Potential scenarios for the progression of a COVID-19 epidemic in the European Union and the European Economic Area, March 2020.

Two months after the emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the possibility of established and widespread community transmission in the European Union and European Economic Area (EU/EEA) is becoming more likely. We provide scenarios for use in preparedness for a possible widespread epidemic. The EU/EEA is moving towards the 'limited sustained transmission' phase. We propose actions to prepare for potential mitigation phases and coordinate efforts to protect the health of citizens.

Enhancing the role of health communication in the prevention of infectious diseases.

Despite the recognized importance of health communication for disease prevention, a gap in knowledge was becoming apparent as regards the extent and nature of its use at the European level to support prevention and control of infectious diseases. To address this gap, the European Centre for Disease Prevention and Control (ECDC) commissioned in 2009 a consortium of universities to undertake a 3-year research project called "Translating Health Communications." The outcomes of this project comprise 2 major areas: (a) primary information gathering to provide insights into how health communication activities are currently being used for communicable disease prevention in the European Union and European Economic Area and (b) synthesis of knowledge on the evidence of use and application of health communication approaches. The overview of main findings of the project presented in this article highlights the many challenges that remain and the various areas of opportunity in order to raise the profile of health communication in the prevention of infectious diseases in the European context.

Low rate of pneumococci non-susceptible to penicillin in healthy Swedish toddlers.

BACKGROUND: Infection caused by Streptococcus pneumoniae is the leading cause of mortality in children worldwide. The aim of this study was to determine if a noted increase in non-susceptibility to penicillin among pneumococcal clinical isolates from young children reflected a similar increase in healthy children. METHODS: During 2004-2005, before the conjugate pneumococcal vaccine was introduced in Sweden, 663 healthy children (13-24 months of age) attending 17 child health centres in Gothenburg, Sweden, were cultured for bacteria in the nasopharynx. Social factors were identified through a parental questionnaire. Pneumococcal serotypes and antibiotic resistance rates were determined. Antibiotic resistance was also monitored in 162 simultaneously obtained nasopharyngeal pneumococci isolated from clinical samples. RESULTS: The healthy children frequently carried pneumococci (45%), Moraxella catarrhalis (54%), and Haemophilus influenzae (22%). The carriage rates for all these pathogens were higher in children attending day care centres compared to children staying at home (p < 0.001). The dominating pneumococcal serotypes were 6B, 19F, 23F, and 6A. Non-susceptibility to penicillin was low (4.0%) and only exceeded by that to trimethoprim-sulfamethoxazole (9.8%). Both rates were higher in the clinical isolates (9.3% and 16.7%, respectively; p < 0.05). No relationships to geographic area, day care attendance, recent antibiotic use, or travel abroad were shown for any specific serotype or for the presence of penicillin-non-susceptible pneumococci in the healthy children. CONCLUSIONS: Pneumococcal resistance rates in the healthy child population were low and did not reflect the higher rates noted at the laboratory in clinical samples obtained before and during the study.

Hepatocellular carcinoma in individuals with HBV infection or HBV-HCV co-infection in a low endemic country.

OBJECTIVE: The aim of this nationwide cohort study was to assess the risk for hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection or HBV and hepatitis C virus (HCV) co-infection in Sweden, a low endemic country. MATERIAL AND METHODS: A total of 12,080 patients with HBV and 3238 patients with HBV-HCV co-infection were notified to the Swedish institute for Infectious Disease Control between 1990 and 2004. After excluding 1850 patients with acute HBV and 584 patients infected in adult life, we analyzed the cohort of 9646 subjects with chronic HBV infection. In the co-infection cohort, 1697 patients were analyzed after excluding 1541 cases with acute HBV. The Swedish national cancer registry was used for follow-up. The HCC incidence rate in the cohorts was compared with the HCC incidence rate in the general population and the standardized incidence ratio (SIR) was calculated for different strata according to estimated infection period. RESULTS: HCC was found in 45 patients in the HBV cohort. In the stratum of 40-49 years of infection we found a SIR of 47 and in stratum 50-59 years the SIR was 54. In the co-infected cohort 10 HCCs were found. The SIR in the stratum 20-29 years of infection was 34 and the SIR in the stratum 30 years and over was 91. CONCLUSIONS: This national cohort study of HBV infected and HBV-HCV co-infected subjects in a low endemic country confirms a highly increased risk of liver cancer compared to the general population.

Imported methicillin-resistant Staphylococcus aureus, Sweden.

Countries such as Sweden that have a low prevalence of methicillin-resistant Staphylococcus aureus (MRSA) offer the opportunity to discern and study transmission of imported cases of MRSA. We analyzed 444 imported cases of MRSA acquisition reported in Sweden during 2000-2003. Risk for MRSA in returning travelers ranged from 0.1 (95% confidence interval [CI] 0.01-0.4) per 1 million travelers to Nordic countries to 59.4 (95% CI 44.5-79.3) per 1 million travelers to North Africa and the Middle East. Most imported cases (246, 55%) were healthcare acquired, but regions with the highest risk for MRSA in travelers showed a correlation with community acquisition (r = 0.81, p = 0.001). Characteristic differences in MRSA strains acquired were dependent on the region from which they originated and whether they were community or healthcare acquired. Knowledge of differences in transmission of MRSA may improve control measures against imported cases.

Serologic analysis of returned travelers with fever, Sweden.

We studied 1,432 febrile travelers from Sweden who had returned from malaria-endemic areas during March 2005-March 2008. In 383 patients, paired serum samples were blindly analyzed for influenza and 7 other agents. For 21% of 115 patients with fever of unknown origin, serologic analysis showed that influenza was the major cause.

Hepatitis A risk in travelers.

BACKGROUND: Traveling to highly endemic areas for hepatitis A is increasing while the immunization level in travelers has been shown to be low in the countries studied. METHODS: In this population-based study, we have estimated the incidence rate of travel-related hepatitis A during 1997 to 2005 by use of the Swedish notification system of communicable diseases and an ongoing national database on travel patterns. We have also acquired airport-based immunization data from 2007. RESULTS: During the study period, 636 cases of travel-related hepatitis A were notified. Traveling to East Africa was associated with the highest incidence rate (14.1 cases/100,000 person months), followed by the Middle East (5.8/100,000 person months), and India with neighboring countries (5.6/100,000 person months). Visiting Friends and Relatives (VFR) travelers represented 83, 91, and 70% of the cases to these three regions. By age-group, the highest incidence was found in children 0 to 14 years (3.1/100,000 travelers) where 88% of the cases were VFR travelers. Incidence rate in unprotected travelers to East Asia, North Africa, and the Middle East was 2, 12, and 18 cases/100,000 person months, respectively. In 2007, 79% of the travelers were immunized against hepatitis A. CONCLUSIONS: We conclude that travelers, and especially children, who are VFR in endemic areas constitute a high-risk group for acquiring hepatitis A infection, while the risk for unprotected tourists to East Asia is low.

The epidemiology of hepatitis C virus infection in Sweden.

In Sweden, infection with hepatitis C virus (HCV) has been a notifiable disease since 1990, when diagnostic methods became available. Blood donor screening indicated that about 0.5% of the Swedish population (9 millions) had been HCV infected. Here we present the Swedish hepatitis C epidemic based on data from all the HCV notifications 1990-2006. During this time about 42,000 individuals (70% men) were diagnosed and reported as HCV infected. The majority (80%) were born in 1950 or later, with a high percentage (60%) born in the 1950s and 1960s. Younger people, 15-24 years old at notification, were reported on the same level each year. The main reported routes of HCV transmission were intravenous drug use in 65%, blood transfusions/products in 6%, and sexual in 2%, though unknown or not stated in 26%. Approximately 6,000 of all notified individuals have died during the study period. To conclude, the Swedish HCV epidemic is highly related to the increase of intravenous drug use in the late 1960s and 1970s, with a high proportion of people now chronically infected for more than 25 years, resulting in an increase of severe liver complications in form of cirrhosis and hepatocellular carcinoma. Furthermore the unchanged number of notifications of newly infected younger people indicates an ongoing HCV epidemic.

Hepatocellular carcinoma and other primary liver cancers in hepatitis C patients in Sweden - a low endemic country.

The aim of this study was to assess the risk of hepatocellular carcinoma (HCC) and other primary liver cancers (PLC) in the nationwide cohort of hepatitis C virus (HCV) infected patients in Sweden. The basis was the total HCV-cohort notified in 1990-2004, after excluding 3238 people also reported with hepatitis B, the study cohort consisted of 36 126 people contributing an observation time of 246 105 person-years. The most common route of transmission was intravenous drug use (57%). The national Cancer Registry was used for follow-up, and 354 developed PLC (mainly HCC), of whom 234 were eligible for statistical analysis. The PLC incidence in the HCV cohort was compared with the incidence in the general population, and a standardized incidence ratio (SIR) was calculated for six different strata according to estimated duration of infection. The highest relative risk, SIR: 46 (95% CI: 36-56) was found in the stratum 25-30 years with HCV infection and SIR: 40 (95% CI: 31-51) in the stratum 30-35 years with infection. In the entire community-based HCV cohort in Sweden we found a highly increased risk of liver cancer compared to the general population. The highest relative risk was among people who had been infected for more than 25 years.

Cause of death in individuals with chronic HBV and/or HCV infection, a nationwide community-based register study.

Studies on chronic viral hepatitis and mortality have often been made on selected populations or in high-endemic countries. The aim of this study was to investigate the causes of death and the mortality rates in the nationwide cohorts of people chronically infected with hepatitis B virus (HBV) and/or hepatitis C virus (HCV) in Sweden, a low-endemic country. All notifications on chronic HBV infection and HCV infection 1990-2003 were linked to the Cause of Death Register. A total of 9517 people with chronic HBV infection, 34 235 people with HCV infection and 1601 with chronic HBV-HCV co-infection were included, and the mean observation times were 6.4, 6.3 and 7.9 years, respectively. The mortality in the cohorts was compared with age- and gender-specific mortality in the general population and standardized mortality ratios (SMR) were calculated. All-cause mortality was significantly increased, SMR 2.3 (HBV), 5.8 (HCV) and 8.5 (HBV-HCV), with a great excess liver-related mortality in all cohorts, SMR 21.7, 35.5 and 46.2, respectively. In HCV and HBV-HCV infected there was an increased mortality due to drug-related psychiatric diagnoses (SMR: 20.7 and 27.6) and external causes (SMR: 12.4 and 11.4), predominantly at younger age. To conclude, this study demonstrated an increased all-cause mortality, with a great excess mortality from liver disease, in all cohorts. In people with HCV infection the highest excess mortality in younger ages was from drug-related and external reasons.

Short- and long-term effects of bacterial gastrointestinal infections.

During 1997-2004, microbiologically confirmed gastrointestinal infections were reported for 101,855 patients in Sweden. Among patients who had Salmonella infection (n = 34,664), we found an increased risk for aortic aneurysm (standardized incidence ratio [SIR] 6.4, 95% confidence interval [CI] 3.1-11.8) within 3 months after infection and an elevated risk for ulcerative colitis (SIR 3.2, 95% CI 2.2-4.6) within 1 year after infection. We also found this elevated risk for ulcerative colitis among Campylobacter infections (n = 57,425; SIR 2.8, 95% CI 2.0-3.8). Within 1 year, we found an increased risk for reactive arthritis among patients with Yersinia enteritis (n = 5,133; SIR 47.0, 95% CI 21.5-89.2), Salmonella infection (SIR 18.2, 95% CI 12.0-26.5), and Campylobacter infection (SIR 6.3, 95% CI 3.5-10.4). Acute gastroenteritis is sometimes associated with disease manifestations from several organ systems that may require hospitalization of patients.

Nosocomial pneumonia in the ICU: a prospective cohort study.

Ventilator-associated pneumonia (VAP) is the most common intensive care unit (ICU)-acquired infection among patients requiring mechanical ventilation. A prospective surveillance programme of all patients has been implemented at the ICU, Karolinska University Hospital, Sweden since 2001. Within this programme, incidence and risk factors for ICU-acquired pneumonia and associated death over a 2-y period have been studied. Of 329 patients enrolled in the study, 221 required mechanical ventilation. 33 of 221 patients (15%) developed VAP, corresponding to a rate of 29 VAP/1000 ventilator d. Risk factors for VAP were aspiration (hazard ratio 3.79; 95% CI 1.48-9.68), recent surgery (HR 3.58; 95% CI 1.15-11.10) and trauma (HR 3.00; 95% CI 1.03-8.71). 11 patients of 33 (33%) with VAP died within 28 d compared to 46 of 288 (16%) without ICU-acquired pneumonia (odds ratio 2.73; 95% CI 0.97-7.63). We conclude that: 1) incidence of VAP was 15% and the most important risk factor was aspiration; 2) APACHE II score > or = 20 is a stronger predictor for poor outcome than VAP; 3) a minority of patients with APACHE II score > or = 20 develop VAP; and 4) continuous surveillance programmes are feasible and provide valuable data for improvement of quality of care.

A meta-analysis on the effects of antibiotic treatment on duration of symptoms caused by infection with Campylobacter species.

Eleven randomized, controlled trials of antibiotic treatment versus placebo in patients with Campylobacter species infection were pooled in a meta-analysis. Antibiotic treatment shortened the duration of intestinal symptoms by 1.32 days (95% confidence interval, 0.64-1.99; P<.0001). Because of problems with drug resistance, a restrictive attitude towards the administration of antibiotics in uncomplicated cases is advised.

Age- and serogroup-related differences in observed durations of nasopharyngeal carriage of penicillin-resistant pneumococci.

Using data from an ongoing Swedish intervention project, the observed durations of nasopharyngeal carriage of penicillin-nonsusceptible Streptococcus pneumoniae (PNSP) (MIC of penicillin G of >or=0.5 microg/ml) stratified by both pneumococcal serogroup and age of the carrier were compared. The means and 95% confidence intervals (CIs) were estimated by fitting a gamma distribution to the observed duration of carriage for each age and serogroup stratum. The mean observed duration of carriage for all cases was 37 days (95% CI, 35 to 38 days). Children below the age of 5 years carried PNSP for significantly longer periods (43 days; 95% CI, 41 to 45 days) compared with older individuals (25 days; 95% CI, 24 to 27 days). There were also differences within the group of cases below the age of 5 years, as the duration of carriage became significantly shorter for each increasing age step: <1, 1 to 2, and 3 to 4 years. In addition, patients <5 years of age carried serogroups 9 and 14 for significantly shorter periods than groups 6 and 23. Serogroup 9 was also carried for significantly shorter periods than group 19. For patients aged 5 years or older, no significant difference in carriage duration for different ages or serogroups could be noted. As young children have the longest duration of PNSP carriage, interventions aiming to reduce the prevalence in this group are of great importance. The results highlight the importance of taking both serogroup and age of the carriers into account when studying the dynamics of pneumococcal transmission in young children.

Modeling pneumococcal resistance to penicillin in southern Sweden using artificial neural networks.

In recent decades, penicillin-resistant pneumococci (PRP) have emerged and spread rapidly between and within countries over the world. In this study we developed an iterative artificial neural network (ANN) model to describe and predict the spread of PRP in space and time as a function of antibiotic consumption and a number of different confounders. Retrospective data from 1997 to 2000 on an international epidemic PRP clone (serotype 9V) and antibiotic consumption data from Southern Sweden were used to train the ANN models and data from 2001 to 2003 for evaluation of the model predictions. Five different ANN models were trained, each with independent topology optimization for alternative sets of input variables to find the most descriptive model. The model containing all variables was the only one performing better than the reference linear models, as assessed by the correlation between predictions and observations. The inability to identify a smaller subset of most predictive parameters may reflect either diffuse causal mechanisms or just the absence of critical experimental indicators from the dataset. The iterative ANN model identified is useful to predict future data. The sensitivity analysis of the model suggests that past incidence has a small effect on the number of PRP cases.

Penicillin-resistant pneumococci in Sweden 1997-2003: increased multiresistance despite stable prevalence and decreased antibiotic use.

Antimicrobial resistance patterns and capsular groups of penicillin-resistant Streptococcus pneumoniae (PRP; MIC penicillin G > or = 0.5 mg/ml) in Sweden between 1997 and 2003 were described, and trends in resistance and antibiotic sales during the same period were compared. The most common serogroups were in descending order 9, 19, 14, 23, and 6. Despite a low and stable annual PRP rate (proportion of PRP out of all pneumococci) of around 2% during the study period, the proportion of PRP resistant to other antibiotics increased. Of all tested PRP isolates, 82% were also resistant to trimethoprim/sulfamethoxazole, 32% had additional resistance to tetracycline, and 26% to erythromycin. Antibiotic sales figures for all studied antibiotic subgroups decreased during the same period. Little correlation was found between antibiotic sales and PRP resistance rates, indicating that there are still other poorly defined factors contributing to the reported resistance levels in the population. However, although PRP strains in Sweden are becoming more commonly resistant to antibiotics other than beta-lactams, the low and further reduced antibiotic sales still might have delayed the development and rapid spread of PRP in the population.

Occurrence of invasive pneumococcal disease and number of excess cases due to influenza.

BACKGROUND: Influenza is characterized by seasonal outbreaks, often with a high rate of morbidity and mortality. It is also known to be a cause of significant amount secondary bacterial infections. Streptococcus pneumoniae is the main pathogen causing secondary bacterial pneumonia after influenza and subsequently, influenza could participate in acquiring Invasive Pneumococcal Disease (IPD). METHODS: In this study, we aim to investigate the relation between influenza and IPD by estimating the yearly excess of IPD cases due to influenza. For this purpose, we use influenza periods as an indicator for influenza activity as a risk factor in subsequent analysis. The statistical modeling has been made in two modes. First, we constructed two negative binomial regression models. For each model, we estimated the contribution of influenza in the models, and calculated number of excess number of IPD cases. Also, for each model, we investigated several lag time periods between influenza and IPD. Secondly, we constructed an "influenza free" baseline, and calculated differences in IPD data (observed cases) and baseline (expected cases), in order to estimate a yearly additional number of IPD cases due to influenza. Both modes were calculated using zero to four weeks lag time. RESULTS: The analysis shows a yearly increase of 72-118 IPD cases due to influenza, which corresponds to 6-10% per year or 12-20% per influenza season. Also, a lag time of one to three weeks appears to be of significant importance in the relation between IPD and influenza. CONCLUSION: This epidemiological study confirms the association between influenza and IPD. Furthermore, negative binomial regression models can be used to calculate number of excess cases of IPD, related to influenza.

Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in Sweden 2000-2003, increasing incidence and regional differences.

BACKGROUND: The occurrence of methicillin-resistant Staphylococcus aureus (MRSA) has gradually become more frequent in most countries of the world. Sweden has remained one of few exceptions to the high occurrence of MRSA in many other countries. During the late 1990s, Sweden experienced a large health-care associated outbreak which with resolute efforts was overcome. Subsequently, MRSA was made a notifiable diagnosis in Sweden in 2000. METHODS: From the start of being a notifiable disease in January 2000, the Swedish Institute for Infectious Disease Control (SMI) initiated an active surveillance of MRSA. RESULTS: The number of reported MRSA-cases in Sweden increased from 325 cases in 2000 to 544 in 2003, corresponding to an overall increase in incidence from 3.7 to 6.1 per 100,000 inhabitants. Twenty five per cent of the cases were infected abroad. The domestic cases were predominantly found through cultures taken on clinical indication and the cases infected abroad through screening. There were considerable regional differences in MRSA-incidence and age-distribution of cases. CONCLUSION: The MRSA incidence in Sweden increased over the years 2000-2003. Sweden now poises on the rim of the same development that was seen in the United Kingdom some ten years ago. A quarter of the cases were infected abroad, reflecting that international transmission is now increasingly important in a low-endemic setting. To remain in this favourable situation, stepped up measures will be needed, to identify imported cases, to control domestic outbreaks and to prevent transmission within the health-care sector.