Epidemiologie Mikrobiologie Imunologie最新文献

Study aim: To determine the genetic diversity of human isolates of Listeria monocytogenes obtained in 2016-2020 from clinical laboratories in various locations of the Czech Republic with a focus on their possible epidemic links and virulence using whole genome sequencing data.

Methods: A total of 102 human L. monocytogenes isolates, serotyped by slide agglutination in combination with multiplex PCR serotyping, were used in this study. Whole genome sequencing was performed retrospectively, and based on the obtained data, the clonal relatedness of the tested strains and the presence of virulence genes were assessed using the Ridom SeqSphere+ software.

Results: In 2016-2020, 102 human isolates of L. monocytogenes were characterized, which represented 65% of all cases of listeriosis reported to the ISIN/EPIDAT systems in the Czech Republic in the monitored period. Serotype 1/2a (57%) was dominant, followed by serotype 4b (30%). Strains of serotype 1/2b (12%) and 1/2c (1%) were rarely detected. Based on the analysis of whole genome sequencing data, the strains were assigned to 26 clonal complexes and 27 sequence types. The cgMLST (core genome Multi-Locus Sequence Typing) analysis revealed four clusters of more than three strains, showing high relatedness (differences up to 10 alleles) with a possible epidemic link. The presence of all key virulence genes was confirmed in all strains. Only three strains (of serotypes 1/2a, 1/2b, and 1/2c) carried a point mutation in the inlA gene responsible for the expression of truncated internalin A protein, which is involved in the mechanism of intestinal barrier crossing by L. monocytogenes.

Conclusion: Molecular epidemiology based on whole genome sequencing is an effective tool to study the population structure of L. monocytogenes strains. This study found high heterogeneity of human L. monocytogenes strains, especially for serotype 1/2a, dominant in the Czech Republic. Several clusters with a possible epidemic link have been identified, and their occurrence will be further monitored.

Malaria is one of the worlds most important infectious diseases, occurring in many tropical and subtropical countries. The causative agent is a parasitic protozoan of the genus Plasmodium, transmitted to humans by infected mosquitoes. More than 200 million people get malaria every year worldwide, and hundreds of thousands of them, mostly children under 5 years of age, die of it. Thanks to prevention programmes implemented by various organisations headed by the World Health Organisation (WHO) with the aim of eliminating malaria, cases have been declining in recent years. However, particularly in African countries, malaria continues to be a health and economic issue.

Aim: An analysis is presented of epidemiological and molecular data from invasive meningococcal disease (IMD) surveillance in the Czech Republic (CR) for 1993-2020, comparing trends in four seven-year periods: 1993-1999, 2000-2006, 2007-2013, and 2014-2020.

Material and methods: IMD surveillance data are generated by linking National Reference Laboratory for Meningococcal Diseases data and epidemiological data routinely reported to the infectious diseases information systems, with duplicate data removal. Whole genome sequencing (WGS) was used for analysis of selected isolates from IMD cases. In this study, WGS data are analysed on 323 isolates recovered from IMD cases in the Czech Republic between 1993-2020.

Results: Over the entire study period 1993-2020, 2,674 cases were recorded in the IMD surveillance programme, of which 272 were fatal. In the first seven-year period, the highest incidence rate of 2.2/100,000 population was reported in 1995, a gradual decline from 0.8 to 0.6/100,000 was observed in the third period, and in the last period, this decline continued until 2020, achieving a low of 0.2/100,000. In all four study periods, the age group 0-11 months was the most affected, followed by 1-4-year-olds and 15-19-year-olds. Serogroup B caused the highest number of cases (43.6%), followed by serogroups C (34.9%), Y (1.8%), and W (1.5%). Serogroup X was only found in three cases. The overall case fatality rate in the entire study period was 10.2%, with no decline seen in the four periods. The highest case fatality rate was associated with serogroup Y (14.6%), followed by serogroups W (12.5%), C (12.0%), and B (8.1%). In terms of age, the highest case fatality rate was observed in people aged 65+ (24.7%). The WGS data for 323 IMD isolates from 1993-2020 showed the highest representation of eight clonal complexes: cc11, cc44/41, cc32, cc267, cc23, cc18, cc35, and cc865. Isolates of serogroup C, cc11, from the last study period form two genetically distinct populations with distinct phenotypes that are genetically distant from the lineage of cc11 isolates from the first two periods. The study population included a unique Czech subpopulation of serogroup W isolates (ST-3342, cc865), recorded only in the last two periods (2007-2020), whose position in the phylogenetic network supports the theory that the serogroup W population in the Czech Republic originated from serogroup B isolates as a result of serogroup switch (capsule switch). Clonal complexes cc41/44, cc32, cc267, cc18, and cc35 are predominantly composed of serogroup B isolates, while cc23 includes exclusively serogroup Y isolates.

Conclusions: The analysis of surveillance data over a 28-year period confirms that the vaccination strategy currently used in the Czech Republic, i.e., vaccination of young children and adolescents with a combination of MenB vaccine and quadrivalent conjugate ACWY vaccine,

Aim: The aim of study was to evaluate completeness and estimate sensitivity of the measles surveillance using the new electronic version of the national notification system of infectious diseases (ISIN) in order to assess its performance.

Material and methods: The completeness of measles reporting in the ISIN for demographic characteristics (week and region of reporting, age and gender), date of onset, complications, hospitalisations, vaccination status, used laboratory methods and country of import from January 2018 to June 2019 was assessed. The register from National Reference Laboratory (NRL) and the ISIN were compared using the capture-recapture method (CRM). Cases were matched using unique personal identifier. The total number of measles cases in the population was assessed using the Chapmans formula. Sensitivity of reporting was calculated by dividing the number of reported cases by the CRM estimated true number of cases.

Results: In the ISIN, 765 measles cases were registered within specified time period. For many variables 100% completeness was found. The data were missing mainly for vaccination status (20%), serology results (55%) and used laboratory methods (8%). The NRL confirmed 653 patient samples in respected period. Within both registries (ISIN and NRL) the total 612 cases were matched. Estimated real number of measles cases using the CRM was 816 (95% CI: 809-823) compared to 806 reported cases. The estimated surveillance system sensitivity was 98.8%. Five percent (n = 41) of cases tested positively in the NRL were not reported to the ISIN.

Conclusions: We found high level of reported measles data completeness in the ISIN for most variables. Estimated real and reported number of cases was in a good correlation and calculated sensitivity of the ISIN was on very high level. Though, the data sources used in the study were not independent on each other, therefore results may not be fully accurate. The technical changes (more mandatory fields and more logical syntax to check data) in the ISIN to improve data completeness are being recommended. Data providers should report all measles cases to the ISIN with maximum precision in entering individual variables and investigating laboratories should send samples for confirmation to the NRL in required cases.

Background: We estimated what risk factors affect hospitalisation for confirmed pertussis cases among infants (child up to 1 year) in the Czech Republic based on data from the questionnaire-based enhanced surveillance system (ESS) in years 2015, 2017 and 2019.

Methods: Retrospective cohort study was conducted in which we assessed demographic, clinical data, vaccination status and risk/protective factors. Vaccination status was extracted from the electronic nationwide notification system (NNS). We performed descriptive, univariable and multivariable analysis using risk ratio (RR) and logistic regression with odds ratio (OR).

Results: A total of 104 confirmed cases (27, 13, 64) were reported in the ESS during 2015, 2017 and 2019. Most cases were in age group 1 month (24), more males (57). Fifteen cases were vaccinated and 89 unvaccinated. Of 88 hospitalised cases, 31 cases reported stay in Intensive Care Unit (ICU). The median length of hospitalisation was 8 days. Although the variable vaccinated in infants was statistically significant in a univariable analysis for outcome hospitalisation, RR 0.76 (95% CI 0.53-1.10), it was not in multivariable. Hospitalisation was strongly associated with the younger age group of 0-3 months adjusted by a smoking family member in a household (OR = 9.72; 95% CI: 2.97-31.81). Stay in ICU was strongly correlated with the younger age group of 0-3 months (OR = 5.07; 95% CI: 1.44-17.87) and with a contact with confirmed or probable pertussis (OR = 7.05; 95% CI: 1.36-36.52).

Conclusions: Our study demonstrated younger age and contact with other pertussis case as risk factors for hospitalisation of infants with pertussis. It is necessary to consider adolescent and adult boosters, including vaccination during pregnancy. We suggest integrating the variables from the enhanced surveillance system into the nationwide notification system, in order to simplify the data reporting and evaluation. Further studies are needed to evaluate the ESS and to monitor the vaccination of pregnant women against pertussis.

Acute gastroenteritis is commonly seen in pediatric clinical practice. It is a largely self-limited disease with a benign course. We present a case of teenager with gastroenteritis resulting in severe acute kidney injury. The decline in glomerular filtration was so significant that renal replacement therapy had to be initiated. We had to continue in intermitent hemodialysis for seven days until sufficient improvement in renal function. Clostridioides difficile was identified as a cause of vomiting, bloody diarrhea and subsequent dehydration. To our knowledge, this is the first reported case of C. difficile-associated diarrhea accompanied by acute kidney injury requiring renal replacement therapy in a child.

Aim: Invasive meningococcal disease (IMD) is still a major threat not only to the youngest age group of children but also to adolescents and young adults. Higher rates of meningococcal disease have also been reported in specific at-risk groups, such as secondary and tertiary students and members of the military. Infection occurs after close contact with a clinically ill individual, but most often with an asymptomatic carrier. The aim of our study was to determine the prevalence of carriage of N. meningitidis in young persons newly enlisted in the Army of the Czech Republic (ACR).Material and methods: During August 2021, persons entering the service in the ACR were asked to participate in the presented study approved by the Ethics Committee. Nasopharyngeal and oropharyngeal swabs were collected from the study participants in August. A questionnaire survey was administered to each of them after signing an informed consent form. The biological samples were cultured on the day of collection and analysed for N. meningitidis. In case of meningococcal detection, the serogroup of N. meningitidis was determined. For most of the study participants, swabs were repeated after 2-3 months, in October and November. Swabs were also collected from additional participants, namely students entering the first year of bachelor and master studies at a military college.Results: A total of 252 newly recruited young military professionals, 201 males and 51 females, were included in the study. Carriage of N. meningitidis was found in 13 study participants, i.e., 5.2 % of all tested subjects, with a predominance of positive findings in the summer period. All carriers were males while in females, meningococcal carriage was not detected. In carriers, serogroup B was predominant over non-groupable isolates (NG). There was no evidence of carriage of meningococcal groups A, C, W, X, or Y. Meningococcal isolation was significantly more successful from oropharyngeal compared to nasopharyngeal swabs. Only in five of 17 positive findings, meningococci were detected from both the oropharynx and nasopharynx. No isolation was made from the nasopharynx alone.Conclusion: The lower percentage of meningococcal carriage in young military professionals in the Czech Republic in the study period 2021 as compared to similar reports on military collectives from other countries can be attributed to the current epidemic situation, where the measures taken in connection with the efforts to prevent the spread of COVID-19 resulted in the loss of seasonality of respiratory diseases and also their significantly lower incidence. This correlates with a reduction in carriage in the monitored age category.

Aim: To assess the trends and changes in the incidence of invasive disease caused by Haemophilus influenzae in the Czech Republic (CR) between 1999 and 2020 with regard to the introduction of childhood vaccination against H. influenzae serotype b (Hib) in 2001. Characterization of strains by multilocus sequence typing (MLST) and search for correlations between serotypes, sequence types, and patient groups or clinical manifestations of the disease.

Material and methods: A total of 623 invasive H. influenzae strains from surveillance of invasive Haemophilus disease in the Czech Republic were analysed. All strains were biotyped based on phenotypic characteristics and serotyped using slide agglutination with specific a-f antisera. Three hundred and eighty-three strains from the collection of the National Reference Laboratory for Haemophilus Infections (NRL HEM) originating from surveillance in the CR were analysed by MLST and assigned to sequence types (ST). For analyses, the dataset was supplemented with five strains from the PubMLST database of serotypes rarely or not at all found in the CR. Similarity calculations based on MLST and strain (serotype, biotype, ST) and patient (diagnosis, sex, age) data were performed in BioNumerics 7.6.

Results: After the introduction of Hib vaccination in 2001, a dramatic decline of more than 90% was observed in invasive Hib disease over the following years. Between 1999 and 2020, a total of 623 cases of invasive disease caused by H. influenzae were recorded in the CR, with about 20 cases reported annually in recent years. At present, the dominant agents causing Haemophilus invasive disease in the CR are non-enveloped strains (HiNT) followed by strains of Hif and Hie serotypes. The most common manifestation of Haemophilus invasive disease in the pre-vaccination era was meningitis, while now it is sepsis. Sequence types of 383 strains from the NRL HEM collection originating from surveillance in the CR were analysed. The results showed high clonality of the encapsulated strains and diversity of HiNT strains, which is consistent with the results of others. Strain similarity analysis showed no demonstrable relationships between patient age or clinical manifestation and serotype and ST.

Conclusion: In invasive Haemophilus disease, there has been a dramatic change as a result of Hib vaccination after 2001, with a reduction of cases caused by Hib from tens to units annually. In the last decade, the situation in the CR has been stable with no significant changes in the number of cases or in the representation of causative serotypes and is in line with the reports from other EU countries. In order to monitor further developments, it is desirable that the NRL HEM should continue the surveillance of invasive disease caused by H. influenzae, including molecular biological characteristics of strains. MLST allows the characterisation of stra

Vibrio spp. are Gram-negative rod-shaped bacteria commonly present in marine, estuarine and natural freshwater environments. A few members of this genus are associated with human diseases. Here we present the study of Vibrio spp. isolations from 20 artificial recreational pools in Slovakia. Water samples were collected from artificial pools filled with mineralized thermal water in eight recreational areas in Slovakia in 2019 and 2020. Ninety six out of 176 samples were positive for Vibrio spp. Totally 118 different strains of Vibrio spp. were isolated, from which 77 belonged to potentially pathogenic species - V. cholerae (34 isolates), V. vulnificus (4 isolates), V. furnissii (3 isolates), V. fluvialis (25 isolates), V. alginolyticus (10 isolates) and V. mimicus (1 isolate). To our knowledge this is the first study demonstrating the presence of pathogenic or potentially pathogenic Vibrio spp. in artificial pools filled with thermal mineralized waters even disinfected with chlorine compounds.

Aim: Colistin resistance poses a serious clinical problem. This study aims to investigate the presence of plasmid-mediated resistance and heteroresistance among Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) clinical isolates at intensive care units of Main Alexandria University Hospital.

Material and methods: Seventy colistin-resistant and 30 colistin-susceptible K. pneumoniae and E. coli isolates constituted the material of the study. The rapid polymyxin NP (Nordmann Poirel) test was performed. Heteroresistance in colistin-susceptible isolates was investigated by population analysis profile. mcr-1 and mcr-2 genes were amplified by polymerase chain reaction (PCR).

Results: The rapid polymyxin NP test showed 100% concordance with the results of BMD (broth microdilution method). Heteroresistance to colistin was detected in 23.3% of colistin-susceptible K. pneumoniae isolates. All colistin-resistant isolates were negative for mcr-1 and mcr-2 genes.

Conclusions: The rapid polymyxin NP test is a reliable screening tool for colistin resistance, but not for heteroresistance. Other colistin resistance mechanisms should be investigated.