Campylobacteriosis - Annual Epidemiological Report 2016 [2014 data]

Key facts

• 240 379 confirmed cases were reported in 2014.
• In 2014, the crude notification rate of campylobacteriosis was 59.8 cases per 100 000 population in the EU/EEA, representing a 13% increase compared with the previous year.
• Human campylobacteriosis was more common in children below five years of age
• In 2014, the notification rate was slightly higher for males than females across all age groups in 2014.
• Campylobacteriosis shows a clear seasonality, with a sharp peak of cases in July. 

Methods

Click here for a detailed description of the methods used to produce this annual report

• In 2014, 28 EU/EEA countries reported data.
• Twelve countries reported using the EU-2008 case definition, ten countries used the one from 2012, and four countries used a case definition described as ‘other’. Belgium and Finland did not specify which case definition they used.
• A total of 22 countries had a compulsory system, five countries relied on a voluntary system, and one country described its surveillance system as ‘other’.

Surveillance was comprehensive in 24 countries, three countries used sentinel surveillance, and one country reported its national coverage as ‘other’ (Annex 1).

Epidemiology

Number of cases

In 2014, 240 379 confirmed cases of campylobacteriosis were reported by 26 EU and two EEA countries. Over the past five years, three countries (Germany, the United Kingdom and the Czech Republic) have had the highest yearly number of cases. In 2014, the cases from Germany (70 530), the United Kingdom (66 790), the Czech Republic (20 750) and Spain (11 481) represented 71% of all reported confirmed cases. The overall rate of 59.8 cases per 100 000 population in the EU/EEA (range 1.3 to 197.4 by countries) was higher than in previous years, with an increase of 13% in comparison with 2013 (Table 1). The countries with the highest notification rates were the Czech Republic, Luxembourg, Slovakia and the United Kingdom with 197, 159, 125 and 104 cases per 100 000 population, respectively (Table 1). Compared to the previous year, cases increased in 25 countries in 2014; a decrease was reported in only three countries (Belgium, Estonia, and Cyprus).

Geographical distribution

The highest burden in terms of number of cases was reported by Germany and the United Kingdom (Figure 1). When adjusting to the population size, Czech Republic and Luxembourg had highest rates of reported confirmed cases per 100 000 population (Figure 2).

Age and gender distribution

Information on gender and age was provided for 239 314 confirmed cases in EU/EEA countries. The male-to-female ratio was 1.19:1 in 2014 (range by countries from 0.61 to 1.48). Overall, 13.0% of all reported cases were children below five years (range by countries from 2.0 to 79.3%), and the rate of infection was 188.5 cases per 100 000 population per year in this age group. Higher rates in males than females were seen across all age groups (Figure 3).

Seasonality

In 2014, Bulgaria and Croatia were not included in the seasonality and trend analysis due to the lack of information on the monthly distribution of reported cases. Human cases of campylobacteriosis follow a clear seasonality, with most cases reported in June, July and August (Figure 4), similar to previous years (Figure 5).

Threats description for 2014

There were no threats reported in 2014 that were related to campylobacteriosis.

Discussion

The campylobacteriosis notification rate has increased by 13% from 52.7 per 100 000 population in 2013 to 59.8 cases per 100 000 population in 2014. The geographical distribution was similar to the previous years, with the majority of the cases (71%) reported from Germany, the United Kingdom, the Czech Republic and Spain. In spite of comprehensive reporting by 28 countries and with national coverage in 22 countries, the reported cases represent only a small proportion of Campylobacter infections occurring in the EU/EEA population [1]. A serology-based methodology has been developed to estimate the incidence of infection from cross-sectional serum samples [2]. ECDC has funded a project to validate this novel methodology for Campylobacter infections, which resulted in the publication of a seroincidence calculator tool that enables the estimation of the annual ‘force of infection’ in a sampled population [3]. A retrospective longitudinal study in a Danish population, using the seroincidence calculator, revealed that there were no differences in Campylobacter seroincidence over an eight-year period while the reported rate increased twofold within the same time period [4].

Children under five years of age are the most affected population in the majority of countries, both for males and females, with an overall notification rate of 187 cases per 100 000 population in 2014 for this age group (range by countries from 5.0 to 968.2 cases per 100 000 population per year).

Similarly to human infections, the colonisation of broiler flocks by Campylobacter shows a clear seasonality, with an increased risk during summer [5].

Public health conclusions

Human campylobacteriosis has been the most frequently reported gastrointestinal disease in Europe since 2005 [6]. In most countries, the most common foodborne source of human campylobacteriosis is poultry meat [6,7]. Handling, preparation and consumption of broiler meat is estimated to account for 20 to 30% of the human cases [8], and proper kitchen hygiene is required to avoid cross-contamination. The poultry reservoir as a whole, including also environmental transmission and direct animal contact in addition to consumption and preparation of poultry meat, has been estimated to account for up to 80% of cases [9]. Additional identified sources are undisinfected drinking water, urban pigeons, pets, and the environment [10]. Several studies have used multi-locus sequence typing to attribute the sources of human campylobacter infections. For example, most campylobacter cases in Luxembourg were attributed to poultry (61%) and ruminants (33%) [11]. In Italy, chicken was the main reservoir (70%), followed by cattle (8%), the environment (6%), wild birds (7%), small ruminants (5%) and pork (3%) [12].

The elimination of Campylobacter in poultry production is challenging, requiring a combination of different strategies in the food chain to reduce the risk of infection in humans [13].

References

1. Gibbons CL, Mangen MJ, Plass D, Havelaar AH, Brooke RJ, Kramarz P, et al. Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods. BMC Public Health. 2014;14:147.
2. Teunis PF, van Eijkeren JC, Ang CW, van Duynhoven YT, Simonsen JB, Strid MA, et al. Biomarker dynamics: estimating infection rates from serological data. Statistics in medicine. 2012 Sep 10;31(20):2240-8.
3. European Centre for Disease Prevention and Control. Seroincidence calculator tool. Stockholm: ECDC; 2015 [accessed 2016 Oct 23]. Available from: http://ecdc.europa.eu/en/data-tools/seroincidence-calculator-tool/Pages/default.aspx.
4. Emborg HD, Teunis P, Simonsen J, Krogfelt KA, Jorgensen CS, Takkinen J, et al. Was the increase in culture-confirmed Campylobacter infections in Denmark during the 1990s a surveillance artefact? Euro Surveill. 2015;20(41).
5. Allain V, Chemaly M, Laisney MJ, Rouxel S, Quesne S, Le Bouquin S. Prevalence of and risk factors for Campylobacter colonisation in broiler flocks at the end of the rearing period in France. Br Poult Sci. 2014;55(4):452-9.
6. European Centre for Disease Prevention and Control. Annual epidemiological report 2014 – food- and waterborne diseases and zoonoses. Stockholm: ECDC; 2014. 
7. European Food Safety Authority. Scientific opinion on Campylobacter in broiler meat production: control options and performance objectives and/or targets at different stages of the food chain. EFSA Journal. 2011;9(4):141.
8. European Food Safety Authority. Scientific opinion on quantification of the risk posed by broiler meat to human campylobacteriosis in the EU. EFSA Journal. 2010;8(1):1437.
9. Wagenaar JA, French NP, Havelaar AH. Preventing Campylobacter at the source: why is it so difficult? Clin Infect Dis. 2013 Dec;57(11):1600-6.
10. Ramonaite S, Kudirkiene E, Tamuleviciene E, Leviniene G, Malakauskas A, Golz G, et al. Prevalence and genotypes of Campylobacter jejuni from urban environmental sources in comparison with clinical isolates from children. J Med Microbiol. 2014 Sep;63(Pt 9):1205-13.
11. Mossong J, Mughini-Gras L, Penny C, Devaux A, Olinger C, Losch S, et al. Human campylobacteriosis in Luxembourg, 2010–2013: a case-control study combined with multilocus sequence typing for source attribution and risk factor analysis. Sci Rep. 2016 Feb 10;6:20939.
12. Di Giannatale E, Garofolo G, Alessiani A, Di Donato G, Candeloro L, Vencia W, et al. Tracing back clinical Campylobacter jejuni in the northwest of Italy and assessing their potential source. Front Microbiol. 2016 Jun 13;7:887
13. Klein G, Jansen W, Kittler S, Reich F. Mitigation strategies for Campylobacter spp. in broiler at pre-harvest and harvest level. Berl Munch Tierarztl. 2015 Mar-Apr;128(3-4):132-40.

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* The European Surveillance System (TESSy) is a system for the collection, analysis and dissemination of data on communicable diseases. EU Member States and EEA countries contribute to the system by uploading their infectious disease surveillance data at regular intervals.