SARS-CoV-2 sero-surveillance in Greece: evolution over time and epidemiological attributes during the pre-vaccination pandemic era

BACKGROUND: Nation-wide SARS-CoV-2 seroprevalence surveys provide valuable insights into the course of the pandemic, including information often not captured by routine surveillance of reported cases. METHODS: A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between March and December 2020. It was designed as a cross-sectional survey repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. RESULTS: Of 55,947 serum samples collected, 705 (1.26%) were found positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (9.09%) observed in December 2020. Highest seropositivity levels were observed in the "0-29" and "30-49" year age groups. Seroprevalence increased with age in the "0-29" age group. Highly populated metropolitan areas were characterized with elevated seroprevalence levels (11.92% in Attica, 12.76% in Thessaloniki) compared to the rest of the country (5.90%). The infection fatality rate (IFR) was estimated at 0.451% (95% CI: 0.382-0.549%) using aggregate data until December 2020, and the ratio of actual to reported cases was 9.59 (7.88-11.33). CONCLUSIONS: The evolution of seroprevalence estimates aligned with the course of the pandemic and varied widely by region and age group. Young and middle-aged adults appeared to be drivers of the pandemic during a severe epidemic wave under strict policy measures

Bedbugs and Infectious Diseases

Bedbugs (Cimex lectularius or Cimex hemipterus) are cosmopolite hematophagus insects, and recent outbreaks have been reported in all major occidental countries. Although they are suspected of transmitting more than 40 infectious agents, no report has yet definitively demonstrated that capacity

Legionella spp. and legionellosis in southeastern Italy: disease epidemiology and environmental surveillance in community and health care facilities

<p>Abstract</p> <p>Background</p> <p>Following the publication of the Italian Guidelines for the control and prevention of legionellosis an environmental and clinical surveillance has been carried out in Southeastern Italy. The aim of the study is to identify the risk factors for the disease, so allowing better programming of the necessary prevention measures.</p> <p>Methods</p> <p>During the period January 2000 - December 2009 the environmental surveillance was carried out by water sampling of 129 health care facilities (73 public and 56 private hospitals) and 533 buildings within the community (63 private apartments, 305 hotels, 19 offices, 4 churches, 116 gyms, 3 swimming pools and 23 schools). Water sampling and microbiological analysis were carried out following the Italian Guidelines. From January 2005, all facilities were subject to risk analysis through the use of a standardized report; the results were classified as <it>good </it>(G), <it>medium </it>(M) and <it>bad </it>(B). As well, all the clinical surveillance forms for legionellosis, which must be compiled by physicians and sent to the Regional Centre for Epidemiology (OER), were analyzed.</p> <p>Results</p> <p><it>Legionella </it>spp. was found in 102 (79.1%) health care facilities and in 238 (44.7%) community buildings. The percentages for the contamination levels < 1,000, 1,000-10,000, > 10,000 cfu/L were respectively 33.1%, 53.4% and 13.5% for samples from health care facilities and 33.5%, 43.3% and 23.2% for samples from the community. Both in hospital and community environments, <it>Legionella pneumophila </it>serogroup (<it>L. pn </it>sg) 2-14 was the most frequently isolate (respectively 54.8% and 40.8% of positive samples), followed by <it>L. pn </it>sg 1 (respectively 31.3% and 33%). The study showed a significant association between M or B score at the risk analysis and <it>Legionella </it>spp. positive microbiological test results (p < 0.001). From clinical surveillance, during the period January 2001 - August 2009, 97 cases of legionellosis were reported to the OER: 88 of community origin and 9 nosocomial. The most frequent symptoms were: fever (93.8%), cough (70.1%), dyspnea (58.8%), shivering (56.7%). Radiological evidence of pneumonia was reported in 68%. The laboratory diagnostic methods used were: urinary antigen (54.3%), single antibody titer (19.8%), only seroconversion (11.1%), other diagnostic methods (14.8%).</p> <p>Conclusions</p> <p>Our experience suggests that risk analysis and environmental microbiological surveillance should be carried out more frequently to control the environmental spread of <it>Legionella </it>spp. Furthermore, the laboratory diagnosis of legionellosis cannot be excluded only on the basis of a single negative test: some patients were positive to only one of the diagnostic tests.</p

Legionnaires' Disease in Hotels and Passenger Ships: A Systematic Review of Evidence, Sources, and Contributing Factors

BackgroundTravel-associated Legionnaires' disease (LD) is a serious problem, and hundreds of cases are reported every year among travelers who stayed at hotels, despite the efforts of international and governmental authorities and hotel operators to prevent additional cases. MethodsA systematic review of travel-associated LD events (cases, clusters, outbreaks) and of environmental studies of Legionella contamination in accommodation sites was conducted. Two databases were searched (PubMed and EMBASE). Data were extracted from 50 peer-reviewed articles that provided microbiological and epidemiological evidence for linking the accommodation sites with LD. The strength of evidence was classified as strong, possible, and probable. ResultsThree of the 21 hotel-associated events identified and four of nine ship-associated events occurred repeatedly on the same site. Of 197 hotel-associated cases, 158 (80.2%) were linked to hotel cooling towers and/or potable water systems. Ship-associated cases were most commonly linked to hot tubs (59/83, 71.1%). Common contributing factors included inadequate disinfection, maintenance, and monitoring; water stagnation; poor temperature control; and poor ventilation. Across all 30 events, Legionella concentrations in suspected water sources were >10,000cfu/L, <10,000cfu/L, and unknown in 11, 3, and 13 events, respectively. In five events, Legionella was not detected only after repeated disinfections. In environmental studies, Legionella was detected in 81.1% of ferries (23/28) and 48.9% of hotels (587/1,200), while all 12 cruise ships examined were negative. ConclusionsThis review highlights the need for LD awareness strategies targeting operators of accommodation sites. Increased standardization of LD investigation and reporting, and more rigorous follow-up of LD events, would help generate stronger, more comparable evidence on LD sources, contributing factors, and control measure effectiveness

Thermal disinfection of hotels, hospitals, and athletic venues hot water distribution systems contaminated by Legionella species

Legionella spp. ( >= 500 cfu liter(-1)) were detected in 92 of 497 water distribution systems (WDS) examined. Thermal disinfection was applied at 33 WDS. After the first and second application of the disinfection procedure, 15 (45.4%) and 3 (9%) positive for remedial actions WDS were found, respectively Legionella pneumophila was more resistant to thermal disinfection than Legionella non-pneumophila spp. (relative risk [RR] = 5.4, 95% confidence intervals [CI] = 1-35). WDS of hotels with oil heater were more easily disinfected than those with electrical or solar heater (RR = 0.4 95% CI = 0.2-0.8). Thermal disinfection seems not to be efficient enough to eliminate legionellae, unless repeatedly applied and in combination with extended heat flushing, and faucets chlorine disinfection

Legionella species colonization in cooling towers: Risk factors and assessment of control measures

Background: Cooling towers can be colonized by Legionella spp, and inhalation of aerosols generated by their operation may cause Legionnaires' disease in susceptible hosts. Environmental investigations of Legionnaires' disease outbreaks linked with cooling towers have revealed poorly maintained systems, lack of control measures, and failure of system equipment. The purpose of this study was to identify Legionella-contaminated cooling towers, identify risk factors for contamination, and assess the effectiveness of control measures. Methods: A total of 96 cooling towers of public buildings were registered and inspected, and 130 samples were collected and microbiologically tested. Microbiological test results were associated with characteristics of cooling towers, water samples, inspection results, and maintenance practices. Results: Of the total 96 cooling towers examined, 47 (48.9%) were colonized by Legionella spp, and 22 (22.9%) required remedial action. A total of 65 samples (50.0%) were positive (>= 500 cfu L(-1)), and 30 (23%) were heavily contaminated (>= 10(4) cfu L(-1)). Of the 69 isolates identified, 55 strains (79.7.%) were L pneumophila. Legionella colonization was positively associated with the absence of training on Legionella control ( relative risk [RR] = 1.66; P = .02), absence of regular Legionella testing (RR = 2.07: P = .002), absence of sunlight protection (RR = 1.63: P = .02), with samples in which the free residual chlorine level in the water sample was, = 1000 cfu L(-1). Conclusions: Cooling towers can be heavily colonized by Legionella spp and thus present a potential risk for infection. This study demonstrates the importance of a risk assessment and management plan. Water chlorination effectively reduces legionellae contamination. Proper training of cooling tower operators is paramount

Standardized inspections of food premises during the 2004 Athens Olympic Games: Descriptive analysis and risk factors for unsatisfactory results

Standardized inspections of food premises are part of environmental health systems implemented worldwide. The food safety strategy for the 2004 Olympic Games included standardized inspections to ensure uniformity and consistency of procedures and effective electronic management of data. Inspections were carried out by 196 inspectors in the five Olympic cities: Athens, Thessalonica, Volos, Iraklio, and Patra. From January 2003 to September 2004, a total of 1,249 food premises were inspected. An unsatisfactory inspection result (C grade) was received by 347 (27.8%) food premises, a relatively satisfactory result (B grade) was received by 332 (26.6%), and a satisfactory result (A grade) was received by 570 (45.6%). About 16% of inspected premises did not hold a valid permit. Unsatisfactory inspection results were more frequent for premises located in the two largest Greek cities in comparison with the other smaller cities (relative risk 1.95, 95% confidence interval [CI] = 1.36 to 2.80). Based on logistic regression analysis, unsatisfactory inspection results were positively associated with food premises that were not located on a ground floor (odds ratio [OR] = 2.56, 95% CI 1.39 to 4.73) and negatively associated with application of hazard analysis critical control point (HACCP) principles (OR 0.27, 95% CI = 0.10 to 0.71). Food hygiene education through formal training programs should be encouraged to improve compliance of food premises. Food premises located on hotel floors and serving buffet meals are at higher risk for unsatisfactory conditions. Businesses that implemented a HACCP system within their operations to ensure food safety operated under more hygienic conditions. Future inspections by Public Health Authorities should involve elements of audit after the legislation for the application of HACCP principles

Assessment of hygiene standards and Hazard Analysis Critical Control Points implementation on passenger ships

The level of hygiene on ferries can have impact on travellers' health. The aim of this study was to assess the hygiene standards of ferries in Greece and to investigate whether Hazard Analysis Critical Control Points (HACCP) implementation contributes to the hygiene status and particularly food safety aboard passenger ships. Hygiene inspections on 17 ferries in Greece were performed using a standardized inspection form, with a 135-point scale. Thirty-four water and 17 food samples were collected and analysed. About 65% (11/17) of ferries were scored with >100 points. Ferries with HACCP received higher scores during inspection compared to those without HACCP (p value <0.001). All 34 microbiological water test results were found negative and, from the 17 food samples, only one was found positive for Salmonella spp. Implementation of management systems including HACCP principles can help to raise the level of hygiene aboard passenger ships

Low acceptance of vaccination against the 2009 pandemic influenza A(H1N1) among healthcare workers in Greece

A questionnaire survey on the attitude of healthcare workers towards pandemic influenza vaccination showed low acceptance (17%) of the pandemic vaccine. Factors associated with vaccine uptake were acceptance of seasonal influenza vaccination, medical profession and age. The main reason for refusal of vaccination was fear of side effects, which was stronger in those who received information on the safety of the vaccine mainly from mass media