Polish Children Research Articles

The role of family health, socio-economic status, and heritability of neurodevelopmental disorders in the severity of cognitive dysfunctions in school-age children with ADHD

Introduction and objective: Little is known about the association between socioeconomic status, alcohol and tobacco use, and specific cognitive functions, like attention, working memory or executive functions in attention-deficit/hyperactivity disorder. We aimed to determine if socioeconomic adversity and unhealthy family behaviours are predictors of cognitive functions in children with attention-deficit/hyperactivity disorder. Materials and methods: We tested 176 Polish children with attention-deficit/hyperactivity disorder aged 10–13 using the PU1 Battery of Cognitive Functions, while the children’s parents completed a questionnaire on socioeconomic status and alcohol and tobacco use at home during their child’s life stages. We applied cluster analysis of family types and moderation analysis that tested the heritability of neurodevelopmental disorders in family interactions. Results: We identified three family types that raise children with attention-deficit/hyperactivity disorder: 1) families with higher socioeconomic status, lower level of unhealthy family behaviours, and average levels of children’s cognitive functioning, 2) families with low socioeconomic status, high level of unhealthy family behaviours, and average levels of children’s cognitive functioning, and 3) families with average socioeconomic status, low level of unhealthy family behaviours and low level of children’s cognitive functioning. We found no statistically significant associations between family predictors, the moderator variable, and cognitive functions in children with attention-deficit/hyperactivity disorder. Conclusions: The results of our study contrast with the large amount of evidence that shows a link between cognitive dysfunctions in children with attention-deficit/hyperactivity disorder and socioeconomic status and alcohol and tobacco use.

Bilinguals’ knowledge of ‘home’ and ‘school’ words revisited: evidence from Polish-English bilinguals

ABSTRACT Bilingual children's total vocabulary in each of their languages is often smaller than that of monolinguals. In their seminal study, Bialystok et al. (2010. ‘Receptive vocabulary differences in monolingual and bilingual children.’ Bilingualism: Language and Cognition 13 (4): 525–531) divided children's vocabulary into ‘home’ and ‘school’ words and found no differences in bilinguals’ knowledge of ‘school’ words compared to monolinguals. In Study 1, we asked 292 parents and teachers to categorize words into ‘home’ or ‘school’ contexts, and in Study 2, we analyzed the vocabulary of 220 Polish-English bilingual and monolingual (English and Polish) children aged 4.5–7. The results show that bilinguals knew fewer ‘home’ and ‘school’ words than monolinguals in each language. However, bilinguals were likely to be exposed to these words either at home or at school, whereas monolinguals would hear them in both contexts. For a small subset of English words that bilinguals heard in both contexts, bilinguals showed similar performance to monolinguals. Our results provide evidence for exposure effects in vocabulary acquisition.

Sex-specific effects of a Mediterranean diet on lower limb bone strength in Polish children

Lifestyle factors have the potential to influence bone health in various ways, whether positively or negatively. As osteoporosis is believed to originate in early years, it is therefore essential to indicate factors that may positively affect bone health during childhood. The aim of our study was to investigate the effects of early and current diet, vitamin D supplementation, and BMI z-score on bone properties in a group of children aged 3–7 years. A cross-sectional sample of 205 preschoolers and their parents participated in the study. Dietary assessment was made using a modified version of the Polish-adapted Mediterranean Diet score (MVP-aMED) on the basis of the data from food frequency questionnaire (FFQ), filled out by the parents. Quantitative ultrasound (QUS) was used in the assessment of bone properties. In the sex-stratified analysis, significant associations were observed between MVP-aMED score (β = 0.193, 95 % CI: 0.005, 0.237; p = 0.04), BMI z-score (β = −0.318, 95 % CI: −1.455, −0.039; p = 0.04) and QUS z-score, exclusively among girls. After adjustment, only the relationship with diet remained significant (β = 0.209, 95 % CI: 0.007, 0.255; p = 0.04), suggesting that a higher adherence to the Mediterranean Diet may be associated with better bone properties in girls aged 3–7 years old. Our results emphasize the importance of fostering healthy dietary habits and maintaining proper weight in children in order to promote optimal bone development.

Polish and American preschool children’s preferences for and perceptions of popular music

Polish and American preschool children’s preferences for and perceptions of popular music

Socioeconomic disparities in children's posture defects: a comparison between private and public educational institutions

The topic of risk factors for posture pathology in Polish children is relevant at present, as it is insufficiently studied and reflects the need to investigate the relationship between family socioeconomic status and the occurrence of posture defects, to develop relevant prevention and treatment strategies in the context of current socioeconomic conditions in Poland. The research aims to study posture defects in children depending on their socioeconomic status in the example of private and public schools. A comparison of the prevalence of deformities and posture disorders of participants in private and public educational institutions from 2017 to 2020 is presented. Theoretical research methods (literature analysis, generalisation); empirical methods (study of other researchers' experience), statistical analysis, and graphical presentation of data were used. More than 1300 Polish schoolchildren from private and public schools took part in this cross-sectional study. The most common problems were flat feet (54.73%), calf muscle contracture (44.30%), and valgus deformity (21.22%). The least common problems were funnel chest (0.37%), cavus foot (0.10%), and hammer toe deformity (0.04%). The general trend shows that problems with flat feet and calf muscle contracture were more common among participants in both types of educational institutions. There was a general trend of increasing the number of nosological forms per patient in both private and public institutions over a period of three years. Private institutions had significantly fewer cases of one patient having more than one nosological form as compared to public institutions.

Use of Dietary Supplements among Polish Children with Inflammatory Bowel Disease: A Two-Center Pilot Study.

Inflammatory bowel disease (IBD) includes Crohn's disease (CD) and ulcerative colitis (UC). These diseases are characterized by inflammation, which may be a consequence of changes in the intestinal microbiota and lead to mineral and vitamin deficiencies. The aims of this study were to determine the level of dietary supplement intake in children with IBD and to determine the influence of factors such as sex, nutritional status, diet, and other comorbidities on supplement intake. The study was conducted from May 2022 to September 2023 and was a prospective study. The group of children with IBD that ultimately qualified for the study numbered 96, and the control group numbered 30. The children who participated in the study were aged 4-18 years. Most parents of children with IBD (81.4%) declared that they use supplementation for their children, while 75% of parents of children without IBD declared giving their children nutritional supplements. Vitamins in both groups were most often given to children as dietary supplements (p = 0.018), including vitamin D. Depending on the diet used, the intake of vitamin B6 (p = 0.018), vitamin E (p = 0.040) and iron (p = 0.006) was significantly different among children with IBD. Statistical significance (p = 0.021) was observed for supplementation use and disease stage among children with IBD. For 80.2% of parents of children with IBD, the main reason for using supplements was a doctor's recommendation. In the control group, 43.3% of parents indicated that the main reason for using supplements was to correct nutritional deficiencies. Supplementation was common in both groups, but attention should be paid to other current diseases in children with IBD and to nutritional status. In our opinion, educating parents about supplementation is important, especially among parents of children with IBD.

Population Norms for Hand Grip and Precision Grip Strengths in Polish Children and Adolescents Aged 3-19.

Background: Normative data on hand and precision grip strengths are essential for evaluating the level of development, the efficacy of rehabilitation, and treatment results. The need for established norms of grip strength in Polish children is one of the problems that Polish physiotherapists and physicians face when treating upper limbs. The aim was to establish normative values of hand and precision grips strengths in Polish children and adolescents aged 3-19. Methods: In the years 2012-2023, a sample of 358 children and adolescents with no history of upper limb injuries or congenital upper extremity defects were randomly chosen from kindergartens, primary schools, middle schools, and high schools. They were living in urban agglomerations and in smaller towns or villages. Hand and precision grips like the pincer, three-point, side, and opposition grip strength were assessed using a hand dynamometer and pinchmeter in standard positions. Results: The strength in all types of examined hand grips increases with chronological age in both genders. The grip strength was higher in the boys' group than in the girls' and it was higher in the right hand than in the left, but the difference was no more greater than 10%. Detailed data with standard deviation were presented in the form of a table, divided by age and sex. Conclusions: Norms for grip strength were provided for Polish children and adolescents aged 3-19, allowing therapists and physicians to compare Polish patients with that of normally developed, healthy children of the same age and sex.

The Normal Weight Obesity (NWO) Problem-Prevalence and Time Changes in Children and Adolescents From Kraków (Poland).

Normal weight obesity can be associated with an increased risk of metabolic abnormalities, systemic inflammation and mortality. The main aim of the study was to analyze the changes in the prevalence of normal weight obesity in 8-18-year-olds from Kraków (Poland) between 2010 and 2020. The study was based on two sets of cross-sectional, school-based data obtained in 2010 and 2020. Body height, weight, and fat percentage were obtained. Body mass index was calculated, and only normal-weight individuals were included. Normal weight obesity was defined as normal BMI with adiposity >85 percentile for age and sex. The prevalence of normal weight obesity among Polish children and adolescents has been alarming for at least the last 10 years. Depending on the sex and age, normal weight obesity was present in more than 10% up to even more than 20% of the examined population. Alarming numbers of Polish children and adolescents suffer from NWO and this problem seems to be present for at least the last decade. A need for a maximally universal definition and cut-offs to diagnose normal weight obesity should also be stressed, as it will be helpful in providing the best prophylaxis and help to persons already suffering from normal weight obesity.

Parental report of vocabulary in 3- to 6-year-old Polish children: Reliable but not valid.

For over 30 years, parental reports have been used to study the vocabulary of children under 4 years of age. Research exploring parental checklists as a measure of vocabulary in older children is very limited. Typically, authors of parental checklists report the reliability of the developed tools but do not explore validity in terms of the agreement between parental assessments and the children's actual word knowledge. We aimed to explore the reliability and validity of a parental checklist for assessing vocabulary in children aged between 3 and 6 years. Furthermore, we aimed to evaluate the agreement between indirect (parental checklist) and direct (picture naming and picture recognition tasks) assessments of children's vocabulary. A group of 94 typically developing monolingual Polish-speaking children aged between 3 and 6 years were first directly tested onsite with picture naming and picture recognition tasks (Cross-Linguistic Lexical Tasks). Subsequently, the participants' parents completed an online checklist containing the same set of 128 items and marked all the words that they had ever heard in their child's spontaneous speech. The parental checklist demonstrated very high internal consistency. The scores of the parental checklist and vocabulary tasks were moderately correlated. We compared the total number of words marked by parents and the number of items correctly identified by children in the picture naming and picture recognition tasks. In picture naming, we found no difference between the children's scores and the number of words selected by parents. However, parents selected significantly fewer words than children correctly recognised in the picture recognition task. When data were analysed at the level of individual items (i.e., whether parents selected exactly the same items that children answered correctly), we found that the level of agreement was low. The level of agreement correlated negatively with the children's vocabulary; that is, the more words a child knew, the lower the agreement between the direct measure and the parental checklist. Parental checklists should be used with caution in children aged between 3 and 6 years, especially if the assessed children have a large vocabulary and if item analysis is planned. Such checklists may be of more use in younger children or in children with limited vocabulary. What is already known on the subject Parental checklists are commonly used to assess the vocabulary of children younger than 4 years of age. Previous research has indicated that parental checklists are reliable in terms of internal consistency and valid in terms of predictive and convergent validity. What this paper adds to the existing knowledge This study introduces a parental checklist designed for assessing the vocabulary of monolingual Polish-speaking children aged between 3 and 6 years. Statistical analyses reveal that while the parental checklist exhibits high reliability, and the scores on the checklist correlate with direct measures of vocabulary, the agreement between parental reports and direct vocabulary measures (i.e., validity) is notably low, particularly when examining individual test items. What are the clinical implications of this work? These findings underscore the importance of exercising caution when using parental vocabulary checklists with children aged between 3 and 6 years. These checklists can serve as a replacement for direct vocabulary tests only when the general/overall score is needed. However, when specific words are the subject of interest, parental reports may not be a valid measure.

Supporting Infants' Motor Development through Water Activities: A Preliminary Case-Control Study.

The first twelve months of an infant's life are the most dynamic time in the development of motor activities. Water activities can positively stimulate the motor skills, visual perception, and cognitive abilities of infants. The purpose of this study was to evaluate the motor development of infants aged 3-12 months participating in water activities. Participants in the study included 43 infants aged 3-12 months who attended water activities classes at Warsaw City swimming pools (n = 21) and infants not attending any classes (n = 22). Two methods of assessing motor development were used in the study: the Alberta Infant Motor Scale (AIMS) and the Early Motor Development Questionnaire (EMQ). The raw scores of the AIMS test and the EMQ questionnaire were statistically significantly different (p < 0.05) in both groups between the first and second examinations. In contrast, there was a statistically significant improvement in motor development measured by AIMS and expressed in percentiles (p = 0.002) and in percentiles for Polish children (p = 0.030) in the water group. The age-independent total score of the EMQ before and after the intervention did not change significantly (p = 0.149). The water environment has the potential to support the motor development of infants aged 3-12 months.

Deficient or Normal Growth Hormone Secretion in Polish Children with Short Stature: Searching for Clinical Differences.

Short stature affects approximately 2.5% of children. Some of them, when diagnosed with growth hormone deficiency (GHD), benefit from recombinant human growth hormone (rhGH) therapy; in others, this treatment is controversial. We aimed to present the clinical characteristics of Polish short stature children in the context of current GHD diagnostic standards, as obtaining more data gives a broader foundation for the potential modifications of diagnostic and therapeutic recommendations. This retrospective analysis was based on a cohort of 277 short stature children divided into two subgroups depending on their peak growth hormone (GH) cutoff level, set at 10 ng/mL: 138 had growth hormone deficiency (GHD) and 137 had normal growth hormone secretion (GHN). These subgroups were then compared based on the extracted clinical data. In the obtained result, no significant differences between the GHD and GHN subgroups were found in any of the variables, including the following: gender distribution, birth weight, bone age delay, height SDS, IGF-1 SDS, vitamin D levels, celiac disease indices, prevalence of hypothyroidism or anemia. As our results point to major clinical similarities between the GHD and GHN children, it seems that distinguishing patients with normal GH secretion from those with deficient GH secretion based on a 10 ng/mL cutoff value might not be clinically relevant.

Acute Pancreatitis in Pediatric Acute Lymphoblastic Leukemia (AcuPA Study): A Nationwide Survey in Poland.

This study aimed to identify the risk factors for acute pancreatitis (AP) and its impact on outcomes in Polish children treated for ALL. The study group included 2303 children receiving intensive chemotherapy for ALL. The group was divided into patients with at least one episode of AP and those who did not develop AP after treatment for ALL. The cumulative incidence of AP in the study group was 4.08%. Older age was an independent risk factor for the development of AP (OR = 1.05; 95%CI = 1.006-1.098; p = 0.03). The overall mortality associated with AP was 2.13%. The probabilities of disease-free survival (p-DFS) and event-free survival (p-EFS) in both subgroups were 0.84 vs. 0.86, log-rank p = 0.65 and 0.75 vs. 0.80, log-rank p = 0.12, respectively. A total of 22 out of 94 patients (23.4%) with AP were re-exposed to asparaginase (ASP) during the subsequent treatment phases. Only one patient re-exposed to ASP (4.5%) developed a second episode of AP. There were no significant differences in p-DFS and p-EFS between patients re-exposed and not re-exposed to asparaginase (0.78 vs. 0.86, log-rank p = 0.27 and 0.63 vs. 0.79, log-rank p = 0.09, respectively). The incidence of AP in children with ALL is low and related to patients' age. The development of AP does not seem to influence p-DFS and p-EFS in children with ALL. Recurrence of AP after re-exposure to asparaginase in patients with ALL and a history of AP is low (4.5%). Re-exposure to asparaginase after the first episode of AP does not improve either p-DFS or p-EFS in children with ALL.

Polish Mother and (Not) Her Children: Intersectional State-Violence against Minors in Poland

This article seeks to explain the political responsibility that Polish right-wing female politicians directly associated with the 2015–2023 Polish government and the then-ruling Law and Justice Party bear in the state-sanctioned violence against minors in the context of LGBT- and immigration-related issues. Its main assumption is that, in times of the nationalist surge that has been sweeping Poland, women using anti-LGBT and anti-immigration discourses helped to legitimize discriminatory state practices and, consequently, made a significant contribution to the enactment of white, Christian, and heteronormative identity on Polish children. Drawing upon Critical Discourse Analysis, this work examines the anti-LGBT and anti-immigration political talk by female politicians who, in their narrative strategies, adopt the position of a “Polish mother” on a mission to save a “child in danger”. Through my analysis, I aim to demonstrate that anti-LGBT and anti-immigration discourses are equally significant areas of women’s political engagement. Despite the prevalent cultural norms of caring motherhood, women do exercise their agency in political struggles as supporters of discriminatory state policies directed against minors by re-politicizing a symbolic figure of the “Polish mother”.

TLR2 and TLR4 Polymorphisms Are Not Associated with Dental Caries in Polish Children.

The aim of the present study was to analyze the association of the TLR2 (Toll-like receptor 2 gene) 2258G>A (rs5743708), TLR4 (Toll-like receptor 4 gene) 896A>G (rs4986790), and TLR4 1196C>T (rs4986791) polymorphisms with dental caries in Polish children. The participants, 261 15-year-old children, were divided into two groups: 82 cases (i.e., children with DMFT (Decayed, Missing, and Filled Teeth) index >5, having either moderate or high caries experience, assigned as the "higher" caries experience group) and 179 controls (i.e., children with DMFT ≤ 5, having either low or very low caries experience, assigned as the "lower" caries experience group). Genomic DNA was isolated from buccal swabs, and genotyping was determined by means of real-time PCR (polymerase chain reaction). There were no significant differences in the genotype or allele distributions in all tested SNPs (single nucleotide polymorphisms) between children with "higher" caries experience and those with "lower" caries experience. TLR4 haplotype frequencies did not differ significantly between cases and controls. In an additional analysis with another case definition applied (subjects with DMFT ≥ 1 were assigned as "cases", whereas children with DMFT = 0 were assigned as "controls"), no significant differences in the TLR2 and TLR4 genotype, allele frequencies, and TLR4 haplotype frequencies were found between the case and the control groups. The results of the present study broaden our knowledge on the potential genetic factors that might affect caries risk and suggest that TLR2 rs5743708 and TLR4 rs4986790 and rs4986791 SNPs are not associated with dental caries susceptibility in Polish children.

The education of Polish children deported to the USSR and evacuated to the near and Middle East during World War II

The text describes fragmentary education gained by children deported from the territory of Poland occupied by the Soviet Union to the forced labour camps and kolkhozes. They were subsequently evacuated from the USSR to Iran and other countries controlled by Great Britain. The release of such a large group of people from Gulag camps and places of isolation was an unprecedented situation in the Soviet system, and the presence of such a large number of civilians along the regular military units being formed at the time was unexampled in history. The authors illustrate education methods and conditions of Polish youth released with their families from Gulag camps and locations of compulsory labour together under the so-called amnesty. They provide details regarding the young refugees’ health issues, numerous cases of starvation to death or symptoms of post-traumatic stress (PTSD ‒ post-traumatic stress disorder). They present the problems with the evacuation itself and confront the standards of living and expulsion from Soviet Russia with a highly positive reception of refugees on the Persian land. They indicate their further fate, including the creation of orphanages and schools, as children in the USSR were deprived of the opportunity to learn. It was important to depict extremely difficult, frequently provisional attempts at schooling Polish youngsters against the background of historic events.

A PROPOSED METHOD FOR SPEECH AND LANGUAGE TESTING WITHIN A HEARING SCREENING PROGRAM FOR CHILDREN STARTING SCHOOL

This article sets out a proposal for how one might expand hearing screening in school children so as to include testing of speech mastery. From 2008 to 2019, the Institute of Physiology and Pathology of Hearing (IPPH) implemented a program to screen the hearing of Polish children starting school, covering over 1 million children. Its success prompted the development of a screening model to cover the entire process of verbal communication. One result was the "Equal Start in Education", a program implemented from 2019 to 2022 in the Lublin province, otherwise known as the "Lublin Program for Early Detection and Therapy of Communication Disorders in Children Starting School". It was conducted by the University Children’s Clinical Hospital in Lublin and the Maria Curie-Sklodowska University, in cooperation with IPPH, and was designed to assess hearing, auditory processing, voice, and speech-language. The program was successful in addressing various issues related to the screening of all communication skills. Here we present findings from the program and propose a testing procedure used to evaluate speech. The screening procedure might be applied more widely in the future, and could diagnose those children requiring audiological and speech-language therapy.

Pathways linking greenspace to behavioural problems in Polish children

BackgroundPrevious cross-sectional studies have found a beneficial relationship between greenspace and children's behaviour. Nevertheless, evidence on the mechanisms underlying this association remains scant. We examined whether the availability of greenspace was related to fewer behavioural problems in Polish children and investigated potential mechanisms. MethodsData were obtained from the case-control NeuroSmog study, in which children with and without attention deficit hyperactivity disorder (ADHD) were tested from October 2020 to September 2022. The analytic sample comprised 679 children aged 10–13 years. Parents reported internalizing, externalizing, and total behavioural problems using the Child Behaviour Check List (CBCL), as well as information about the presence of a domestic garden and potential mediators: greenspace perception, neighbourhood social cohesion, and physical activity. Tree and grass covers were extracted in 500 m and 1 km buffers around lifelong residences. Structural equation modelling (SEM) was used to examine the psychosocial pathways linking the greenspace metrics to behavioural problems. ResultsGreenspace was only indirectly related to fewer behavioural problems. Specifically, tree cover was related to greater levels of physical activity which, in turn, was related to fewer internalizing and total behavioural problems. Tree cover and presence of garden were related to greenspace perception which, in turn, was associated with higher neighbourhood social cohesion which, in turn, was linked to fewer behavioural problems. The patterns of associations in children without ADHD were very similar to those in the full sample except that the associations from garden to greenspace perception and from physical activity to total behavioural problems were no longer significant. The only association persisted among girls was from neighbourhood social cohesion to behavioural problems and among boys were from tree cover to physical activity and tree cover and garden to greenspace perception. ConclusionTrees and garden, but not grass, are linked to fewer behavioural problems through greenspace perception, neighbourhood social cohesion, and physical activity in Polish children.

Lifelong greenspace exposure and ADHD in Polish children: Role of physical activity and perceived neighbourhood characteristics

Previous research found a protective association between greenspace exposure and attention deficit hyperactivity disorder (ADHD) diagnosis, but previous studies did not investigate mediatory pathways involving child physical activity (PA) and environmental perceptions. Here, we examined the association between lifelong exposure to greenspace and ADHD diagnosis and potential underlying mechanisms (i.e., perceived greenspace, PA, neighbourhood social cohesion, and neighbourhood safety) in children aged 10–13 with and without ADHD. The sample (N = 689) was collected within the NeuroSmog case-control study, where children with (N = 203) and without ADHD (N = 486) were recruited from 18 towns in Southern Poland. ADHD diagnosis was ascertained according to the International Classification of Diseases 11th Revision criteria. Greenspace exposure was defined as the percentage of grass and tree cover in 500 m and 1 km buffers around lifelong residential addresses, respectively. Parents reported information about the availability of domestic garden and data on potential mediators was collected with questionnaires. Structural equation modeling was used to examine hypothesized pathways, and their interplay, linking the three greenspace measures to ADHD. We found that greenspace was indirectly related to ADHD diagnosis: tree cover was positively related to PA, and PA was subsequently negatively related to ADHD diagnosis. Tree cover and garden were both associated with higher levels of perceived greenspace, which in turn related to stronger perceptions of neighbourhood social cohesion. Our findings suggest that exposure to greenspace may lead to lower likelihood of ADHD diagnosis indirectly through PA. These findings highlight how providing children with better access to natural environments for PA may support normal neurodevelopment.

Molecular Detection of HPV, EBV, HSV-1, HCMV, and H. pylori Pathogens: An Evaluation among Polish Children with Molar Incisor Hypomineralization (MIH).

Molar incisor hypomineralization (MIH) is a congenital disorder of the enamel tissue, characterized by a quantitative deficiency. In childhood, infections such as EBV, HSV-1, HCMV, or H. pylori may occur and cause various diseases. This study aimed to investigate the prevalence of HPV, EBV, HSV-1, HCMV, and H. pylori infections in two groups of children: children with molar incisor hypomineralization (MIH) and a control group, using molecular methods. The study group included 47 children aged between 6-13 years who had been diagnosed with MIH. The control group consisted of 42 children. The study found that, in the MIH group, the prevalence of HPV-16 was 6.38%, HPV-18 was 4.26%, EBV was 31.91%, HSV-1 was 4.26%, HCMV was 4.26%, and H. pylori was 12.77%. There were no significant differences in the prevalence of any of tested pathogens between the study and the control group (p > 0.05). However, the study found a higher prevalence of EBV infection in children who had smallpox/pneumonia by the age of 3 years. Ten children were found to have at least two pathogens present. Moreover, both groups had a high prevalence and activity of EBV. These findings provide new insights into the carriage of pathogens among children with MIH, providing new information for parents, scientists, and healthcare professionals.

Фонологични процеси в усвояването на плавните съгласни р и л от деца, овладяващи славянски езици (по данни на проф. д-р Иван Георгов и съвременни данни)

The report is devoted to phonological processes in the acquisition of liquid consonants r and l in early childhood (up to 3 years) by children learning Slavic languages. The starting point of this research is a publication by Prof. Dr. Ivan Georgov from the beginning of the last century (1913). The thesis of the Bulgarian researcher was that up to the age of three, children mastering Slavic languages regularly replace r with l in certain phonological positions due to their similar place of articulation (both are alveolar, differing only in the manner of articulation: r is vibrant, whereas l is lateral). The report compares Georgov's Bulgarian data with contemporary empirical material: contemporary Bulgarian data excerpted from author’s own corpus as well as Polish and Russian data taken from the CHILDES international database). The results point to two main strategies in the acquisition of the vibrant consonant r by children speaking the three Slavic languages: First, a dominant substitution of r with l. This strategy was followed by the Polish children (thus emphasizing the relevance of the conclusions made by Georgov more than a century ago). Second, dominant elision of р (r) along with limited cases of substitution by means of л (l) and (or) й (y). This strategy was followed by the Bulgarian children from the author’s contemporary corpus and by the Russian subject. The differences in the two strategies are explained in the light of the changes in our language over the last decades.