Characterization of orthopoxviruses isolated from man and animals in Germany.

Fourteen orthopoxvirus strains isolated from humans, cats, a dog, a cow, and an elephant in Germany were characterized. All were classified as cowpox virus based on haemorrhagic lesions induced on the chorioallantoic membrane of chicken eggs and reactivity of a 160 kDa protein with anti-A-type inclusion protein hyperimmune serum in a Western blot. More detailed comparison of the isolates by restriction endonuclease mapping using HindIII and XhoI demonstrated a close relationship between all isolates and confirmed them as cowpox viruses. However, some minor differences between the isolates were detected which proved to be of epidemiological value. One group consisting of five closely related isolates contained a unique 4.0 kb HindIII fragment. In a Southern blot this fragment failed to hybridize with other cowpox virus isolates including the reference strain.

Characteristic but unfamiliar--the cowpox infection, transmitted by a domestic cat.

An 11-year-old girl had been suffering from 2 recently developed reddish ulcerated nodules on the right side of her neck and, concomitantly, from a very hard swelling as well as from painless lymphadenopathy. Subsequently, thick black eschars appeared on the surface of the ulcers. Using the negative staining technique, an orthopox virus infection could be identified by electron microscopy. The patient's characteristic history as well as her close contact with a cat frequently hunting nice indicated the diagnosis of a cowpox infection, which was unequivocally confirmed by identification of both the viral culture and specific antibodies in the serum of the patient.

[Experiences with immunization against orthopox viruses of humans and animals using vaccine strain MVA]. / Erfahrungen bei der Schutzimpfung gegen Orthopocken von Mensch und Tier mit dem Impfstamm MVA.

Immunizations against orthopox virus infections require a replicating, but safe vaccinia virus. The strain MVA is well suited concerning this matter. Human beings and animals can be vaccinated without any risk. The virus propagated in cell culture is non-virulent and lost its contagiosity. Multiplication in vaccinated men and animals is limited and excretion does not happen. As known for other attenuated virus strains, there must be a minimal effective virus concentration in the vaccine, which is 10(7.5) TCID50 per ml for MVA. To achieve a solid basic immunity which endures for a minimal of one year, two parenteral applications of MVA at intervals of at least 3 weeks are necessary.

[Congenital "ectromelia" in fur-bearing animals caused by Orthopoxvirus muris]. / Kongenitale "Ektromelie" bei Pelztieren durch Orthopoxvirus muris.

Orthopox virus infection is endemic in farms with fur-bearing animals in the Czech Republic (Bohemia and Moravia). This disease is called ectromelia of silver foxes and minks. The infection is congenitally transmitted and manifests itself in reproductive disorders, stillbirth or birth of sick neonates. Adult animals are usually free of clinical symptoms. The infective agent was isolated from recent outbreaks and was identified as a mouse pox virus (Orthopoxvirus muris) by its cultural and immunological characteristics. The significance of this pox virus infection, hitherto not described in Western Europe, is discussed.

Papovavirus-induced trichogenous tumours in Syrian hamsters (Mesocricetus auratus).

Tumorous, virus-induced skin lesions in two golden hamsters (Mesocricetus auratus) were characterized macroscopically and by means of light- and electron-microscopy. Evidence of a virus was demonstrated in the ultra-thin sections and by the negative staining method. The morphological findings confirm the assumption that infections with papoviruses--probably of the polyomavirus genus--were involved.

Investigation of living cells in the nanometer regime with the scanning force microscope.

Membrane structures of different types of cells are imaged in the nanometer regime by scanning force microscopy (SFM). The images are compared to those obtained with a scanning electron microscope (SEM). The SFM imaging can be done on the outer cell membrane under conditions that keep the cells alive in aqueous solutions. This opens up the possibility of observing the kinematics of the structures that determine the interaction of a cell with its environment. Therefore, STM observations, together with information obtained with the electron microscope, open up new ways of studying the development of biological structures. With the currently possible resolution, the SFM gives access to processes such as antibody binding or endo- and exocytosis, including processes correlated to the infection of cells by viruses.

[Catpox in Germany]. / Katzenpocken in Deutschland.

Since the initial detection of pox in domestic cats in Germany 1988, fourteen further cases have been confirmed and the infective agent (a cowpox-like virus) identified. The disease was not recognized in the field and was detected only by coincidence during a laboratory investigation. Cats become sick between June and November in different regions of the country. Current epidemiological and infectiological findings are discussed. Of special interest to veterinarians and physicians alike is the role of catpox as a potential human pathogen.

Structural and functional analysis of orthopoxvirus epitopes with neutralizing monoclonal antibodies.

Neutralizing monoclonal antibodies (MAbs) were produced in BALB/c mice immunized with live modified vaccinia virus Ankara or infected with sublethal doses of the neurovirulent vaccinia virus strain Munich 1. The immunization scheme proved to be important for obtaining MAbs of different specificity. The MAbs could be classified into three epitope groups (1 A, 1 B and 2). Immunogold electron microscopy demonstrated that the epitopes were localized on the virus surface. In immunoblotting, MAbs were reactive with polypeptides of 14K, 16K and 30K. Purified MAbs binding to the epitopes 1 A and 2 showed a 50% reduction of 100 p.f.u./0.05 ml vaccinia virus M1 with respectively 3.9 and 5.9 ng of immunoglobulin/0.05 ml. MAbs binding to the epitope 1 B neutralized the virus at a concentration of 250 ng/0.05 ml. In intraperitoneal challenge experiments, MAbs binding to the epitopes 1 A and 2 protected mice against 4 LD50 of vaccinia virus M1, but not against local lesions by subcutaneous application. MAbs against epitope 1 B had no protective effect in vivo. The three epitopes were present in 14 of 16 orthopoxviruses tested but with quantitative differences. Maximal binding (Vmax) and the antibody concentration at half-maximal binding (Km) which were calculated as for Michaelis-Menten kinetics from regression analysis of the ELISA data and the MAb concentration giving 50% plaque reduction were the basis for the evaluation. In monkey-pox virus Kopenhagen the epitopes 1 A and 1 B were absent. MAbs binding to epitope 2 reacted just as well as with vaccinia viruses. Ectromelia virus lacked all the epitopes.

Camel papillomatosis in Somalia.

Outbreaks of papillomatosis in camels (Camelus dromedarius) were detected for the first time in Somalia. Electron microscopic investigations revealed typical papillomavirions in skin lesions. Histopathological sections showed alterations which are regarded as pathognomonic for warts. The presumptive diagnosis of the skin disease was contagious ecthyma, as this infection was found simultaneously in some affected herds with symptoms similar to those of papillomatosis.

Establishment of an ELISA for the detection of orthopox viruses based on neutralizing monoclonal and polyclonal antibodies.

Various combinations of polyclonal and neutralizing monoclonal antibodies (MAbs) of distinct specificity were evaluated as capture or detecting antibodies in an orthopox virus antigen ELISA. Acceptable results were achieved in an assay based on polyclonal antibodies. A 10 times higher sensitivity, however, was obtained using a combination of one monoclonal catching antibody reactive with viral envelope epitopes and polyclonal detection antibodies. This configuration proved to be superior in sensitivity to all others. Specificity was confirmed with 5 vaccinia virus strains (including one recombinant virus) and 8 species of orthopox viruses. Monkeypox and mousepox virus reacted exclusively in the polyclonal assay due to a lack of the specific epitope for the monoclonal antibody. The detection limit compared to the infectivity titer amounted to 10(3)-10(4) in the monoclonal/polyclonal and to 10(4)-10(5) TCID50/0.1 ml in the polyclonal combination. The correlation between infectivity- and ELISA-titer was demonstrated by a study of the replication cycle of the rabbitpox virus Uetrecht in the permanent rabbit kidney cell line RK-13. With the established ELISAs vaccinia virus could also be detected in organ suspensions of lethally infected NMRI-mice, depending on the level of infectivity.

[The detection and identification of poxvirus in domestic cats]. / Nachweis und Identifizierung von Pockenvirus bei Hauskatzen.

Two cases in Southern Germany of pox in cats could be diagnosed virologically. A cowpox-like virus was isolated, its biological and serological characteristics defined. The source of infection could not be traced. The contraindication of treatment with corticosteroids and the pathogenicity of the orthopoxvirus demonstrated here for humans is pointed out.

[The possibilities and limits for virus inactivation in the household]. / Möglichkeiten und Grenzen der Virusinaktivierung im Haushalt.

Viruses of importance brought into the household or excreted by its members vary in their resistance and are decimated or even completely inactivated by natural environmental influences as well as by washing and cleaning. Steps to disinfect the household should be limited to specific indications and performed with virucidal compounds harmless to the environment. Naturally antiviral influences such as heat, UV-rays, sunshine, acids, the effectiveness of washing and cleaning procedures in the household and some selected strongly virucidal, but non-pollutant disinfectants are discussed.

[Testing the immunity to orthopoxviruses in the white mouse with vaccinia virus]. / Prüfung der Immunität gegen Orthopockenviren an der weissen Maus mit Vacciniavirus.

An infection model was developed, which allows the study of humoral and cellular immune response mechanisms induced by Orthopox viruses in mice. The optimal infection route for neurovirulent vaccinia virus strains was investigated and resulted in well-defined clinical symptoms in non-immunized susceptible mice. Signs of disease were taken as a basis for comparison. Challenge infections by intracutaneous (i.c.) and intraperitoneal (i.p.) application of vaccinia strain Munich 1 (M1) appeared to be most suited to testing immunities of different status in vivo. Mice passively immunized with an anti-vaccinia immune serum survived intraperitoneal challenge infection with 4LD50/mouse. After an intracutaneous challenge infection with 10(4) TCID50/animal, however, they were fully susceptible. Mice immunized with live vaccinia virus showed a solid immunity to both intracutaneous and intraperitoneal challenge.

[Cowpox virus infection in a young girl]. / Infektion eines Mädchens mit Kuhpockenvirus.

An genuine cowpox virus was isolated in a 6-year-old girl with a circumscribed skin lesion between the thumb and forefinger. In the beginning, the lesion was a proliferating skin change, which later became ulcerative with central hemorrhagic necrosis (umbilicated pock). Electron microscopy as well as histological, biological (cell and host range) and serological methods were used to characterize the virus. Cats and rodents are discussed as potential virus carriers. Voluntary vaccination against orthopox should be provided for persons at risk of infection.

[Effect of silver compounds on viruses in water]. / Uber die Wirkung von Silberverbindungen auf Viren in Wasser.

Two commercial substances, Certisil and Micropur, containing microbicidal silver compounds and destinated for decontamination as well as preservation of water were examined for virus inactivating activity against ECBO-, influenza A, Newcastle Disease, pseudorabies and vaccinia viruses in drinking water. In the recommended concentration as well as higher concentrated the lability of the viruses was increased by the silver compounds. This activity which cannot be designated as a true virucidal effect was clearly evident in the case of ECBO and vaccinia viruses, moderate on influenza and pseudorabies viruses but insignificant on Newcastle disease virus. Two combined silver compounds, Certisil-Combina and Sanosil, each containing an immediate microbicidal part besides silver differed in their antiviral activity. The chlorine separating part of Certisil-Combina didn't cause an improvement or acceleration of the destabilizing effect on viruses compared to the pure silver compound, while the hydrogen peroxide part of Sanosil led to a better and continuing inactivating influence on the viruses which were merely reduced in infectivity by 99,9% within one day. Only in the case of evident or suspected contamination of water reservoirs by viruses the addition of a combined silver drug with oxygen separating part seems to be useful.