External quality control system in medical microbiology and parasitology in the Czech Republic

The External Quality Control System (EQAS) of laboratory activities in medical microbiology and parasitology was implemented in the Czech Republic in 1993 with coded sera samples for diagnosis of viral hepatitis and bacterial strains for identification distributed to first participating laboratories. The number of sample types reached 31 in 2003 and the number of participating laboratories rised from 79 in 1993 to 421 in 2003. As many as 15.130 samples were distributed to the participating laboratories in 2003. Currently, almost all microbiology and parasitology laboratories in the Czech Republic involved in examination of clinical material participate in the EQAS. Based on the 11-year experience gained with the EQAS in the Czech Republic, the following benefits were observed: higher accuracy of results in different tests, standardisation of methods and the use of most suitable test kits.     

Diagnosis and notification of rotavirus infection in the Czech Republic

In 1998 in 33 laboratories in the Czech Republic 1,223 rotavirus infections were revealed. The largest number of positive infections was recorded in children under the age of 3 years. The most frequent diagnostic procedure is latex agglutination which was used in 29 laboratories. In six departments the positive findings are reported directly to the appropriate epidemiological department. In the information system of the hygiene service, Epidat, in 1998 239 cases were reported, i.e. 19.5% of those confirmed by laboratory tests. The authors discuss the contemporary impact of rotavirus infections in the Czech Republic.     

Multiresistant Salmonella enterica subspecies enterica serovar Typhimurium DT104 in the Czech republic 2000-2001

Salmonelloses belong to the most important alimentary diseases. From 1989 the main source of infection is S. Enteritidis (95% and more). The ratio of S. Typhimurium in the etiology declined gradually since 1994 from 3% in 1993 to 1.9% in 2001. The number of detected multiresistant strains STM DT104 is so far low in the Czech Republic. In 2000 laboratory tests confirmed 53 and in 2001 a total of 63 strains. Analysis of these strains revealed: 1. the proportion of multiresistant strains STM DT104 of the total number of isolated STM strains increased from 7% in 2000 to 11.5% in 2001, 2. the territory in the CR where these multiresistant strains were found expanded, 3. the relationship of proportions of the most frequently detected STM phagotypes in the human population changes: in 2000 this ratio was balanced, in 2001 the ratio of phagotype DT104 is roughly three times higher than of DT 141, 4. analysis of all STM strains from the environment and animals indicates that the frequency of STM DT104 is 73%. Almost 90% of these strains are multiresistant (resistant to one or several antimicrobial substances). The highest number was found in calves, piglets but also in poultry. With regard to the results of the submitted work it is important to concentrate attention on detection and further laboratory examination of STM strains in the human and animal population.     

Serologic detection of hantavirus antibodies

Within the framework of diagnosis of highly dangerous infections in the Army of the Czech Republic serological assessment of hantaviral antibodies was introduced. Because military units in the field can be in contact with sources of hantaviral infections, the authors investigated this population sample. In 1999-2000 a total of 542 healthy subjects were examined (age 20-40 years). Hantaviral antibodies were detected in 9. In three antibodies against the serotype Hantaan were found, in two antibodies against serotype Puumala and in four against serotype Seoul. The mean seropositivity was 1.66%. As compared with results which were obtained in the National Institute of Public Health in Prague in 1998 in a sample of the general population (430 subjects) where seropositivity of hantaviral antibodies was 0.93% the seropositivity in military units is higher. It is thus essential to make this laboratory diagnosis in the laboratories of the Army of the Czech Republic.     

Longitudinal epidemiology of leptospirosis in the Czech Republic (1963-2003)

After higher rates of occupational or leisure diseases recorded in the Czech Republic in the second half of the last century it was found that the last climatic changes and catastrophic floods of 1997 and 2002 were followed by outbreaks of leptospirosis as the only re-emerging postflood infection. While in tropics and subtropics the monsoon season is typically followed by highly increased rates of leptospirosis in humans, even, with fatal outcomes, this phenomenon remained unknown under the climatic conditions of the Czech Republic where human leptospirosis has been reported rather sporadically, mostly in natural foci of infection, and its incidence rate is usually about 0.3% per 100,000 population. Nevertheless, after the unexpected vast floods of 1997 and 2002 that also afflicted natural foci of leptospirosis, the rates of reported and serologically confirmed cases of leptospirosis in the Czech Republic were three times as high as usual with the specific morbidity reaching 0.9 case per 100,000 population. In 1997, as many as 7156 persons were tested for leptospirosis in the Czech Republic: the disease was diagnosed and reported in 94 patients and in 2002, 92 out of 4999 persons tested were diagnosed with leptospirosis. Two thirds of these cases were from inundation areas, half of them being directly associated with floods (exposure to residual water, flood mud in cellars, etc.). Four case of Weil disease reported in 1997 were fatal. As many as 41 deaths from Weil disease have been reported in the Czech Republic since 1963 when the disease became reportable.     

Heterosexual anal intercourse: increasing prevalence, and association with sexual dysfunction, bisexual behavior, and venereal disease history

Representative samples of the Czech population were surveyed with regard to sexual behavior in 1993, 1998, 2003, and 2008 (N = 7,720). Lifetime prevalence of Heterosexual Anal Intercourse increased from 1993 to 2008 (16.6% to 19.7% among women, 15.7% to 25.3% among men). Anal intercourse was associated with lifetime number of sex partners, current masturbation, and histories (prevalence of which increased from 1993 to 2008) of homosexual sex, prostitution, venereal disease (adjusted for number of sex partners), and women's sexual dysfunction. The authors discuss the possible reasons for the increasing prevalence and the associations. Multivariate predictors of ever having a sexual dysfunction or a venereal disease are also presented.     

The complex relation between access to opioid agonist therapy and diversion of opioid medications: a case example of large-scale misuse of buprenorphine in the Czech Republic

Opioid agonist therapy (OAT) has been available in a standard regime in the Czech Republic since 2000. Buprenorphine is the leading medication, while methadone is available only in a few specialised centres. There is an important leakage of buprenorphine onto the illicit market, and the majority of Czech opioid users are characterised by the misuse (and injecting) of diverted buprenorphine medications. Most prescribed buprenorphine for OAT is not covered by current national health insurance schemes, and patients have to pay considerable prices to afford their treatment. This affordability barrier together with limited accessibility is likely the leading factor of limited coverage of OAT and of recent stagnation in the number of patients in the official treatment programmes in the Czech Republic. It also encourages doctor shopping and the re-selling of parts of their medication at a higher price, which represents the main factor that drives the Czech illicit market for buprenorphine, but at the same time co-finances the medication of clients in official OAT programmes. Improving access to OAT by making it financially affordable is essential to further increase OAT coverage and is one of the factors that can reduce the illicit market with OAT medications.     

Quality control of the serological diagnosis of dengue in laboratories throughout the Americas, 1996-2001]

OBJECTIVE: To report the results from participating laboratories for four external quality control proficiency tests of dengue serological diagnosis that were carried out in the Region of the Americas in the period of 1996-2001. METHODS: External quality control proficiency tests of dengue serological diagnosis were carried out in 1996-1997, 1998-1999, 1999-2000, and 2000-2001. Panels made up of 20 serum samples (12 of them positive for dengue IgM antibodies) were sent to participating laboratories in the Region. The sera were negative for HIV antibodies, hepatitis C virus antibodies, and hepatitis B surface antigen. The sera were stored at -20 degrees C until they were sent in refrigerated shipments to the participating laboratories. The presence of IgM antibodies was determined through IgM-capture enzyme-linked immunosorbent assay (ELISA), while the IgG antibody titer was determined by hemagglutination inhibition or by IgG ELISA. The results of the IgM antibody testing that differed from those of the reference center were considered discordant. The IgG antibody titer was considered discordant when the results differed by two dilutions or more with respect to the reference center's results. RESULTS: A total of 27 laboratories received a total of 59 serum panels over the 1996-2001 period, and the results from testing 54 of those panels (91.5%) were sent back in. Of the total of 1 080 sera samples from those 54 panels, the results from 95.6% of the IgM antibody tests were concordant with the results from the reference center. With 47 of the 54 panels (87.0%) the participating laboratories' agreement with the reference center's results for the IgM antibody testing was 90.0% or higher. The laboratories sent back results from a total of 27 IgG antibody titer tests, and 22 of them (81.5%) coincided with those from the reference center. Considering the IgM antibody testing results from the four periods, the findings from 22 of the participating laboratories coincided with those from the reference center for at least 90% of the samples, and 13 of the laboratories were in complete concordance with the reference center. CONCLUSIONS: The majority of the participating laboratories showed an excellent level of performance in detecting dengue IgG and IgM antibodies. However, the deficiencies found in some instances confirm the need for continuing to improve laboratory diagnosis of dengue in the Region of the Americas.     

Quality of HIV laboratory testing in Tanzania: a situation analysis

Tanzania is scaling up prevention, treatment, care and support of individuals affected with HIV. There is therefore a need for high quality and reliable HIV infection testing and AIDS staging. The objective of this study was to assess laboratories capacities of services in terms of HIV testing and quality control. A baseline survey was conducted from December 2004 to February 2005 in 12 laboratories which were conveniently selected to represent all the zones of Tanzania. The questionnaires comprised of questions on laboratory particulars, internal and external quality control for HIV testing and quality control of reagents. Source and level of customer satisfaction of HIV test kits supply was established. Of 12 laboratories, nine used rapid tests for screening and two used rapid tests for diagnosis. In the 12 laboratories, four used double ELISA and five used single ELISA and three did not use ELISA. Confirmatory tests observed were Western Blot in three laboratories, DNA PCR in two laboratories, CD4 counting in seven laboratories, and viral load in two laboratories. Although all laboratories conducted quality control (QC) of the HIV kits, only two laboratories had Standard Operating Procedures (SOPs). Internal and external quality control (EQC) was done at varied proportions with the highest frequency of 55.6% (5/9) for internal quality control (IQC) for rapid tests and EQC for ELISA, and the lowest frequency of 14.3% (1/ 7) for IQC for CD4 counting. None of the nine laboratories which conducted QC for reagents used for rapid tests and none of the five which performed IQC and EQC had SOPs. HIV kits were mainly procured by the Medical Store Department and most of laboratories were not satisfied with the delay in procurement procedures. Most of the laboratories used rapid tests only, while some used both rapid tests and ELISA method for HIV testing. In conclusion, the survey revealed inadequacy in Good Laboratory Practice and poor laboratory quality control process for HIV testing reagents, internal and external quality control.     

External performance evaluation of screening in blood banks in Argentina: results and strategies for improvement]

OBJECTIVES: Because there was no program for the external evaluation of the quality of the screening for transfusion-transmitted infections (TTIs) in blood banks in Argentina, in 1999 the Hemotherapy Service of Garrahan Hospital, in Buenos Aires, launched an ongoing external evaluation program, with the support of the Pan American Health Organization and the Argentine Hemotherapy and Immunohematology Association. METHODS: A panel of 12 samples that were reactive to all the markers screened for in Argentine blood banks was distributed. The panel was delivered to 52 laboratories in 1999, 102 laboratories in 2000, and 118 laboratories in 2001. The participating laboratories were classified into one of four categories according to their performance: A: 0 or 1 false positive (FP) results; B: 2 or 3 FPs; C: 4 or more FPs; and D: at least 1 false negative result. Workshops were held with the participants in order to jointly analyze the results. RESULTS: Out of the laboratories that received the panel of samples, the percentage of laboratories that sent in their results was 92.3% in 1999, 92.2% in 2000, and 83.9% in 2001. These response levels demonstrate the interest in evaluation activities. However, the annual average percentage of the laboratories that received a "D" classification was very high (30%), which indicates that there are problems in the performance of TTI screening. This poor showing could be related to the difficulty in taking corrective measures throughout the system, given the large number of laboratories involved. CONCLUSIONS: Evaluations of this type should be included in Argentina's National Blood Program as a tool for the ongoing assessment of the blood banking situation, for decision-making, and for monitoring the quality of screening.     

Prevalence of overweight,obesity and low weight in the Czech child population up to 18 years of age in the last 50 years

Aim  The main purpose of the study was to analyze the changes in the prevalence of underweight, overweight, and obesity among Czech children and adolescents aged 3–18 within the last 50 years. The secondary purpose of the study was to determine the prevalence of overweight and obesity among children and adolescents in 2001 and compare it to the reference standards recommended by the International Obesity Task Force (IOTF). Subject and methods  Anthropometric data collected from nationally representative samples of 3–18-year-old children and adolescents in the Czech Republic in 1951, 1981, 1991, and 2001 were analyzed in the study. The prevalence of child overweight and obesity among Czech children using data from the most recent 2001 National Anthropological Survey was estimated using the 1991 Czech reference values and the IOTF standards. Results  There has been a gradual increase in the number of children in both extreme categories of BMI values in most age categories, including underweight (<10th percentile), overweight (>90th percentile), and obesity (>97th percentile) between 1951 and 2001. In both genders, the number of underweight children increased dramatically in the lowest age categories. At the same time, the rates of overweight and obesity increased among 6–11- and 11–15-year-old individuals. The prevalence of underweight has also increased among older adolescents. However, our study indicated that the 2001 prevalence of overweight/obesity among Czech adolescents, especially in older age categories and among girls, was lower compared to the 1991 reference values. Conclusion  Given the continuous increase in child obesity rates in the US and most of Europe, it is interesting that the prevalence of overweight and obesity has remained relatively low among children and adolescents in the Czech Republic. Given the increased number of Czech school-aged children with excess adiposity, a gradual rise in the prevalence of overweight and obesity among Czech adolescents could be expected.     

Molecular epidemiology of tuberculosis among prisoners

The subject of the investigation is a group of 27 strains of Mycobacterium tuberculosis isolated in 2000 from prisoners with the diagnosis of tuberculosis, 19 Czechs and 8 foreigners (mean age 41 and 35 years resp.). The molecular-epidemiological examination of these strains was made using the RFLP fingerprint technique (Restriction Fragment Length Polymorphism) with evidence of the insertive sequence IS6110 and the technique of spoligotyping, based on detection of hybridization of spacer oligonucleotides. DNA fingerprinting revealed a high polymorphism in the number and molecular weight of sequence IS6110 which is common in Czech and other European strains of M. tuberculosis. All strains with the exception of two had mutually different fingerprint profiles. In the two with identical fingerprints probably a duplicit examination of the same material was involved which occurred by mistake during transport or in the laboratory. The fingerprint method thus did not prove interhuman transmission of tuberculosis between the examined prisoners. The technique of spoligotyping revealed the finding of genotype Beijing M. tuberculosis in two sick prisoners, one Algerian and one Albanese, and in one Czech prisoner. This genotype found in a high percentage of patients in southeastern Asia and in migrants from this area was detected for the first time in the Czech Republic. The findings are evidence of a satisfactory standard of the programme of tuberculosis control in the Czech prison system and at the same time draw attention to the potential possibility of the spread of tuberculosis from migrants coming from areas with a high prevalence.     

Molecular epidemiology of tuberculosis in Prague and South Moravia, Czech Republic: genetic analysis of Mycobacterium tuberculosis isolates by IS6110-RFLP fingerprinting and spoligotyping

OBJECTIVES: To genetically characterize and compare Mycobacterium tuberculosis isolates among culture-confirmed TB cases in two regions in the Czech Republic in 1998. METHODS: Consecutive M. tuberculosis isolates from 111 TB patients in Prague and 120 patients in the South Moravia region were genotyped using the standardized IS6110 Southern blot hybridization method and by spoligotyping. RESULTS: Eighty of the Prague patients (72.1%) had isolates with unique RFLP patterns, while 31 (27.9%) had isolates which belonged to 10 clusters. Seventy-eight (64.7%) of the South Moravia strains displayed unique RFLP pattern and 42 (35.3%) were assigned into 15 clusters. The spoligotype profiles previously identified in the U.S. were found in 69 (33%) samples and newly identified Czech spoligotypes in 24 (11.4%) of the total number of examined strains. CONCLUSIONS: The present population-based molecular epidemiological study performed in two regions of the Czech Republic in 1998 demonstrated the distribution of individual genotypes as well as clustered strains of M. tuberculosis isolated from TB patients, and confirmed the similarity between the Czech strain collection and the European Community TB Database, that includes countries with low TB rate. The sporadic import of TB cases from foreign countries and recent transmission events probably do not play significant roles in the epidemiological situation in the Czech Republic.     

Low-weight neonatal survival paradox in the Czech Republic

Analysis of vital statistics for the Czech Republic between 1986 and 1993, including 3,254 infant deaths from 350,978 first births to married and single women who conceived at ages 18-29 years, revealed a neonatal survival advantage for low-weight infants born to disadvantaged (single, less educated) women, particularly for deaths from congenital anomalies. This advantage largely disappeared after the neonatal period. The same patterns have been observed for low-weight infants born to black women in the United States. Since the Czech Republic had an ethnically homogenous population, virtually universal prenatal care, and uniform institutional conditions for delivery, Czech results must be attributed to social rather than to biologic or medical circumstances. This strengthens the contention that in the United States, the black neonatal survival paradox may be due as much to race-related social stigmatization and consequent disadvantage as to any hypothesized hereditary influences on birth-weight-specific survival.     

Analysis of parasuicide, psychiatric care and completed suicides, implications for intervention strategy (Czech Republic, 1996–2000)

Summary Background:  This retrospective study analyses the differences between suicide with and without previous parasuicide. The Czech Republic was one of the countries with the traditionally highest level of suicide mortality. During collapse of the communist regime and deep societal changes in the Czech Republic after the year 1989 the escalation of suicides was expected. Mortality from suicides decreased, however the gender and age differences increased. Methods:  A total of 2,711 suicides in the Czech Republic (1996–2000) were studied. Effects of socioeconomic characteristics, psychiatric diagnosis and care, and lifetime history of parasuicide on the risk of death from suicide were estimated using logistic regression. Results:  Twenty-three percent of persons who committed suicide had a prior history of parasuicide and almost twenty percent of them received no psychiatric care after the attempt. Young males with basic education, economically active and diagnosed with substance abuse related disorders and the elderly were least likely to receive psychiatric care before their suicide death. Conclusions:  Implications for age specific primary and secondary prevention are discussed. Submitted: 08 June 2007; Revised: 19 December 2007; Accepted: 28 February 2008     

Effects of climate change on the incidence of tick-borne encephalitis in the Czech Republic in the past two decades

The study objective was an attempt to explain uneven distribution of the incidence of tick-borne encephalitis (TBE) throughout the past two decades. A sharp rise was recorded in the last decade: while 2596 TBE cases were reported in the decade 1983-1992, as many as 5892 TBE cases were reported in the decade 1993-2002, with high rates persisting also in the following years (606 TBE cases reported in 2003). Data from the database TBE EPIDAT of the National Institute of Public Health, Prague, and that of the Communicable Diseases Information System, Ostrava, were used for analysis. Meteorological data were taken from the database of the Czech Institute of Hydrometeorology, Prague. In 1971 to 2003, 13 231 laboratory confirmed TBE cases were reported in the Czech Republic. Uneven distribution of these TBE cases in time is consistent with the observations of climate variation made between 1931 and 2000. The increase in the TBE incidence in the Czech Republic in the last decade was characterized by the following features: 1) higher rates of TBE cases manifested in regular TBE natural focuses, 2) reemergence of TBE in the same localities after 20 and more year intervals and 3) emergence of TBE in localities where it was not reported before. At the same time shifts in TBE seasonal trends (i.e. to March and October-November) were observed, associated with a TBE incidence peak in autumn. Field research revealed that the major factor are the climate-related changes in ecology of the TBE vector Ixodes ricinus and resulting variation in its population density. TBE emergence in new areas is linked to the occurrence of ticks Ixodes ricinus at higher altitudes (previously found at 700 m and currently spreading to 1200 m) as well as to a coming warm climate era.     

Chromosomal aberrations in lymphocytes of healthy subjects and risk of cancer

There is evidence that increased frequency of chromosomal aberration (CA) in peripheral blood lymphocytes is a predictor of cancer, but further data are needed to better characterize CA as marker of cancer risk. From the archives of 15 laboratories we gathered cytogenetic records of 11,834 subjects who were free of cancer at the moment of blood drawing and who underwent cytogenetic examination for preventive purposes in the Czech Republic during 1975-2000. We linked these records to the national cancer registry, revealing a total of 485 cancer cases. Subjects were classified according to the percentiles of CA distribution within each laboratory as low (0-33rd percentile), medium (34-66th percentile), and high (66-100th percentile). Subjects were further classified by occupational exposure and by subclass of CA. We found a significant association between the overall cancer incidence and the presence of chromosome-type aberrations [relative risk (RR) for high vs. low CA level = 1.24; 95% confidence interval (CI), 1.03-1.50] but not chromatid-type aberrations. Stomach cancer showed a strong association with frequency of total CA (RR = 7.79; 95% CI, 1.01-60.0). The predictivity of CA observed in subjects exposed to various classes of carcinogens did not significantly differ from the group of nonexposed subjects. This study contributes to validation of CA as a predictive marker of cancer risk, in particular, of stomach cancer; the association between CA frequency and cancer risk might be limited to chromosome-type aberrations.     

Severe childhood burns in the Czech Republic: risk factors and?prevention

Objective

To assess risk factors for paediatric burn injuries in the Czech Republic and to suggest preventive measures.

Methods

This study included all children aged 0–16 years hospitalized during 1993–2000 at the Prague Burn Centre and data from the Czech Ministry of Health on national paediatric burn hospitalizations during 1996–2006. Personal, equipment and environmental risk factors were identified from hospital records.

Findings

The incidence of burn admissions among 0–14 year-olds increased from 85 to 96 per 100 000 between 1996 and 2006, mainly due to a 13% increase among 1–4 year-olds. Between 1993–2000 and 2006, the proportion of burn victims in the country hospitalized at the Prague Burn Centre increased from 9% to 21%. Detailed data were available on 1064 children (64% boys). Around 31% of all burn hospitalizations were in 1 year-olds. Some 79% of burns occurred at home: 70% in the kitchen, 14% in the living room or bedroom and 11% in the bathroom. Of the 18% occurring outdoors, 80% involved boys. Scalds from hot liquids accounted for 70% of all burns. The mean hospital stay was 22 days for boys and 18 days for girls.

Conclusion

Most burns involved scalds from hot liquids at home: beverages in kitchens and water in bathrooms. There is a need for passive preventive measures, such as redesigned domestic cooking and eating areas, safer electrical kettles and temperature control devices for bathrooms. Educational programmes should be developed for parents and caregivers. A national plan for child burn prevention with specific targets would be helpful.     

Smoking attributable hospital treatment, treatment costs and smoking attributable mortality in the Czech Republic in 2002

OBJECTIVES: The main objective of this work is to quantify the number of hospitalizations caused by smoking, estimate the costs of hospital treatment and to estimate contribution of smoking to mortality in the Czech Republic (CR) in 2002. METHODS: The estimate of the proportion by which smoking contributed to hospitalizations and to mortality in the CR was computed using the method of smoking-attributable fractions (SAF). The SAF was computed from relative risks established in the American study Cancer Prevention Study II and from estimates of the prevalence of smoking in the CR from a nationwide study conducted in 2002. RESULTS: In 2002, based on data provided by the General Health Insurance Company, there were 145,336 hospitalizations, and the total cost of hospital treatment was estimated as 4.727,612 (in thousands) CZK. The total number of deaths caused by smoking was 20,550 (95% CI: 18,851-22,262), 14,525 in men and 6,025 in women. Deaths caused by smoking represented 19% of the total nationwide mortality for 2002. Earlier estimates were published by Peto and Lopez for 1995 (22,300 deaths caused by smoking) and 2000 (17,746 deaths). The estimate arrived by authors using the SAF method for 2002 corresponds quite well with that by Peto and Lopez for 2000. CONCLUSIONS: The high morbidity and mortality rate related to smoking is directly connected to high prevalence of smoking in the Czech Republic. An effective tobacco control policy, including restrictive measures on availability of tobacco products combined with preventive programmes and smoking cessation programmes, could contribute to the reduction of smoking and save lives and treatment costs caused by smoking.     

Surveillance of serious diseases caused by group A streptococci in the Czech Republic in 2003--the Strep-EURO project

Results obtained in the first year of active surveillance of serious diseases caused by group A streptococci in the Czech Republic carried out within the Strep-EURO project are summarized. From January to December 2003, 28 Czech laboratories referred to the National Institute of Public Health 59 group A streptococcal strains isolated from invasive diseases meeting the Strep-EURO definition. At the same time, clinical-epidemiological data and information on the catchment area population were provided. For 2003, the total morbidity and case fatality rates were calculated to be 1.3/100,000 population and 13.5%, respectively. A high proportion (23.7%) of the 59 strains were of type emm 1, initially labeled M1. As many as 24.1%, 17.2% and 20.7% of the strains tested were resistant to erythromycin, clindamycin and tetracycline, respectively. The seemingly lower morbidity rate and higher case fatality rate from serious diseases caused by group A streptococci reported in the Czech Republic for 1994-1996, i.e. 0.4/100,000 and 46.5%, respectively, in comparison with the latest data can be explained by the use of softer international criteria for the Strep-EURO definition of invasive disease.