Genetic Structure of Introduced Plasmodium vivax Malaria Isolates in Greece, 2015-2019.

Greece has been malaria-free since 1974, after an intense malaria control program. However, as Greece hosts migrant populations from P. vivax malaria-endemic countries, there is a risk of introducing the disease to specific vulnerable and receptive areas of the country. Knowledge of the genetic diversity of P. vivax populations is essential for understanding the dynamics of malaria disease transmission in a given region. We used nine highly polymorphic markers to genotype 124 P. vivax-infected archived DNA samples from human blood specimens referred to the NMRL from all over Greece throughout 2015-2019. The genotypic variability of the samples studied was noted, as they comprised several unique haplotypes, indicative of the importation of a large number of different P. vivax strains in the country. However, only a few events of local transmission were recorded. Genotyping revealed and confirmed the same clusters as those identified through epidemiological investigation. In only one introduction event was the index case found. No sustained/ongoing malaria transmissions in/between the studied regions or during consecutive years or additional foci of local transmission were observed. Genotyping is an important component in assisting malaria surveillance, as it provides information concerning the patterns of introduction and the effectiveness of implemented malaria control and elimination measures.

Innate Immune Gene Polymorphisms and COVID-19 Prognosis.

COVID-19 is characterized by a heterogeneous clinical presentation and prognosis. Risk factors contributing to the development of severe disease include old age and the presence of comorbidities. However, the genetic background of the host has also been recognized as an important determinant of disease prognosis. Considering the pivotal role of innate immunity in the control of SARS-CoV-2 infection, we analyzed the possible contribution of several innate immune gene polymorphisms (including TLR2-rs5743708, TLR4-rs4986790, TLR4-rs4986791, CD14-rs2569190, CARD8-rs1834481, IL18-rs2043211, and CD40-rs1883832) in disease severity and prognosis. A total of 249 individuals were enrolled and further divided into five (5) groups, according to the clinical progression scale provided by the World Health Organization (WHO) (asymptomatic, mild, moderate, severe, and critical). We identified that elderly patients with obesity and/or diabetes mellitus were more susceptible to developing pneumonia and respiratory distress syndrome after SARS-CoV-2 infection, while the IL18-rs1834481 polymorphism was an independent risk factor for developing pneumonia. Moreover, individuals carrying either the TLR2-rs5743708 or the TLR4-rs4986791 polymorphisms exhibited a 3.6- and 2.5-fold increased probability for developing pneumonia and a more severe disease, respectively. Our data support the notion that the host's genetic background can significantly affect COVID-19 clinical phenotype, also suggesting that the IL18-rs1834481, TLR2-rs5743708, and TLR4-rs4986791 polymorphisms may be used as molecular predictors of COVID-19 clinical phenotype.

Effectiveness of a Self-Decontaminating Coating Containing Usnic Acid in Reducing Environmental Microbial Load in Tertiary-Care Hospitals.

Surfaces have been implicated in the transmission of pathogens in hospitals. This study aimed to assess the effectiveness of an usnic-acid-containing self-decontaminating coating in reducing microbial surface contamination in tertiary-care hospitals. Samples were collected from surfaces 9 days before coating application, and 3, 10, and 21 days after its application (phases 1, 2, 3, and 4, respectively). Samples were tested for bacteria, fungi, and SARS-CoV2. In phase 1, 53/69 (76.8%) samples tested positive for bacteria, 9/69 (13.0%) for fungi, and 10/139 (7.2%) for SARS-CoV-2. In phase 2, 4/69 (5.8%) samples tested positive for bacteria, while 69 and 139 samples were negative for fungi and SARS-CoV-2, respectively. In phase 3, 3/69 (4.3%) samples were positive for bacteria, 1/139 (0.7%) samples tested positive for SARS-CoV-2, while 69 samples were negative for fungi. In phase 4, 1/69 (1.4%) tested positive for bacteria, while no fungus or SARS-CoV-2 were detected. After the coating was applied, the bacterial load was reduced by 87% in phase 2 (RR = 0.132; 95% CI: 0.108-0.162); 99% in phase 3 (RR = 0.006; 95% CI: 0.003-0.015); and 100% in phase 4 (RR = 0.001; 95% CI: 0.000-0.009). These data indicate that the usnic-acid-containing coating was effective in eliminating bacterial, fungal, and SARS-CoV-2 contamination on surfaces in hospitals.Our findings support the benefit ofan usnic-acid-containing coating in reducing the microbial load on healthcare surfaces.

The rs1883832 Polymorphism (CD40-1C>T) Affects the Intensity of IgA Responses after BNT162b2 Vaccination

The effectiveness of coronavirus disease 2019 (COVID-19) vaccination strategies is affected by several factors, including the genetic background of the host. In our study, we evaluated the contribution of the functional polymorphism rs1883832 affecting the Kozak sequence of the TNFSF5 gene (c.-1C>T), encoding CD40, to humoral immune responses after vaccination with the spike protein of SARS-CoV-2. The rs1883832 polymorphism was analyzed by PCR-RFLP in 476 individuals (male/female: 216/260, median age: 55.0 years, range: 20−105) of whom 342 received the BNT162b2 mRNA vaccine and 134 received the adenovirus-based vector vaccines (67 on ChAdOx1-nCoV-19 vaccine, 67 on Ad.26.COV2.S vaccine). The IgG and IgA responses were evaluated with chemiluminescent microparticle and ELISA assays on days 21, 42, and 90 after the first dose. The T allele of the rs1883832 polymorphism (allele frequency: 32.8%) was significantly associated with lower IgA levels and represented, as revealed by multivariable analysis, an independent risk factor for reduced anti-spike protein IgA levels on days 42 and 90 following BNT162b2 mRNA vaccination. Similar to serum anti-spike IgA levels, a trend of lower anti-spike IgA concentrations in saliva was found in individuals with the T allele of rs1883832. Finally, the intensity of IgA and IgG responses on day 42 significantly affected the prevalence of COVID-19 after vaccination. The rs1883832 polymorphism may be used as a molecular predictor of the intensity of anti-spike IgA responses after BNT162b2 mRNA vaccination.

Antimicrobial Effectiveness of an Usnic-Acid-Containing Self-Decontaminating Coating on Underground Metro Surfaces in Athens.

(1) Background: Surfaces have been implicated in the transmission of infections. We aimed to assess how effective an usnic-acid-containing self-decontaminating coating was on the surfaces of the Athens underground metro. (2) Methods: Two samples were collected from each of 60 surfaces of a station and a wagon before the application of the coating and 9 and 20 days after, and they were tested for bacteria, fungi, and SARS-CoV-2 using conventional microbiological and molecular methods. Bacteria and fungi growth were expressed in colony forming units (CFUs)/102cm2. (3) Results: Before the application of the coating, 50% of the samples tested positive for the targeted microbes: 91.7% for bacteria, 18.3% for fungi, and 8.3% for SARS-CoV-2. After nine days, 3.3% of the samples tested positive for bacteria and 6.6% after 20 days. The average amount of bacteria before the coating was applied was 8.5 CFU/102cm2 compared to 0 and 0 CFU/102cm2 after application (100% and 95% reduction); all samples collected after the application were negative for SARS-CoV-2 and fungi (100% reduction). (4) Conclusion: An usnic-acid-containing self-decontaminating coating was highly effective in eliminating bacterial, fungal, and SARS-CoV-2 contamination of surfaces in the underground metro.

Adherence to Recommendations for Βacillus Calmette-Guérin Vaccination of High-risk Neonates in Greece.

In 2016 a Βacillus Calmette-Guérin vaccination policy targeting high-risk neonates for tuberculosis before discharge from maternity hospital was adopted in Greece. Vaccination rates were 38.2% in 2019 and 24.7% in 2020. Vaccination coverage varied by risk group (higher for neonates in close contact with an active noncompliant or multidrug-resistant tuberculosis case and lower for Roma and immigrant neonates).

Performance Evaluation of a Rapid Antigen Test (RAT) during Omicron Pandemic Wave in Greece, Conducted by Different Personnel, and Comparison with Performance in Previous Wave (Alpha Variant) Period.

Due to the prevailing ambiguity regarding the performance of rapid antigen tests (RATs) for B.1.1.529 (Omicron) variant diagnosis, a commercial RAT was evaluated in the emergency ward of a general hospital in Larissa, Central Greece. The sampling and the evaluation were repeated twice by different personnel. Discordance between the two samplings was observed regarding the sensitivity (47.5%, 95% CI: 39.0-56.1 vs. 78.6%, 95% CI: 69.1-86.2) and specificity (93.8%, 95% CI: 86.0-97.9 vs. 100.0%, 95% CI: 93.3-100.0) of the RAT. Furthermore, the test displayed slightly lower sensitivity (78.6% vs. 85.5%, 95% CI: 79.1-90.5) compared to its initial evaluation that was conducted by our team when the B.1.1.7 (Alpha) variant was dominant.

Vaccination coverage rates and attitudes towards mandatory vaccinations among healthcare personnel in tertiary-care hospitals in Greece.

OBJECTIVES: Our aim was to estimate vaccination and susceptibility rates against vaccine-preventable diseases among healthcare personnel (HCP) in eight hospitals. METHODS: Cross-sectional survey. RESULTS: A total of 1284 HCP participated (physicians: 31.3%, nursing personnel: 36.6%, paramedical personnel: 11.1%, administrative personnel: 13.2%, supportive personnel: 7.3%). Vaccination rates were 32.9% against measles and mumps, 38.1% against rubella, 5.7% against varicella, 9.2% against hepatitis A, 65.8% against hepatitis B, 31.8% against tetanus-diphtheria, 7.1% against pertussis, 60.2% against influenza, and 80.1% against COVID-19. Susceptibility rates were as follows: 27.8% for measles, 39.6% for mumps, 33.4% for rubella, 22.2% for varicella, 86.3% for hepatitis A, 34.2% for hepatitis B, 68.2% for tetanus-diphtheria, and 92.9% for pertussis. Older HCP had higher susceptibility rates against mumps, rubella, varicella, hepatitis A, hepatitis B, tetanus-diphtheria, and pertussis (p-values <0.001 for all). Mandatory vaccinations were supported by 81.85% of HCP. CONCLUSIONS: Although most HCPs supported mandatory vaccinations, significant vaccination gaps, and susceptibility rates were recorded. The proportion of susceptible HCP to measles, mumps, rubella, and varicella has increased in the past decade, mostly because of reduction in acquired cases of natural illness. Vaccination programs for HCP should be developed. A national registry to follow HCP's vaccination rates is urgently needed.

Attitudes toward Vaccinations and Vaccination Coverage Rates among Dental Students in Greece.

Our aim was to study attitudes toward vaccinations, full vaccination rates and susceptibility rates against vaccine-preventable diseases among students attending a University Dental School. A total of 134 students were studied. Full vaccination rates were as follows: 56.5% against measles and mumps, 70.6% against rubella, 32.3% against varicella, 44.1% against hepatitis A, 45.9% against hepatitis B, and 87.7% against COVID-19. In the past decade, 63.2% of students had received a booster shot against tetanus-diphtheria, 47.8% against pertussis, and 28.1% against poliomyelitis, while 29.4% of students had been vaccinated against influenza in the past year. Susceptibility rates were 40.4% for measles, 42.4% for mumps, 28.3% for rubella, 32.3% for varicella, 55.3% for hepatitis A, 54.1% for hepatitis B, 36.8% for tetanus-diphtheria, 52.2% for pertussis, and 71.9% for poliomyelitis. Overall, 123 (91.8%) students favored mandatory vaccinations, mainly for all dentists (88.4%), while 11.6% of students favored them only for dentists who provide care to high-risk patients. In conclusion, most dental students favored mandatory vaccinations, yet we found significant vaccination gaps and susceptibility rates against vaccine-preventable diseases. Vaccinations for dental students should be intensified. A national vaccination registry for healthcare personnel including dental students is urgently needed.

A study of the evolution of the third COVID-19 pandemic wave in the Athens metropolitan area, Greece, through two cross-sectional seroepidemiological surveys: March, June 2021.

We studied the third coronavirus disease 2019 (COVID-19) pandemic wave in Athens metropolitan area (3 738 901 inhabitants) through two seroepidemiological surveys. Persons presenting in 12 healthcare facilities across Athens in March and June 2021 were studied (764 and 901, respectively). Immunoglobulin G antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein were measured by a chemiluminescent microparticle immunoassay. In March the seroprevalence rate was 11.6%, meaning that 435 208 residents of Athens had evidence of immunity. The respective values in June were 55.7% and 2 082 568 residents. The highest seroprevalence rates attributed to SARS-CoV-2 infection were recorded in persons <18 years (16.3% in March and 31.6% in June), while immunity was mainly vaccine-induced in persons 18-64 years and >65 years. Infection-attributed immunity also increased in older-age groups. Wide ranges in seroprevalence rates were noted across areas in March and June. The highest seroprevalence rates were recorded in Piraeus (47.2%) and West Attica (37.5%). However, the highest increase (>5 times) occurred in Piraeus and the South Section of Athens, which are among the most densely populated areas in Athens. In both study periods, history of COVID-19 or febrile episode, and having a cohabitant with COVID-19 were associated with increased risk for seropositivity among unvaccinated persons (p values <0.001 for all). Residing in Piraeus, the South Section or West Attica was associated with increased risk for seropositivity in June (p values <0.001). Wide heterogeneity in seroprevalence rates was found across areas in Athens, which is mainly attributed to population density. The impact of population mobility and socioeconomic status should be explored.

MBL deficiency-causing B allele (rs1800450) as a risk factor for severe COVID-19.

The COVID-19 pandemic represents one of the greatest challenges in modern medicine. The disease is characterized by a variable clinical phenotype, ranging from asymptomatic carriage to severe and/or critical disease, which bears poor prognosis and outcome because of the development of severe acute respiratory distress syndrome (SARS) requiring ICU hospitalization, multi-organ failure and death. Therefore, the determination of risk factors predisposing to disease phenotype is of outmost importance. The aim of our study was to evaluate which predisposing factors, including MBL2 genotyping, affected clinical phenotype in 264 COVID-19 patients. We demonstrated that older age along with underlying comorbidities, primarily obesity, chronic inflammatory disorders and diabetes mellitus, represent the most important risk factors related to hospitalization, the development of pneumonia and SARS. Moreover, we found that the presence of the MBL deficiency-causing B allele (rs1800450) was significantly associated with almost 2-fold increased risk for developing pneumonia and requiring hospitalization, suggesting its usage as a molecular predictor of severe disease in SARS-CoV-2 infected individuals.

Environmental testing for SARS-CoV-2 in three tertiary-care hospitals during the peak of the third COVID-19 wave.

Contamination of surfaces has been implicated in transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We tested by real-time PCR for SARS-CoV-2 contamination environmental samples from three hospitals during the peak of the third pandemic wave. Overall, 19 of 463 (4.1%) samples tested positive: 12 of 173 (6.9%) samples from a COVID-19 hospital, 3 of 177 (1.7%) samples from a non-COVID-19 hospital, and 4 of 113 (3.5%) samples from a pediatric hospital with dedicated COVID-19 clinics. Most positive samples originated from emergency departments (EDs) (47.3%) and the intensive care units (ICUs) (26.3%) of the COVID-19 hospital. Positive samples belonged almost exclusively (18/19) to the highly transmissible B.1.1.7 cluster, that might explain environmental contamination at this stage of the pandemic. The frequency and efficiency of disinfection in high-risk patient areas, such as EDs and ICUs, should be reinforced, especially during this period where highly transmissible variants of concern are widespread.

Indoor Air Quality Evaluation Using Mechanical Ventilation and Portable Air Purifiers in an Academic Dentistry Clinic during the COVID-19 Pandemic in Greece.

The coronavirus disease 2019 (COVID-19), which is mainly transmitted through droplets without overlooking other sources of transmission, rendered attention on the air quality in indoor areas and more specifically in healthcare settings. The improvement of indoor air quality (IAQ) is ensured by frequent changes of the air that must be carried out in healthcare areas and with assistance from special devices that undertake the filtration of the air and its purification through special filters and lamps. In this research, the performance of air purifiers is assessed in terms of the limitation of PM2.5, PM10, VOCs and CO2 in a postgraduate clinic of the Dentistry School of the National and Kapodistrian University of Athens in parallel with mechanical ventilation. Our findings indicate that the use of mechanical ventilation plays a key role on the results, retaining good IAQ levels within the clinic and that air purifiers show a positive impact on IAQ by mainly reducing the levels of PM2.5 and secondly of TVOC.

COVID-19 Outbreak on a Passenger Ship and Assessment of Response Measures, Greece, 2020.

We describe response measures to an outbreak involving 128 (33.4%) coronavirus disease cases (46.1% asymptomatic) among 383 persons onboard a passenger ship. Multivariate analysis indicated that dining in certain rooms and bar areas, nationality, working department (for crew members), and quarantining onboard the ship were significantly associated with infection.

Preparing dental schools to refunction safely during the COVID-19 pandemic: an infection prevention and control perspective.

In late 2019 a novel coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in China and spread throughout the world over a short period of time causing a pandemic of a respiratory disease named coronavirus disease 2019 (COVID-19). SARS-CoV-2 is easily transmitted from person to person through respiratory droplets and direct contact. The scarce available data indicate that dental healthcare personnel are at increased risk for acquisition of infection. Following the lockdown lifting, dental schools should be prepared to refunction safely and provide essential educational and healthcare services while protecting their students, patients, and personnel. The generation of aerosols in dental practice, in association with the high-transmissibility of SARS-CoV-2 through aerosol-generation procedures, the simultaneous provision of dental services to patients in the same areas, and the fact that asymptomatic and pre-symptomatic infected persons may transmit the virus, render the implementation of specific infection prevention and control measures imperative for dental schools. Herein we review the few evidence-based data available to guide infection prevention and control measures for COVID-19 in dental schools.

Influenza vaccination policies for health workers in low-income and middle-income countries: A cross-sectional survey, January-March 2020.

INTRODUCTION: The World Health Organization (WHO) recommends vaccination of health workers against influenza, but uptake in low-resource settings remains low. To complement routine global data collection efforts we conducted a detailed survey on influenza vaccination policies for health workers in low-income and middle-income countries (LMICs) in early 2020. METHODS: Health worker vaccination policy data were collected via a web-based survey tool sent to Expanded Programme on Immunization managers or equivalent managers of all eligible countries. High-income countries and countries with active civil war were excluded from the participation. The survey was sent by email to 109 LMICs in all WHO Regions to invite participation. Data were analyzed by World Bank income category and WHO Region. Statistical methods were applied to assess mean vaccination rates across countries. RESULTS: Sixty-eight (62%) out of 109 invited LMICs were studied. Thirty-five (51.5%) reported to have a policy for influenza vaccination of health workers. Vaccinations were voluntary in 23 countries (66%), mandatory in 4 (11%), while in 8 countries (23%) mixed vaccination policies existed. A mechanism to estimate vaccine uptake existed in 26 countries (74%). Low-income and African Region countries were less likely to have influenza vaccination policies for health workers (p-values < 0.001 and 0.009, respectively). The most common reason for not having a vaccination policy for health workers was influenza not being a priority (48.5%). CONCLUSIONS: Despite policies being in place in more than half LMICs studied, gaps remain in translating vaccination policies to action, particularly in low-income and African Region countries. To optimize the operationalization of policies, further research is needed within countries, to enable evidence-based introduction decisions, categorization of health workers for vaccination, identification of factors impacting effective service delivery, strengthening monitoring and estimation of vaccination uptake rates and ensure sustainability of funding.

The Importance of an Active Case Detection (ACD) Programme for Malaria among Migrants from Malaria Endemic Countries: The Greek Experience in a Receptive and Vulnerable Area.

Greece has been malaria-free since 1974. In October 2011, following an outbreak of 36 locally acquired malaria (LAM) cases in Evrotas Municipality, a Pro-Active Case Detection (PACD) program for malaria was implemented among migrants from malaria-endemic countries, to support early diagnosis and treatment of cases. We evaluated the PACD program for the years 2012-2017 using indicators such as the number of locally acquired cases, the detection rate/sensitivity and the timeliness of diagnosis and treatment. We visited each migrant home every 7-15 days to screen migrants for malaria symptoms, performing Rapid Diagnostic Tests (RDTs) and blood smears on symptomatic patients. We estimated: (i) the number of malaria cases detected by the PACD, divided by the total number of reported malaria cases during the same period among the same population; (ii) the time between onset of symptoms, diagnosis and initiation of treatment. The total number of migrants who were screened for malaria symptoms for the years 2012-2017 was 5057 with 84,169 fever screenings conducted, while 2288 RDTs and 1736 blood smears were performed. During the same period, 53 imported P. vivax malaria cases were detected, while incidence of malaria among migrants was estimated at 1.8% annually. Ten and one LAM cases were also reported in 2012 and 2015, respectively. Sensitivity of PACD ranged from 86% to 100%; median timeliness between onset of symptoms and diagnosis decreased from 72 h in 2012 to 12 h in 2017 (83% decrease), while timeliness between diagnosis and treatment initiation was 0 h. The implementation of PACD could be considered an effective prevention and response tool against malaria re-introduction.

SARS-CoV-2 Infection in Healthcare Personnel With High-risk Occupational Exposure: Evaluation of 7-Day Exclusion From Work Policy.

BACKGROUND: As of late February 2020, Greece has been experiencing the coronavirus disease 2019 (COVID-19) epidemic. Healthcare personnel (HCP) were disproportionately affected, accounting for ~10% of notified cases. Exclusion from work for 7 days was recommended for HCP with high-risk occupational exposure. Our aim was to evaluate the 7-day exclusion from work policy for HCP with high-risk exposure. METHODS: HCP with a history of occupational exposure to COVID-19 were notified to the Hellenic National Public Health Organization, regardless of their exposure risk category. Exposed HCP were followed for 14 days after last exposure. RESULTS: We prospectively studied 3398 occupationally exposed HCP; nursing personnel accounted for most exposures (n = 1705; 50.2%). Of the 3398 exposed HCP, 1599 (47.1%) were classified as low-risk, 765 (22.5%) as moderate-risk, and 1031 (30.4%) as high-risk exposures. Sixty-six (1.9%) HCP developed COVID-19 at a mean of 3.65 (range: 0-17) days postexposure. Of the 66 HCP with COVID-19, 46, 7, and 13 had a history of high-, moderate- or low-risk exposure (4.5%, 0.9%, and 0.8% of all high-, moderate-, and low-risk exposures, respectively). Hospitalization and absenteeism were more prevalent among HCP with high-risk exposure. A logistic regression analysis showed that the following variables were significantly associated with an increased risk for the onset of COVID-19: male, administrative personnel, underlying disease, and high-risk exposure. CONCLUSIONS: HCP with high-risk occupational exposure to COVID-19 had increased probability of serious morbidity, healthcare seeking, hospitalization, and absenteeism. Our findings justify the 7-day exclusion from work policy for HCP with high-risk exposure.

Genetic Spatiotemporal Anatomy of Plasmodium vivax Malaria Episodes in Greece, 2009-2013.

An influx of immigrants is contributing to the reemergence of Plasmodium vivax malaria in Greece; 1 persistent focus of transmission is in Laconia, Pelopónnese. We genotyped archived blood samples from a substantial proportion of malaria cases recorded in Greece in 2009-2013 using 8 microsatellite markers and a PvMSP-3α gene fragment and plotted their spatiotemporal distribution. High parasite genetic diversity with low multiplicity of infection was observed. A subset of genetically identical/related parasites was restricted to 3 areas in migrants and Greek residents, with some persisting over 2 consecutive transmission periods. We identified 2 hitherto unsuspected additional foci of local transmission: Kardhítsa and Attica. Furthermore, this analysis indicates that several cases in migrants initially classified as imported malaria were actually locally acquired. This study shows the potential for P. vivax to reestablish transmission and counsels public health authorities about the need for vigilance to achieve or maintain sustainable malaria elimination.