Evaluation of clinical specimens for influenza A virus positivity using various diagnostic methods.

The diagnostic method for Influenza A virus, utilizing the SERION ELISA Antigen kit (SERION EIA), if results were evaluated according to the manufacturer's instructions, has repeatedly failed to detect a great number of clinical samples positive by virus isolation and RT-PCR. Therefore we compared the SERION EIA with the one-step 44/107L-Px immunocapture enzyme immunoassay (44/107L-Px EIA), developed in our laboratory (Tkácová and Varecková, J. Virol. Methods 60, 65-71, 1996). Seventy-three clinical specimens, of which 65 were positive by virus isolation (used as reference method), were tested by both EIAs. By the SERION EIA, out of the 65 reference-positive samples only 8 (12%) were positive, 5 (8%) were ambiguous, and 52 (80%) were negative, which corresponded to the sensitivity of 12%. On the contrary, the sensitivity of the 44/107L-Px EIA was 74%. However, the calculation of cut-off values for the evaluation of positivity of clinical specimens in these two assays were not the same. If the evaluation procedure used for the 44/107L-Px EIA was applied to the SERION EIA, the sensitivity and the specificity of both EIAs became comparable, namely 71% and 100% for the SERION EIA and 74% and 100% for the 44/107L-Px EIA, respectively. From these results it follows that not the detection ability of the SERION EIA, but the evaluation procedure recommended by its manufacturer led to a loss of large number of positive specimens.

[Influenza and influenza-like acute respiratory diseases in Slovakia in the 1999-2000 season]. / Chrípka a chrípke podobné akútne respiracné ochorenia na Slovensku v sezóne 1999-2000.

BACKGROUND: Acute respiratory infections (ARI) represent the most frequent cause of morbidity. Their epidemic outbreaks become a severe problem not only in healthcare, but also in economical and social spheres. OBJECTIVE: Presentation of epidemiological and virologic characteristics of the 1999-2000 influenza season in Slovakia; their comparison with the same Influenza season in other European countries, as well as with the situation during the preceding season in Slovakia. METHODS: The epidemiological analysis of Influenza and influenza-like diseases is based on the duty of attending physicians to report the number of new cases, complications, cases of working inability due to disease, and death cases. The reports are required on a compulsory weekly basis, and the reported cases are structured into 4 age groups. The laboratory diagnosis is based on virus isolation, rapid detection of antigen and serological tests. RESULTS: The outbreak of Influenza spread through Slovakia during the period between the 4th and 8th calendar weeks with its peak appearing during the 6th calendar week, when its incidence reached 2821 cases/100,000. The age group mostly afflicted by morbidity during the entire investigated season were children at the age of 0-5, while during the outbreak, the highest morbidity was reported among school children at the age of 6-14. The epidemic broke out on the entire territory of the Slovak Republic at the same time. 5 death cases were reported. Complicated cases were reported in 6.1% of the diseased. 34.1% of the group at the age from 15 to 59 were reported to be unable to work due to disease. 25 isolates of influenza virus were obtained from 505 nasopharyngeal swabs. 2 strains were found to be atigenetically similar to the vaccine strain A(H3N2)/Sydney 5/97 and A(H3N2)/Moscow 10/99. Regarding ARI aetiology, influenza viruses were serologically confirmed in 1356 samples; out of which type A(H3N2) was confirmed in 930 cases, A(H1N1) in 143 cases, type B in 283 cases; adenoviruses were detected in 467 samples; RS viruses in 779 samples; and Mycoplasma pneumoniae in 859 samples. Mixed infection caused by two viruses was diagnosed in 27 cases. DISCUSSION: The outbreak which hit Slovakia in the 1999/2000 season was a part of the European epidemic wave. As to its extent, it was a mild epidemic outbreak. It was significantly low as to its incidence among children. During autumn months, ARI aetiology was dominated by M. pneumoniae, viruses of type A(H3N2) prevailed. CONCLUSION: The identification of strains isolated during the investigated season confirmed that strains of influenza virus similar to strain A(H3N2)/Sydney 5/97 which is contained within the vaccine which has been assessed for this season, circulated in Slovakia during the past two subsequent seasons. Similar experience was reported from the majority of European countries involved in the international WHO programme of influenza Surveillance. These facts explain the mild extent of the investigated epidemic outbreak. (Tab. 5, Fig. 7, Ref. 8.)

[Prenatal virus infections and orofacial clefts]. / Prenatálne vírusové infekcie a orofaciálne rázstepy.

A potential teratogenic activity of virus infections caused by the viruses of rubella, influenza, parotitis, hepatitis B, cytomegalovirus and the Epstein-Barr virus was investigated. Specific antibodies against these viruses were examined serologically in children with orofacial clefts and in their mothers and the results were compared with those obtained in control children and their mothers. Different micromethods were used in performing the examinations (ELISA, RIA, NIR, KFR, HIT). Evaluation of the results and their statistical processing supports the assumption that prenatal infection may have occurred in the series studied induced by the viruses of influenza, rubella, cytomegalovirus, and possibly also by the Epstein-Barr virus. No association with the viruses of parotitis and hepatitis B was established. (Tab. 5, Ref. 36.)

Transient increase of HBsAg levels following human IFN alpha treatment signalises the patient's response in chronic active hepatitis B.

Eleven patients in early stages of chronic active hepatitis B (CAH-B) were treated for weeks or months with a natural or recombinant human interferon alpha (Hu IFN alpha). Changes of serum levels of selected hepatitis B virus (HBV) markers were observed after Hu IFN alpha administration. Increase of HBsAg level accompanied by more or less simultaneous HBeAg level depression was the most interesting observation. These changes were well expressed in 5 reactive patients only; they usually ceased after withdrawal of IFN therapy. Reaction of the remaining 6 patients was either poor or not demonstrable. The possible mechanism for HBsAg/HBeAg serum level changes during the IFN therapy of CAH-B is discussed.

Immunological markers in patients with different forms of viral hepatitis B treated by "conventional" therapy or with HuIFN alpha.

Selected immunological, biochemical, and other viral hepatitis B (VH-B) markers were followed and analysed during "conventional" or human interferon alpha (HuIFN alpha) therapy of patients with different forms of VH-B. The immunological data obtained from "conventionally"-treated acute hepatitis B (AH-B), prolonged acute hepatitis B (AH-BP) or chronic active hepatitis B (CAH-B) patients disclosed differences unsatisfactory for comparison of the influence of HuIFN alpha therapy on changes of the immunological markers. More valuable data were obtained through continuous registration of the dynamics of selected blood markers. Partial effects on immunological parameters were seen after HuIFN alpha administration to 2 patients with developing CAH-B infection. Progression of the disease was markedly halted in these both patients after IFN treatment.

Dynamics of serum markers in the different course of hepatitis B virus (HBV) infection.

The presence of serum markers of hepatitis B virus (HBV) infection in different stage of illness has a specific pathogenic and diagnostic significance. Based on the frequency of the appearance of HBV markers in patients' sera at different stages of the illness, we attempted a grouping possibly helpful for differentiation, epidemiologic and prognostic evaluation of hepatitis. The significance for chronic disease development of the dynamics of HBV marker levels in the serum is discussed.

[Etiological and immunopathological markers in hepatitis B patients in the early convalescence stage during the development of chronic liver involvement]. / Etiologichekie i immunopatologicheskie markery u patsientov s gepatitom B na stadii rannei rekonvalestsentsii pri razvitii khronicheskogo porazhenie pechni.

Etio- and immunopathological markers in hepatitis B are analysed. Combinations of specific HB markers in a highly aggressive process are characterized in comparison with the lack of this aggressiveness. Among immunopathological markers, most informative were the levels of C3 component of complement and of immunocomplexes from the point of view of acute hepatitis B prognosis. The frequency and features of mixed hepatitis infection: HA and HB, HB and delta-infection are discussed.