[Mumps outbreak in the Plzen Region in 2011]. / Epidemie príusnic v Plzenském kraji v roce 2011.

AIM: The mumps outbreak in the Plzen Region in 2011 was analysed retrospectively using the epidemiological, clinical, and laboratory data. Vaccine efficacy analysis was also conducted in various population groups. MATERIAL AND METHODS: The routine procedure and standard form were used by the epidemiologists to collect data on the age, sex, place of residence, presence in collectivities, date of disease onset, type of complications and date of their onset, hospital admission, vaccination, and results of laboratory analyses. Based on the records of general practitioners for children and adolescents, data on the vaccination of children born in the previous three years have been provided to the epidemic control departments every year by 30 June since 1989. To estimate the vaccination coverage rate, the numbers of single-dose or two-dose recipients are related to the number of children registered in a given year. The first year of vaccine recipients were children born in 1986 who were aged 25 in 2011. The data collected on the population of the Plzen Region were used for the primary analyses. To estimate the efficacy of the mumps vaccine, age and vaccine coverage cohort analysis was performed using the screening method. To analyse categories, the chi-square test with Yates correction was applied at a significance level of p = 0.05 % (EPIINFO version 6.04d). RESULTS: In 2011, 721 mumps cases were reported in the Plzen Region (incidence: 126.1 cases per 100 000 population). The average patient age was 19.4 years, with a median of 18 years (age range 1-77 years). Four hundred and seventeen (57.8%) patients were males. Biological specimens from 375 (52.0%) patients were investigated serologically in the virology laboratory and mumps were laboratory confirmed in 316 (43.8%) of them - in 222 patients, one blood specimen was analysed. The most afflicted area was the Klatovy district with the incidence of 449.3/100 000 population. The most affected age group were 15-19 year-olds with the incidence of 1008.2/100 000 population. Forty-two (5.8%) patients were diagnosed with complications and 68 (9.4%) patients were admitted to the hospital. No statistically significant difference was found in the incidence of complications between the vaccinated and non-vaccinated patients. The assessment of hospitalisation risk showed a statistically significant difference between the vaccinated and non-vaccinated persons in both the whole study cohort and subcohort of patients who received the mumps vaccine within the childhood immunization schedule (p = 0.000 and p = 0.004, respectively). The average age of the vaccinated patients was 16.1 years (median of 17) and that of the non-vaccinated patients was, 29.3 years (median of 27). At the six to ten-month interval, as laid down by the legislation, the second dose of the vaccine was only given to 83.6 % of the patients. The screening method showed a high efficacy of the vaccine in the age group 20-25 years (97.6% in two-dose recipients), declining to 29.6% in the most affected age group of 15-19 years. CONCLUSIONS: Mumps outbreak may has been a result of the accumulation of high numbers of susceptible individuals in the population. The most affected area was the Klatovy district where the last epidemic outbreak occurred 23 years ago. To make the favourable epidemiological situation with occasional local outbreaks continue, the high two-dose vaccine coverage rate needs to be maintained.

[Long-term experience with testing family and sexual contacts of HBsAg positive persons]. / Dlouhodobé zkusenosti s vysetrováním rodinných a sexuálních kontaktu HBsAg+ osob.

UNLABELLED: The study objectives were to identify HBsAg positive persons and to offer free vaccination against the infection to their family and sexual contacts found negative in screening for viral hepatitis B (VHB) postinfection markers. MATERIAL AND METHODS: Any person testing HBsAg positive in the Plzen region was registered in cooperation with laboratories. The collected data included reason for testing, clinical diagnosis and ethnicity. Contacts were screened for postinfection markers and vaccinated. RESULTS: Between 1997 and 2004, 939 HBsAg positive persons were registered by laboratories in the Plzen region. Their mean age was 42.2 (0-90) years. As many as 63.4 % of the infected persons appeared to be "healthy" carriers. Nevertheless, a significant upward trend in HBsAg positivity was recorded among immigrants (mainly those from Vietnam). Altogether 18.2 % of 829 family and sexual contacts tested positive for VHB postinfection markers (HBsAg, anti-HBc). The highest percentages of infected contacts were detected among siblings and parents of HBsAg positive persons (36.5 % and 27.3 %, respectively). Free vaccination has been requested by 82.2 % of susceptible contacts. CONCLUSION: Systematic vaccination of family and sexual contacts of HBsAg positive persons can contribute to more rapid VHB elimination in the Czech Republic. Currently, special attention in detecting infected persons is to be paid to immigrants from Asia.

[Improvement in the laboratory methods of assessing the safety of the of the pertussis component of DPT vaccine adsorbed]. / Usovershenstvovanie laboratornykh metodov otsenki bezvrednosti kokliushnogo komponenta AKDS-vaktsiny.

The mouse paw edema test and the tests for the determination of leukocytosis-stimulating and histamine-sensitizing activity are reproducible if standard samples are used and the properties under test are evaluated with reference to the characteristics of standard samples. The standard character of the weight gain test on mice is also enhanced if all conditions of the test are standardized. The most accurate information on the toxicity of the pertussis component of adsorbed DPT vaccine can be obtained if a single human dose (0.5 ml) is injected to mice and the toxicity of the vaccine is estimated from the weight gain registered in the test mice and the control animals. The use of standard samples in each test makes it possible to observe the conditions for controlling the toxicity of the tested preparations.

The role played the lipid fractions of Mycobacterium bovis BCG in the development of antituberculosis immunity in an animal experiment.

The authors investigated the antituberculosis and antitumour immunogenicity as well as tuberculin allergenicity of the lipid fractions from Mycobacterium bovis BCG strains of Danish, French, Japanese origin and of Czechoslovak 725. The fractions explored included phospholipids, Cord factor, ethanol-extractable lipids, waxes A, B, C + D and fats. The fractions were divided into three groups according to their effectiveness. 1. The Cord factor and phospholipids from all the studied strains were effective in the antituberculosis and antitumour models with the only exception of strain 725 phospholipids. Phospholipids from all strains were capable of inducing tuberculin allergy. 2. In the second group (waxes A, C + D and lipids extractable by ethanol) a variance was observed in the antigenic properties of identical fractions from different strains suggesting differing metabolism in the strains producing these fractions. A mixture of waxes C + D from the French and Danish strains showed a degree of suppression in its antituberculosis effectiveness. 3. Waxes B and fats were entirely ineffective in the antitumour model and, with the exception of waxes B from strain 725 and fats from the Japanese strain, in the antituberculosis model. The antituberculosis and antitumour effectiveness directly depended on the content of a mycolic acid complex in fractions. Tuberculin allergenicity was associated with the intensity of phospholipid production by mycobacteria.

The immunological properties of listerial complex Ei.

Factor Ei, besides exerting toxic reactions, is amphipathic, antigenic, chemotaxinogenic, causes blastic transformation, adjuvant effect, hypersensitivity (MIF, skin test), activates the RES (splenomegaly), increases the macrophage production, prevents listerial infection in mice, mycobacterial infection in guinea pigs and enhances the effect of BCG experimental tuberculosis and neoplasia in mice (Sa 180).

Biological and immunological properties of avirulent strain of Listeria innocua.

The strain isolated by Dr. J. H. Welshimer from plants has antigenic formula V (VI) IX; XV; XI; AB, C--serovar 6a, is non-haemolytic, produces lipase, and toxic factor Ei, is avirulent for adult mice, but causes encephalitis in sucklings. In organs of intravenously injected mice the strain persists and multiplies for 1-3 weeks. The protective effect against listerial infections in mice of this strain administered 2-14 days before challenge is dose depending. After 3 weeks induces resistance of guinea pigs to infection with Mycobacterium tuberculosis H37Rv measured by spleen weight and Feldman index. The hypersensitivity induced in animals is detectable by factor Ei and PPD or OT tuberculins using MIF method. A suspension of living cells of this strain injected intraperitoneally causes resistance to Mycobacterium kansasii in mice, measured by inhibition of loss of weight and decrease of the number of bacillus in their lungs.

Comparative study of rat-paw oedema tests for assessing reactivity of B. pertussis-containing combined vaccines.

Two volumetric (electrocapacity plethysmography and mercury volumetry) and two linear methods (a new type of scale and a calliper rule) for rat-paw oedema measurement used in local reactivity of combined vaccines containing a B. pertussis component were compared. The reproducibility and sensitivity of the methods was tested on a diphtheria-tetanus-pertussis vaccine and a toxic pertussis suspension. The linear methods proved more adequate for measuring small and chiefly unidirectionally (vertically) progressing oedemas.

Enhancement of immunostimulating and immunotherapeutic effect of BCG vaccines using listerial endotoxin-like substances.

On the basis of experience with the immunomodulating effect of the endotoxin-like component of Listeria monocytogenes, designated factor Ei, the time parameters concerning the onset and duration of hypersensitivity induced by listeriae, mycobacteria and their components were compared. Their differences, just like different mechanism of their effect, following their simultaneous and repeated administration, furnish means of significantly enhancing the anti-tuberculosis and anti-tumor effect of strong BCG vaccines in animal experiments. This enhancement of effect makes it possible to lower the number of BCG doses otherwise required to produce the same or similar results.

Comparison of bcg strains for delayed hypersensitivity induction tested in vivo in guinea pigs and in vitro.

Previous studies performed on guinea pigs demonstrated a direct dependence of tuberculin reaction size (in vivo hypersensitivity) on immunogenicity in a number of BCG strains. The present work used an in vitro method, MIF detection, for assessing hypersensitivity and compared the results obtained with tuberculin hypersensitivity tests, correlating the data with the immunogenicity of the individual BCG strains employed. The following strains were used: the Czechoslovak BCG strain No. 725, Japanese BCG strain Tokyo, Danish BCG strain Copenhagen and Soviet BCG strain Moscow. The results obtained by the two hypersensitivity testing methods, in vivo and in vitro were in a direct correlation; a direct relationship was also demonstrated between hypersensitivity tested by the in vitro method and immunogenicity. The in vitro method of MIF detection is reproducible and comparable with the other two methods employed and may be used as an alternative approach to BCG vaccine efficacy testing. It might probably also be applicable to estimation of the status of cell-mediated immunity against intracellularly parasitizing bacteria in general.

Resistance to Mycobacterium tuberculosis H37Rv infection induced by Listeria and mycobacterial lipids.

The avirulent strain Listeria monocytogenes (Welshimer) induced upon a single injection 4 weeks prior to challenge with Mycobacterium tuberculosis H37Rv resistance in guinea-pigs, which was manifested by a significant decrease of spleen weight and Feldman's index in immunized animals. The degree of resistance was dependent on the immunizing dose and time of administration. Repeated high doses of Listeria yielded only a low or no effect. Further increase of resistance was obtained using the BCG lipids; however, stimulation of resistance with listeria lipids was not successful and, finally, Freund's incomplete adjuvant was significantly effective in the Feldman index only. The BCG lipids, extracted with ethanol, which contained nitrogen and water-soluble substances, induced a significant resistance against M. tuberculosis infection. The chloroform-methanol BCG lipids were also effective, however, significantly less than the ethanol-extracted material. The listeria factor Ei itself or together with Freund's incomplete adjuvant possessed only low effectiveness against mycobacterial infection. However, if injected together with ethanol-extracted BCG lipids, it produced a significant degree of resistance which was higher than that induced by lipids only. The degree of resistance was comparable with the effect of living BCG strain which served as a source of isolated lipids.

Studies of local reactivity to B. pertussis suspensions by means of the rat paw oedema.

In the present study, the authors verified earlier experience with the rat-paw-oedema test and tried to improve the method and to increase its sensitivity so as to make possible, by means of this test, to screen vaccines producing different reactivity. Toxic and non-toxic B. pertussis suspensions were used as test material. The sensitivity of the animal to the suspension was increased by sensitization of the rats using Alditepera and by influencing the pituitary using different doses of Hydrocortisone. Influencing the pituitary by means of cortisone was found to be more suitable for screening assessment of the reactivity to suspension than sensitizing the animals.