Romanian journal of virology最新文献

In this work are reported the results of the researches performed by the authors more than a decade ago, aimed at assessing the clinical benefit of the introduction of the drug "Zovirax" in the treatment of recurrent herpetic infections with genital or ocular location. The results of the treatment carried out on a restricted group of patients were positive both in cases of genital herpes and of herpetic keratitis. The clinical benefit consisted in the reduction of the mean duration of the disease, in the shortening of the period of the infective virus elimination from the lesion, as well as in the decrease of the intensity and duration of the clinical symptomatology as a whole. With respect to these clinical parameters, the observations of the authors performed on a low number of cases are consistent with the data obtained by other authors in the framework of more extensive studies. The renewed discussion of these clinical and laboratory observations carried out by the authors during the first years after the introduction in our country of this drug in the therapeutic arsenal of herpetic infections is aimed at establishing a landmark for the comparison with more recent results of similar studies, starting from the idea of the opportunity of assessing periodically the sensitivity of herpes simplex virus strains, circulating among the autochthonous population, to the inhibitory action of some antiviral drugs. In other words, the in vitro testing of the susceptibility of these strains to the chemotherapeutic agents in current use is predictive for the efficacy degree of these drugs in the treatment of some forms of herpetic infections. This evaluation represents at the same time, undoubtedly, a useful epidemiological surveillance means of the circulation of human herpes viruses among the population. We refer especially to the risk of appearance of pharmacoresistant mutants, a risk possible under the conditions of the increased access of patients to the antiviral chemotherapeutic medication, which implicitly augments the probability of a fortuitous administration of treatments insufficient as regards the dose or the duration. In this work there are also shown the results regarding some experimental aspects related to the immune control mechanisms of the herpetic infection, which may complement the chemotherapeutic action. Under the treatment with acycloguanosine the synthesis of herpetic antigens is kept at a level sufficient for the circulating antibody synthesis induction and the HSV infected cells treated with the drug are recognized and lysed by effectors of the cell-mediated immune response of the host. Hence, it may be asserted that, in some clinical cases of recurrent herpes with frequent episodes, it is useful to perform immunostimulating treatments, able to potentiate the cell-mediated immune mechanisms possibly involved in the limitation of the herpetic infection at the peripheral level and of its spreading in the central nervous syst

The inactivated vaccines prepared with parainfluenza viruses type 1 and type 3, administered to mice by nasal or oral route, either as monovalent preparations in succession or as bivalent associated preparations according to the experimental models used, imparted a significant protection against the infection with the homologous active viruses. The routes of administration of vaccines, nasal and oral, which make equal demands upon the immune secretory serum and cell system, as well as the alternative of inactivated preparations for active virus vaccines are discussed.

The main aims of the present study were to evaluate the transfusional risk concerning HBV and HBV-HDV infections and the prevalence of viral serum markers in apparently healthy persons. Our study included 226 apparently healthy persons in whom we performed tests for HBV (HBsAg, HBsAb, HBcAb) and HDV (Delta Ab) serum markers, using the enzyme immunoassay. In 45 (19.9%) subjects we detected serum HBsAg. In the 181 HBsAg-negative apparently healthy persons, our tests detected HBsAb (31 subjects) and HBcAb (49 subjects). Thus, 125 (55.3%) of the 226 apparently healthy persons had serologic evidence of past HBV infections. Delta Ab were detected in 3 (1.3%) of our subjects. We must state that one of the three Delta Ab-positive apparently healthy persons tested negative for both HBsAg and HBcAb.

In October 1995, The Ministry of Health has initiated the national immunization program of newborns against hepatitis B. Owing to the frequency of asymptomatic Hepatitis B clinical forms in children, as well as the deficiencies in the surveillance system, the assessment of the vaccination efficacy can be performed objectively only by the detection of the prevalence of anti HBs antibodies in children to whom the complete three doses of immunization schedule have been administered (at 0, 2 and 6 months of age). We report in this study the results of a seroprevalence research carried out on a group of 272 children from orphanages who have been vaccinated. A protective anti HBs titer (> 10 mIU) was recorded only in 66.3% of cases; other 10 samples contained antibodies at a titer lower than the protective level. In the 80 children without seroconversion the presence of anti HBc antibodies (marker for the natural infection) was investigated. 30% of the seronegative children have anti HBc antibodies from which 54.2% have also HbsAg. Significant differences were recorded in the seroconversion level and in the geometric mean of titers between the various units in which sera were collected. In four orphanages (district Arad, Jassy, Sibiu and Teleorman) the seroconversion exceeded 90%, in 5 orphanages it was over 80% and in the others it ranged from 30% to 70%. The lowest seroconversions were recorded in the orphanages in Bucharest, Botoşani, Galaţi and Olt. The possible causes of the low immunogenicity are analyzed: non-vaccination or incomplete vaccination; low immunoreactivity of children, many of whom are premature; high HbsAg carriage rate among the mother's etc. Although the evolution of the post vaccinal seroconversion is not a routine practice in the appraisement of Hepatitis B vaccine immunogenicity, our results require the extension of the study in order to adopt the most effective vaccinal strategy.

A serosurvey of Hepatitis B infection markers was conducted in two orphanages that adhered to Hepatitis B vaccination policy. In spite of comparable sizes (80-90 children per facility), housing conditions and infection control practices, the level of HbsAg endemicity was different in each unit in direct relation with the mean age of the children. The prevalence of HbsAg carriers and the interval spent in collectivity strongly affect the seroconversion rate after HB vaccination. Other elements that can explain the low seroconversion rate were: the proportion on fully vaccinated children, the number of vaccine administered doses and the delayed age at which childhood immunization schedule was initiated. In order to increase the protective antibody response, booster doses were administered to a limited number of nonseroconvertors or to children with a nonprotective level of anti-HBs antibody (< 10 UI). This intervention provides evidence of prompt rising in antibody titers, comparable with titers found in children with wild infection.

17 samples of total cell DNA isolated from cervical smears from women suspected of condyloma or papilloma were analysed by PCR with appropriate primers, in order to establish the presence of viral DNAs (HPV and/or HCMV). HPV DNA was found in seven cases, and so was for HCMV DNA. Only in three cases a coinfection was present. The RFLP allowed to specify the involvement of HPV6 in 3 cases suspected of condyloma and in one suspected of papilloma; the other three HPV positive samples had another genotype, which we could not determine by the methods used.

The prevalence of human immunodeficiency virus types 1 and 2 in rural areas of Nigeria was estimated using 1089 sera collected in 18 locations from 1992 to early 1994. The sera were tested with Enzyme linked Immunosorbent Assay (ELISA) and confirmed by Western Immunoblotting technique. Overall, 13 (1.2%) of the 1089 sera were positive for antibodies to HIV-1 and HIV-2. Prevalence of 0.6% and 0.8% were obtained for HIV-1 and HIV-2 respectively. The highest prevalence of HIV-1 and HIV-2 (50.0%) were found in Zuhlrrua and Umubuzu. A seroprevalence of 1.2% was obtained for both male and female groups tested. The highest prevalence of HIV was found among individuals 30-39 years age group. An overall increase in prevalence of HIV-1 and HIV-2 infection was obtained over the three years during which samples were collected for this study (0.7% in 1992, 1.0% in 1992 and 3.4% in 1994). In addition, two sera were positive for both HIV-1 and HIV-2. The detection of antibodies to HIV-1 and HIV-2 in the rural areas where blood samples were collected for this study shows that both viruses are widespread in the rural communities of Nigeria.

The UV-A and PUV-A treatments were applied on the Sendai virus and the changes of the biological properties of HN surface glycoprotein were monitorized. Under the UV-A action the HA and NA activities are inhibited in a dose-correlated way. When the irradiation was done in the presence of a photoreagent (8-MOP) the HA activity remained unchanged, but the enzymic activity was affected. The possible mechanisms of these inhibition processes are discussed.

Hepatitis C is and will be a major public health concern. Confirmed infections were reported from all Romanian counties but important differences between regions raise several explanations. Differences may reflect the different levels of testing, the performances of laboratories in confirming initially reactive samples or the risk factors higher prevalence. We have suggested that the prevalence of anti HCV infections can be a surrogate marker for the quality of parenteral medical or paramedical interventions. Present report identified additional problems in the surveillance of HCV infection in children. We screened 1787 samples from children hosted in orphanages (children under three years old) or in preschool children institutions (between 3-7 years old). We detected 31 repeatedly reactive samples with two EIA screening kits but confirmed only 8 in WB anti HCV. Four confirmed samples come from children under four months old suggesting maternally transmitted antibodies. In highly endemic area, many infants have maternally derived antibodies and the wane of reactivity comes with age above 12 months. Therefore, the prevalence of anti HCV antibody in infants reflects the prevalence in adult population. Confirmatory tests are mandatory for the serosurvey in children. More frequent than adults samples, children EIA reactive samples give indeterminate or negative Western Blot profiles. Only the viral load evaluation can confirm those samples as false positive or, on the contrary, samples at the beginning of seroconversion.