Epidemiologie Mikrobiologie Imunologie最新文献

Aim: We aimed to determine the prevalence of SARS-CoV-2 infection, including both symptomatic and asymptomatic courses, and to identify predictors of asymptomatic or symptomatic SARS-CoV-2 infection in patients within seven months after allo-HSCT (allogenic hematopoietic stem cell transplantation) in the Omicron period.

Methods: Prevalence of the past SARS-CoV-2 infection was determined in patients within seven months after allo-HSCT in the Omicron period using the cellular and humoral immune response against the SARS-CoV-2 nucleoprotein (NCP).

Results: Positive markers of past infection were identified in 45.2% of patients (n = 42). The infection was asymptomatic in 68.4% of anti-NCP positive patients. The search for risk factors for symptomatic SARS-CoV-2 infection in allo-HSCT recipients revealed that a low level of B cell reconstitution was the only significantly associated risk factor.

Conclusion: A high proportion of allo-HSCT recipients who were asymptomatically infected within up to seven months after transplantation from 2022 to 2023 despite being immunosuppressed and unvaccinated indicates an attenuation of the circulating virus and may signal less risk for transplanted patients from SARS-CoV-2 infection in the Omicron period. Vaccination of these patients against SARS-CoV-2 was shown to be associated with a low but significant risk of exacerbation of cured chronic GVHD (graft versus host disease) and the risk of de novo GVHD. The low level of B-cell reconstitution was the only significant risk factor for symptomatic SARS-CoV-2 infection in HSCT recipients.

Objective: Observational study of patients diagnosed with severe community acquired pneumonia (sCAP) carried out to evaluate levels of interleukin 17A (IL-17A) and T helper 17 (Th17) lymphocyte count in peripheral circulation and bronchoalveolar lavage fluid (BALF) in the early course of sCAP of different etiology and to compare them with patient's characteristics and outcome.

Material and methods: Cohort of 74 patients with sCAP was analyzed and respective microbial etiology established. According to pathogens, 3 subgroups of patients were created: bacterial, viral and mixed etiology. Th17 count and IL-17A levels were measured using flow cytometry and ELISA in peripheral blood and BALF. Data were compared with respect to etiology and their correlation with 30and 90-day mortality was statistically analyzed.

Results: There was no statistically significant correlation in Th17 count and IL-17A levels in blood and BALF between etiological subgroups of CAP and no correlation was found with respect to measured parameters and 30and 90-day mortality. Nevertheless, increased Th17 cell count and IL-17A levels in peripheral blood, but not in BALF, in the early course of sCAP are correlated with increased relative risk of death from sCAP. Other factors increasing relative risk of death in patients with sCAP found in our cohort were male sex and advanced age.

Conclusions: Systemic Th17 count and IL-17A levels in the early course (up to 7 days from admission) of sCAP may be correlated with severity and outcome of sCAP.

Aim: To determine the occurrence of species of Babesia potentially pathogenic for humans in ticks and in the blood of dogs and deer in selected regions of the Czech Republic. To compare the prevalence of Babesia spp. in ticks with that of other tick-borne pathogens, such as Borrelia spp., Anaplasma spp., and Rickettsia spp.

Material and methods: Tick samples were individually homogenized. DNA was isolated from tick samples and animal blood. The detection of Babesia spp. was based on PCR of the 18S rRNA gene, and the identification to the species level was done by sequencing analysis of the PCR products.

Results: In 2014-2016, ticks and blood of dogs and deer collected in various areas of the Czech Republic were analyzed. In a set of 675 Ixodes ricinus ticks, the positivity rate for Babesia spp. varied from 0.0 to 3.3 %. The species Babesia venatorum, Babesia microti (both pathogenic for humans), and Babesia capreoli were identified in ticks by sequencing analysis. The prevalence of Babesia spp. in ticks compared to that of other pathogens such as Borrelia burgdorferi s. l. (29.3 %) or Anaplasma phagocytophilum (4.9 %) was lower and comparable to that of Rickettsia spp. (1.6 %). Co-infection with Borrelia burgdorferi s.l (B. venatorum - Borrelia garinii, Borrelia afzelii, and B. microti - B. afzelii) was found in a third of Babesia spp. positive ticks. Out of 109 dog blood samples, 3.7 % were positive for Babesia spp., specifically Babesia gibsoni and Babesia vulpes. Of 50 blood samples of wild deer from the natural ecosystem, the positivity rate reached 4.0 %. The species Babesia divergens, a major human pathogen, was identified. Out of 80 blood samples from farmed deer, 5.0 % were positive for the species Babesia odocoilei. Nucleotide sequences of the agents causing human babesiosis were deposited in the gene bank under accession numbers ON892053 (B. venatorum), ON892061 (B. microti), and ON892067 (B. divergens).

Conclusions: Using PCR of the 18S rRNA gene and amplicon sequencing, three species of Babesia causing human babesiosis were detected in the Czech Republic: B. divergens, B. venatorum, and B. microti. Babesia spp. pathogenic for humans pose a potential risk especially in asplenic and immunocompromised patients. The detected co-infections with Borrelia spp. can be the cause of a complicated course of the disease.

Tularemia is a zoonosis caused by Francisella tularensis, a gram-negative aerobic bacterium belonging to the class of Gammaproteobacteria and the family Francisellaceae. Despite its undeniable importance for human health, there is little data on the current distribution of F. tularensis in various hematophagous arthropods. The aim of this study was to perform a mass molecular screening of different possible hematophagous vectors: ticks (4348 ticks of the species Ixodes ricinus, Dermacentor reticulatus, and Haemaphysalis concinna), mosquitoes (4100 specimens of Aedes vexans), and blackflies (6900 specimens of the Simulium spp.) for the presence of F. tularensis in the Břeclav district in 2022. Only two specimens were positive for the specific DNA of Francisella tularensis subsp. holarctica. Both samples originated from D. reticulatus, one collected from infested roe deer and the other included in a pooled sample (n = 10). Both positive samples were sequenced, and the presence of F. tularensis subsp. holarctica was confirmed. In addition, the absence of F. tularensis in mosquitoes and black flies was documented.

The numbers of diagnosed and reported cases of infection with the SARS-CoV-2 virus causing the disease COVID-19, which grew into a global pandemic, have remained consistently low in all countries, including the Czech Republic, since May 2023, when the World Health Organization declared an end to the pandemic. However, it must be said that the measures implemented to control this infection did not meet all expectations. Although new mutations of the virus that can potentially cause disease, continue to emerge, it appears that most people have gradually learned to coexist with them. However, due to some unique properties of the SARS-CoV-2 virus and its variants, there will still be predisposed individuals who will develop illness and need hospitalization along with effective treatment to be supported and monitored by adequate laboratory tests. This article is a commentary on this issue and deals primarily with the diagnosis and care of early-phase COVID-19 patients. Author's translation of the article into English is available at: https://www.spadia.cz/media/2085/lessons fromthecovid-19pandemic.pdf.

A systematic investigation of an outbreak of postoperative sepsis in nine patients following surgery in the operating rooms of a primary-type hospital between November 26 and 28, 2018 was conducted to determine the extent of the outbreak, the vehicle, and the route of transmission. The comprehensive investigation included epidemiological, microbiological, molecular biological, and environmental methods. A retrospective cohort study was used to find associations between individual exposure factors and outcomes, the respective septic conditions. Nine of 24 surgery patients were infected (AR 37.5 %). An identical strain of Acinetobacter calcoaceticus was found in biological specimens of two infected patients. The combined investigation did not reveal the vector or route of transmission. Immediate infection prevention and control measures avoided new cases of postoperative sepsis.

Aim: An analysis is presented of whole genome data of Streptococcus pneumoniae serotypes 8 and 22F isolated in the Czech Republic from invasive pneumococcal disease (IPD) in 2014-2020. New multivalent pneumococcal conjugate vaccines (PCVs) are effective against these serotypes. Recently, serotypes 8 and 22F have been among the leading causes of IPD in the Czech Republic. S. pneumoniae isolates from the Czech Republic were compared with those of the same serotypes recovered in other countries in the same period and available in the international database PubMLST.

Material and methods: Isolates from IPD of serotypes 8 (22 isolates) and 22F (21 isolates) recovered in the Czech Republic in 2014-2020 were subjected to whole genome sequencing (WGS). The genomes were analysed and compared using the international database PubMLST.

Results: Most of the studied Czech serotype 8 isolates belong to two main subpopulations. The first subpopulation, dominated by ST-53 isolates, is part of a highly abundant group of genetically close European and non-European isolates that are clearly separated on the phylogenetic network. The second subpopulation of Czech serotype 8 isolates (dominated by ST-404) is more genetically variable and forms a separate lineage on the global phylogenetic network, with no other European isolates. Czech isolates of serotype 22F are a homogeneous population with a clear predominance of ST-433, which belongs to a genetically close European population.

Conclusion: The analysis of WGS data of IPD isolates of serotypes 8 and 22F provided a detailed insight into the genetic relationships between the Czech populations of these serotypes. It also allowed comparison of the Czech populations with the matched populations from other European and non-European countries. The obtained results add to the body of knowledge about the spread of genetic lineages causing IPD in the Czech Republic in the post-vaccination period and provide a basis for considering whether the use of the new multivalent PCVs in the Czech Republic would be beneficial.

The novel personal protection equipment based on a face mask equipped with a nanofiber filter functionalized with povidone iodine has been developed and tested in a clinical trial. This nanofiber filter was characterized with a low flow resistance and, thus, allowed comfortable breathing. The performed study proved that the novel nanofiber filter with incorporated povidone-iodine was characterized with a slow release of iodine which minimized side effects but kept disinfection efficiency. Our clinical study performed on 207 positively tested SARS-CoV-2 patients wearing the PPE for 4-8 hours daily for 1 to 4 days has shown that even the iodine amount as low as 0.00028 ppm was sufficient to significantly decrease the reproduction number and, very importantly, to protect against severe course of disease.

Human papillomavirus (HPV) is the most common sexually transmitted viral infection worldwide, which may result in the development in benign lesions or malignant tumors. The prevalence of HPV infection is twice as high in pregnancy as in non-pregnant women. Additionally, there is a risk of vertical transmission of HPV from mother to fetus during pregnancy or childbirth. Various studies have reported an increased risk of adverse pregnancy outcomes in HPV-positive women, including miscarriage, preterm birth, premature rupture of membranes, preeclampsia, fetal growth restriction, and fetal death. HPV vaccination is not currently recommended during pregnancy. On the other hand, there is no evidence linking HPV vaccination during pregnancy with adverse pregnancy outcomes and termination of pregnancy is not justified in this case.

Objectives: Given the lack of data on the seriousness of respiratory syncytial virus (RSV) infections in the Czech Republic, an analysis was made of available data on hospitalizations and the hospitalization risk was estimated by age group.

Methods: Data from the National Registry of Reimbursed Health Services and the National Registry of Hospitalizations were used for the analyses. Hospitalizations and deaths due to RSV infection (diagnoses J12.1, J20.5, J21.0) from 2017-2022 were analyzed by age group.

Results: Over the six-year period, there were 6,138 hospitalizations with the above diagnoses, ranging between years from 307 to 2,162. The estimated overall hospitalization risk per 100,000 population and year for diagnoses J12.1, J20.5, and J21.0 was 9.64, varying between 2.87 (2020) and 20.56 (2021). Age-group analysis showed the highest risk for children under 6 months of age (891.6/100,000 population and year) and the lowest for 20-34-year-olds (0.1/100,000 population and year). Children under 1 year of age accounted for 63.1% of hospitalizations with the above diagnoses. For patients 65 years and older, the annual hospitalization rates varied between 3.3-15.3%. The most frequent cause of RSV-associated hospitalizations was bronchitis, diagnosed in 55.4% of patients. Among those hospitalized with diagnoses J12.1, J20.5, and J21.0, 38 deaths were reported, representing a case fatality rate of 0.62%. The highest case fatality rate (6.5%) was observed in the age group 35-49 years.

Conclusions: RSV-associated hospitalizations have been reported in all age groups in the Czech Republic. The highest RSV-associated hospitalization risk in 2017-2022 was estimated among children under 6 months of age. Passive surveillance using the available registries could currently provide the basis for measures specifically tailored to the youngest age categories. Data on the hospitalization of adults, particularly senior citizens, must be improved and complemented with active surveillance.