The evidence of circulation of some viruses in a great town of Romania during the first half of 1992.

Complex serological survey performed in the town B. during the first half of 1992 emphasized an active circulation of some respiratory viruses, especially of parainfluenza type 3 and 1, influenza subtypes A(H3N2) and A(H1N1), adeno and syncytial respiratory as well as of Mycoplasma pneumoniae. Less important was the frequence of antibodies against Chlamydia psittaci, East equine, West Nile and tick-borne encephalitis as well as parainfluenza type 2 and influenza type B viruses.

Data on the experimental transmission in the guinea pig of some human chronic degenerative diseases: Creutzfeldt-Jakob and Alzheimer's disease.

Guinea pigs were inoculated intracerebrally with cerebrospinal fluid (CSF) and/or brain tissue suspensions from 8 patients with Creutzfeldt-Jakob disease (CJD) and with CSF from 2 patients with Alzheimer's disease. After a very long incubation period (over 360-420 days) a serially transmissible experimental disease appeared in the guinea pigs inoculated with CSF from 5 of the CJD patients, with either CSF or brain suspension from one CJD patient and with brain suspensions from the remaining 2 CJD patients. The disease was characterized by tremor, ataxia, convulsions and morphopathological lesions, such as spongiform change, glial hyperplasia and vacuolation of the neurons. Inoculations of CSF from the two Alzheimer's disease cases gave negative results.

Serological investigations on the presence of antibodies to tick-borne encephalitis virus in domestic animals and birds and in humans.

The presence of hemagglutination-inhibiting antibodies to tick-borne encephalitis virus was investigated in serum samples from domestic animals (217 from swine, 214 from cattle, 179 from goats and 161 from sheep) and birds (214 from geese and 171 from ducks), as well as from 511 apparently healthy subjects of a biotope with particular ornithological and entomological characteristics. The proportion of positive reactions was very low in cattle (1.4%) and goats (1.1%) and more elevated in humans (11.3%). All the serum samples from swine, sheep, geese and ducks gave negative serological results.

Laboratory investigations in Balkan endemic nephropathy.

Serum samples from three patients with Balkan endemic nephropathy (BEN) were inoculated intraperitoneally to guinea pigs. After a very long incubation period (58-273 days) the animals developed an experimental disease characterized by apathy, tremor, convulsions and a fatal outcome. The disease could be serially propagated, the same clinical symptoms being recorded at each of the three passages performed. The morphological features of the experimental disease included glomerular and tubular lesions and the presence of interstitial fibrous and lymphoplasmocytic reactions. Different hypotheses on the etiology of BEN are discussed.

Creutzfeldt-Jakob disease: experimental transmission in the guinea pig.

An experimental disease could be serially propagated in the guinea pig by intracerebral inoculation of cerebrospinal fluid or brain suspensions from 8 patients with Creutzfeldt-Jakob disease (CJD). The disease, characterized by tremor, ataxia and convulsions, appeared after a long incubation period (370-420 days). Microscopic lesions and electron optic features were similar to those described in human CJD and in experimental CJD in the chimpanzee.

Serological investigations concerning the presence of antibodies to arboviruses in wild birds.

Serum samples from 8 species of migratory birds (Ardea cinerea, Plegadis falcinellus, Anas querquedula, Anser albifrons, Gavia arctica, Fulica atra, Phalacrocorax carbo, Larus minutus) were tested for the presence of hemagglutination-inhibiting (HAI) antibodies to alpha- and flaviviruses. HAI antibodies to alphaviruses (eastern equine encephalitis, western equine encephalitis, Sindbis, Middelburg, Semliki Forest) ranging in titer from 1/20 to 1/160 were detected in 46 serum samples; 22 serum samples gave positive reactions (titers: 1/20 - 1/80) to flaviviruses (West Nile, Ntaya). In certain cases antibodies to several antigens could be made evident in the same serum sample. The serological results are discussed in the light of the birds' migration pattern.

Further data on experimental Creutzfeldt--Jakob disease (spongiform encephalopathy) in the guinea pig.

Intracerebral inoculation to guinea pigs of cerebrospinal fluid or brain suspensions from 6 patients with Creutzfeldt--Jakob disease was followed in 4 cases by the appearance, after a long incubation period, of a serially transmissible experimental disease. The disease was characterized by tremor, discrete ataxia and convulsions and led to a fatal outcome within several days. Microscopic lesions in the brain of guinea pigs with the experimental disease consisted in glial proliferation, spongiform change and vacuolation of neuron cytoplasm. Electron microscopy proved that the vacuoles were situated in the endoplasmic reticulum and in the cytoplasmic processes.

Endemic Balkan nephropathy, a slow virus disease?

Serum samples from patients with endemic Balkan nephropathy (EBN) were inoculated intraperitoneally to four species of laboratory animals. It was only in the guinea pig that a serially transmissible experimental disease occurred, after a long incubation period. The morphopathological features in the guinea pig were similar to those encountered in the terminal phase of human EBN. The hypothesis that EBN might be a slow virus disease is discussed.

Laboratory data on the experimental transmission of Creutzfeldt--Jakob disease in the guinea pig.

Cerebrospinal fluid samples collected from 3 patients with Creutzfeldt-Jakob disease were inoculated intracerebrally to guinea pigs. After an incubation period of 4-14 months the animals developed a serially transmissible disease, characterized by loss of appetite, loss of weight, difficulty in movement, myoclonic convulsions and a fatal outcome within several days. The microscopic lesions caused by the experimental disease consisted in glial proliferation, spongiform change and vacuolation of the cytoplasm of proximal dendritic regions.

Electron optic study of the lesions induced by Creutzfeldt--Jakob disease virus in the guinea pig.

An electron microscopic study was performed in brain sections from guinea pigs with experimental Creutzfeldt-Jakob disease. Vacuolation of the neuropil, dilatations of the endoplasmic reticulum and lipid accumulations were observed in the grey matter, while the white matter exhibited intramyelinic vacuoles.

Serological investigations into the presence of antibodies to Yaba 1--Lednice 110 virus in Romania.

Sera collected from several migratory birds of the Danube Delta, from humans and domestic birds and animals of three Romanian counties were tested by hemagglutination-inhibition reaction for the presence of antibodies to Yaba 1--Lednice 110 virus. Antibodies could be detected in only 8 of the 14 species of migratory birds included in the study, especially in wild geese and ducks.

Coxsackie B2 virus isolation from a case of postnatal meningoencephalitis.

Clinical, morphopathological and virological data are presented with reference to a fatal case of postnatal meningoencephalitis from which a Coxsackie B2 virus strain could be isolated. The lesions consisted mainly in a meningeal inflammatory process with fibrocytes, a few lymphocytes and rare polynuclear cells. Marked stasis, diffuse and perivascular infiltrates with lymphcoytes and polynuclear cells, as well as lympho-glial nodules were observed in the brain parenchyma.

Investigations on the presence of antibodies to Tahyna virus in Romania.

Serological results are presented of the HAI reaction to Tahyna virus performed in 1,749 apparently healthy subjects from two countries of Romania where Culex pipiens mosquitoes occur frequently, in 113 febrile patients (some of which exhibited signs of interstitial pneumonia) and in 675 domestic animals (swine, cattle, sheep and goats).

Investigations on the presence of antibodies to alphaviruses, flaviviruses, Bunyavirus and Kemerovo virus in humans and some domestic animals.

The presence of antibodies to some alphaviruses, flaviviruses, bunyaviruses and orbiviruses was studied in the sera from humans and domestic animals of biotopes "C" and "T" in the south-east of Romania. Specific antibodies were found in humans to 3 alphaviruses (eastern equine encephalitis, western equine encephalitis and Sindbis), in a very low proportion, and to 3 flaviviruses (tickborne encephalitis, West Nile and Ntaya), at a much higher percentage. Very low percentages of antibodies to Bunyavirus and Kemerovo virus were also detected. The proportion of antibodies to flaviruses (tick-borne encephalitis, West Nile and Ntaya) detected in domestic animals (sheep, cattle and swine) is much lower than that found in humans of the same biotope ("T").

Detection of antibodies to alphaviruses and flaviviruses in some migratory birds of the Danube Delta.

Data are reported on the presence of antibodies to some group A(alphavirus) B(flavivirus) arboviruses in 8 species of migratory birds (Ardea cinerea, Plegadis falcinellus, Anas querquedula, Anser albifrons, Gavia arctica, Fulica atra, Larus minutes and and Phalacrocorax corbo) of the Danube Delta.