Co-infection with plasmodium falciparum and COVID-19 with lethal outcome. First clinical case from Bulgaria.

The symptoms of COVID-19 include febrility and mainly catarrhal symptoms. In severe cases, patients present with progression to lower respiratory tract and acute respiratory distress (ARDS) and multi-organ dysfunction. Malaria caused by P. falciparum is a severe, endemic parasitosis, mainly in Africa. In some cases, it can be complicated with ARDS. We present a case of a patient who returned from Nigeria with respiratory symptoms, in which both COVID-19 infection and tropical malaria were proven; with a fatal outcome.

Molecular Analysis of Dihydropteroate Synthase Gene Mutations in Pneumocystis jirovecii Isolates among Bulgarian Patients with Pneumocystis Pneumonia.

Pneumocystis jirovecii pneumonia (PCP) is a significant cause of morbidity and mortality in immunocompromised people. The widespread use of trimethoprim-sulfamethoxazole (TMP-SMZ) for the treatment and prophylaxis of opportunistic infections (including PCP) has led to an increased selection of TMP-SMZ-resistant microorganisms. Sulfa/sulfone resistance has been demonstrated to result from specific point mutations in the DHPS gene. This study aims to investigate the presence of DHPS gene mutations among P. jirovecii isolates from Bulgarian patients with PCP. A total of 326 patients were examined via real-time PCR targeting the P. jirovecii mitochondrial large subunit rRNA gene and further at the DHPS locus. P. jirovecii DNA was detected in 50 (15.34%) specimens. A 370 bp DHPS locus fragment was successfully amplified in 21 samples from 19 PCP-positive patients, which was then purified, sequenced, and used for phylogenetic analysis. Based on the sequencing analysis, all (n = 21) P. jirovecii isolates showed DHPS genotype 1 (the wild type, with the nucleotide sequence ACA CGG CCT at codons 55, 56, and 57, respectively). In conclusion, infections caused by P. jirovecii mutants potentially resistant to sulfonamides are still rare events in Bulgaria. DHPS genotype 1 at codons 55 and 57 is the predominant P. jirovecii strain in the country.

Study on the Prevalence of Pneumocystis jirovecii as a Causative Agent of Lung Pathology in People with Different Immune Status.

BACKGROUND: Pneumocystis pneumonia (PCP) commonly affects immunocompromised individuals, whereas in immunocompetent persons, it occurs relatively rarely, and in most cases, the Pneumocystis infection is detected as an asymptomatic colonization. The present study aimed to establish the prevalence of Pneumocystis jirovecii infection in human hosts with different immune status (immunocompromised and immunocompetent), using molecular diagnostic methods, and to compare their diagnostic value with that of classical staining methods. METHODS: We used the collected-to-this-moment data from a prospective study on the prevalence of pneumocystosis among the Bulgarian population. Clinical specimens (including throat secretions, induced sputum, tracheal aspirates, and bronchoalveolar lavage) collected from 220 patients suspected of PCP (153 immunocompetent and 67 immunocompromised patients) were examined with microscopic staining methods and real-time PCR for detection of P. jirovecii. Results: DNA of the pathogen was detected in 38 (17%) specimens (32 immunocompromised patients and 6 immunocompetent subjects). From all 220 clinical samples examined by staining methods, only five (2%) P. jirovecii cysts were detected by the Gomori stain. All patients with PCP were treated with trimethoprim-sulfamethoxazole, but in ten of them (HIV-positive patients), the disease had a fatal outcome. CONCLUSIONS: This study is the first in Bulgaria including the main available laboratory methods for diagnosis of human pneumocystosis. Regarding the etiological diagnosis of PCP, in our study the sensitivity of real-time PCR was higher compared to the staining methods. The choice of a method for sample collection and examination has an important role in the efficiency of the laboratory diagnostics.

Epidemiological and clinical characteristics of imported malaria in Bulgaria: A retrospective study of а 21-year period.

BACKGROUND: Bulgaria, with a high endemicity for malaria in the past, was declared by the WHO as a malaria-free country in 1965. We intended to analyze the epidemiological and clinical implications of imported malaria cases in Bulgaria. METHODS: This is a retrospective cross-sectional analysis of all recorded cases of imported malaria in Bulgaria over a 21-year period (2000-2020). Patients' clinical records and information gathered from the epidemiological survey of each recorded malaria case were reviewed. RESULTS: A total of 232 cases of imported malaria were reported, 147 (63.4%) were Bulgarian citizens (BC) and 85 (36.6%) were foreign nationals (FN). Two thirds (66.4%) of cases were diagnosed from April to October. Most BCs had travelled for work (66.6%) to Africa (93.9%) and were infected with P. falciparum (83.3%), while most FNs were migrants (54.7%), exposed in Asia (63.5%) with P. vivax infection (62.4%). Clinical complications and a fatal outcome were noted in 14.7% (n = 34) and 3.5% (n = 8) of cases respectively. All complicated cases were in BNs with P. falciparum infection. CONCLUSIONS: Bulgaria experiences a steady import of malaria. Efforts to improve diagnosis, management and prevention of malaria, as well as maintenance of a high degree of epidemiological vigilance are needed.

First case of ocular dirofilariosis in Bulgaria caused by gravid female Dirofilaria repens.

Dirofilariosis caused by Dirofilaria (Nochtiella) repens is recorded sporadically among people in Europe, Asia and Africa. Still a worldwide controversy exist upon human parasite hosting. Herein, the first case of ocular dirofilariosis in Bulgaria caused by gravid female is presented. A single nematode was removed from the eye of the 76- year-old patient in the course of cataract surgery. Microscopic examination of the histological slides revealed microfilariae in the parasite's uterus, but not in the blood. Knott's method for detection of microfilariae in the peripheral blood was negative and the rest of laboratory blood and biochemical tests were within reference limits. A comprehensive review of the etiology, pathogenesis and clinical presentation of Dirofilaria repens infection is also highlighted.

Study of IgG avidity and the level of specific IgA antibodies and their significance in the diagnosis of human toxocarosis.

Toxocarosis is a zoonotic disease caused by migration and subsequent localization of nematode larvae of Toxocara spp. in human organs and tissues, which is manifested with development of various non-specific clinical symptoms. Main diagnostic methods are serological and consists in proving the presence of anti-Toxocara IgG antibodies in patient's sera. In humans, anti-Toxocara IgG has been shown to persist in the serum for a long time and cannot be used to distinguish between past and recent infection. Aim of the present work is to investigate the diagnostic significance of the specific IgG avidity level, determined by an immuno enzyme test developed by us, and the presence of anti-Toxocara IgA for distinguishing between acute and chronic toxocarosis. The study included 130 patients with positive results in routine serological ELISA and Western blot tests and with clinical symptoms of visceral and ocular toxocarosis. The results revealed low IgG avidity (≤40%) in nine (7.3%) and presence of anti-Toxocara IgA antibodies in 36 (26.2%) of the subjects. Low avidity of IgG antibodies was found only in the first tests, and a presence of specific IgA for up to 9 months. The results of our study give us reason to believe that determination of the IgG avidity in toxocarosis is of greater diagnostic value than the presence of IgA to establish the stage of the disease.

Extra-hepatopulmonary cystic echinococcosis in Bulgaria: frequency, management and outcome of the disease.

In the endemic countries, human cystic echinococcosis (CE) poses a serious medical and social problem. Because it most often affects the liver and lungs we aimed to define the proportion of cases with different organ localization, the diagnostic and therapeutic approaches in such cases, and the outcome of them. For a period 2010-2019, a total of 2863 cases of CE were registered in Bulgaria, of which 148 (5.17%) with organ localization other than liver and/or lung. The majority of patients with extra-hepatopulmonary localization of CE were adults. The distribution by gender showed predominance of female patients (57.43%) over those of males and primary cases (85.14%) exceeded the cases of recurrence. According to our study most common is the spleen involvement, followed by involvement of the abdominal cavity, kidneys and muscle/subcutaneous tissue. Other extra-hepatopulmonary organ localizations are significantly less common. This study shows that the extra-hepatopulmonary localization of CE is not so rare, and in most cases it is a primary disease. In respect of this, clinicians should consider hydatidosis in the differential diagnosis when cystic formation(s) is found, regardless of the organ involved.

Epididymal Dirofilariasis in a Child: First Case Report from Bulgaria.

OBJECTIVE: To present case of a child with epididymal dirofil-ariasis. CLINICAL PRESENTATION AND INTERVENTION: An 11-year-old boy was admitted to the Clinic of Pediatric Urology for elective surgery treatment of epididymal cyst on the left side. After removal, the cyst was sent for histological examination. Microscopic examination of the histological slides revealed cross-sections of a nematode belonging to Dirofilaria spp., differentiated morphologically as D. repens. After surgery, the patient recovered completely. CONCLUSIONS: In most parts around the world, dirofilariasis is a rare and neglected infection. Nevertheless, the clinicians and pathologists must be informed about it.

Imported malaria in Bulgaria, status and prognosis after eradication in 1965.

BACKGROUND: This retrospective analysis assessed all recorded malaria cases in Bulgaria after 1965, when the country was certified as malaria-free by the World Health Organization (WHO), and evaluated the readiness of the public health system to interrupt an outbreak of local transmission in case of infection importation. METHODS: The cases were analyzed according to causative species; geographic origin of the imported case; and the citizenship, age, and gender of the infected individuals. RESULTS: In the 50-year study period (1966-2015), there were a total of 3011 cases of malaria imported to Bulgaria from different regions of the world. The majority of the cases originating in Africa were caused by Plasmodium falciparum (65.5%), while most of these originating in Asia were caused by P. vivax (80.9%). The potential season for malaria transmission in Bulgaria is from April to October, and 58.5% of the malaria cases were imported during that time of the year. CONCLUSIONS: The increasing movement of people to and from areas endemic for malaria requires the health authorities of countries with appropriate conditions for reintroduction to conduct enhanced measures for surveillance and control of this potentially deadly disease.

Human Parasitic Diseases in Bulgaria in Between 2013-2014.

BACKGROUND: In Bulgaria, more than 20 autochthonous human parasitic infections have been described and some of them are widespread. Over 50 imported protozoan and helminthic infections represent diagnostic and therapeutic challenges and pose epidemiological risks due to the possibility of local transmission. AIMS: To establish the distribution of autochthonous and imported parasitic diseases among the population of the country over a 2-year period (2013-2014) and to evaluate their significance in the public health system. STUDY DESIGN: Cross sectional study. METHODS: We used the annual reports by regional health inspectorates and data from the National Reference Laboratory at the National Centre of Infectious and Parasitic Diseases on all individuals infected with parasitic diseases in the country. Prevalence was calculated for parasitic diseases with few or absent clinical manifestations (oligosymptomatic or asymptomatic infections). Incidence per 100.000 was calculated for diseases with an overt clinical picture or those that required hospitalisation and specialised medical interventions (e.g. surgery). RESULTS: During the research period, parasitological studies were conducted on 1441.244 persons, and parasitic infections were diagnosed in 22.039 individuals. Distribution of various parasitic pathogens among the population displayed statistically significant differences in prevalence for some intestinal parasites (enterobiasis 0.81%, giardiasis 0.34% and blastocystosis 0.22%). For certain zoonotic diseases such as cystic echinococcosis (average incidence of 3.99 per 100.000) and trichinellosis (average incidence of 0.8 per 100.000), the incidence exceeds several times the annual incidence recorded in the European Union. CONCLUSION: Parasitic diseases still pose a substantial problem with social and medical impacts on the residents of our country. Improved efficiency regarding autochthonous and imported parasitic diseases is essential in providing the public health system the tools it needs to combat these diseases. Attention should be focused on the various imported vector-borne parasitic diseases (e.g. malaria and cutaneous leishmaniasis) for which the country is potentially endemic.

Some aspects of the epidemiology, clinical manifestations, and diagnosis of human dirofilariasis caused by Dirofilaria repens.

In recent years, zoonotic filariae Dirofilaria immitis and Dirofilaria (Nochtiella) repens are gaining popularity as incidental human parasitic pathogens. The usual hosts for these nematodes are domestic and wild carnivorous animals. The medical significance of human dirofilariasis is due to frequent misdiagnosis as malignancy and in many cases diagnosis is made after invasive surgical procedures. The aim of this study was to ascertain the geographical distribution and clinical manifestations of a relatively rare among people zoonotic disease such as dirofilariasis, whose epidemiological features depends on prevalence of the parasite among usual hosts, presence of suitable vector, and human activities favoring exposure. Data for a 39-year period were analyzed, during which, in Bulgaria, were recorded 47 cases of human dirofilariasis with various organ localizations. Morphological methods were also used for species identification of Dirofilaria (N.) repens and serological diagnostic tests for filariasis. Some epidemiological parameters such as annual incidence, prevalence for different geographic areas in Bulgaria, distribution by gender (28 females and 19 males) and age (from 19 to 77 years of age) of the diseased were identified, and aspects of the clinical manifestations, diagnosis, and treatment of the disease were discussed. Comparison was made between the number of cases in Bulgaria and those in other European countries. Although the climatic and faunal conditions in Bulgaria are favorable for disease transmission between animal reservoir hosts and humans, the diagnosis of dirofilariasis is often omitted.

Clinical features, diagnostic tools, and treatment regimens for visceral leishmaniasis in Bulgaria.

PURPOSE: Visceral leishmaniasis (VL), caused by the parasite Leishmania infantum, which was once largely confined to Southern Europe is now being diagnosed throughout Northern Europe, including Great Britain. In an effort to help EU clinicians improve their diagnosis and management of VL, this paper defines clinical features typical of the disease as it presents in Bulgaria, where VL is endemic. METHODS: The list of clinical symptoms presented here was gleaned from the medical records (patient histories, epidemiological survey cards, laboratory data) of 59 Bulgarian patients with VL. This study also includes microscopic, serological, and molecular laboratory techniques. RESULTS: Described and analyzed are the clinical features, diagnostic techniques, and therapeutic regimens of 59 cases--part of the total number of VL case histories (P = 120, 116 Bulgarian and 4 not Bulgarian) collected in Bulgaria over the past 24 years (1988-2011). Although all of the studied 59 cases presented with classical symptoms of VL, only in three occasions, the initial diagnosis was correct. CONCLUSIONS: Left untreated, zooanthroponotic VL leads to debilitating chronic disease and even death. Yet, because VL is hard to recognize and relatively new to Northern Europe, misdiagnosis is common and treatment too often inappropriate and delayed.