[A seroepidemiologic and virological study of the presence of arboviruses in Moldavia in 1961-1982]. / Studiul seroepidemiologic si virologic al prezentei unor arbovirusuri pe teritoriul Moldovei, 1961-1982.

ABSTRACT

In Romania, St. Draganescu et al., Miszkolczy et al., based on clinical and epidemiological observations, affirmed the possible presence of "tick-borne encephalitis (TBE)". However, critical retrospective evaluation of certain others' papers published through 1958-1971 reveal some uncommon features. By way of example a very high incidence of CF- and HI-antibodies in acute and chronic CNS illnesses as well as in general population; replication in nucleus and maturation in mitochondria of a strain of "TBE virus" isolated from a patient CSF; isolation of "group B arbovirus" from Ixodes persulcatus on Romanian territory. As known, this tick was not identified in Romania, "no tick-borne Flavivirus isolated outside the U.S.S.R. proved to be a strain of RSSE virus" and "no arbovirus (Alpha- and Flavivirus or Bunyavirus) was ever detected in nucleus". Based on the HI reaction with West Nile (WN) virus, strain Egypt 101, human, domestic and wild vertebrates sera, treated with acetone for removal of nonspecific inhibitors, were tested as part of a control study, in Moldavia in 1961. WN virus was selected for its capacity to crossreact in the HI test with many members of the family Flaviviridae, genus Flavivirus (formerly Group B arboviruses), including the agents of Central European encephalitis. In order to avoid the interference of nonspecific inhibitors, a new single radial haemolysis test for the assay of antibodies to haemagglutinating arboviruses was calibrated in 1979. The seroepidemiological study performed on all 19.853 sera (10.698 human, 6.452 domestic mammals, 2.477 wild small rodents and 226 migrating aquatic birds) pointed out a very low circulation of Flaviviruses in the investigated area. The attempts to isolate such viruses from Ixodes ricinus on suckling mice yielded a single strain of Kemerovo (genus Orbivirus) virus. The need of extending the study to other viruses transmitted by arthropods and rodents, and mainly on the haemorrhagic fever with renal syndrome, an illness already clinically identified in Moldavia, is emphasized. Final consideration of viability (specificity, sensitivity, accuracy and precision) of the tests used and the need for continuous quality control is also presented.