An outbreak of respiratory disease due to a type 5 adenovirus identified as genome type 5a

A cluster of adenovirus type 5-caused acute respiratory diseases was observed in Prague in the autumn-winter season of 1978/79. An analysis of viral DNA by sequence-specific restriction enzymes in two out of 39 isolates revealed that these isolates, identical to each other, were clearly distinct from adenovirus type 5 prototype strain. The designation "adenovirus genome type 5a" is suggested for these isolates.

Enhancement and inhibition of CELO virus pathogenicity in quail by avian adenovirus-associated virus

Dual infection of 12 day-old quail (Colinus virginianus) with 10(6) plaque forming units of CELO virus and low doses of avian adeno-associated virus (A-AV), resulted in significant enhancement of CELO virus-induced mortality, whereas dual infections with high doses of A-AV resulted in a delay in mortality. A-AV induced enhancement and inhibition of CELO virus pathogenicity could be blocked by the addition of A-AV antiserum prior to infection.

The molecular weight of the egg drop syndrome (EDS) avian adenovirus (strain B8/78) DNA estimated by digestion with restriction endonuclease enzyme R X EcoRI. Brief report

The restriction endonuclease R X EcoRI cleaved at two sites of the EDS adenovirus (strain B8/78) DNA generating 3 fragments with molecular weights of 13.5 X 10(6), 5.0 X 10(6) and 4.4 X 10(6) daltons, respectively. The estimated molecular weight of the whole undigested DNA is about 22.9 X 10(6) daltons.

A new intermediate adenovirus type causing conjunctivitis

A new adenovirus of intermediate type involved in conjunctivitis has been isolated. The virus is related to adenovirus types 13 and 30 by neutralization and to types 10 and 19 by hemagglutination inhibition. Since 1976 the agent has been causing sporadic cases of conjunctivitis in different parts of The Netherlands. Twenty-three cases have been established by virus isolation from the affected eyes. The symptoms of the disease range from epidemic keratoconjunctivitis to pharyngoconjunctival fever. Also, adenovirus type 13-30/10-19 has been isolated from the cervix uteri of four women in a series of 1,477 women with cervicitis.

Egg transmission of avian adenovirus-associated virus and CELO virus during a naturally occurring infection

Both avian adenovirus-associated virus (A-AV) and CELO virus were isolated from the embryonating eggs of 25-week-old black sex-linked hens during a naturally occurring infection. In the first 7 days of egg collection, A-AV was isolated from 10 of 43 (23.2%) embryonating eggs, and CELO virus was isolated from 8 of 43 (18.6%) embryonating eggs. Both viruses were isolated from six eggs. In the next 16 days of egg collection, A-AV and CELO virus were coisolated from 1 of 127 (0.8%) eggs; all other samples were negative for both viruses. All six hens transmitting A-AV to eggs and 5 of 6 hens transmitting CELO virus showed seroconversions (fourfold increase in antibody concentrations). Viruses were not isolated from eggs after the hens showed a fourfold increase in antibody concentrations.

Egg drop syndrome, 1976 (EDS'76)

A description is given of the new clinical condition in fowl now known as EDS 76. This is characterised by the production of thin shelled, soft shelled and shell less eggs by apparently healthy birds. The effects on egg production are seen around 30 weeks of age and are seen either as an apparent fall in production or as a failure to obtain predicted production targets. Haemagglutinating viruses have been isolated from these flocks and evidence from experimental and field investigations suggest these are the aetiological agents of EDS 76. Biochemical and biological studies indicate that these viruses are duck adenoviruses. Epidemiological evidence suggests the virus is egg transmitted and that lateral spread between flocks is not important if care is taken whilst bleeding and vaccinating flocks. It is postulated that this virus may have been introduced into flocks by the use of a contaminated vaccine. Control in Northern Ireland has been by eradication of the virus from the basic breeding stock.

Enteric adenoviruses: detection, replication, and significance

Adenoviruses can be demonstrated readily in the stools of pediatric gastroenteritis patients by electron microscopy or counterimmunoelectrophoresis, but in 45% of these cases the virus will not grow in cell culture. Indirect immunofluorescence microscopy can be used to detect nongrowing strains of adenovirus; these strains have a unique single-cell fluorescence pattern. Hematoxylin and eosin staining reveals adenovirus-like inclusion bodies in the same distribution as fluorescent cells. Pretreatment of nongrowing adenovirus with convalescent-phase patient serum neutralized its ability to infect the cell culture and produce fluorescent cells. Indirect immunofluorescence microscopy compared favorably with electron microscopy in demonstrating virus in the stools of patients.

Adenovirus types 8 and 19 infection of rabbit corneal organ cultures

Adenovirus types 8 and 19 are responsible for a large number of cases of acute follicular conjunctivitis, mainly in the form of epidemic keratoconjunctivitis (EKC). This study successfully demonstrates the establishment of adenovirus infection in rabbit corneal organ cultures. Normal rabbit corneas were maintained in culture without significant morphologic alterations for up to 7 weeks. Adenovirus types 8 and 19 replication in rabbit corneas was demonstrated by viral growth curves and subpassage studies. Intracellular localization of adenoviral antigens was confirmed with immunofluorescent techniques. The characteristic cytopathic effects of adenoviral infection were observed with the use of various histochemical stains. Thus an in vitro corneal organ culture model was established for the study of the pathogenesis of corneal lesions in adenovirus EKC.

Experimental infection of broiler and Leghorn chickens with virulent and avirulent isolates of hemorrhagic enteritis virus

The effects of virulent and avirulent isolates of hemorrhagic enteritis virus were studied in Leghorn and broiler chickens. The viruses caused subclinical infections in both strains of birds. The avirulent isolate produced enlarged spleens, inclusion bodies, and antibody in all inoculated Leghorns. In broilers the avirulent virus produced infection in only half of the inoculated birds. Inclusion bodies were widely dispersed in the spleens of both types of birds. The virulent virus produced infection in all inoculated birds of both strains. Inclusion bodies were numerous in the spleens of Leghorn birds and were widely scattered in the spleens of broilers.

Three serologic types of adenovirus infections of owl monkeys

From a colony of 131 owl monkeys, adenovirus was isolated 68 times from 433 oropharyngeal and rectal swab sample pairs collected over a 2-year period. A total of 63 of 68 adenovirus isolates were grouped by neutralization into 1 of 3 types designated owl monkey adenovirus types (OMAV Ty) I, II, and III. The OMAV Ty I and Ty II were identified by neutralization with antiserum to squirrel monkey adenovirus type I and adenovirus SV-11, respectively. The OMAV Ty III was partially neutralized by antiserum to OMAV Ty II. The OMAV Ty I was isolated from 8 of 30 newly imported owl monkeys within 3 weeks of arrival. A total of 13 of 26 owl monkeys had a fourfold or greater rise in serum-neutralization (SN) titer with 25 of 27 developing SN titers of greater than or equal to 1:80. A total of 40 of 87 other owl monkeys in the colony had SN titers of greater than or equal to 1:5. The OMAV Ty II was isolated from 51 (12%) of 433 swab samples pairs. Virus was isolated from 26 owl monkeys with 13 having persistent infections. Viral isolations spanned a 10- to 17-month period for five of these owl monkeys. In 114 owl monkeys, 101 (86%) had SN titers to OMAV Ty II greater than or equal to 1:20. The OMAV Ty III was isolated from three owl monkeys. Of 114 owl monkeys, 93 (82%) had SN titers to OMAV Ty III of greater than or equal to 1:20. Although the distribution of SN titers were similar for OMAV Ty II and Ty III, 42 (37%) of 114 owl monkeys had eightfold or greater differences in SN titers between OMAV Ty II and Ty III.

Identification of an enteric adenovirus by immunoelectroosmophoresis (IEOP) technique

Infantile gastroenteritis can be caused by several of the established adenovirus types. There are also adenoviruses that defy in vitro cultivation but have been recognized by electron microscopy. One isolate of these viruses, which have been designated enteric adenoviruses, has been characterized. Several of the established adenovirus types are shed in stools over long periods. The conditions for direct identification of enteric adenoviruses by immunoelectroosmophoresis (IEOP) have therefore been evaluated. Application of this technique requires highly specific reagents. However, a high prevalence of antibodies in rabbits reacting with human rotavirus was noted. For these reasons, immunoadsorbent purified antibodies were prepared. Because of the difficulty in purifying immunogens from stools, an immunization procedure characterized by immunization with adenovirus subunits bound to affinity chromatography beads was elaborated. An identification procedure for adenoviruses causing infantile gastroenteritis based a) on IEOP using group-specific and monospecific antibodies and b) on the determination of the in vitro cultivatability is suggested.

Isolation and identification of a bovine adenovirus type 3 with an adenovirus-associated virus

A bovine adenovirus with agglutinating activity was isolated from feedlot calves and classified as serotype 3. The agglutinating activity was shown to be the property of an adenovirus-associated virus (AAV). The AAV was isolated from the bovine adenovirus by isopycnic centrifugation in CsCl; the AAV had a density of 1.4 g/cm2. This AAV is serologically related to bovine AAV-TR-15, but is distinct from bovine parvovirus-1 and primate AAV types 1 to 4, using counterimmunoelectrophoresis and hemagglutination-inhibition.

Isolation of bovine adenovirus type 7 from calves with pneumonia and enteritis

Bovine adenovirus type 7 was isolated from a 10-month-old calf with fibrinopurulent pneumonia and from 2 newborn calves with pneumoenteritis. The viruses were isolated on calf lung and adrenal gland cell cultures and were identified as serotype 7 by immunoelectron microscopy and serum-neutralization tests.

General features of persistent virus infections

Persistent virus infections are discussed from the virus point of view in terms of the bodily sites in which the infection persists. Glands and body surfaces are thought to be significant because they give the virus protection at the topographical level from immune forces, and because they are appropriate sites for the shedding of virus to the exterior. Germ cells are relevant sites because infection can thus be transmitted vertically from generation to generation in the host. The central nervous system, however, is generally a 'dead end' from which there is no shedding to the exterior. Persistance in blood may be relevant when continued arthropod transmission becomes possible. Most persistent viruses infect lymphoreticular tissues, and this is interpreted by suggesting that it results in an impaired immune response to the infecting virus, which in turn favours persistence. It is suggested that the biological function of virus transformation and the integration of viral into host cell DNA is that it enables the infection to persist in the host and undergo reactivation. Papovaviruses, adenoviruses and oncornaviruses are considered from this point of view.