Seroepidemiology of mumps in Europe (1996-2008): why do outbreaks occur in highly vaccinated populations?

Mumps outbreaks have recently been recorded in a number of highly vaccinated populations. We related seroprevalence, epidemiological and vaccination data from 18 European countries participating in The European Sero-Epidemiology Network (ESEN) to their risk of mumps outbreaks in order to inform vaccination strategies. Samples from national population serum banks were collected, tested for mumps IgG antibodies and standardized for international comparisons. A comparative analysis between countries was undertaken using age-specific mumps seroprevalence data and information on reported mumps incidence, vaccine strains, vaccination programmes and vaccine coverage 5-12 years after sera collection. Mean geometric mumps antibody titres were lower in mumps outbreak countries [odds ratio (OR) 0·09, 95% confidence interval (CI) 0·01-0·71)]. MMR1 vaccine coverage ⩾95% remained protective in a multivariable model (P < 0·001), as did an interval of 4-8 years between doses (OR 0·08, 95% CI 0·01-0·85). Preventing outbreaks and controlling mumps probably requires several elements, including high-coverage vaccination programmes with MMR vaccine with 4-8 years between doses.

Hepatitis A outbreak in a Roma village in eastern Slovakia, August-November 2008.

We describe an outbreak of hepatitis A in Lomnicka, a village in the eastern part of Slovakia. The outbreak was limited to the village and did not spread either to other districts of Slovakia or to the neighbouring countries. The number of cases reported from 28 August to 30 November 2008 was 298. All cases but one occurred in the Roma population. The outbreak was associated with low socio-economic conditions which facilitated person-to-person transmission. No common source of the outbreak was verified.

A comparison of hepatitis B seroepidemiology in ten European countries.

To inform current and future vaccination strategies, we describe the seroepidemiology of hepatitis B virus (HBV) infection in ten representative European countries using standardized serology that allowed international comparisons. Between 1996 and 2003, national serum banks were compiled by collecting residual sera or by community sampling; sera were then tested by each country using its preferred enzyme immunoassays and testing algorithm, and assay results were standardized. Information on current and past HBV vaccination programmes in each country was also collected. Of the ten countries, six reported low levels (<3%) of antibodies against HBV core antigen (anti-HBc). Of the eight countries testing for HBV surface antigen (HBsAg), the highest prevalence was reported in Romania (5.6%) and in the remaining seven countries prevalence was <1%. Universal HBV vaccination programmes had been established in seven countries as recommended by the World Health Organization, but the seroprevalence of antibodies against HBsAg (anti-HBs) was lower than the reported vaccine coverage in three countries. Regular serological surveys to ascertain HBV status within a population, such as reported here, provide important data to assess the need for and to evaluate universal HBV vaccination programmes.

The comparative sero-epidemiology of varicella zoster virus in 11 countries in the European region.

The European sero-epidemiology network (ESEN2) aims to standardise serological surveillance of varicella zoster virus (VZV) in 11 participant countries. In each country, serum banks were collected between 1996 and 2003 and tested for VZV antibodies. Assay results were standardised so that international comparisons could be made. Age-specific forces of infection were calculated for three age groups (<5, 5-9 and >or=10 years of age) and used to estimate the base reproduction number (R(0)) and the herd immunity threshold (H). Most VZV infection occurred in childhood, but there was a wide variation in transmissibility, with R(0) ranging from 16.9 in the Netherlands to 3.3 in Italy. Herd immunity thresholds varied from 70% in Italy to 94% in the Netherlands. There are substantial differences in VZV sero-epidemiology within the European region, which will need to be taken into account in designing national policies regarding VZV vaccination.

[Changes in the epidemiology of human leptospirosis in the Slovak Republic]. / Zmeny epidemiológie leptospiróz l'udí v Slovenskej republike.

BACKGROUND: The epidemiologic patterns of infectious diseases are liable to change in the course of time. References to such changes in leptospirosis are very rare and of low systematic value. OBJECTIVES: The study is aimed at the detection of changes in the epidemiology of leptospirosis within the 20 years in Slovakia. METHODS: Basic epidemiologic characteristics of leptoospirosis were compared within two chronological periods. 598 registered cases were analyzed during the first period (1970-1976), and 200 cases of leptospirosis were analysed during the second period (1986-1991). MAIN RESULTS: The second period yielded a decrease in total incidence to approximately 50% (yearly average was 0.9/10(5) of the population). At the same time the cyclic character of morbidity has almost entirely disappeared. The incidence of leptospirosis has significantly decreased in the group of population between 40 and 59 years of age, thus causing a particular shift in morbidity towards the younger population. Cases of leptospirosis caused by L. tarassovi and L. canicola ceased to occur, however one case of infection caused by L. hardjo has been registered in the Slovak population. A significant decrease in the incidence of diseases caused by the Sejroe group serovars was detected, especially in housewives, retired people, industrial and agricultural workers. In contrast to the latter, the proportion of leptospirosis cases caused by L. icterohaemorrhagiae/copenhageni increased particularly in pupils and students, as well as those caused by L. pomona in slaughter-house workers. Consequently, the most dominating disease is represented by field fever (L. gripotyphosa), the second highest incidence is ascribed to Weil disease (L. icterohaemorrhagiae/copenhageni), while the incidence of infections caused by the group of Sejroe serovars dropped from the first to the fourth place. The possible reasons of these changes are presented. No changes in the incidence of leptospirosis according to sex and seasonal occurrence were registered. CONCLUSION: The results of this study are in accordance with the current knowledge of the development of epidemiologic signs of infectious diseases, including leptospirosis. The results provide a pattern of the current situation in the field of leptospirosis epidemiology in the territory of Slovakia and emphasize the importance of systematic surveillance enabling the assessment of appropriate measures suppressing these infections. (Fig. 7, Ref. 7.).

Spread of multidrug-resistant Streptococcus pneumoniae among hospitalized children in Slovakia.

A multidrug-resistant serotype 14 strain of Streptococcus pneumoniae was isolated from sterile-site specimens and nasopharyngeal secretions from > 200 children in Slovakia between 1985 and 1990. Nasopharyngeal culture surveys were done to determine the extent of spread and means of transmission of this strain. The resistant strain was isolated from cultures of 8 (33.0%) of 24 children at hospital A and from 1 (0.8%) of 130 children attending outpatient clinics or day care centers (P < .001). One-quarter of the initially uncolonized children at hospital A acquired the resistant strain during hospitalization. Among hospitalized children, frequent antimicrobial drug use (P < .01), prior hospitalization (P < .005), and length of hospital stay (P < .001) were associated with infection with the resistant strain. These findings support limiting broad-spectrum antimicrobial drug use and nonessential hospitalizations in settings were drug-resistant pneumococci are prevalent. Development of a pneumococcal vaccine that is immunogenic in young children is urgently needed.

Multiple antimicrobial resistance of pneumococci in children with otitis media, bacteremia, and meningitis in Slovakia.

Penicillin-resistant pneumococci have been isolated from middle ear fluid, blood, cerebrospinal fluid, and nasopharyngeal secretions of several hundred children in Slovakia since 1985; 116 of these isolates were serotyped and tested for susceptibility to antimicrobial drugs at the Centers for Disease Control and Prevention. To define the prevalence of drug-resistant pneumococci and identify risk factors for infection, laboratory and medical records were reviewed. Nearly all (96%) of the resistant strains tested were serotype 14. Of these, all were resistant to penicillin (MIC, 4-16 micrograms/mL); most were resistant to cefaclor, erythromycin, tetracycline, and chloramphenicol; and many had decreased susceptibility to trimethoprim-sulfamethoxazole and ceftriaxone. Frequent antibiotic use, prior hospitalization, and length of hospital stay (P < .001 for all 3) were associated with infection with resistant strains. These findings suggest the need for routine screening of pneumococcal isolates for penicillin resistance and highlight the importance of controlling globally the spread of resistant pneumococci.

[Isolation of tick-borne encephalitis viruses from the cervical spinal cord in meningoencephalitis]. / Izolácia vírusu kliest'ovej encefalitídy z krcnej miechy pri meningoencefalitíde.

In 1988 the organs of a male were examined post mortem for the presence of viruses in isolation experiments on white suckling mice. The virus isolated from the cervical spinal cord was identified as the virus of tick-borne encephalitis. Although death from tick-borne encephalitis is rather rare in Slovakia, the disease requires great attention with special focus on preventive measures.