Abstract
Lyme disease is an infectious disease caused by bacteria of the Borrelia burgdorferi sensu lato (Bbsl) complex and is characterized by predominant lesions of the skin, cardiovascular system, nervous system and musculoskeletal system. We have described a clinical case of first- degree atrioventricular block in a 14-year-old boy caused by Lyme borreliosis. The disease started with the manifestations of cardiovascular system involvement. The patient and his parents did not recall observing a tick bite or manifestation of erythema migrans (EM). The boy was prescribed doxycycline. Three weeks after antibiotic therapy a second ECG examination was performed and showed no abnormalities.

Multisystem inflammatory syndrome in children (MIS-C) associated with Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) usually develops 1-1.5 months after mild or asymptomatic COVID-19 in countries with high incidence. MIS-C has a polymorphism of clinical manifestations, which include prolonged fever, polymorphic rash, non-purulent conjunctivitis, pneumonia complicated by distress syndrome, myocarditis, coronary artery disease, toxic shock syndrome, limb edema, polyserositis, severe abdominal syndrome with diarrhea and others. Establishing this diagnosis requires significant efforts to rule out diseases of other etiology. The aim of our study was to analyze the clinical and laboratory features of children with MIS-C associated with SARS-CoV-2 and severe abdominal syndrome. Six children with MIS-C associated with SARS-CoV-2 and severe abdominal syndrome were hospitalized in Lviv Regional Children’s Clinical Hospital “OHMATDYT”, Ukraine, from April 2020 to September 2021. For differential diagnosis IgM, IgG to SARS-CoV-2 by ELISA, RNA to SARS-CoV-2 by PCR, bacteriological tests of blood, urine and feces were performed. Furthermore, the diagnostic work up included chest radiography, echocardiography, ultrasound of the lungs and abdominal organs. Laboratory findings revealed an increase in the normal value of inflammatory markers and high levels of IgG to SARS-CoV-2. Administration of intravenous immunoglobulin at a dose of 1 to 2 g/kg body weight per day prevented further coronary artery disease in patients and provided regression in already affected coronary arteries. At the same time, regression of abdominal syndrome was observed. Early diagnosis of MIS-C in patients with SARS-CoV-2 and severe abdominal syndrome allows to define the appropriate treatment strategy.

Хвороба Лайма (кліщовий бореліоз, Лайм-бореліоз) – це інфекційне природно-осередкове трансмісивне захворювання, яке спричиняється бактеріями комплексу Borrelia burgdorferi sensu lato і характеризується переважним ураженням шкіри, серцевосудинної системи, нервової системи й опорно-рухового апарату. Комплекс Borrelia burgdorferi sensu lato включає 8 різних видів борелій, 3 із них мають патогенний потенціал для людини : B. Burgdorferi sensu strico, B. Afzelii, B. bavariensis, B. bissettii, B. Garinii, B. Kutenbachii, B. Lusitaniae, B. Spielmanii, B. Valasiana. Найчастіше зустрічаються 3 види: B. Burgdorferi sensu strico (Пн Америка і Європа), B. Afzelii (Європа та Азія, ураження шкіри), B. Garinii (Європа, ураження ЦНС). Офіційна реєстрація хвороби Лайма в Україні проводиться з 2000 року. За даними Центру Громадського Здоров’я, протягом 2019 року було зареєстровано 4 482 випадки хвороби Лайма серед українців, з них - 492 випадки у дітей до 17 років. У США щорічно реєструють близько 300 000 випадків хвороби Лайма і дане захворювання посідає друге місце за частотою після ВІЛ-інфекції. У Канаді з 2009 по 2022 рік було зафіксовано 17080 випадків хвороби Лайма. У Західній Європі виявляють 22 випадки хвороби Лайма на 100 000 населення за рік

As more data is collected, hematologists will be able to gain more insight into the impact of coronavirus disease 2019 (COVID-19) on pediatric patients with hematological malignancies. Material and methods: We analysed 21 cases of COVID-19 in pediatric patients with onco-hematological diseases treated in the Western Ukrainian Pediatric Medical Center from March 2020 through May 2021. The majority of patients (71.4%) were diagnosed with acute lymphoblastic leukemia. All patients from the analyzed cohort had an asymptomatic, mild or moderate course of coronavirus-19 infection. The most common symptoms of COVID-19 were fever, cough, gastrointestinal symptoms, and dermatitis. Severe severe acute respiratory syndrome coronavirus 2 increased the risk of liver toxicity and venous thrombosis. Results and conclusion: Our analysis showed that pediatric patients with hematological malignancies need the same treatment approach for COVID-19 as for other infective complications.

SARS-CoV-2 infection, in the vast majority, affects adult patients. The severity of COVID-19 and mortality are directly correlated with the increasing age of patients and the number of comorbidities. However, with the further development of the COVID-19 pandemic, severe cases of COVID-19 have been reported in children. About 0.8-1% of sick children require hospitalization in an intensive care unit. The main syndromes that cause disease severity and mortality in children are acute respiratory distress syndrome, multisystem inflammation syndrome and multiple organ failure. The rapid development of severe respiratory failure and hypoxemia in respiratory distress syndrome leads to the use of various methods of respiratory therapy, and in case of their ineffectiveness to extracorporeal membrane oxygenation (ECMO). In our report, we present two clinical cases of successful use of ECMO in children with COVID-19, who developed severe ARDS.