Disinfectant 3. These losses on effectivity could be corrected through extension of exposure time or increase of concentration.

Review of the literature on avian influenza A viruses in pigeons and experimental studies on the susceptibility of domestic pigeons to influenza A viruses of the haemagglutinin subtype H7.

The scientific literature of the past century is reviewed on fowl plague (presently termed highly pathogenic avian influenza, HPAI) in pigeons. HPAI viruses cause epidemic disease outbreaks with high rates of losses in many avian species, particularily in chickens and turkeys. Also susceptible to disease are quails, guinea fowl, ducks, geese, ostriches, passerine birds, and birds of prey whereas conflicting reports on the susceptibility of the domestic pigeon exist. Based on literature reports and on own experiments, and applying as criteria for judgements clinically overt forms of disease, virus multiplication plus shedding and seroconversion, it is concluded that domestic pigeons are only partially susceptible to influenza A viruses of the haemagglutinin subtype H7. Infection of pigeons with H7 viruses results only in some of them in signs, virus shedding and seroconversion. Using the same criteria, pigeons appear to be even less susceptible to infection with influenza A viruses of the H5 subtype. Only one of five publications describe in 1/19 pigeons exposed to H5 influenza A virus depression one day before death, and only 2/19 multiplied and excreted virus, and 1/19 developed circulating antibodies. Consequently, pigeons play only a minor role in the epidemiology of H5 influenza viruses. In contrast, following infection with influenza A virus of the subtype H7 clinical signs in pigeons consist of conjunctivitis, tremor, paresis of wings and legs, and wet droppings. H7-infected pigeons multiply and excrete H7 viruses and develop circulating antibodies. Albeit of the status of infection, free-flying domestic pigeons can act as mechanical vectors and vehicles for long-distance transmission of any influenza A virus if plumage or feet were contaminated.

Undesirable reactions of domestic pigeons to vaccination against paramyxovirus type 1.

Subcutaneous vaccination of fancy and racing pigeons with inactivated oil-based vaccines protects against all clinical manifestations caused by the Paramyxovirus type 1. Correct application of the vaccine may occasionally result in the development of granulomas or abscess-like lesions on the site of vaccine application. Although protected against disease as proven by challenge experiments, a variable proportion of vaccinated pigeons do not react with the formation of detectable serum antibodies. The pathogenesis of granuloma and abscess-like lesion developments and the failure to form humoral antibodies are presently not understood. Questions relating to legal liability of vaccinating veterinarians are briefly discussed.

Investigations on suitability of different materials for carriers to be used for virucidal testing of chemical disinfectants in the veterinary field.

Various materials with rough surfaces were tested to determine their suitability for virus carrier tests designed to evaluate virucidal activity of chemical disinfectants. A non-enveloped RNA virus, bovine enterovirus type 1, strain LCR 4 [entero cytopathogenic bovine orphan virus (ECBO)] and an enveloped RNA virus, paramyxovirus type 1 [Newcastle disease virus (NDV), strain Montana] served as test viruses. Experiments with ECBO virus were carried out in four sets, and those with NDV in three sets. In the first set we used poplar wood, frosted glass slides and Sartorius membrane filters. The second set comprised of poplar wood, frosted glass slides, polyamide filters, and cellulose nitrate filters and, in the third set, glass fibre filters and glass fibre pre-filters were added. The fourth test included poplar wood, frosted glass slides, and polyethersulphone ultra filters. Because of their extremely low levels of virus recovery, glass, polyamide, cellulose nitrate and glass fibre filter, glass fibre pre-filter, and polyethersulphone ultra filters are not suitable for sufficient recovery of ECBO virus. Only poplar wood carriers allowed sufficient recovery rates of ECBO virus. In the first and second set of tests, NDV could be sufficiently recovered from poplar wood, glass slides, and polyamide filter. In the third set, the virus recovery from polyamide filter was very low. Poplar wood carrier is recommended as a reliable carrier for the tests with both viruses, but methods for virus recovery must be improved, e.g. by more vigorous and longer shaking or optimizing the ultrasonic treatment.

Avian host range of Chlamydophila spp. based on isolation, antigen detection and serology.

Published reports and our own diagnostic data on the avian host range of avian Chlamydophila spp. are presented in an attempt to provide evidence for the large number of bird species that have been naturally infected with chlamydia. The term 'chlamydia-positive' is based on either isolation of the organism and antigen detection or on serological detection of circulating antibodies. The list of chlamydia-positive birds contains the six major domestic species (chicken, turkey, Pekin duck, Muscovy duck, goose, and pigeon), the three minor domestic species (Japanese quail, bobwhite quail, and peafowl) and a total of 460 free-living or pet bird species in 30 orders. The order Psittaciformes contains by far the most (153 of 342; 45%) chlamydia-positive bird species. More than 20% of all species per order are positive for chlamydia in the orders Lariformes (gulls, 26 of 92 species; 28%), Alciformes (alks, six of 23 species; 26%), Sphenisciformes (penguins, four of 16 species; 25%), and Anseriformes (ducks and geese, 33 of 157 species; 21%). Only 5% of all bird species (14 of 259 species) in the order Phasianiformes (gallinaceus birds) are chlamydia-positive. The different percentages of chlamydia-positive bird species reflect: (i) a high rate of investigations (e.g. of domestic birds) compared with infrequent testing (e.g. of Charadriiformes or Cuculiformes), (ii) frequent zoonotic implications (e.g. psittacine and columbiform birds), and (iii) an assumed high susceptibility to infection and subsequent seroconversion (e.g. waterfowl).

[Disinfection of caliciviruses at 20 and 10 degrees C]. / Desinfektion von Caliciviren bei Temperaturen von 20 und 10 degrees C.

Five disinfectants, Venno FF super, Venno Vet 1 super, Venno Oxygen, M&Enno-Veterinär B neu und Neopredisan 135-1, were tested to evaluate their efficacy against caliciviruses at 20 and 10 degrees C. As model test virus served feline calicivirus type F9 (FCV F9). All disinfectants were tested according to Guidelines of the German Veterinary Association (DVG). The investigations were performed in suspension tests and germ carrier tests. The suspension tests were carried out without and with protein load. As protein was used foetal calf serum at the concentration of 40%. Venno FF super showed less protein dependence, however a considerable temperature dependence. This matter can be corrected by increase of concentration on 2%. Venno Vet 1 super was without protein especially effective. The losses on the effectiveness through low temperature and protein load can be annulled also here by increase of concentration. Venno Oxygen was more effective in the comparison to that here named both preparations. The effects of temperature can be corrected by extension of reaction time. The most effective preparation was M&Enno Veterinär B neu. The disinfection occurred at 20 degrees C with 0.5% solution within 120 min and at 10 degrees C with 1.0% solution within 60 min. The fifth disinfectant Neopredisan was in suspension tests without protein load and carrier tests with gauze at 20 and 10 degrees C relative convincing but in germ carrier tests with poplar wood, no complete disinfection could be achieved within tested concentrations and reaction times.

Evaluation of virucidal activity of three commercial disinfectants and formic acid using bovine enterovirus type 1 (ECBO virus), mammalian orthoreovirus type 1 and bovine adenovirus type 1.

A modified version of the test method of the Comité Européen de Normalisation (CEN) was developed using formic acid and three commercial disinfectants to evaluate virucidal activity against three non-enveloped viruses, bovine enterovirus type 1 (ECBO virus), mammalian orthoreovirus type 1 and bovine adenovirus type 1 (BAV 1). Determination of the effects of temperature was carried out at 20 and 10 degrees C. All tests with protein load used bovine serum albumin (BSA) and yeast extract. The investigations were performed in suspension tests and in carrier tests using poplar wood virus carriers. The carrier tests showed that ECBO virus could be inactivated at 20 degrees C with 1% formic acid within a 60 min reaction time. For disinfection of ECBO virus at 10 degrees C within 60 min, a 2% concentration of formic acid was necessary. Formic acid was ineffective against reovirus and bovine adenovirus and cannot be recommended as a reference disinfectant. Inactivation of ECBO virus and adenovirus type 1 using a disinfectant containing aldehydes and alcohols could be achieved, but only at room temperature. The disinfection of reovirus type 1 at room temperature with this product was possible without a protein load. This disinfectant exhibited disinfection ability at 10 degrees C at a concentration of more than 2% or with a longer exposure time. A disinfectant containing aldehydes was effective at room temperature but its effect was reduced in the presence of organic matter. Inactivation at 10 degrees C was found only against adenovirus. The fourth disinfectant, which contained peroxiacetic acid, inactivated all test viruses at a concentration of 0.5% within 15 min independent of temperature and protein load.