PROBLEMS of Infectious and Parasitic Diseases最新文献

{"title":"SARS-COV-2: INSIGHT INTO THE EMERGING GENETIC VARIANTS","authors":"N. Korsun, I. Trifonova, Veselin Dobrinov, Iliyana Grigorova, S. Angelova, I. Alexiev","doi":"10.58395/pipd.v49i3.73","DOIUrl":"https://doi.org/10.58395/pipd.v49i3.73","url":null,"abstract":"SARS-CoV-2 is a highly contagious virus, which appeared in China in late 2019, spread rapidly and caused the largest pandemic in the last 100 years. Despite the intensive research, there is no specific antiviral drug currently. Effective vaccines have been developed in a short time and they are already widely used. As a RNA virus, SARS-CoV-2 mutates constantly, and several thousand genetic variants have emerged in the course of the pandemic, some of which are associated with increased infectivity, reinfection risk, reduced activity of therapeutic antibodies and reduced effectiveness of vaccines. This review highlights the features in SARS-CoV-2 structure and replication cycle that would help to understand the significance of individual mutations contained in the emerging genetic variants and to predict the impact of mutations on viral transmissibility, disease severity, diagnostics, therapeutics or immune escape. The main characteristics of the variants of concern are presented.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130970091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DRUG RESISTANCE MUTATIONS AND TRANSMISSION CLUSTERS OF THE HIV-1 CRF01_AE SUB-EPIDEMIC IN BULGARIA","authors":"Lyubomira Grigorova, Reneta Dimitrova, Aleksandra Partsuneva, A. Gancheva, Asya Kostadinova, I. Elenkov, N. Yancheva, M. Stoycheva, T. Doychinova, L. Pekova, Minas Kosmidis, I. Alexiev","doi":"10.58395/pipd.v49i3.68","DOIUrl":"https://doi.org/10.58395/pipd.v49i3.68","url":null,"abstract":"Background. In Bulgaria the second most predominant HIV-1 strain after subtype B is CRF01_AE.\u0000Material and Methods. 270 HIV-1 polymerase (pol) CRF01_AE sequences collected between 1995–2019 were analyzed with the phylogenetic approach. To identify transmission clusters, we used two different genetic distance thresholds (d), i. e. 1.5% and 0.5%.\u0000Results. Genetic distance d=1.5% defined more distant infections in a huge cluster of 154 sequences composed mostly of people, who inject drugs (PWID), whereas when (d) was reduced to 0.5%, we determined more recent transmissions and the large cluster disintegrated into smaller ones. Different drug resistance mutations (DRM) were detected in patient’s HIV-1 pol sequences and were most common in male heterosexual (HET) single sequences.\u0000Conclusions. Our data showed repeated introduction of CRF01_AE in Bulgaria and rapid spread of the infection among PWID groups. Molecular monitoring of the epidemic among PWID communities could help reduce the spread of HIV-1 infection.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115708956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NOROVIRUSES - A HIDDEN THREAT","authors":"A. Stoyanova","doi":"10.58395/pipd.v49i3.71","DOIUrl":"https://doi.org/10.58395/pipd.v49i3.71","url":null,"abstract":"Acute nonbacterial gastroenteritis is ubiquitous, and noroviruses are considered to be among the most common etiological agents. Noroviruses affect people of all ages. As a rule, infections caused by them are mild and self-limiting within 1-3 days but there is always a risk of a more severe course, especially in infants and the elderly. Being considered as mild and fast transient, noroviruses receive less attention than other infectious pathogens. The clinical and economic burden of norovirus gastroenteritis is often underestimated. Detection of the etiological role of noroviruses is essential not only from the clinical point of view, but also from the economic one because of the damage that norovirus infections cause to tourism and food industry. At present, prevention and counter disinfection measures are the only weapon against norovirus infections.\u0000In this narrative review, results from a non-systematic search on the recent literature on noroviruses are presented. The review describes the basic biological characteristics of noroviruses, their genetic diversity and current classification, as well as the epidemiological aspects of the norovirus infection, its clinical manifestation, the diagnostic approaches, prevention and control measures and current state-of-the art for norovirus vaccine development.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120975527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STUDIES ON THE EPIDEMIOLOGICAL AND MOLECULAR CHARACTERISTICS OF THE HEPATITIS E VIRUS IN BULGARIA: A COMPREHENSIVE REVIEW","authors":"E. Golkocheva-Markova, C. Ismailova, Tencho Tencho Tenev, L. Nikolaeva-Glomb","doi":"10.58395/pipd.v49i3.75","DOIUrl":"https://doi.org/10.58395/pipd.v49i3.75","url":null,"abstract":"Hepatitis E virus (HEV) is a RNA virus that belongs to the family Hepeviridae. The virus causes self-limited acute hepatitis in immunocompetent individuals, but can become chronic or present with extrahepatic manifestations in immunosuppressed patients. In recent years, due to the increased scientific interest in HEV infection, the number of laboratory-confirmed cases have also increased. The first study of HEV infection in Bulgaria was carried out in mid-90s of the last century by Teoharov et al. Ten years later, more in-depth studies of HEV infection began. The main focus was on the evaluation of HEV seroprevalence among different target populations. Attention was also paid to the zoonotic potential of the infection. The aim of the present review is to summarize studies on HEV conducted by Bulgarian authors in regards to HEV seroprevalence among humans and animals, clinical and epidemiological characteristics of HEV infection, and molecular-characteristics of HEV.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"227 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126955492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PREVALENCE OF MEASLES IGG ANTIBODIES AMONG HEALTHCARE WORKERS IN BULGARIA","authors":"S. Krumova, Ivona Andonova, S. Stoitsova, R. Stefanova, N. Vladimirova, K. Parmakova, A. Kurchatova","doi":"10.58395/pipd.v49i2.64","DOIUrl":"https://doi.org/10.58395/pipd.v49i2.64","url":null,"abstract":"Background: Healthcare workers are at greater risk of acquiring measles than the general population. Transmission occurs from infected patients to staff and from infected staff to patients and colleagues. In inpatient and outpatient settings, susceptible patients suffering from other conditions, especially the elderly and severely ill patients in intensive care units are at a high risk of severe disease or death if infected with measles. The most effective preventive measure against measles is vaccination with two doses of a measles-containing vaccine.\u0000Aim: To perform a serological assessment of the presence of measles IgG antibodies among healthcare workers.\u0000Materials and Methods: The present study involves serological testing performed on samples from persons working in hospitals and Regional Health Inspectorates in the country. Screening started in connection with a reported measles outbreak in Bulgaria in 2019, and continued into early 2020. An indirect ELISA assay for the detection of specific measles IgG antibodies in serum samples was used.\u0000Results: The tested 152 healthcare workers were from 5 regions of the country, i.e. Sofia-capital (n=87), Burgas (n=6), Blagoevgrad (n=5), Dobrich (n=8) and Pazardzhik (n=46). Anti-measles IgG antibodies were detected in 85.5% of the participants (130/152). Negative results, indicating a possible lack of protective immunity against measles, were obtained primarily in samples from persons younger than 40 years of age.\u0000Conclusion: Screening to identify healthcare workers who lack presumptive evidence of protective immunity against measles should be reinforced, especially among younger healthcare workers, in order to minimize the risk of measles both among healthcare workers and among patients.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129225686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"STRUCTURE AND DYNAMICS OF IMPORTED PARASITIC DISEASES IN BULGARIA (2014-2020)","authors":"R. Harizanov, I. Rainova, I. Kaftandjiev","doi":"10.58395/pipd.v49i2.72","DOIUrl":"https://doi.org/10.58395/pipd.v49i2.72","url":null,"abstract":"The aim of this study is to analyze data on the structure and dynamics of imported parasitic diseases and the potential risk of local spread of already eradicated diseases, and of those that do not have local spread so far, but there are environmental conditions for their occurrence.\u0000Material and Methods. This is a retrospective cross-sectional analysis of imported parasitic diseases in the country for a seven-year period. We used data from the annual analyzes of parasitic morbidity developed by the NCIPD, data from the diagnostic and reference activity of the National Reference Laboratory for Diagnosis of Parasitic Diseases, and data from the annual reports of the Regional Health Inspectorates.\u0000Results. During the period 2014-2020, 22 862 persons were studied, of whom 896 (3.9%) were Bulgarian citizens and 21 966 (96.1%) were foreigners. Imported parasite diseases were found in 794 people (prevalence 3.47%). Different types of parasites causing pathology of the gastrointestinal tract accounted for 87.53% (n = 695) of the identified pathogens, while the relative share of vector-borne parasitic diseases was 12.47% (malaria 11.09%, visceral and cutaneous leishmaniasis 1.38%).\u0000Conclusion. There are favorable climate and fauna conditions in the country for the local spread of a number of parasitic diseases. Control measures with respect to this pathology are associated with timely detection and remediation of the source of infection. In the country, there is an algorithm for diagnosis, hospitalization, treatment, prevention and control of imported parasitic diseases, but it is difficult to be applied to migrants entering in the country illegally. The deficiencies in the surveillance and control of imported parasitic diseases pose a real danger for a local spread of already eradicated parasitic diseases, such as malaria, and from outbreaks of diseases that do not have local spread till the present moment.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125901574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEROEPIDEMIOLOGICAL STUDY OF THE PREVALENCE OF TOXOCARIASIS AMONG HEALTHY PERSONS IN SOME AREAS OF BULGARIA","authors":"E. Kaneva","doi":"10.58395/pipd.v49i2.66","DOIUrl":"https://doi.org/10.58395/pipd.v49i2.66","url":null,"abstract":"Background. Human toxocariasis is a zoonotic disease in which the human being is an accidental host. The broad distribution of its definitive hosts determines the presence of the disease worldwide. Demographic factors, the way and standard of living, the existence of domestic animals in the household and their infestation are important for the epidemiology of the infection and determine the differences in reported seroprevalence.\u0000Data on the prevalence of toxocariasis in our country are limited. In this regard, the aim of the present study is to determine the seroprevalence of this parasitic infection among healthy individuals, in three regions of Bulgaria (Plovdiv, Stara Zagora and Smolyan).\u0000Material and Methods. Serum samples obtained from 247 individuals were tested by enzyme-linked immunosorbent assay (ELISA) for anti-Toxocara IgG antibodies.\u0000Results. Positive results were found in 26 (10.5%) of them, which indicated the presence of an asymptomatic form of the disease in our country. We found different seropositivity rates in the studied districts of the country.\u0000Conclusions. Performing immunological tests among various groups of the population is of great importance for the early detection of Toxocara infection, as well as for determining the main factors for the spread of the disease.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116460618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RECORDS OF IXODID TICKS ON WILD BIRDS IN BULGARIA","authors":"Nadya Ivanova Aleksandrova, I. Christova, D. Dimitrov, Martin P Marinov, E. Panayotova, I. Trifonova, E. Taseva, T. Gladnishka, G. Kamenov, M. Ilieva, Pavel Zehtindjiev","doi":"10.58395/pipd.v49i2.65","DOIUrl":"https://doi.org/10.58395/pipd.v49i2.65","url":null,"abstract":"Background: Ixodid ticks are widely studied due to their epidemiological and epizootic importance. It is of great value to know vertebrate host preferences of ticks in order to understand their ecological relationships and distribution. Earlier studies report birds as important hosts of Ixodid tick and a total of 136 ticks species have been frequently found in birds worldwide. However, only few studies related to host preferences of ticks among wild birds in Bulgaria were conducted till now.\u0000Aim: To obtain new data on the host preferences of ixodid ticks among wild birds at three locations in Bulgaria.\u0000Material and methods: The study was conducted between 2010 – 2020 in three sites in Bulgaria – Biological Experimental Station Kalimok (Silistra region), near Brodilovo village (Burgas region), and the city of Sofia (city park). The birds were caught by mist nets and inspected for ticks. Ticks found were removed by fine tweezers or a special removal tool for ectoparasites. Tick identification was based on external morphological characteristics.\u0000Results: A total of 2419 individual birds belonging to 78 species were examined. Of these, 70 individuals (16 species) carried ticks, thus representing 2.9% infestation rate. A total of 262 ticks were collected and identified as: Ixodes ricinus, Hyalomma marginatum, Haemaphysalis punctata, Hae. concinna, Hae. sulcata and two specimens could only be identified to the genus Haemaphysalis. Ixodes ricinus was the most commonly encountered tick (224/262), predominantly nymphs, followed by Hyalomma marginatum (27/262). The highest prevalence of tick infestation was observed among the Eurasian Blackbird, Turdus merula (28.6%), followed by the common nightingale, Luscinia megarhynchos (12.9%) and the common chaffinch, Fringilla coelebs (11.3%). These three bird species harboured the majority of ticks on their heads – some single individuals were infested by 10 up to 25 ticks per bird.\u0000Conclusion: Ixodes ricinus was found as the predominant tick species in this study. Nymphs were the most frequently observed stage. Infesting both birds and humans, this tick species has the potential to spread local tick-borne infections.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116747148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SEROLOGICAL STUDY OF BULGARIAN PATIENTS WITH BRUCELLOSIS","authors":"R. Nenova, I. Tomova, Liliya Goryanova","doi":"10.58395/pipd.v49i2.48","DOIUrl":"https://doi.org/10.58395/pipd.v49i2.48","url":null,"abstract":"Background: Brucellosis is a widespread zoonotic infection with significant health and socio-economic impacts. This determines the need of a reliable laboratory diagnosis both in endemic areas around the world and in countries where it is rare and under diagnosed. Due to prolongedand hazardous cultivation procedures, the diagnosis is mostly serologically confirmed.\u0000Aim: Serological study of Bulgarian citizens with clinical and/or epidemiological data compatible to brucellosis for the period 2005-2015.\u0000Materials and methods: Based on clinical and epidemiological data obtained via standard questionnaire 3394 persons suspected for brucellosis along with 106 controls were serologically studied with Rose Bengal slide test, Standard agglutination test, Coombs’ test, Brucellacapt and ELISA.\u0000Results: Brucellosis was confirmed in 174 patients. In outbreak related cases the tests listed above were positive in 127 (78.88%), 115 (71.43%), 34 (91.98%), 143 (95.33%) and 104 (96.30%), respectively. A statistically significant positive correlation was found between Coombs’ and Brucellacapt in the studied 55 sera samples (rs = 0,72; p < 0,0000). The profile of anti-Brucella antibodies was investigated in 46 patients with different duration of the disease. In 29 (63.0%) of them the initial serum sample was positive for the three classes of antibodies and in 17 (36.9%) the primary testing didn’t detect IgM, but IgG and IgA.\u0000Conclusion: None of the serological tests alone could ensure an accurate diagnosis of brucellosis. It is necessary to use a diagnostic algorithm with appropriately selected serological tests in which Brucellacapt could successfully replace Coombs' test´ for detection of incomplete antibodies in brucellosis with long duration.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129094678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PREVALENCE OF NEISSERIA GONORRHOEAE AND MYCOPLASMA GENITALIUM IN BULGARIAN POPULATION FROM SOFIA MUNICIPALITY OF REPRODUCTIVE AGE, 2018-2019","authors":"I. Philipova, V. Levterova, I. Simeonovski, Z. Ivanova, L. Boyanova, T. Kantardjiev","doi":"10.58395/pipd.v49i2.56","DOIUrl":"https://doi.org/10.58395/pipd.v49i2.56","url":null,"abstract":"Background: N. gonorrhoeae and M. genitalium infections remain public health concern due to emerging antimicrobial resistance which compromise effective treatment and infection prevention and control.\u0000Objective: To estimate the prevalence for N. gonorrhoeae and M. genitalium infections and identify demographic and sexual behavioral risk factors in Bulgarian population of reproductive age from Sofia municipality.\u0000Material and methods: Participants were sexually active 443 men and 198 women aged 18-49 years. They answered questionnaires on sexual behavior and provided samples for N. gonorrhoeae and M. genitalium testing.\u0000Results: The prevalence of N. gonorrhoeae infection was 3.28% (21/641) and with M. genitalium infection it was 2.49% (16/641). For both infections the presence of urogenital symptoms was associated with greater risk of being infected. Among gonococcal infections an increased number of lifetime partners and partners during the last 6 months, previously diagnosed STIs and use of contraception other than condoms were associated risk factors.\u0000Conclusions: The prevalence of N. gonorrhoeae and M. genitalium infections in Bulgarian population of reproductive age from Sofia municipality was relatively low but due to significant disease burden data on prevalence and identified risk factors should help the development of future control strategies.","PeriodicalId":124630,"journal":{"name":"PROBLEMS of Infectious and Parasitic Diseases","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114750083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}