U.S. Travel Update: Lyme Disease in Europe

Prior to the COVID-19 pandemic, Americans made more than 38 million trips to Europe in a single year.¹ Now that official agencies have declared an end to the COVID-19 public health emergency (PHE) and travel restrictions have been lifted for the majority of the world, exploring Europe is once again possible.

The pandemic brought many changes not just to our lives, but also to our understanding of infectious diseases including the importance of disease surveillance and prevention. One result that Pfizer’s research on disease surveillance has revealed is that Lyme disease (Lyme Borreliosis) is a growing public health concern in Europe. So, it’s important for travelers to Europe to be informed before they go.

Special journal issue: Lyme Disease in Europe

Lyme disease is the most common vector-borne disease in the United States.² According to the Centers for Disease Control and Prevention (CDC), there are approximately 476,000 cases annually with most occurring in the Northeast, Mid-Atlantic, and Upper Midwest.³ However, many are unaware that the condition is also common in Europe,⁴ as there have been fewer extensive efforts to quantify and describe the burden across the entire continent. In light of this, Pfizer’s research, published in a special edition of Vector-Borne and Zoonotic Diseases journal, includes 11 cutting edge, peer-reviewed studies, which provide a comprehensive overview of the epidemiology  of Lyme disease across Europe.^5-16

How common is Lyme disease in Europe?

Analysis of European surveillance data shows that the burden of Lyme disease continues to rise in endemic regions of Europe, while also emerging in new areas. So how can a traveler from the U.S. determine the risk of Lyme disease when visiting Europe?

The most effective way to measure risk for a disease is understanding the incidence. Incidence is a measurement which quantifies disease burden by defining the number of new cases of a disease within a given time frame.¹⁷

Clusters of countries and subnational regions with high Lyme disease incidence (>100 per 100,000 persons per year) are evident across Eastern, Northern, and Western Europe.⁵ Estonia, Lithuania, Slovenia and Switzerland were identified as the countries with the highest national incidence.⁵ Although several countries, such as Belgium, Czech Republic, France, Germany, and Poland, have relatively moderate national incidence values, there are local areas in each country that show high incidences.⁵

Unfortunately, not all countries in Europe conduct surveillance for Lyme disease. Of 44 countries in total, only 28 European countries have Lyme disease surveillance in place.¹⁴ Thus, our knowledge of the risk in Europe is not complete.

Zooming in: A closer look at country-specific incidence of Lyme disease

The Netherlands represents a particularly popular travel destination for those from the U.S., with 1.5 million visiting in 2019.¹⁸ However, Pfizer's latest research confirms that Lyme disease incidence remains substantial throughout the Netherlands with no indication of decline in the past 5 years.¹¹ The highest incidence of Lyme disease was seen in the forested provinces of Drenthe and Overjssel, both of which are popular tourist destinations for outdoor activities such as hiking.¹¹

France is another European country frequently visited by U.S. tourists, with 3.1 million Americans visiting in 2019.¹⁸ During the same year, 50,133 new cases of Lyme disease were recorded in primary care, a number that has almost doubled since 2010.⁷ Research has shown that although it is endemic in all parts of France, risk of Lyme disease varies significantly by region.⁷

Thus, for those venturing outside Paris to Burgundy, Champagne, Lorraine, Lyon or Limoges, it is useful to take precautions.

Understanding the risks

Preventative measures, including applying insect repellent and checking for ticks,¹⁹ are recommended to help with personal protection while travelling. However, there’s limited evidence that they’re having an impact on reducing the annual number of cases of Lyme disease. So, scientists are working toward a Lyme disease vaccine to improve prevention. Travelers should also remain aware of signs of infection even after they return to the U.S. as early symptoms may not appear until up to 30 days after a tick bite.²⁰

Traveling individuals should remain vigilant and recognize risk behaviors to help prevent infection.

“While we want to equip individuals with knowledge and resources to keep themselves out of harms way, it’s also imperative that health authorities adopt and invest in robust, sustainable, and systematic approaches of Lyme disease surveillance similar to the approach taken by the CDC in the U.S. that leverage multiple methodologies to assess the true burden of Lyme disease,” says James Stark, PhD, Global Medical and Scientific Affairs Lead, Lyme Disease Vaccine at Pfizer.

“By better understanding the regional and local burden across Europe, we can more accurately assess the need for public health interventions and geographically-focused prevention strategies.”

“Ultimately,” he says, “this will help to protect people against Lyme disease.”

References:

1. Statista. Number of tourist arrivals from the United States to Europe from 2019 to 2021, by region of destination. Available at: https://www.statista.com/statistics/311580/outbound-travel-from-the-us-to-europe-by-destination/. Last accessed: May 2023
2. CDC. Lyme Disease. Available at: https://www.cdc.gov/lyme/index.html. Last accessed: May 2023.
3. CDC. Lyme Disease. Data and Surveillance. April 2021. Available at: https://www.cdc.gov/lyme/datasurveillance/index.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Flyme%2Fstats%2Findex.html. Last accessed: May 2023.
4. European Environment Agency. Vector-borne diseases. Available at: https://www.eea.europa.eu/data-and-maps/indicators/vector-borne-diseases-2/assessment. Last accessed: May 2023
5. Burn, L, Tran, TMP, Pilz, A, et al. Incidence of Lyme Borreliosis in Europe from National Surveillance Systems (2005–2020). Vector Borne and Zoonotic Diseases 2023; 23(4):156-171. DOI: 10.1089/vbz.2022.0071
6. Burn, L, Pilz, A, Vyse, A, et al. A Seroprevalence of Lyme Borreliosis in Europe: Results from a Systematic Literature Review (2005–2020). Vector Borne and Zoonotic Diseases 2023; 23(4):195-220. DOI: 10.1089/vbz.2022.0069
7. Nuttens, C, Bessou, A, Duret, S, et al. Epidemiology of Lyme Borreliosis in France in Primary Care and Hospital Settings, 2010–2019. Vector Borne and Zoonotic Diseases 2023; 23(4):221-229. DOI: 10.1089/vbz.2022.0050
8. Paradowska-Stankiewicz, I, Zbrzez´niak, J, Skufca, J, et al. A Retrospective Database Study of Lyme Borreliosis Incidence in Poland from 2015 to 2019: A Public Health Concern. Vector Borne and Zoonotic Diseases 2023; 23(4):247-255. DOI: 10.1089/vbz.2022.0049
9. Skufca, J, Tran, TMP, Brestrich, G, et al. Incidence of Lyme Borreliosis in Germany: Exploring Observed Trends Over Time Using Public Surveillance Data, 2016–2020. Vector Borne and Zoonotic Diseases 2023; 23(4):237-246. DOI: 10.1089/vbz.2022.0046
10. Skufca, J, De Smedt, N, Pilz, A et al. Incidence of Lyme Borreliosis in Finland: Exploring Observed Trends Over Time Using Public Surveillance Data, 2015–2020. Vector Borne and Zoonotic Diseases 2023; 23(4):256-264. DOI: 10.1089/vbz.2022.0047
11. E. Houben, de Jong, H, HH Penning-van Beest, F, et al. Incidence of Lyme Borreliosis in the Dutch General Practice Population: A Large-Scale Population-Based Cohort Study Across the Netherlands Between 2015 and 2019. Vector Borne and Zoonotic Diseases 2023; 23(4):230-236. DOI: 10.1089/vbz.2022.0048
12. Olsen, J, Angulo, JF, Pilz, A, et al. Estimated Number of Symptomatic Lyme Borreliosis Cases in Adults in Finland in 2021 Using Seroprevalence Data to Adjust the Number of Surveillance-Reported Cases: A General Framework for Accounting for Underascertainment by Public Health Surveillance. Vector Borne and Zoonotic Diseases 2023; 23(4):265-272. DOI: 10.1089/vbz.2022.0051
13. Stark JH, Pilz A, Jodar L, . Moı¨si, JC. The Epidemiology of Lyme Borreliosis in Europe: An Updated Review on a Growing Public Health Issue. Vector Borne and Zoonotic Diseases 2023; 23(4):139-141. DOI: 10.1089/vbz.2022.0068
14. Nagarajan, A. Skufca, J, Vyse, A, et al. The Landscape of Lyme Borreliosis Surveillance in Europe. Vector Borne and Zoonotic Diseases 2023; 23(4):142-155. DOI: 10.1089/vbz.2022.0067
15. Burn, L, Vyse, A, Pilz, A, et al. Incidence of Lyme Borreliosis in Europe: A Systematic Review (2005_2020). Vector Borne and Zoonotic Diseases 2023; 23(4):172-194. DOI: 10.1089/vbz.2022.0070
16. Higgs S, Brissette, CA. An Overview of Lyme Disease in Europe. Vector Borne and Zoonotic Diseases 2023; 23(4):137-138. DOI: 10.1089/vbz.2023.29006.hig
17. CDC. Principles of Epidemiology. Lesson 3: Measures of Risk. Available at: https://www.cdc.gov/csels/dsepd/ss1978/lesson3/section2.html. Last accessed: May 2023.
18. Bucholz K. The Most Popular Destinations for U.S. Travelers Abroad. Statistia. 2020. Available at: https://www.statista.com/chart/18742/most-popular-destinations-with-us-travelers/. Last accessed: May 2023.
19. Preventing Tick Bites on People. U.S. Centers for Disease Control and Prevention. https://www.cdc.gov/lyme/prev/on_people.html. Last accessed May 2023.
20. CDC. Signs and Symptoms of Untreated Lyme Disease. Available at: https://www.cdc.gov/lyme/signs_symptoms/index.html. Last accessed: May 2023.