Introduction. The burden of liver diseases is a major health issue, being underestimated both at the national and international level. In the Republic of Moldova, there are over 70 thousand patients with chronic hepatitis and over 10 thousand people suffering from liver cirrhosis. 70% of patients with cirrhosis develop liver cancer. Over 2,000 patients die annually from complications caused by liver cirrhosis, and over 400 patients die due to primary liver cancer. Material and methods. The statistical analysis of 2000-2019 reports, presented by the Agency for Public Health, as well as of 3666 patient medical records retrieved from „Timofei Mosneaga” Republican Hospital, „Toma Ciorba” Clinical Hospital and “Sfinta Treime” Clinical Hospital was carried out. Results. 89290 cases of chronic hepatitis, liver cirrhosis and liver cancer have been officially registered. Most of them exhibited a viral etiology. The death rate was mostly recorded in patients aged 70-79. The mean age of patients with chronic hepatitis was 57.74±11.22, liver cirrhosis - 56.21±10.17, and liver cancer- 59.05±10.94. The risk factors included unprotected sex, use of sharp objects, scissors and syringes, noncompliance with dietary regimens, alcohol and tobacco use, etc. Close relatives were also investigated for the presence of viral markers in only 38.81% of cases of chronic hepatitis and in 24.37% patients with liver cirrhosis Conclusions. The study of common epidemiological evolution of chronic hepatitis, liver cirrhosis and primary liver cancer in the population, while considering the patient’s close relationship, might reduce both morbidity and medical and socio-economic impact.

Introduction. Poultry meat and eggs represent a risk of contamination with zoonotic bacterial agents. This requires permanent laboratory monitoring throughout the production chain segment. Material and methods. The research material consisted of samples retrieved from poultry carcasses and eggs for current consumption. There were examined 80 samples of eggs and 110 samples of poultry carcasses. Results. S. Gallinarum, S. Enteritidis and S. Infantins serotypes were isolated in 12.7% of samples out of 110 examined carcasses, whereas S. Gallinarum, S. Dublin ?i S. Typhimurium serotypes were detected in 6.25% of 80 egg samples. Conclusions. Bacteriological research on poultry carcasses and eggs showed the presence of pathogenic serotypes of Salmonella spp., which is a major risk to public health.

Introduction. The emergence of the new coronavirus (SARS-CoV-2) has led to a rapid spread of novel infection (COVID-19) worldwide. Since February 1, 2021, to date, more than 103,989,900 cases and more than 2 million deaths have been reported globally. The infection incidence and death rate among medical staff worldwide, as well as in the Republic of Moldova continues to be very high, whereas the preventive measures to prevent infections among medical staff remains imperative. Material and methods. Data on morbidity, incidence, prevalence and mortality of COVID-19 were analyzed and evaluated among healthcare workers, based on the selection of data from the digital information-epidemiological surveillance system of COVID-19 infection with SARS CoV-2 virus. The epidemiological methods (retrospective, prospective) recommended by WHO, CDC, ECDC were used. Results. Until 01.02.2021, the Republic of Moldova registered 153,371 cases of SARS-CoV-2 infection among healthcare workers, of which 4,103 were doctors, 6,406 were nurses, 4,435 were auxiliary staff, and over 70 employees of medical institutions died. Conclusions. The share of infection cases among medical staff accounts for 9.45% out of the total number of infections and about 39.08% of infections were registered in Chisinau. Most cases were registered among nurses (41.7%), whereas female health workers are more frequently affected (80.4%), the ratio of female to male being of 4:1.

Introduction. Monitoring acute flaccid paralysis (AFP) is a key strategy used by the Global Polio Eradication Initiative (GPEI) in assessing the progress towards the global eradication goal. Material and methods. A cross-sectional descriptive study was conducted during the years 2002-2017. The current research was carried out within the National Agency for Public Health - Virology Laboratory. The study focused on a period of 15 years (2002-2017), during which the Republic of Moldova was included as a polio-free country. Results. Thus, over 15 years (2002-2017) there were reported and registered 118 non-polio cases (AFP) on the territory of the Republic of Moldova. The data of our study determined the rate of non-polio cases for the period 2002-2017, which ranged between 0.3-2.3 per 100 000 children, cumulatively, the incidence being of 17.9 cases per 100 000 children. The rate of males diagnosed with acute flaccid paralysis accounted for 54.2%. Most cases were registered in the Central areas, including Chisinau city (29.7%) and other localities involving the same area 28.8%. Conclusion. The study results showed that the Republic of Moldova has feasible monitoring of the epidemiological situation on polio, including an action plan for further preventive measures and surveillance of poliomyelitis, where detection, registration and investigation of AFP is the "gold standard" aimed at providing a favourable epidemiological situation.

Introduction. Hemodi?lysis p?tients ?re ?t higher risk of tr?nsmitting vir?l infections, including hep?titis B virus (HBV) infection, due to the frequent need for blood tr?nsfusions ?nd the potential exposure to cont?min?ted di?lysis equipment. M?teri?l ?nd methods. The study was conducted on a risk group of 121 hemodi?lysis p?tients, ?ged between 18 ?nd 70 ye?rs, the me?n ?ge being 48.1±13.1 ye?rs. Results. The prevalence of the serological m?rker of hep?titis B virus (HBs?g) accounted for 7.4±2.4% (n=9) of cases and no ?nti-HBs m?rker w?s detected in 47.7±5.3% of the hemodi?lysis p?tients investig?ted. M?les were positive for the HBs?g m?rker in 8.7±3.4% (n=6) of cases, whereas most patients being from the Central ?re? (13.8±6.5%). Conclusion. The serological prevalence of the hepatitis B virus infections markers, ?s well ?s the ?ssessment of the immune response in people undergoing hemodi?lysis tre?tment might outline the b?sic monitoring and control tools in the development of specific ?ntiepidemic me?sures against this infection.

Introduction. Currently, COVID-19 treatment includes several options, including the use of convalescent plasma. Therefore, the presence of anti-SARS-CoV-2 in blood donors after the clinical recovery of COVID-19, depending on their place of residence, age and the clinical manifestation of the disease is of scientific-practical interest. Material and methods. A total of 119 donors among patients were examined, namely males aged 18-60 years, having a past history of COVID-19 disease, being confirmed by PCR and treated, showing a negative PCR-based test result, which was performed at least 14 days after clinical recovery. The presence/absence of anti-SARS-CoV-2 was assessed by enzyme-linked immunosorbent assay. Results. The obtained data showed that 87.4% of plasma donors responded to COVID-19 infection by anti-SARS-CoV-2 IgG expression, being predominantly found in the 26-35 age group. Most donors experienced mild and medium clinical forms. It is important to note that all severe clinical manifestations of the infection were followed by formation of anti-SARS-CoV-2 IgG. Urban living environment was predominantly found in convalescent donors (75.0%), which indicates that they are better informed by medical institutions. Conclusions. The study shows that male blood donors aged 18-60 years, subsequently cured and being positive to anti-SARS-CoV-2 IgG can serve as a source of fresh plasma used for the treatment of COVID-19 patients.

Introduction. Trophic ulcer continues to be a major clinical problem, currently having a significant socio-economic impact. The association of microbial infections, especially with antibiotic-resistant bacteria, is one of the most common complications of trophic ulcers. In this context, trophic ulcers associated with methicillin-resistant Staphylococcus (MRS) have a high epidemiological and clinical significance. Material and methods. The determination of risk factors, antimicrobial resistance, as well as the clinical and socio-economic impact of trophic ulcers caused by MRS strains was performed based on a retrospective case-control study. The research group included 52 observation sheets of patients with trophic ulcers caused by methicillin-resistant Staphylococcus (MRS), the control group - 39 sheets of patients with trophic ulcers caused by methicillin-sensitive Staphylococcus (MSS). Results. MRS strains isolated from trophic ulcers had high rates of antibiotic resistance compared to MSS strains. As a risk factors of trophic ulcer from which MRS strains have been isolated, people over the age of 50, repeated hospitalizations, microbial associations and exposure to intensive care are highlighted. Conclusions. Risk factors and local epidemiology knowledge in trophic ulcers with MRS is the key factor in implementing and complying with surveillance and control measures.

Introduction. RVI (rotavirus infection) is the most common cause of dehydration in infants and young children. The implementation of the sentinel surveillance of RVI in infants from 2008 in the Republic of Moldova demonstrated the high rate of this infection (40.0%), being an argument in recommending the antirotaviral immunization in children within the National Immunization Program. Material and methods. The study enrolled 193 children with acute diarrheal disease, included in the sentinel supervision (2012-2016) and treated in the Unit for Acute Diarrheal Diseases at Children’s Clinical Hospital no. 1. The biological material was examined by serological enzyme-linked immunosorbent assay (ELISA) and genotyping, revealed by polymerase chain reaction (PCR). Results. The rotavirus infection was confirmed in 193 infants, of which 121 children were not vaccinated against RVI, and 72 were immunized. Depending on the genotypes encountered before and after vaccination, it was found that G9P [8], G3P[8], G4P[8] were detected before vaccination, although postvaccine prevailed G2P[4], G4P[8]. In addition, the incidence of RVI is decreasing and the disease evolution is much better. Conclusions. This article reflects the evolution of the genotypic properties of rotaviruses and the clinical-paraclinical particularities of RVI in infants, highlighting the importance of the implementation of antiretroviral immunization in children within the National Immunization Program in the Republic of Moldova.

Introduction. Acinetobacter baumannii is a pathogen and a major cause of nosocomial infections in the current healthcare system worldwide due to its high resistance to antibiotics, including those considered as a last resort, thus posing threat to severe clinical forms, as well as exhibiting significant economic and clinical impact. Material and methods. A descriptive longitudinal and cross-sectional epidemiological study was carried out based on the model of multidisciplinary care hospitals. Results. The generalized clinical forms of Acinetobacter nosocomial infections predominate in 56.30%, including: pulmonary sepsis – 25.59%, abdominal sepsis – 11.81%, septicemia – 9.45%, wound sepsis– 6.30%, biliary sepsis – 1.97%, and urosepsis – 1.18% of cases. Local infections were found in 16.93% of wound infections and in 14.57% of pneumonia cases. A. baumanii was present in the etiological structure of 98.18% of cases, exhibiting an increased resistance to antibiotics, particularly to monobactams – 100.0%, macrolides – 98.82%, penicillins – 98.08%, cephalosporins – 97.65%, penicillins with beta-lactamase inhibitors – 93.20%, fluoroquinolones – 87.16%, and amphenicols – 84.17% of cases. A. baumanii strains isolated from patients with nosocomial infections were found to be multidrug resistant to antibiotics in 93.08% of cases. Conclusions. Acinetobacter baumannii nosocomial infections represent a major public health issue that requires the implementation of strict surveillance and control strategies, including the rational use of antibiotics.

Introduction. Vaccination is now entering the third century of its practice and it is the most important medical intervention that has ever been implemented. Due to vaccines, the incidence of infectious diseases, which have killed hundreds of millions throughout the history has been dramatically reduced and made a substantial contribution to life expectancy. Recently, new technologies have emerged in the development of vaccines that are being implemented in the control of the COVID-19 pandemic. The successful immunoprophylaxis and the better understanding of the immune response mechanisms suggest that vaccination would also help in curing cancer and chronic diseases in the nearest future. Material and methods. There were analyzed 43 scientific articles on both vaccination and its future potential. Results. On 8 May 1980, the World Health Organization certified that smallpox had been eradicated globally. For the first time in history, the humankind defeated a disease. It was certainly the greatest medical achievement of the twentieth century. Recently, however, new technologies have emerged in the development of vaccines, based on mRNA, viral vectors and other technologies. Conclusions. Vaccines are the most important medical achievement ever made with a great impact in eradicating and controlling emerging and re-emerging infectious diseases.

Introduction. Hepatitis delta virus (HDV) is a small, defective RNA virus that is related more to plant viroids than to other human pathogens. Material and methods. Nearly 50 research articles from various sources were reviewed and a comprehensive analysis was done regarding various parameters concerning HDV. Articles published over a period of 30 years were selected based on their experimental and statistical relevance to HDV. This review gives a brief insight into epidemiology, genetics, clinical evolution and treatment of chronic hepatitis delta. Results. Chronic hepatitis delta remains a major cause of morbidity in Eastern European countries and the Mediterranean region. At the same time, there is a resurgence of HBV and HDV infection in young people (under the age of 50) in Western Europe, as a consequence of the intra-familial and sexual mode of acquisition among immigrants from Eastern Europe, the Mediterranean region and from countries of the former Soviet Union, Africa high burdened regions of Asia and South America. Prevalence among IVDU was found to be higher especially in western european countries and other regions of low HDV prevalence. Chronic delta viral hepatitis is a dynamic, progressive process. A direct cytopathic pattern of liver tissue damage was also observed, especially in the presence of HDV genotype 3. Chronic hepatitis D is reported to progress to cirrhosis and hepatocellular cancer, and this trend is greater the higher the level of HDV viremia at the time of presentation. Conclusions. Flaws in screening and on-time diagnosis still remain due to the insufficient research and data available. While still not classified as a carcinogen by IARC, our review ends up in support of the notion that HDV infection increases the chances and fastens the pathogenic processes leading to HCC.

Introduction. Clostridium difficile has been identified as the leading cause of antibiotic therapy-associated diarrhea and colitis, which has evolved from sporadic complications of antimicrobial therapy to severe, sometimes fatal events that have eventually become an endemic life-threatening issue among hospitalized and immunosuppressed patients worldwide. Material and methods. The analysis of the relevant bibliographic sources retrieved from the PubMed, Google Scholar, and other platforms was carried out. All the articles related to these research objectives were selected, followed by exclusion of articles focused on clinics and diagnosis. The study included 43 content-based relevant articles. This present article reveals the evolving epidemiology of C. difficile infection (CDI). Results. Clostridium difficile is a sporulated bacterium responsible for infectious diarrhea and pseudomembranous colitis, showing high morbidity and mortality rates among patients, especially in high-risk groups. C. difficile mainly affects hospitalized people over 65 years old, who have been exposed earlier to antibiotics. The risk factors for C. difficile in these individuals include depletion of the protective intestinal flora by antibiotics and a low immune response to C. difficile due to both advanced age and medical comorbidities. The major outbreaks commonly occur in health care, as well as in long-term care institutions. However, CDI is not supervised in the Republic of Moldova. Conclusions. A system for reporting and monitoring of C. difficile infection needs to be implemented in order to promptly and efficiently manage hospital outbreaks.

Introduction. There are approximately 20 million cases of HVE annually worldwide, leading to approximately 3.3 million symptomatic cases of acute hepatitis E. The WHO estimates that HEV caused approximately 44,000 deaths in 2015 accounting for 3.3% of the mortality rate due to viral hepatitis. Material and methods. The study of 75 bibliographic sources was carried out. The scientific platforms EMBASE, PubMed, HINARI, data from the national libraries as well as international relevant reference data were thoroughly examined. Results. The present relevant study has highlighted important aspects of hepatitis E virus infection. Along with the improved living conditions and water quality standards, the latter being a disease-causing factor in the transmission of HEV, both the developed and developing countries are facing HEV, particularly in high-risk population groups, including people who are employed in the pork-processing industry and beneficiaries of blood transfusions. Conclusions. The countries capacity to detect and control this infection is limited since it has not been included within the surveillance policies and programs yet. Risk factors associated with the epidemic process should be elucidated to provide and develop appropriate evidence-based measures to optimize the surveillance and control system in order to reduce the risk of contracting HEV and maintain favorable conditions for epidemiological safety.