Large and prolonged food-borne multistate hepatitis A outbreak in Europe associated with consumption of frozen berries, 2013 to 2014.

In May 2013, Italy declared a national outbreak of hepatitis A, which also affected several foreign tourists who had recently visited the country. Molecular investigations identified some cases as infected with an identical strain of hepatitis A virus subgenotype IA. After additional European Union/European Economic Area (EU/EEA) countries reported locally acquired and travel-related cases associated with the same outbreak, an international outbreak investigation team was convened, a European outbreak case definition was issued and harmonisation of the national epidemiological and microbiological investigations was encouraged. From January 2013 to August 2014, 1,589 hepatitis A cases were reported associated with the multistate outbreak; 1,102 (70%) of the cases were hospitalised for a median time of six days; two related deaths were reported. Epidemiological and microbiological investigations implicated mixed frozen berries as the vehicle of infection of the outbreak. In order to control the spread of the outbreak, suspected or contaminated food batches were recalled, the public was recommended to heat-treat berries, and post-exposure prophylaxis of contacts was performed. The outbreak highlighted how large food-borne hepatitis A outbreaks may affect the increasingly susceptible EU/EEA general population and how, with the growing international food trade, frozen berries are a potential high-risk food.

Immunoproteomic analysis of Trichinella spiralis larval crude antigens recognized by sera from patients with trichinellosis after treatment with albendazole.

Antibody responses and antigen recognition were monitored during and after treatment with albendazole (ABZ) in nine patients selected from a trichinellosis outbreak that occurred in north-west Poland in 2007. Seven out of the nine patients yielded positive serum IgG response during treatment. One month after treatment, the IgG response decreased in most patients. Serum levels of ABZ and main metabolites greatly varied among patients without correlation with the IgG response. Two-dimensional electrophoresis and western blot with serum from each patient showed highly immunoreactive spots located between 3- 10 pI and 45-97 kDa in all patients. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF) and MALDI-TOF/time-of-flight mass spectrometry (TOF MS) analysis identified actine, enolase, p49 protein, Caenorhabditis elegans-targeted antigen, and serine protease as the most reactive proteins. A minor spot located at 6 pI and 26 kDa identified as annexin I failed recognition in most patients showing decline in IgG response and clinical improvement after treatment. This protein could constitute a sensitive marker for the effectiveness of ABZ against trichinellosis.

Incidence and factors predicting whooping cough due to parapertussis diagnosis among patients referred to general practitioners, Poland, 2009-2011.

Parapertussis leads to similar symptoms as pertussis, both being caused by bacteria from the genus Bordetella. Poland does not routinely diagnose nor conduct surveillance for parapertussis. We estimated parapertussis incidence and determined predictors of parapertussis diagnosis in the Polish population. Between July 2009 and April 2011, we conducted a prospective cohort study among patients attending 78 general practices. We included patients aged ≥ 3 years, with cough lasting >2 weeks, interviewed patients and collected a nasopharyngeal swab. We confirmed cases by real-time PCR. We estimated parapertussis incidence rates by dividing the number of cases by the summed person-time of observation in respective practices. We assessed predictors of PCR-confirmed parapertussis by comparing cases with patients testing negative. Using logistic regression, we calculated odds ratios (ORs) and 95% confidence intervals (95%CI). We identified 78 cases among 1,231 patients meeting inclusion criteria. The incidence rate was 39/100,000 person-years (95%CI 31-49). The highest rates (140/100,000; 95%CI 74-239), were among children 3-5 years of age and the lowest (24/100,000; 95%CI 13-40) among persons aged 20-39 years of age. Boys aged 3-5 years (7.1; 2.1-25.3) and women aged >40 years (4.1; 1.4-11.7) or living in crowded households (4.3; 1.4-12.9) or contacting persons with prolonged cough (2.3; 1.1-4.5) were more likely to be diagnosed. Our results suggest that laboratory diagnosis could be prioritized for children in the preschool age and women aged over 40 who were referred to their GP with prolonged cough. In the absence of vaccine, post-exposure prophylaxis for close contacts of parapertussis cases could an adequate preventative measure.

Campylobacter seroconversion rates in selected countries in the European Union.

As a major foodborne pathogen, Campylobacter is frequently isolated from food sources of animal origin. In contrast, human Campylobacter illness is relatively rare, but has a considerable health burden due to acute enteric illness as well as severe sequelae. To study silent transmission, serum antibodies can be used as biomarkers to estimate seroconversion rates, as a proxy for infection pressure. This novel approach to serology shows that infections are much more common than disease, possibly because most infections remain asymptomatic. This study used antibody titres measured in serum samples collected from healthy subjects selected randomly in the general population from several countries in the European Union (EU). Estimates of seroconversion rates to Campylobacter were calculated for seven countries: Romania, Poland, Italy, France, Finland, Denmark and The Netherlands. Results indicate high infection pressures in all these countries, slightly increasing in Eastern EU countries. Of these countries, the differences in rates of notified illnesses are much greater, with low numbers in France and Poland, possibly indicating lower probability of detection due to differences in the notification systems, but in the latter case it cannot be excluded that more frequent exposure confers better protection due to acquired immunity.

Ensuring safety of home-produced eggs to control salmonellosis in Poland: lessons from an outbreak in September 2011.

Implementation of control measures in line with European Commission regulations has led to a decrease in salmonellosis in the European Union since 2004. However, control programmes do not address laying hens whose eggs are produced for personal consumption or local sale. This article reports an investigatxion of a salmonellosis outbreak linked to home-produced eggs following a family event held in a farm in September 2011 near Warsaw, Poland. In the outbreak, 34 people developed gastroenteritis symptoms. Results from a cohort study indicated a cake, prepared from raw home-produced eggs, as the vehicle of the outbreak. Laboratory analysis identified Salmonella enterica serotype Enteritidis (S. Enteritidis) in stool samples or rectal swabs from 18 of 24 people and in two egg samples. As no food items remained, we used phage typing to link the source of the outbreak with the isolated strains. Seven S. Enteritidis strains analysed (five from attendees and two from eggs) were phage type 21c. Our findings resulted in culling of the infected laying hens and symptomatic pigeons housed next to the hens. Salmonella poses as a public health problem in Poland: control measures should not forget home-produced eggs, as there is a risk of infection from their consumption.

Did public health travel advice reach EURO 2012 football fans? A social network survey.

We posted a survey on the Union of European Football Associations (UEFA)'s EURO 2012 Facebook profile to evaluate whether public health travel advice, specifically on the importance of measles vaccination,reached fans attending EURO 2012. Responses suggested that these messages were missed by 77% of fans. Social networks could serve as innovative platforms to conduct surveys, enabling rapid access to target populations at low cost and could be of use during upcoming mass gatherings such as the Olympics.

Incidence of self-reported acute gastrointestinal infections in the community in Poland: a population-based study.

A retrospective cross-sectional survey of self-reported acute gastrointestinal infection (AGI) incidence in the community was performed in Poland, from December 2008 to November 2009. The aim of the study was to estimate the magnitude and distribution of self-reported AGI, in order to calibrate the routine AGI surveillance system in Poland. The study population were randomly selected residents of all Polish regions, having a fixed telephone line. An equal number of telephone interviews were collected each month, requesting the interviewee to identify gastrointestinal symptoms that had occurred in the previous 4 weeks. The international AGI case definition was used. In total 3583 complete interviews were obtained. The compliance ratio was 26%. Of 3583 respondents, 240 (6.7%) individuals fulfilled the AGI case definition. The annualized incidence of acute gastroenteritis was 0.9/person-year (95% confidence interval 0.8-1.0). Comparison of the obtained annual AGI estimate (33.3 million infections) with the number of cases reported to national surveillance during the corresponding period (73 512), yielded an underreporting factor of 453 cases occurring in the community for each reported case. Of the 240 AGI cases, 30.4% consulted a general practitioner, and 4.6% were admitted to hospital. Samples for microbiological confirmation were collected from four (1.6%) cases. This first population-based study in eastern Europe has confirmed that AGI places a high burden on Polish society, which is underestimated by national surveillance data. Efforts are necessary to improve AGI reporting and diagnostic practices in order to increase the effectiveness of the Polish surveillance system in detecting threats related to new AGI pathogens, new routes of transmission or the potential for international spread.

Usefulness of seroconversion rates for comparing infection pressures between countries.

Salmonella is a frequent cause of foodborne illness. However, since most symptomatic cases are not diagnosed, the true infection pressure is unknown. Furthermore, national surveillance systems have different sensitivities that limit inter-country comparisons. We have used recently developed methods for translating measurements of Salmonella antibodies into estimates of seroincidence: the frequency of infections including asymptomatic cases. This methodology was applied to cross-sectional collections of serum samples obtained from the general healthy population in three European countries. Denmark and The Netherlands had the lowest seroincidence (84,169 infections/1000 person-years), whereas Poland had the highest seroincidence (547/1000 person-years). A Bayesian method for obtaining incidence rate ratios was developed; this showed a 6·3 (95% credibility interval 3·3-12·5) higher incidence in Poland than in Denmark which demonstrates that this methodology has a wider applicability for studies of surveillance systems and evaluation of control programmes.

Is there a need for anti-rabies vaccine and immunoglobulins rationing in Europe?

Rabies is a lethal encephalitis caused by a lyssavirus and transmitted from animals to humans via bite wound, scratch wound, or licking of mucous membranes. It is preventable by timely administration of post-exposure prophylaxis (PEP) consisting of four or five doses of rabies vaccine combined, in the most severe cases of exposures, with anti-rabies immunoglobulin (RIG). Although the rabies incidence in humans remains low, rabies is still present in some European countries. Moreover, rabid animals imported from enzootic areas are reported every year in rabies-free areas. These importations threaten the rabies-free status of terrestrial animals in western European countries and challenge the public health surveillance system and the health structures responsible for rabies prophylaxis and control. The importations frequently result in the prescription of a large number of PEP including RIG, especially in western European countries. The situation is inverted in some central and eastern European countries where RIG is underprescribed. Only a limited number of rabies vaccines and particularly of RIG are licensed for use in Europe. Their availability is also limited, a situation that may become worse in the future. It therefore seems important to study the possibility of comparing and unifying national PEP guidelines in Europe, if needed, and to generate effective solutions in the event of a shortage of anti-rabies biological products and RIG in particular, such as rationing these products.

The first report on Campylobacter coli family outbreak detected in Poland in 2006.

A family outbreak of gastroenteritis caused by Campylobacter coli occurred in May 2006 in Bielsko-Biala, in the south of Poland. Four members of a family had non-bloody diarrhea and abdominal cramps. C. coli were isolated in three of the four patients. PFGE and PCR-RFLP-flaA patterns confirmed the link between cases, showing the usefulness of these methods in outbreak investigation. At the same time, the epidemiological and environmental investigations of this outbreak were very limited and did not provide enough evidence to identify the source of infection, and thus to support the hypothesis formulated by the local epidemiologist. It is necessary to improve surveillance of campylobacteriosis mainly by multidisciplinary training of epidemiologists, microbiologists and general practitioners.

Rabies surveillance, trends in animal rabies and human post-exposure treatment in Poland, 1990 -2004.

This paper describes recent changes in the epizootical and epidemiological situation of rabies in Poland. Analysis of routine surveillance data on animal cases and human post-exposure treatment was performed in order to examine the impact of introduction of cell culture vaccine for human use and the implementation of the fox immunisation programme. The success of the immunisation programme for wild animals has become evident during the past 3 years, as a 9-fold decrease in animal rabies cases has been observed. To date, however, the downward trend in animal rabies cases has had no effect on the frequency of administration of the post-exposure treatment for humans. Moreover, two cases of locally acquired human rabies have occurred in patients who did not receive post-exposure vaccination. These cases prove that rabies should be still considered a public health concern in Poland.

[Phylogenetic relationship of street rabies virus strains and their antigenic reactivity with antibodies induced by vaccine strains. I. Analysis of phylogenetic relationship of street rabies virus strains isolated in Poland]. / Filogenetyczne pokrewienstwo ulicznych szczepów wirusa wscieklizny a reaktywnosc ich antygenów z przeciwcialami indukowanymi szczepem szczepionkowym. I. Ocena pokrewienstwa szczepów wirusa wscieklizny izolowanych w Polsce.

The aims of these studies were: genetic characteristic of street rabies virus strains isolated from different animal species in Poland and determination of phylogenetic relationships to reference laboratory strains of the street rabies viruses belonging to genotype 1 and 5. The variability of rabies isolates and their phylogenetic relationship were studied by comparing the nucleotide sequence of the virus genome fragment. The Polish strains of genotype 1 belong to four phylogenetic groups (NE, CE, NEE, EE) corresponding to four variants: fox-racoon dog (F-RD); European fox 1 (F1); European fox 2 (F2) and European fox 3 (F3). On the Polish territories there are no rabies strains representing the variant dog-wolf and typical for arctic fox variant. The similarity of nucleotide and amino acid sequences of street rabies strains belonging to genotype 1 and laboratory strain CVS is very high. It is about 91% similarity at nucleotide level and 95% at amino acid level. Rabies strain CVS is similar to genotype 5 bat strains (EBL 1) only in about 69% and 74% at nucleotide and amino acid level, respectively. The genetic divergence of rabies strains circulating in Poland raised the need of permanent epidemiological and virological surveillance. The genotype and variant of isolated strains should be determined (using PCR and RLFP methods).

[Phylogenetic relationship of street rabies virus strains and their antigenic reactivity with antibodies induced by vaccine strains. II. Correlation between genetic distance and antibody reactivity]. / Filogenetyczne pokrewienstwo ulicznych szczepów wirusa wscieklizny a reaktywnosc ich antygenów z przeciwcialami indukowanymi szczepem szczepionkowym. II. Zaleznosc pomiedzy dystansem genetycznym a reaktywnoscia przeciwcial.

The aim of these studies was the estimation of the influence of genetic divergence of reactivity with sera of people vaccinated against rabies of Polish rabies strains. Genetic similarity between CVS strain and street rabies strains of genotype 1 is relatively high. However, CVS strain showed the highest reactivity with standard immunoglobulin and sera of antirabies vaccinated people (measured by western blot method). It was completely different from street viruses. Cluster method based on genetic and serologic features indicated high difference between CVS strain and street rabies strains belonging to genotype 1 and genotype 5. On this basis CVS strain was classified as a separate cluster. The genetic divergence of rabies strains circulating in Poland suggests the need of permanent epidemiological and virological surveillance. Strains different in their genotypic and biotypic characteristics should be estimated according to their antigenic similarity to vaccine strain. In practice neutralisation test using mono- and polyclonal sera should be performed. Strains isolated from new or atypical animal species should be studied first of all.

[Rabies in Poland in 1997]. / Wscieklizna w Polsce w 1997 roku.

Mass oral vaccination of wild animals against rabies introduced in 1993, shows a positive impact on the epizootic situation of rabies in Poland. In parallel to the decreasing number of rabies cases in animal, the number of persons exposed to rabid parallel animals declines. No case of rabies in human beings has been reported in Poland since 1986. Of 7566 persons vaccinated in Poland against rabies only 1492 (19.7%) were bitten by or were in contact with a rabid animal. Main reason of vaccination against rabies were contact with animals of category C (rabies not excluded) (68.8%) and with animals healthy during the exposition (category D) (11.5%).