Although recent reports of Tick-borne encephalitis (TBE) in Croatia belie the fact that this disease has been steadily declining for five decades, the impact of TBE in Croatia is comparable to that of the main form of arthropod-borne encephalitis in the United States. See graph

TBE was first reported in Croatia in 1953, and mandatory reporting was instituted in 1987. There is only one natural focus in the northern part of the country, between the Sava and Drava Rivers. Alleged cases in Zadar and Pula, have not been certified. 75% of cases occur from May to July.

Approximately 20 cases per year are reported in Koprivnica-Krizevci County, characterized by a relatively mild illness without neurological residua.

References:
1. Berger SA. Infectious Diseases of Croatia, 2010. 356 pp. Gideon e-book series. http://www.gideononline.com/ebooks/country/infectious-diseases-of-croatia/
2. Berger SA. Tick-borne Encephalitis: Global Status, 2010. 52 pp. Gideon e-book series. http://www.gideononline.com/ebooks/disease/tick-borne-encephalitis-global-status/

The first cases of Lyme disease (LD) were recognized in Lyme, Connecticut in 1975. Although many assume that the condition is largely limited to the United States, LD has been reported in 63 countries as of 2010, with cases in Latin America, Asia, Europe and North Africa. Surprisingly, the world’s highest LD rates are reported in Slovenia, followed by the Baltic countries and Czech Republic (see graph). [1,2]

Borrelia burgdorferi was first isolated from patients in Slovenia in 1988, and from ticks in 1993.

Prevalence surveys:
7.7% to 46% of febrile illness following tick bite
45.5% of ticks in the Italy/Slovenia transborder territory (2008 publication)

Seroprevalence surveys:
15.4% of children and young adults in Slovenia (2000 publication)
23.8% of forestry workers (ELISA, 2002)

Infecting species:
– Borrelia burgdorferi, B. afzelii and B. garinii are encountered.
– B. afzelii accounts for the majority of isolates; however, B. garinii predominates among strains cultured from cerebrospinal fluid.
– B. bissettii has been isolated from humans with Lyme disease in Slovenia.
– Borrelia spielmanii (Borrelia A14S) has been implicated in cases of erythema chronicum migrans in Slovenia.

References:
1. Berger SA. Infectious Diseases of Slovenia, 2010, 373 pp. Gideon e-book series. http://www.gideononline.com/ebooks/country/infectious-diseases-of-slovenia/
2. Berger SA. Lyme disease: Global Status, 2010, 66 pp. Gideon e-book series. http://www.gideononline.com/ebooks/disease/lyme-disease-global-status/

Rates of tick-borne infections in the United States have been increasing dramatically since 2000. See attached graph (Lyme disease displayed as cases/100,000 to allow fit). Although this phenomenon might reflect changes in human population density and artifacts of reporting and diagnosis, I suspect that these data are related to increasing tick and animal reservoir populations.

Update: Also referenced in ProMED

As America once again enters the “Lyme disease season” information regarding this major infectious disease continues to evolve rapidly. The following material has been generated using GIDEON, an interactive on line program that can be used to diagnose or explore the status of all infectious diseases: signs and symptoms, status in every country, ongoing epidemics, antibiotics, vaccines, parasites, virus … in real time. So, let’s test your knowledge about Lyme disease:

1. True or false: Lyme disease is a relatively new infection that is primarily limited to the United States.
2. You have probably heard that Lyme disease is transmitted by ticks. How many tick-borne diseases occur in the world ? In the United States ?
3. Many other infectious diseases are characterized by severe illness, involving many body systems. Are there any truly unique features to Lyme disease ?
4. How many antibiotic agents are available ? How many are effective against the bacterium that causes Lyme disease ?

I put these four questions to GIDEON … (more…)

Steve is quoted in ProMED again:

A recent ProMED-mail posting is a reminder that Lyme disease is extremely common in the Baltic region. In fact, disease rates are several fold higher in this area than in the USA (see graph at http://exhibit.gideononline.com/Lyme-Baltic.jpg).

Additional background data abstracted from GIDEON (primary references available on request):

The 1st cases (3) of Lyme borreliosis in Lithuania were diagnosed in 1987; and Estonia reported its 1st cases in 1988.
Endemic foci exist in the western, eastern, and southern regions of Estonia. The areas of highest risk are concentrated along the Finnish Gulf coast in Harjumaa and Western Virumaa, in Parnumaa and Eastern Virumaa counties, and on the island of Saaremaa.
In Latvia, 2.7 per cent of workers in high-risk occupations and 3 per cent of healthy persons in the Karksi Nuia region (south) of Estonia are seropositive.
_Ixodes ricinus_ is abundant in Estonia, and _Ixodes persulcatus_ is found in the east and south of the country; 3 per cent of _I. ricinus_ adults and 5 per cent of the _I. persulcatus_ adults are infected with _Borrelia burgdorferi_; 31 per cent in Narva-Joesuu, 12 per cent in Western Virumaa, and 14 per cent in Tartumaa. Borreliae are found in 15 per cent of ticks (_I. ricinus_) on Vormsi Island. Tick infection by _B. afzelii_ and _B. garinii_ has also been demonstrated.
_B. afzelii_ is the dominant species among _I. ricinus_ and _I. persulcatus_ in Latvia, followed by _B. garinii_ and _B. burgdorferi_ (1993 to 2002). In Lithuania, 11 per cent of adults and 1 per cent of nymphal _I. ricinus_ ticks are infected with Borrelia (1988 to 1991).