PROBLEMS of Infectious and Parasitic Diseases <p><strong>"PROBLEMS of Infectious and Parasitic Diseases"</strong> <span id="result_box" class="" lang="en">is <span class="">a <a href="" target="_blank" rel="noopener">peer-reviewed</a> open-access medical journal of scientific papers covering research on microbiological diagnostics of human infectious diseases. It is published by</span></span><span id="result_box" class="" lang="en"> <a href="" target="_blank" rel="noopener">National Centre of Infectious and Parasitic Diseases</a>, in English on paper and in digital form with periodicity three issues annualy</span>.</p> <p style="text-align: justify;"><strong><span class="" lang="en"><span class="">ISSN: 0204-9155</span></span></strong></p> National Centre of Infectious and Parasitic Diseases en-US PROBLEMS of Infectious and Parasitic Diseases 0204-9155 <p><a title="CC-BY 4.0" href="" target="_blank" rel="noopener">CC-BY 4.0</a></p> DO WE KNOW RHINOVIRUSES AND THEIR CLINICAL IMPACT? <p>Acute respiratory infections cause significant morbidity and mortality even before the COVID-19 pandemic. Pandemic restrictions decreased circulation of many respiratory viruses but some less troubling infections such as common cold are still circulating.</p> <p>One of the most frequent causative agents of common cold are rhinoviruses. The fact that these pathogens have been able to slip through anti-COVID preventive measures raises the question of whether we really know this group of viruses and whether these viruses cause only common cold. The clinical impact of rhinoviruses seems to be underestimated.</p> <p>In searching of an answer how rhinoviruses have slipped through the anti-COVID precautions we referred to the work of infectious disease specialists, virologists and epidemiologists -much of it conducted decades before the current pandemic. A non-systematic search of the literature is performed. Some of the latest findings on rhinoviruses along with basic knowledge on their biology and clinical impact are summarized in this review.</p> Irina Georgieva Asya Stoyanova Svetla Angelova Savina Stoitsova Silvia Voleva Neli Korsun Lubomira Nikolaeva-Glomb Copyright (c) 2021 Irina Georgieva, Asya Stoyanova, Svetla Angelova, Savina Stoitsova, Silvia Voleva, Neli Korsun, Lubomira Nikolaeva-Glomb (Author) 2021-04-16 2021-04-16 49 1 5 12 CORRELATION BETWEEN THE ANTIBODY RESPONSE TOWARD SPECIFIC HCV PROTEINS AND HCV VIRAL LOAD <p><strong>Background:</strong> Hepatitis C virus (HCV) is an RNA virus causing acute or chronic infection and affecting more than 2% of population worldwide. The firstline tests for diagnosis of HCV infection are 3rd or 4th generation enzyme immunoassays - ELISA and CIA. They indicate the presence of antibodies against HCV in serum. These tests are characterized by high sensitivity and specificity, but they cannot distinguish past, acute or chronic infection, and sometimes produce false positive results. Confirmatory tests, such as recombinant immunoblot-line immune assay (LIA), and quantitative PCR, are used to validate the positive antibody response. The recombinant immunoblot assay can be used to determine the specificity of antibody to HCV. The aim of the present study is to determine the correlation between the anti-HCV response in confirmatory immunoblot assay and the HCV viral load, measured by PCR.</p> <p><strong>Materials and methods:</strong> Twenty-nine anti-HCV positive sera were included in the study. Third generation ELISA assay was used for anti-HCV screening of the samples and for detection of anti-HCV antibodies against specific HCV proteins. Third generation line immunoassay INNO-LIA HCV Score, based on the principle of an enzyme immunoassay, was used as a confirmatory test. The HCV viral load was measured by quantitative PCR method – Abbott Real Time HCV (Abbott Molecular Inc., USA) with linear sensitivity range from 1.08 Log 10 IU/ml (12 [IU/ml]) to 8.00 Log 10 IU/ml (100 000 000 [IU/ml]).</p> <p><strong>Results:</strong> HCV RNA was quantified in all studied samples. Ten of 29 serum samples (34%, Group I) were HCV RNA negative. The rest of the samples were HCV RNA positive as follows: 3 serums were with minimal viral load from &lt; 12 to 10 000 IU/ml (10%, Group II); 3 serum samples –between 10 000 and 100 000 IU/ml (10%, Group III); 10 serum samples – between 100 000 and 1 000 000 IU/ml (34%, Group IV) and in 3 serum samples HCV RNA concentration was over 1 000 000 IU/ml (10%, Group V).</p> <p><strong>Conclusion:</strong> HCV screening strategies involving anti-HCV detection by ELISA combined with recombinant immunoblot assay can be the method of choice in laboratories with limited equipment and finances.</p> Chiydem Ismailova Vlilana Yontcheva Tencho Tenev Elitsa Golkocheva-Markova Copyright (c) 2021 Chiydem Ismailova, Vlilana Yontcheva, Tencho Tenev, Elitsa Golkocheva-Markova (Author) 2021-04-16 2021-04-16 49 1 13 18 IS THERE AN OUTBREAK OF TICK-BORNE ENCEPHALITIS IN PERNIK DISTRICT, BULGARIA? FOUR CASES REGISTERED FOR A PERIOD OF FOUR YEARS – CLINICAL MANIFESTATIONS AND EPIDEMIOLOGICAL RELATIONS <p>In Europe, the number of tick-borne encephalitis (TBE) cases has been increasing in the last decade, and the number of endemic areas has also been increasing. Bulgaria, located in southeastern Europe, is not in the TBE endemic area. However, sporadic TBE cases have been occasionally detected. The disease has a natural-focal nature, pronounced seasonality, with a vector- <em>Ixodes</em> ticks that transmit the infection from animals to humans. TBE is severe infection with specific lesions of the central nervous system (CNS), with residual phenomena and high lethality. The first cases of TBE in Pernik district were registered in 2015. The aim of the study is to consider clinical cases of TBE in Pernik district during period 2017-2020, to look for an epidemiological link between them and to monitor severity of the infection. We briefly present the most characteristic clinical and laboratory features of four laboratory confirmed cases of tick-borne encephalitis in the last 4 years. The mean age of all of the patients was 56. All four cases were observed in May, June, and July. They proceeded relatively smoothly with a favorable outcome, without paresis or paralysis of the limbs, without seizures or loss of consciousness. In the first case of computed tomography, no pathological changes in the brain were observed, while in the other three cases multiinfarction encephalopathy, evidence of initial cerebral edema and two porencephalic foci were found. Two of the patients had meningoradicular irritation with positive symptoms of Kerning, Brudzinski and Babinski, while in the other two patients these symptoms were absent. In all four cases there was a classic change in the hemogram: moderate leukocytosis with granulocytosis, and in the study of cerebrospinal fluid - a slight increase in total protein, moderate pleiocytosis and normal values of sugar and chloride. Only one of the patients was reported to be bitten by a tick, and the other three were most likely infected through food (raw goat's milk). Confirmed cases of TBE in Pernik district, although isolated, show that the virus is circulating in this region. This is facilitated by a number of factors: climate change, activity of the epizootic process in the tick population, different species of vertebrates in natural foci; presence of a large number of goats infected with viruses. Although cases of TBE have been reported only sporadically due to a lack of sufficient testing, TBE virus is circulating in Pernik district. Comprehensive measures are needed: through good awareness of clinicians, search for infection in patients with viral meningitis, increased screening of raw milk by the Bulgarian Food Safety Agency, future studies on ticks and farm animals for presence of TBE in this region. This study is a prerequisite for future research in this direction.</p> Evgeniya Taseva Iva Christova Elitsa Panayotova Diana ilieva Valentina Pavlova Copyright (c) 2021 Evgeniya Taseva, Iva Christova, Elitsa Panayotova, Diana ilieva, Valentina Pavlova (Author) 2021-04-16 2021-04-16 49 1 19 25 COMPARATIVE ANALYSIS OF CLINICAL AND LABORATORY PARAMETERS BETWEEN VIRAL AND BACTERIAL NEUROINFECTIONS <p>Neuroinfections are acute inflammatory diseases of the central and peripheral nervous system that can lead to serious consequences, and even death. Recently, viruses have played a leading role in the emergence of neuroinfections. Rapid identification of the etiological agents is an important prerequisite for proper therapy and a good outcome of the disease. The aim of this study is to determine the role of the cytokines IL-6 and IFN-γ in the cerebrospinal fluid and serum of patients with viral and bacterial neuroinfections in relation to their diagnosis and prognosis.</p> <p><strong>Materials and methods:</strong> From 2012-2018, 91 patients were included, aged from 2 months to 82 years. They were divided into 3 groups: 57 with viral neuroinfections , 24 - with bacterial and 10 - control group with cerebral edema. Clinical, epidemiological, laboratory, microbiological, serological and molecular tests were performed in all patients, and in some of them imaging techniques (CT and MRI) had been performed. Cytokines IL-6 and IFN-γ in serum and cerebrospinal fluid were determined by immunological tests.</p> <p><strong>Conclusion:</strong> Viral neuroinfections are more common than bacterial ones, they had a milder clinical course and a more favorable outcome. Cytokine levels in the cerebrospinal fluid are a better indicator of inflammatory process in terms of severity than those in the serum. IL-6 levels in the cerebrospinal fluid of viral neuroinfections were higher than IFN-γ. A proportional relationship was established between leukocytes and IL-6 in the cerebrospinal fluid of patients with aseptic meningitis.</p> Liliya Pekova Krasimira Halacheva Ivaylo Dochev Copyright (c) 2021 Liliya Pekova, Krasimira Halacheva, Ivaylo Dochev (Author) 2021-04-16 2021-04-16 49 1 26 31 SARCOIDOSIS <p>Sarcoidosis is a systemic granulomatous inflammatory disorder that affects multiple organs – lungs, skin, heart, kidneys, liver, eyes, and nervous system, among others. The clinical course of sarcoidosis ranges from spontaneous resolution to chronic progressive disease which can be life-threatening. Most often, patients suffer from cough, shortness of breath, chest pain, and severe fatigue. In more severe cases, there is pulmonary fibrosis and/or irreversible damage to the organs affected by granulomas. Recent studies demonstrate innovative research in the field of sarcoidosis, thus significantly improved our knowledge of epidemiology and causative origins of the disease. Despite numerous studies, the aetiology of sarcoidosis is still not fully understood. It is proposed that the disease is caused by an unknown antigen (antigens) in humans with abnormal immune response, and a genetic predisposition. Here, we overview the current advances in sarcoidosis research.</p> Borislava Tsafarova Copyright (c) 2021 Borislava Tsafarova (Author) 2021-04-16 2021-04-16 49 1 32 36 CLINICAL CASE OF CRYPTOCOCCAL MENINGITIS IN A LIVER TRANSPLANT PATIENT <p>The incidence of infections caused by Cryptococcus neoformans has increased significantly in recent years, especially in the settings of immune deficiency (HIV infection transplantation, etc.). Most often after inhalation of spores dissemination of yeast to the brain parenchyma occurs, leading to meningitis (meningo-encephalitis). Our clinical case, is a patient with cryptococcal meningitis after liver transplantation , who died despite the onset of antifungal therapy. This is further evidence of the severe prognosis of CNS cryptococcosis, especially in immunocompromised patients.</p> Lyubomira Boyanova Zoya Ivanova Copyright (c) 2021 Lyubomira Boyanova, Zoya Ivanova (Author) 2021-04-16 2021-04-16 49 1 37 40 OCULAR TOXOPLASMOSIS <p>Toxoplasmosis in humans is a zoonotic parasitic disease caused by a ubiquitous protozoan, <em>Toxoplasma gondii</em>. Toxoplasmosis is an opportunistic infection that can cause serious damage in immunocompromised patients. While in the non-immunocompromised individuals it is most often latent and asymptomatic, about one-third of the world’s population is estimated to be infected. Toxoplasmosis is the most common cause of posterior uveitis in non-immunocompromised individuals and the second most common cause of chorioretinitis after cytomegalovirus infection in people with HIV / AIDS. The infection can be acquired congenitally or postnatally and ocular lesions may present during or years after the occurance of the acute infection. Molecular biology techniques to diagnose ocular toxoplasmosis have been available for many years and are now accessible as standard laboratory tests in many countries. Aqueous humor or vitreous evaluation to detect parasite DNA by polymerase chain reaction or specific antibodies may provide evidence for diagnosis. Oral pyrimethamine and sulfadiazine plus corticosteroids are an effective therapy for ocular toxoplasmosis. Recent data supports the use of other treatment options, including intravitreal antibiotics. The aim of the present review is to discuss briefly the new diagnostic and treatment approaches for ocular toxoplasmosis.</p> Iskren Kaftandjiev Rumen Harizanov Copyright (c) 2021 Iskren Kaftandjiev, Rumen Harizanov (Author) 2021-04-16 2021-04-16 49 1 41 50