Cryptosporidiosis - Annual Epidemiological Report for 2014

Key facts

• In 2014, 7 316 cryptosporidiosis cases, 7 285 of which were confirmed, were reported in the EU/EEA. This represents a 5% increase from 2013.

• The notification rate was 2.4 confirmed cases per 100 000 population.

• Cases aged 0–4 years showed the highest notification rate with 11.2 confirmed cases per 100 000 for males and 9.2 confirmed cases per 100 000 for females.

• As in previous years, reported cases peaked in the late summer and autumn (August–October).

Methods

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

In 2014, 23 EU/EAA countries reported cryptosporidiosis cases. Three countries reported 0 cases (Croatia, Cyprus and Malta).

Of all reporting countries, 19 countries used the current EU case definition for reporting cryptosporidiosis cases to TESSy, as published in 2008 and 2012. One country used the 2002 EU case definition for cryptosporidiosis, which excludes molecular detection methods, and three countries used other unspecified case definitions.

Twenty countries have mandatory reporting of cryptosporidiosis cases at the national level, and three countries use active surveillance (Annex).

Epidemiology

The number of confirmed cryptosporidiosis cases (N=7 285) reported in EU/EEA countries in 2014 was 5% higher than in 2013 (Table 1). Confirmed cases represented 99% of all reported cases. Five countries accounted for the majority (95%) of cases, namely the United Kingdom (56%), Germany (23%), Sweden (6%), Ireland (5%) and Spain (5%) (Table 1, Figure 1).

Notification rates

The notification rate in the EU/EEA in 2014 was 2.4 cases per 100 000 population, slightly higher than in 2013 (2.3). As in the previous year, the highest notification rate was observed in Ireland (8.4), followed by the United Kingdom (6.4) and Sweden (4.2) (Table 1, Figure 2). Spain and Belgium were not included in these calculations since their cryptosporidiosis surveillance system does not have national coverage (Table 1).

The highest notification rate was observed in Ireland, but at the same time Ireland’s 8.4 cryptosporidiosis cases per 100 000 population also represent a 25% decrease compared with the notification rate in the country in 2013 (Table 1, Figure 1). An increase in notifications was observed in Germany, with the notification rate nearly doubling between 2010 and 2014 (from 1.1 to 2.1.). Similarly, the number of cryptosporidiosis cases reported by Spain increased nearly sixfold: in 2010, 57 cases were reported, while in 2014 Spain reported 328 cases (Table 1, Figure 2).

All confirmed cholera cases in 2014 were in adults between 17 and 63 years of age. Nine infections were in females and five in males.

Age and gender distribution

Age and gender data were available for 99% of all reported confirmed cryptosporidiosis cases (7240/7285). The highest notification rate for the EU/EAA was observed in the age group 0–4 years, with 11.2 confirmed cases per 100 000 males and 9.2 confirmed cases per 100 000 females (Figure 3). The highest notification rate in that age group was reported by Ireland (55.6 cases per 100 000), followed by the UK (24.8 cases per 100 000). At 0.9:1, the male-to-female ratio was almost equal to one.

Seasonal distribution

As in previous years, the reported confirmed cryptosporidiosis cases followed a seasonal pattern in 2014 (Figure 4). Cases peaked in late summer and autumn. A small peak was observed in spring. Of the five countries reporting the majority of cases, all but Ireland reported a peak in late summer and autumn. Ireland reported a peak of cases in the spring but not in late summer/autumn (Figure 4).

During the period 2010–2014, a peak in confirmed cryptosporidiosis cases was observed between July 2012 and January 2013 (Figure 5). The number of reported cases in 2014 decreased, bringing the 12-month moving average towards what was observed in 2010–2011.

Threats description for 2014

No threats were reported to/detected by ECDC in 2014 in relation to unusual increases in cryptosporidiosis cases.

Discussion

Cryptosporidiosis remains a concern for human health and an important cause of severe gastrointestinal disease, especially in immunocompromised patients [1]. In 2013, Cryptosporidium spp. ranked fifth on a FAO/WHO list of globally important foodborne parasites for risk management. With only 23 of 31 EU/EEA Member States reporting cryptosporidiosis to TESSy, of which 15 reported 0–10 cases, it is likely that cryptosporidiosis is underreported in Europe. The notification rate of 2.4 cryptosporidiosis cases per 100 000 population in 2014 is about the same as what was reported for 2010, 2011 and 2013; the peak in cases in 2012 was explained by a simultaneous increase of cases in the Netherlands, the United Kingdom and Germany [2].

Importantly, the collected data do not include species and subtype information. The latter is critical in distinguishing human from non-human sources, understanding transmission chains and providing data for action in outbreak investigations.

Laboratory testing for cryptosporidiosis varies between countries, which also limits the knowledge of the epidemiology of this disease in the EU/EEA [3]. Clusters and outbreaks due to rare, virulent serotypes continue to be reported in the EU/EEA [4-6], along with genetic recombination among genotypes [7].

Public health conclusions

Although with a relatively low notification rate for the EU/EEA, cryptosporidiosis is an important enteric disease to be monitored and controlled. It is critical to better understand the epidemiology of this disease in Europe in terms of species/subtypes, underlying trends, and transmission chains. This can be achieved through increased laboratory testing, pathogen isolation and speciation, and subtyping. Such data were initially not collected in TESSy but ECDC revised cryptosporidiosis surveillance by including data on speciation, and species data can now be reported.

References

1. Abeywardena H, Jex AR, Gasser RB. A perspective on Cryptosporidium and Giardia, with an emphasis on bovines and recent epidemiological findings. Adv Parasitol. 2015 Apr;88:243-301.

2. Fournet N, Deege MP, Urbanus AT, Nichols G, Rosner BM, Chalmers RM, et al. Simultaneous increase of Cryptosporidium infections in the Netherlands, the United Kingdom and Germany in late summer season, 2012. Euro Surveill. 2013 Jan 10;18(2).

3. Chalmers RM, Katzer F. Looking for Cryptosporidium: the application of advances in detection and diagnosis. Trends Parasitol. 2013 May;29(5):237-51.

4. Fuentes I, Martín C, Beristain X, Mazón A, Saugar JM, Blanco A, et al. Cryptosporidium hominis genotypes involved in increased incidence and clusters of cases, Navarra, Spain, 2012. Epidemiol Infect. 2015 Apr;143(5):1033-6.

5. Goñi P, Almagro-Nievas D, Cieloszyk J, Lóbez S, Navarro-Marí JM, Gutiérrez-Fernández J. Cryptosporidiosis outbreak in a child day-care center caused by an unusual Cryptosporidium hominis subtype. Enferm Infecc Microbiol Clin. 2015 Dec;33(10):651-5.

6. Utsi L, Smith SJ, Chalmers RM, Padfield S. Cryptosporidiosis outbreak in visitors of a UK industry-compliant petting farm caused by a rare Cryptosporidium parvum subtype: a case -control study. Epidemiol Infect. 2016 Apr;144(5):1000-9.

7. Guo Y, Tang K, Rowe LA, Li N, Roellig DM, Knipe K, et al. Comparative genomic analysis reveals occurrence of genetic recombination in virulent Cryptosporidium hominis subtypes and telomeric gene duplications in Cryptosporidium parvum. BMC Genomics. 2015 Apr 18;16:320. doi: 10.1186/s12864-015-1517-1.