O1 HIV-1 diversity in Bulgaria (current molecular epidemiological picture) Ivailo Alexiev, Reneta Dimitrova, Anna Gancheva, Asya Kostadinova, Mariyana Stoycheva, Daniela Nikolova, Ivaylo Elenkov O2 Knowledge, attitudes and practices of the general population on HIV/AIDS, hepatitis B and C in Romania Cătălin Tilișcan, Mioara Predescu, Bogdan Păunescu, Anca Streinu-Cercel, Oana Săndulescu, Claudiu Mihai Șchiopu, Mădălina Hristache, Lăcrămioara Aurelia Brîndușe, Adrian Streinu-Cercel O3 The prevalence of human leukocyte antigen-B*57:01 allele carriers and CXCR4 tropism among newly diagnosed HIV infected patients in Serbia Marija Todorovic, Marina Siljic, Dubravka Salemovic, Valentina Nikolic, Ivana Pesic-Pavlovic, Jovan Ranin, Djordje Jevtovic, Maja Stanojevic O4 HIV transmission among stable serodiscordant couples from the former Pediatric Cohort follow up in the National Institute of Infectious Diseases Ana Maria Tudor, Delia Vlad, Mariana Mărdărescu, Sorin Petrea, Cristina Petre, Ruxandra Neagu-Drăghicenoiu, Rodica Ungurianu, Alina Cibea, Odette Chirilă, Cristian Anghelina, Ileana Coserea O5 Unemployment is associated with syringe sharing among people who inject drugs in Greece Pantelia-Amalia Krikelli, Eirini Pavlitina, Mina Psichogiou, Demetris Lamnisos, Leslie Williams, Anya Korobchuk, Britt Skaathun, Pavlo Smyrnov, John Schneider, Vana Sypsa, Dimitrios Paraskevis, Angelos Hatzakis, Samuel R. Friedman, Georgios K. Nikolopoulos O6 Correlation of adipocytokine levels in different types of lipodystrophy in HIV/AIDS patients Gordana Dragović, Danica Srdić, Al Musalhi Khawla, Ivan Soldatović, Jelena Nikolić, Djordje Jevtović, Devaki Nair O7 IP10 – a possible biomarker for the progression of HIV infection Aura Temereanca, Adelina Rosca, Luminita Ene, Benchawa Soontornniyomkij, Carmen Diaconu, Claudia Dita, Cristian Achim, Simona Ruta O8 A permanent challenge: persistent low viremia in HIV positive patients on ART Șerban Benea, Ruxandra Moroti, Raluca Jipa, Eliza Manea, Andrada Stan, Elisabeta Benea, Dan Oțelea, Adriana Hristea O9 Infections in IDUs according to their HIV status Adriana Hristea, Irina Lăpădat, Raluca Jipa, Ruxandra Moroti, Șerban Benea, Doina Antonică, Irina Panait, Roxana Petre O10 Trends in combined antiretroviral therapy used in methadone program integrated with HIV care - 20 years of experience Justyna D. Kowalska, Ewa Pietraszkiewicz, Ewa Grycner, Ewa Firlag-Burkacka, Andrzej Horban O11 Extracellular cyclophilin A – inflammatory mediator in HIV infected patients Ovidiu Vlaicu, Leontina Bănică, Simona Paraschiv, Ana-Maria Tudor, Ruxandra Moroti, Dan Oțelea O12 High cardiovascular disease risk in Serbian population, an issue of concern Bojana Dimitrijević, Ivan Soldatović, Đorđe Jevtović, Jovana Kusić, Dubravka Salemović, Jovan Ranin, Gordana Dragović O13 Genotypic rifampicin resistance in HIV/ tuberculosis coinfected patients from a tertiary level infectious diseases hospital Dragoș Florea, Ioana Bădicuț, Alexandru Rafila, Cornel Camburu, Adriana Histrea, Mihaela Frățilă, Dan Oțelea O14 Occurrence of residual HCV RNA in liver and peripheral blood mononuclear cells among patients with chronic hepatitis C infection and/or HCV/HIV coinfection after IFN-based therapy Ivana Gmizic, Dubravka Salemovic, Ivana Pesic-Pavlovic, Marina Siljic, Valentina Nikolic, Miljana Djonin-Nenezic, Ivana Milosevic, Branko Brmbolic, Maja Stanojevic O15 Romanian nationwide screening for infection with HIV and hepatitis B and C viruses Anca Streinu-Cercel, Oana Săndulescu, Alina Cristina Neguț, Mioara Predescu, Alexandra Mărdărescu, Mihai Săndulescu, Adrian Streinu-Cercel O16 Treatment emergent variants to combined direct antiviral agents therapy against hepatitis C virus Ana Belen Pérez, Natalia Chueca, Marta Álvarez, Juan Carlos Alados, Antonio Rivero, Francisco Vera, Marcial Delgado, Javier Salmeron, Miguel Jiménez, Maria José Blanco, Moises Diago, Miguel Garcia-deltoro, Marta Alvarez, Francisco Téllez, Federico García O17 Clinical and epidemiological aspects in tuberculosis/HIV coinfected patients Diana Tănase, Eliza Manea, Rodica Bacruban, Dragoș Florea, Dan Oțelea, Alexandru Rafila, Mariana Mărdărescu, Adriana Hristea O18 Resistance to NS3 protease inhibitors in persons with chronic hepatitis C infected with hepatitis C virus subtype 1a from Croatia Ivana Grgic, Ana Planinic, Maja Santak, Lana Gorenec, Snjezana Zidovec Lepej, Adriana Vince O19 Analysis of a simplified diagnostic score for tuberculous meningitis in HIV-infected adults with meningitis Eliza Manea, Adriana Hristea, Șerban Benea, Ruxandra Moroti, Diana Tănase, Cristian M. Niculae, Simona Merisor, Raluca Jipa O20 Molecular tracing of the origin of HIV-1 infection among persons who inject drugs in Athens: a phyloethnic study Dimitrios Paraskevis, Evangelia Kostaki, Georgios K. Nikolopoulos, Vana Sypsa, Mina Psichogiou, Dimitra Paraskeva, Athanassios Skoutelis, Meni Malliori, Samuel R. Friedman, Angelos Hatzakis O21 The dynamics of virological response to HIV-1 infection and antiretroviral therapy initiation in patients with and without HLA-B*5701 Allele Malgorzata Hackiewicz, Piotr Zabek, Ewa Firlag-Burkacka, Andrzej Horban, Justyna Dominika Kowalska O22 Increase in the numbers of non-B subtypes and potential recombinant forms circulating among Slovenian MSM in the recent years Maja M. Lunar, Jana Mlakar, Mario Poljak O23 Genotyping intrahost polymorphisms in hepatitis C virus E2 protein associated with resistance to antibody neutralization Leontina Bănică, Eliza Martin, Valeriu Gheorghiță, Andrei Petrescu, Dan Oțelea, Costin-Ioan Popescu, Simona Paraschiv O24 Genotyping of HCV...

Background: Pericardial and pleural effusions are two complications recently described in patients hospitalized with COVID-19 infections. There are several mechanisms that have been proposed and refer to SARS-CoV-2’s capacity to bind to cell surfaces via various receptors and its broad tissue tropism that might cause significant complications. The aim of the present study is to evaluate the incidence of pericardial and pleural effusions during COVID-19 infection as well as to determine the risk factors associated with these complications. Methods: We conducted a retrospective single-center study that included 346 patients admitted to the National Institute of Infectious Disease “Prof. Dr. Matei Bals” (Bucharest, Romania), from 1 January to 25 May 2021, during the third wave of the pandemic. Socio-demographic and anthropometric data were collected for each patient. The patients were evaluated clinically, biologically, and radiologically within 48 h of admission. Patients were divided into 3 groups: (1) patients with pericardial effusions—18; (2) patients with pleural effusions—28; (3) patients without pericardial/pleural effusions—294. Results: After exclusion criteria were applied, 337 patients were analyzed. The median age of the participants was 58.26 ± 14.58 years. More than half of the hospitalized patients had associated respiratory failure (61.5%), of which 2.7% had a critical form of the disease and 58.8% had a severe form. The cumulative percentage for pericardial and pleural effusions for the study group was 12.8% (43 patients out of 337). The prevalence of pericardial effusion was 5.3%, twice more frequent among male respondents. Pleural effusion was identified in 8.3% patients. Most patients had unilateral effusion (17), compared to 11 patients who had bilateral involvement. Based on laboratory results, patients with pericardial and pleural effusions exhibited increased levels of C reactive protein, erythrocyte sedimentation rate, NT proBNP, and a higher value of neutrophil/lymphocyte count ratio. In contrast to patients without pleural and pericardial effusions, those with these symptoms experienced a higher frequency of severe or critical illness and longer hospital stays. Conclusions: Pericardial and pleural effusions can complicate COVID-19 infections. In our study, the prevalence of pericardial and pleural effusions in hospitalized patients was low, being associated with the same comorbidities and a number of clinical and biological parameters.

Mpox has become a significant health concern since the global outbreak that began in 2022. The aim of this study is to present the epidemiological situation of Mpox in Romania during 2022–2023 and to describe a severe case of Mpox in a patient who survived despite multiple co-pathologies. Forty-seven confirmed cases were reported at the national level, all in men, in 2022. The median age was 33 years. Twenty-six cases involved men who have sex with men (MSM), and twenty-three tested positive for HIV. We also describe a severe case involving a 34-year-old bisexual male with newly diagnosed AIDS who developed severe Mpox with persistent necrotic skin lesions, respiratory involvement, and multiple opportunistic infections: tuberculosis, pneumocystis pneumonia, syphilis, and oral candidiasis. The patient presented with fever, night sweats, weight loss, and dyspnea, with a single ulcerative facial lesion that later disseminated. Mpox infection was confirmed through PCR from skin lesion, serum, saliva, urine, rectal, nasal, and pharyngeal swab samples, with high viral loads persisting despite prolonged Tecovirimat therapy. The patient developed immune reconstitution inflammatory syndrome following the initiation of antiretroviral therapy. This case emphasizes the challenges of treating Mpox in immunocompromised patients.