Unraveling the Dynamics of Omicron (BA.1, BA.2, and BA.5) Waves and Emergence of the Deltacton Variant: Genomic Epidemiology of the SARS-CoV-2 Epidemic in Cyprus (Oct 2021-Oct 2022).

Commencing in December 2019 with the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), three years of the coronavirus disease 2019 (COVID-19) pandemic have transpired. The virus has consistently demonstrated a tendency for evolutionary adaptation, resulting in mutations that impact both immune evasion and transmissibility. This ongoing process has led to successive waves of infections. This study offers a comprehensive assessment spanning genetic, phylogenetic, phylodynamic, and phylogeographic dimensions, focused on the trajectory of the SARS-CoV-2 epidemic in Cyprus. Based on a dataset comprising 4700 viral genomic sequences obtained from affected individuals between October 2021 and October 2022, our analysis is presented. Over this timeframe, a total of 167 distinct lineages and sublineages emerged, including variants such as Delta and Omicron (1, 2, and 5). Notably, during the fifth wave of infections, Omicron subvariants 1 and 2 gained prominence, followed by the ascendancy of Omicron 5 in the subsequent sixth wave. Additionally, during the fifth wave (December 2021-January 2022), a unique set of Delta sequences with genetic mutations associated with Omicron variant 1, dubbed "Deltacron", was identified. The emergence of this phenomenon initially evoked skepticism, characterized by concerns primarily centered around contamination or coinfection as plausible etiological contributors. These hypotheses were predominantly disseminated through unsubstantiated assertions within the realms of social and mass media, lacking concurrent scientific evidence to validate their claims. Nevertheless, the exhaustive molecular analyses presented in this study have demonstrated that such occurrences would likely lead to a frameshift mutation-a genetic aberration conspicuously absent in our provided sequences. This substantiates the accuracy of our initial assertion while refuting contamination or coinfection as potential etiologies. Comparable observations on a global scale dispelled doubt, eventually leading to the recognition of Delta-Omicron variants by the scientific community and their subsequent monitoring by the World Health Organization (WHO). As our investigation delved deeper into the intricate dynamics of the SARS-CoV-2 epidemic in Cyprus, a discernible pattern emerged, highlighting the major role of international connections in shaping the virus's local trajectory. Notably, the United States and the United Kingdom were the central conduits governing the entry and exit of the virus to and from Cyprus. Moreover, notable migratory routes included nations such as Greece, South Korea, France, Germany, Brazil, Spain, Australia, Denmark, Sweden, and Italy. These empirical findings underscore that the spread of SARS-CoV-2 within Cyprus was markedly influenced by the influx of new, highly transmissible variants, triggering successive waves of infection. This investigation elucidates the emergence of new waves of infection subsequent to the advent of highly contagious and transmissible viral variants, notably characterized by an abundance of mutations localized within the spike protein. Notably, this discovery decisively contradicts the hitherto hypothesis of seasonal fluctuations in the virus's epidemiological dynamics. This study emphasizes the importance of meticulously examining molecular genetics alongside virus migration patterns within a specific region. Past experiences also emphasize the substantial evolutionary potential of viruses such as SARS-CoV-2, underscoring the need for sustained vigilance. However, as the pandemic's dynamics continue to evolve, a balanced approach between caution and resilience becomes paramount. This ethos encourages an approach founded on informed prudence and self-preservation, guided by public health authorities, rather than enduring apprehension. Such an approach empowers societies to adapt and progress, fostering a poised confidence rooted in well-founded adaptation.

Implementation of a hospital antimicrobial stewardship program to improve vancomycin use in Cyprus: Challenges and opportunity.

Background: The Republic of Cyprus is among the highest consumers of antibacterials for systemic use in Europe. The antimicrobial resistance of invasive isolates in Cyprus is also high compared to the European Union. Formal antimicrobial stewardship initiatives are scarce in Cyprus, raising an urgent need to address the challenges for implementing hospital antimicrobial stewardship. Aim: To implement an antimicrobial stewardship program and improve vancomycin use in a tertiary care hospital in Cyprus, through implementation of a protocol for treatment and therapeutic drug monitoring (TDM) and to discuss the current challenges present in Cyprus. Methods: Following a local audit of practices, we established a hospital antimicrobial stewardship program with limited resources, towards a model of stewardship which included a persuasive approach, education, selective reporting of antimicrobial susceptibility, providing comments on the microbiology results and regular microbiology clinical ward rounds. Findings: By implementing our vancomycin protocol, we achieved a statistically significant improvement (P<0.01) in achieving vancomycin therapeutic levels over a 2-year period, while improving administration practices. Conclusion: Meaningful steps toward implementing a local antimicrobial stewardship program are possible even in resource-limited and unfavourable settings.

Genomic Epidemiology of the SARS-CoV-2 Epidemic in Cyprus from November 2020 to October 2021: The Passage of Waves of Alpha and Delta Variants of Concern.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 resulted in the coronavirus disease 2019 (COVID-19) pandemic, which has had devastating repercussions for public health. Over the course of this pandemic, the virus has continuously been evolving, resulting in new, more infectious variants that have frequently led to surges of new SARS-CoV-2 infections. In the present study, we performed detailed genetic, phylogenetic, phylodynamic and phylogeographic analyses to examine the SARS-CoV-2 epidemic in Cyprus using 2352 SARS-CoV-2 sequences from infected individuals in Cyprus during November 2020 to October 2021. During this period, a total of 61 different lineages and sublineages were identified, with most falling into three groups: B.1.258 & sublineages, Alpha (B.1.1.7 & Q. sublineages), and Delta (B.1.617.2 & AY. sublineages), each encompassing a set of S gene mutations that primarily confer increased transmissibility as well as immune evasion. Specifically, these lineages were coupled with surges of new infections in Cyprus, resulting in the following: the second wave of SARS-CoV-2 infections in Cyprus, comprising B.1.258 & sublineages, during late autumn 2020/beginning of winter 2021; the third wave, comprising Alpha (B.1.1.7 & Q. sublineages), during spring 2021; and the fourth wave, comprising Delta (B.1.617.2 & AY. sublineages) during summer 2021. Additionally, it was identified that these lineages were primarily imported from and exported to the UK, Greece, and Sweden; many other migration links were also identified, including Switzerland, Denmark, Russia, and Germany. Taken together, the results of this study indicate that the SARS-CoV-2 epidemic in Cyprus was characterized by successive introduction of new lineages from a plethora of countries, resulting in the generation of waves of infection. Overall, this study highlights the importance of investigating the spatiotemporal evolution of the SARS-CoV-2 epidemic in the context of Cyprus, as well as the impact of protective measures placed to mitigate transmission of the virus, providing necessary information to safeguard public health.

Healthcare-associated transmission of Panton-Valentine leucocidin positive methicillin-resistant Staphylococcus aureus: the value of screening asymptomatic healthcare workers.

BACKGROUND: Three patients hospitalised in the coronary care unit of a general district hospital (England, UK) were tested positive for Panton-Valentine leucocidin methicillin-resistant Staphylococcus aureus colonisation during their routine weekly screening for methicillin-resistant Staphylococcus aureus (MRSA). The isolates were indistinguishable and all three patients have previously had negative screening tests. The outbreak investigation team considered exploring the possibility of PVL-MRSA transmission from members of staff to the patients and potentially between members of staff. METHOD: As part of the investigations, healthcare workers on coronary care unit and intensive care unit were screened for MRSA carriage. RESULTS: Among 134 screened healthcare workers, five staff members (3.7%) were MRSA colonised. Among these isolates, four were Panton-Valentine leukocidin positive. However, only two healthcare workers had an indistinguishable isolate with the isolate identified among the colonised patients. Decolonisation treatment was offered to all colonised patients and healthcare workers. CONCLUSION: In low MRSA prevalence settings, healthcare workers may be a reservoir of MRSA and an important potential source of transmission to patients. Screening and decolonisation of colonised healthcare workers may provide a valuable strategy in managing linked hospital acquisitions and reduce the risk of occupationally acquired complications. MRSA mass screen of healthcare workers should be considered in transmission with a strain that has a potentially increased virulence, such as Panton-Valentine leucocidin methicillin-resistant Staphylococcus aureus.

Application of chemometric methods for assessment and modelling of microbiological quality data concerning coastal bathing water in Greece.

BACKGROUND: Worldwide, the aim of managing water is to safeguard human health whilst maintaining sustainable aquatic and associated terrestrial, ecosystems. Because human enteric viruses are the most likely pathogens responsible for waterborne diseases from recreational water use, but detection methods are complex and costly for routine monitoring, it is of great interest to determine the quality of coastal bathing water with a minimum cost and maximum safety. DESIGN AND METHODS: This study handles the assessment and modelling of the microbiological quality data of 2149 seawater bathing areas in Greece over 10-year period (1997-2006) by chemometric methods. RESULTS: Cluster analysis results indicated that the studied bathing beaches are classified in accordance with the seasonality in three groups. Factor analysis was applied to investigate possible determining factors in the groups resulted from the cluster analysis, and also two new parameters were created in each group; VF1 includes E. coli, faecal coliforms and total coliforms and VF2 includes faecal streptococci/enterococci. By applying the cluster analysis in each seasonal group, three new groups of coasts were generated, group A (ultraclean), group B (clean) and group C (contaminated). CONCLUSIONS: The above analysis is confirmed by the application of discriminant analysis, and proves that chemometric methods are useful tools for assessment and modeling microbiological quality data of coastal bathing water on a large scale, and thus could attribute to effective and economical monitoring of the quality of coastal bathing water in a country with a big number of bathing coasts, like Greece. Significance for public healthThe microbiological protection of coastal bathing water quality is of great interest for the public health authorities as well as for the economy. The present study proves that this protection can be achieved by monitoring only two microbiological parameters, E. coli and faecal streptococci/enterococci instead four microbiological parameters (the two mentioned above plus Total coliforms and Faecal coliforms) that are usually monitored today. As a consequence, countries, especially those with large quantities of coastal bathing sites, can perform microbiological monitoring of their bathing waters by checking only the mentioned two parameters, thus ensuring economies of scale. Thus, funds can be used in other actions to preserve the quality of coastal water and human health. This in turn, would aid in the assessment of the quality of coastal bathing waters and provide a more timely indication of bathing water quality, hence contributing to the immediate health protection of bathers.

Pertussis Epidemiology in Greece and Emerging Risk Groups during the Vaccination Era (1980-2008).

To study the epidemiology of pertussis in Greece and epidemiologic changes throughout a period of twenty-nine years, we conducted a retrospective analysis of available data of pertussis cases for the past twenty-nine years (1980-2008) and a prospective analysis of hospitalized pertussis cases from a children's hospital in Athens for eight years (2001-2008). From 1980 through 2008, the incidence of pertussis in Greece declined from 11.2 to 0.05 cases per 100,000. Epidemic cycles occurring every 3 to 5 years were observed. Since pertussis circulation cannot be fully controlled by present immunization programs, efforts should be made to vaccinate infants at the recommended age, early diagnose, treatment as well as contact tracing of pertussis cases. Control of pertussis in social susceptible populations is necessary. A national program with adolescent and adult booster could decrease the circulation of B. pertussis. Despite an overall decrease for pertussis cases, pertussis is still a present and future challenge of public health service in Greece.

Elevated bathing-associated disease risks despite certified water quality: a cohort study.

Bacteriological water quality criteria have been recommended to ensure bathers' health. However, this risk-assessment approach is based mainly on routine measurements of fecal pollution indicator bacteria in seawater, and may not be adequate to protect bathers effectively. The aim of this study was to assess the risks of symptoms related to infectious diseases among bathers after exposure to seawater which was of excellent quality according to EU guidelines. This study is a cohort study recruiting bathers and non-bathers. Water samples were collected for estimating bacterial indicators. Univariable and multivariable analysis was performed to compare the risks of developing symptoms/diseases between bathers and non-bathers. A total of 3805 bathers and 572 non-bathers were included in the study. Water analysis results demonstrated excellent quality of bathing water. Significantly increased risks of symptoms related to gastrointestinal infections (OR = 3.60, 95% CI 1.28-10.13), respiratory infections (OR = 1.92, 95% CI 1.00-3.67), eye infections (OR = 2.43, 95% CI 1.27-4.63) and ear infections (OR = 17.21, 95% CI 2.42-122.34) were observed among bathers compared with non-bathers. Increased rates of medical consultation and medication use were also observed among bathers. There was evidence that bathers experienced increased morbidity compared with non-bathers though the bathing waters met bacteriological water quality criteria. These results suggest that risk assessments of recreational seawaters should not only focus on bacteriological water quality criteria.

Bather density as a predominant factor for health effects related to recreational bathing: results from the Greek bathers cohort study.

Our aim was to examine the health effects on bathers from exposure to recreational seawater on three beaches with different microbiology quality and bather density through a cohort study. An initial questionnaire and a 10 day follow up were used. Univariate and backward logistic regression analyses were used to asses the risk of developing symptoms or diseases among the bathers. In total, 3805 bathers were included in the study and 149 samples were collected from the three beaches. Despite all the beaches being characterized of high quality the levels of bacterial indicators differed among them. Health effects among bathers were not associated with bacterial indicators. A statistically significant increased risk for symptoms related to respiratory illness, gastroenteritis, medical consultation and use of medication was observed among bathers at the higher bather density beaches. Beach bather numbers should always be taken into account when considering a risk assessment approach.

Determinants of exposure to Environmental Tobacco Smoke (ETS) among non smoking adolescents (aged 11-17 years old) in Greece: results from the 2004-2005 GYTS Study.

The aim of the study is to investigate the determinants of exposure to ETS among Greek adolescents aged 11-17 years old. The GYTS questionnaire was completed by 5,179 adolescents. About 3 in 4 responders (76.8%) were exposed to ETS at home, and 38.5% were exposed to ETS outside of the home. Gender, age group, parental and close friends smoking status were significant determinants of adolescent's exposure to ETS. The results of the study could be valuable for the implementation of public health initiatives in Greece aiming to reduce the burden of adolescent's exposure to passive smoking.

Application of multivariate statistical methods for groundwater physicochemical and biological quality assessment in the context of public health.

Three representative areas (lowland, semi-mountainous, and coastal) have been selected for the collection of drinking water samples, and a total number of 28 physical, chemical, and biological parameters per water sample have been determined and analyzed. The mean values of the physical and chemical parameters were found to be within the limits mentioned in the 98/83/EEC directive. The analysis of biological parameters shows that many of the water samples are inadequate for human consumption because of the presence of bacteria. Cluster analysis (CA) first was used to classify sample sites with similar properties and results in three groups of sites; discriminant analysis (DA) was used to construct the best discriminant functions to confirm the clusters determined by CA and evaluate the spatial variations in water quality. The standard mode discriminant functions, using 17 parameters, yielded classification matrix correctly assigning 96.97% of the cases. In the stepwise mode, the DA produced a classification matrix with 96.36% correct assignments using only ten parameters (EC, Cl-, NO3-, HCO3-, CO3(-2), Ca+2, Na+, Zn, Mn, and Pb). CA and factor analysis (FA) are used to characterize water quality and assist in water quality monitoring planning. CA proved that two major groups of similarity (six subclusters) between 17 physicochemical parameters are formed, and FA extracts six factors that account for 66.478% of the total water quality variation, when all samples' physicochemical data set is considered. It is noteworthy that the classification scheme obtained by CA is completely confirmed by principal component analysis.

Diagnostic clinical and laboratory findings in response to predetermining bacterial pathogen: data from the Meningitis Registry.

BACKGROUND: Childhood meningitis continues to be an important cause of mortality in many countries. The search for rapid diagnosis of acute bacterial meningitis has lead to the further exploration of prognostic factors. This study was scheduled in an attempt to analyze various clinical symptoms as well as rapid laboratory results and provide an algorithm for the prediction of specific bacterial aetiology of childhood bacterial meningitis. METHODOLOGY AND PRINCIPAL FINDINGS: During the 32 year period, 2477 cases of probable bacterial meningitis (BM) were collected from the Meningitis Registry (MR). Analysis was performed on a total of 1331 confirmed bacterial meningitis cases of patients aged 1 month to 14 years. Data was analysed using EPI INFO (version 3.4.3-CDC-Atlanta) and SPSS (version 15.0-Chicago) software. Statistically significant (p<0.05) variables were included in a conditional backward logistic regression model. A total of 838 (63.0%) attributed to Neisseria meningitidis, 252 (18.9%) to Haemophilus influenzae, 186 (14.0%) to Streptococcus pneumoniae and 55 (4.1%) due to other bacteria. For the diagnosis of Meningococcal Meningitis, the most significant group of diagnostic criteria identified included haemorrhagic rash (OR 22.36), absence of seizures (OR 2.51), headache (OR 1.83) and negative gram stain result (OR 1.55) with a Positive Predictive Value (PPV) of 96.4% (95%CI 87.7-99.6). For the diagnosis of Streptococcus pneumoniae, the most significant group of diagnostic criteria identified included absence of haemorrhagic rash (OR 13.62), positive gram stain (OR 2.10), coma (OR 3.11), seizures (OR 3.81) and peripheral WBC > or = 15000/microL (OR 2.19) with a PPV of 77.8% (95%CI 40.0-97.2). For the diagnosis of Haemophilus influenzae, the most significant group of diagnostic criteria included, absence of haemorrhagic rash (OR 13.61), age > or = 1 year (OR 2.04), absence of headache (OR 3.01), CSF Glu < 40 mg/dL (OR 3.62) and peripheral WBC < 15,000/microL (OR 1.74) with a PPV of 58.5% (95%CI 42.1-73.7). CONCLUSIONS: The use of clinical and laboratory predictors for the assessment of the causative bacterial pathogen rather than just for predicting outcome of mortality seems to be a useful tool in the clinical management and specific treatment of BM. These findings should be further explored and studied.

Analysis of seawater microbiological quality data in Greece from 1997 to 2006: association of risk factors with bacterial indicators.

This study deals with the examination of quality of seawater bathing areas in Greece over a 10-year period and identifies risk factors for high bacteria indicator organism concentrations. Qualitative descriptive analysis was applied and the microbiological test results of 231,205 water samples were associated with pollution markers and other parameters. Measurements of Escherichia coli (99.6%) and enterococci (100%) were found to be in accordance with the mandatory value guidelines set by the new European Directive. An increasing trend for the yearly mean value of faecal streptococci was noted. Using logistic regression analysis, phenolic smell (OR = 2.10, CI = 2.04-2.16), rainfall the day before sampling (OR = 1.67, CI = 1.64-1.74), high seas (OR = 1.42, CI = 1.39-1.46) and rainfall on the day of sampling (OR = 1.27, CI = 1.20-1.33) were positively independently associated with high levels of bacterial indicators (total coliforms, faecal coliforms, faecal streptococci and E. coli). The highest risk, absolute risk value 42.8% (RR = 3.17, CI = 2.97-3.38), was measured when previous day rainfall, phenolic smell and high seas were simultaneously recorded. Such parameters should be further investigated as predetermining factors for the assessment of beach bathing water quality, providing a timely indication of water risk assessment.

Development and assessment of a questionnaire for a descriptive cross-sectional study concerning parents' knowledge, attitudes and practises in antibiotic use in Greece.

BACKGROUND: Upper Respiratory Infections (URIs) are common in children. The cause is usually viral, but parents' attitude often contributes to inappropriate antibiotic prescribing, promoting antibiotic resistance. The objective is to describe the process of developing a questionnaire to assess parents' Knowledge, Attitude and Practices (KAP) concerning the role of antibiotics when children suffer from URIs, as well as to evaluate the response rates, the completeness and the reliability (Cronbach) of the questionnaires. Finally, to note any limitations of the study. METHODS: Literature review, along with pre-testing yielded a questionnaire designed to assess the parents' KAP-level. A postal survey was set, in a national sample of 200 schools stratified by geographical region. The participants consist of a multistage geographical cluster sample of 8000 parents. The influence of demographic characteristics (i.e. sex, age, education) was analyzed. Cronbach index test and factor analysis were used to assess the reliability of the questionnaire. RESULTS: The response rate of the parents was 69%. Islands presented the lowest response rate while in Northern Greece the response rate was the highest. Sixty-eight point nine percent of the sample returned questionnaires fully completed, while 91.5% completed 95% of the questions. Three questions out of 70 were answered in a very low rate which was associated mostly with immigrant respondents. The section describing parents' attitude toward antibiotic use was not completed as much as the sections of knowledge or practices. The questions were factor analyzed and 10 out of the 21 extracted factors were finally evaluated, reducing the number of independent variables to 46. The reliability of the questionnaire was 0.55. However, only items that increased the Cronbach when added were eventually included in the final scales raising the internal consistency to 0.68. Limitations of the study, such as the vocabulary and form of the questionnaire and the idiocycrancy of the respondents, emerged during the analysis. CONCLUSION: The response rate and the completeness of the questionnaires were higher than expected, probably attributed to the involvement of the teachers. The study findings were satisfactory regarding the development of a reliable instrument capable to measure parents' KAP characteristics.

Regional differences in mortality in Greece (1984-2004): the case of Thrace.

BACKGROUND: Mortality differences at national level can generate hypothesis on possible causal association that could be further investigated. The aim of the present study was to identify regions with high mortality rates in Greece. METHODS: Age adjusted specific mortality rates by gender were calculated in each of the 10 regions of Greece during the period 1984-2004. Moreover standardized mortality rates (SMR) were also calculated by using population census data of years 1981, 1991, 2001. The mortality rates were examined in relation to GDP per capita, the ratio of hospital beds, and doctors per population for each region. RESULTS: During the study period, the region of Thrace recorded the highest mortality rate at almost all age groups in both sexes among the ten Greek regions. Thrace had one of the lowest GDP per capita (11,123 Euro) and recorded low ratios of Physicians (284) per 100,000 inhabitants in comparison to the national ratios. Moreover the ratio of hospital beds per population was in Thrace very low (268/100,000) in comparison to the national ratio (470/100,000). Thrace is the Greek region with the highest percentage of Muslim population (33%). Multivariate analysis revealed that GDP and doctors/100000 inhabitants were associated with increased mortality in Thrace. CONCLUSION: Thrace is the region with the highest mortality rate in Greece. Further research is needed to assess the contribution of each possible risk factor to the increased mortality rate of Thrace which could have important public health implications.

Tobacco use among students aged 13-15 years in Greece: the GYTS project.

BACKGROUND: Data on the prevalence of tobacco use among teenagers in Greece are limited. We examined the prevalence of smoking among middle-school students in Greece using the Global Youth Tobacco Survey (GYTS). METHODS: The Global Youth Tobacco Survey was implemented in Greece during the academic year 2004-2005 by the University of Thessaly and the National School of Public Health. Data were collected using the GYTS self-administered anonymous questionnaire, which was distributed by specifically trained field workers to a nationally representative sample of middle-school students aged 13-15 years (through randomly selected schools and classes), randomly selected through a two-stage cluster sample design. Data processing and statistical analyses were performed at the Centers for Disease Control and Prevention (CDC). RESULTS: About one third of the students 32.1% (29.4-35.0) reported that they had tried tobacco in the past, while 16.2% (14.3-18.4) reported being current users of tobacco products. In addition, 1 in 4 of ever smokers reported that they began smoking before the age of 10 years old. Almost 1 in 5 never smokers reported being susceptible to initiate smoking in the next year and about 89.8% (88.3-91.1) of the respondents were exposed to environmental tobacco smoke in their homes and 94.1% (93.2-94.9) in public places. Finally, a strikingly high number of students 95% (89.5-97.7) reported that they were able to buy their own cigarettes without restrictions. CONCLUSION: The results of the GYTS show that the prevalence of smoking in middle-school children is alarmingly high in Greece. Smoking among young people constitutes a significant problem that is destined to worsen in the absence of any comprehensive efforts focused on strict anti-smoking legislation, policies and tobacco control interventions targeting children at a young age.

Management of environmental health issues for the 2004 Athens Olympic Games: is enhanced integrated environmental health surveillance needed in every day routine operation?

BACKGROUND: Management of environmental health issues is an integral part of public health systems. An active integrated environmental health surveillance and response system was developed for the Athens Olympics to monitor and prevent exposure to environmental hazards. The potential for permanent implementation of the program was examined. METHODS: The environmental health surveillance and response system included standardization, computerization and electronic transmission of data concerning environmental inspections of 17 site categories (restaurants, swimming pools etc) of public health interest, drinking and recreational water examinations and suggested corrective actions. The Olympic Planning Unit integrated and centrally managed data from 13 public health agencies, recommended, supervised and coordinated prompt corrective actions. Methods used to test the effectiveness of the program were the assessment of water quality test and inspection results trends over time using linear regression and epidemiological surveillance findings. RESULTS: Between January 2003 and September the 30th, 2004, 196 inspectors conducted 8562 inspections, collected 5024 water samples and recommended 17 027 corrective actions. In 10 cruise ships used as floating hotels inspectors conducted 10 full inspections, 2 re-inspections, and 27 follow-up inspections. Unsatisfactory inspection results (r = 0.44, p < 0.0001) and positive water quality tests (r = 0.39, p < 0.001) presented an overall decrease trend over time. In August, 2003, an outbreak of salmonellosis was linked to a hotel restaurant which accommodated athletes during a test event. CONCLUSION: Lessons learned for future events include timely implementation and installation of communication processes, and rapid and coordinated response to unsatisfactory inspection results. Routine national programs need to adopt enhanced environmental health surveillance aimed at public health decision-making, but with a different perspective.