The Romanian HIV epidemic is characterized by a high prevalence among children born in the late '80s, perinatally infected. The impact of long-term treatment on their offspring is unknown. We evaluated the influence of prenatal care on the rate of premature birth among the HIV-exposed children of heavily treated HIV-infected mothers in two Romanian centers. We retrospectively analyzed data on all patients born by HIV-infected mothers between 2006 and 2012 followed up in two main regional centers. We compared the rate of premature birth and the differences between the sites regarding children and maternal demographic characteristics and antiretroviral exposure in pregnant women. A total of 358 children born to 315 women were enrolled between 2006-2012, 262 children from the National Institute for Infectious Diseases "Prof. Dr. Matei Balş" Bucharest (NIID) and 96 children from the Clinical Infectious Diseases Hospital Constanţa (IDHC). Gender rate in newborns and mean age in mothers were similar. We recorded statistically significant differences between centers in the rate of HIV vertical transmission (16.8% vs. 6.2%, p=0.002) and prematurity (25.2 vs. 14.6%, p=0.023). The most used antiretroviral combination during pregnancy in IDHC was boosted lopinavir and fixed dose zidovudine-lamivudine (66% of cases), while in NIID a greater diversity of antiretrovirals were used. Women from IDHC were more frequently treated during pregnancy (83.3% vs. 68.6%, p=0.004). HCV coinfection and illegal drug use were associated with prematurity in the NIID cohort (p=0.037, p=0.024). We found a higher rate of premature birth and HIV infection in NIID. In IDHC we found a higher rate of low birth weight in children and a higher rate of heavily treated women. Prematurity was associated with hepatitis C infection and illegal drug use in the NIID cohort.

Background/Objectives: This study presents a comprehensive and updated epidemiological and public health assessment of human immunodeficiency virus (HIV) in Romania during 2022–2024, situated within the wider European context. Methods: For this retrospective descriptive study, we analyzed national surveillance data from the National Institute of Infectious Diseases “Prof. Dr. Matei Balș” and European Centre for Disease Prevention and Control (ECDC) reports, between 1985–2024, focusing especially on 2022–2024 period. Key indicators included incidence, mortality, transmission routes, age and gender distribution, and treatment coverage. Comparative analyses were performed between Romania and European Union (EU)/Eastern Europe data. Results: Between 1985 and 2024, Romania registered a cumulative total of 28,793 HIV cases, with 18,768 individuals living with HIV (PLHIV) as of 2024. In that year, 810 new HIV cases were diagnoses, indicating a modest uptick compared with 2022–2023. Heterosexual transmission continued to predominate (59.4%), followed by cases among men who have sex with men (MSM) (30.5%) and intravenous drug users (IDUs) (5.2%). Men represented more than three-quarters of all new infections. Mortality displayed considerable year-to-year variability, increasing from 125 HIV-related deaths in 2023 to 193 in 2024. Despite this, treatment coverage improved steadily, with 16,464 individuals receiving antiretroviral therapy (ART) by the end of 2024. At 2.51 cases per 100,000 population, Romania’s incidence remained below the European average of 3.5 per 100,000. Nonetheless, the proportion of infections attributable to MSM transmission rose sharply—from 3.91% in 2007 to 32% in 2024—bringing Romania’s epidemiological profile increasingly in line with broader trends observed in Eastern Europe. Conclusions: These findings suggest that although Romania maintains a comparatively lower HIV incidence than the European average, the evolving transmission dynamics—most notably the substantial increase in MSM-related cases—signal a shifting epidemiological landscape that warrants strengthened, population-specific prevention measures and continued investment in comprehensive treatment and monitoring frameworks.

Introduction: Despite the advances in its prevention, invasive meningococcal disease (IMD) remains a serious health problem worldwide due to its high morbidity and mortality, including in Romania, with 22% mortality rate. The objectives were to describe the trends of IMD cases admitted to a tertiary care hospital in Romania, over 24 years, and the case fatality rate (CFR) by age, year of admission, and Neisseria meningitidis serogroups. Materials and Methods: A retrospective study was conducted in IMD patients admitted to the National Institute for Infectious Diseases “Prof. Dr. Matei Bals”, Bucharest, Romania, between 2001 and 2024. Results: A total of 256 IMD patients were admitted, 171 under fourteen years, out of which 75 were infants. Most cases were reported before 2008. The case distribution showed 90 patients (35%) with meningitis, 84 (32%) with meningococcaemia, and 82 (32%) with an association of both. Serogroup B was the most frequently and steadily found (58 cases). The overall CFR was 12%. CFR was highest in infants younger than 6 months (19%) and meningococcaemia cases (29%). Conclusions: In our study, IDM had the highest frequency and CFR in infants and meningococcaemia cases. The trends showed a decline in cases after 2008. Serogroup B was the most prevalent and stable strain over 24 years.

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 and Objectives: Antiretroviral therapy used during pregnancy in HIV infected women effectively reduces vertical transmission, though concerns about potential adverse newborn outcomes persists. This study focused on prematurity and low birth weight in antiretroviral HIV-exposed children in two major Romanian centers, Bucharest and Constanța, in the context of free access to antiretroviral treatment for pregnant women in Romania since 2001. Materials and Methods: A retrospective observational study was performed including couples of HIV-infected women and their live singleton newborns from 2006 and 2012. Preterm delivery was defined as birth before week 37 and low birth weight was defined as birth weight less than 2500 g in full-term babies. Results: A total number of 352 children and 313 women were enrolled. Mean maternal age at delivery was 23.1 years. Mean newborn birth weight was 2726 g. In the children group, 191 (54.2%) were boys, and the rate of HIV transmission was 13.9%. The prematurity rate was 21.5% and low birth weight rate was 25.56%. Preterm birth was associated with high HIV RNA in the third trimester, HIV-positive final status in infants, and vaginal delivery. Low birth weight was associated with lack of antiretroviral treatment during pregnancy and HIV-positive status in infants. No association was found between prematurity and low birth weight in full-term newborns and exposure to any antiretroviral class, any specific antiviral drug, or with any number of maternal regimens, duration of antiretroviral treatment prior to conception, or maternal exposure during puberty. Conclusions: In our study, preterm birth was significantly associated with HIV vertical transmission in newborns and with exposure to high maternal viral replication during the last trimester of pregnancy. Low birth weight in full-term babies was significantly associated with lack of antiretroviral exposure in utero in our analysis.