Lyme disease in Western Europe: an emerging problem? A systematic review

Objectives: Lyme borreliosis is the most common zoonotic disease in Europe and causes an estimated total burden of 10.55 disability-adjusted life years (DALY) per 100 000 population. Its incidence in Western Europe is assumed to be increasing, yet this remains to be confirmed. The aim of this study was to assess the emergence of Lyme disease in Western Europe by performing a systematic review of the scientific literature.Methods: Pubmed, Embase and grey literature were searched from database inception until August 2018 for articles reporting the incidence of Lyme borreliosis in Western European countries. We included observational studies in English that reported data on a random sample of the population and fulfilled our definition of Lyme disease diagnosis. Annual population-weighted averages and the evolution of Lyme borreliosis incidence were extracted or calculated for every Western European country.Results: Our review identified 1514 and included 18 studies next to seven surveillance reports reporting data from 16 Western European countries. Incidence of Lyme borreliosis ranged from 0.001 (Italy) to 632 (Sweden, Blekinge county) cases/100 000/year. Iceland reported the strongest emergence with an average yearly increase of 21.15% over a 12-year period, whereas Italy reported the strongest average yearly decrease of 52.71% over a 5-year period. Very limited high-quality data were available on Lyme borreliosis incidence in the southern Western European countries.Conclusion: Diagnosis of Lyme borreliosis is on the rise in some Western European countries, mostly in the northern and central part. Better surveillance in the southern countries is necessary.

Surveillance perspective on Lyme borreliosis across the European Union and European Economic Area

Lyme borreliosis (LB) is the most prevalent tick-borne disease in Europe. Erythema migrans (EM), an early, localised skin rash, is its most common presentation. Dissemination of the bacteria can lead to more severe manifestations including skin, neurological, cardiac, musculoskeletal and ocular manifestations. Comparison of LB incidence rates in the European Union (EU)/European Economic Area (EEA) and Balkan countries are difficult in the absence of standardised surveillance and reporting procedures. We explored six surveillance scenarios for LB surveillance in the EU/EEA, based on the following key indicators: (i) erythema migrans, (ii) neuroborreliosis, (iii) all human LB manifestations, (iv) seroprevalence, (v) tick bites, and (vi) infected ticks and reservoir hosts. In our opinion, neuroborreliosis seems most feasible and useful as the standard key indicator, being one of the most frequent severe LB manifestations, with the possibility of a specific case definition. Additional surveillance with erythema migrans as key indicator would add value to the surveillance of neuroborreliosis and lead to a more complete picture of LB epidemiology in the EU/EEA. The other scenarios have less value as a basis for EU-level surveillance, but can be considered periodically and locally, as they could supply complementary insights.

Meningomyeloradiculitis as an Unusual Presentation of Neuroborreliosis in Childhood

We report a pediatric case of Lyme neuroborreliosis-associated meningomyeloradiculitis with atypical manifestations and negative initial cerebrospinal fluid borrelial antibodies. Transverse myelitis and painful radiculoneuritis have rarely been described in pediatric neuroborreliosis. Clinical manifestations are wide ranging and nonspecific, and the serologic diagnosis is often delayed in the acute phase.

Ticks on passerines from the Archipelago of the Azores as hosts of borreliae and rickettsiae

We examined the presence of borreliae and rickettsiae bacteria in ticks from wild passerine birds on three islands of the Archipelago of the Azores, the westernmost region of Palearctic. A total of 266 birds belonging to eight species from seven families were examined on São Miguel, Santa Maria and Graciosa islands in 2013. Ticks collected from these birds consisted of 55 Ixodes frontalis (22 larvae, 32 nymphs, 1 adult female) and 16 Haemaphysalis punctata nymphs. Turdus merula and Erithacus rubecula were the birds most infested with both tick species. Three T. merula in Santa Maria were infested with 4 I. frontalis infected with Borrelia turdi. No rickettsiae were found in the ticks. We report for the first time the presence of I. frontalis and B. turdi on the Azores islands and we showed that the spatial distribution reaches further west than previously thought.

First Detection of Borrelia burgdorferi sensu lato DNA in Serum of the Wild Boar (Sus scrofa) in Northern Portugal by Nested-PCR

Lyme borreliosis is the most common tick-borne zoonosis in the northern hemisphere. Several vertebrates are crucial in the epidemiological cycle of Borrelia burgdorferi sensu lato, but the role of wild boar as a reservoir is still unknown. Sera were collected from 90 wild boars shot in the Trás-os-Montes region, Northern Portugal (hunting season 2011/2012). In this study, Borrelia DNA was detected for the first time by nested-PCR in three different sera, suggesting that the wild boar may be a potential reservoir for this spirochete. Sequencing results show 100% similarity with Borrelia afzelii. Further studies are needed to evaluate the public health risks associated with boar hunting.

Lyme disease: sudden hearing loss as the sole presentation

BACKGROUND

Lyme disease is an uncommon tick-borne multisystemic infection caused by Borrelia burgdorferi. The most common clinical manifestation is erythema migrans. In this report, a very unusual presentation of this condition is described, in which sudden onset sensorineural hearing loss was the sole presenting symptom.

METHODS

Case report and review of English-language literature.

RESULTS

A patient presented with sensorineural hearing loss, with no other symptoms or signs. Acute Lyme infection was detected by laboratory tests. Magnetic resonance imaging showed signs of labyrinthitis of the same inner ear. After hyperbaric oxygen and systemic antibiotic treatment, the patient showed total hearing recovery, and magnetic resonance imaging showed complete resolution of the labyrinthitis.

CONCLUSION

To our knowledge, this is the first reported case of Lyme disease presenting only with sensorineural hearing loss. Borreliosis should be considered as an aetiological factor in sensorineural hearing loss. Adequate treatment may provide total recovery and prevent more severe forms of Lyme disease.

Neuroborreliosis presenting as acute disseminated encephalomyelitis

We report a case of a 5-year-old boy with acute disseminated encephalomyelitis as the initial presentation of neuroborreliosis. Parents report an upper-airway infection a few days before the development of acute encephalopathy, mild facial palsy, and seizures. The patient needed mechanical ventilation for 10 days, and after extubation, he presented hypotonia, ataxia, dysarthria, as well as weak gag and cough reflexes. Brain magnetic resonance imaging showed hyperintense lesions on T2- and fluid-attenuated inversion recovery sequences on the right subcortical occipital and parietal region, left posterior arm of the internal capsule, and in the medulla oblongata. Borrelia burgdorferi was identified in the plasma and cerebrospinal fluid by polymerase chain reaction and in the plasma by Western blotting. He was treated with ceftriaxone, methylprednisolone, and human immunoglobulin. Recovery was partial.

The hard-tick fauna of mainland Portugal (Acari: Ixodidae): an update on geographical distribution and known associations with hosts and pathogens

This work is an updated revision of the available information on Portuguese ixodid tick species. It includes data on tick biology, ecology, taxonomy and host/pathogen-associations. The current list of Portuguese ixodid ticks comprises twenty species: Dermacentor marginatus (Sulzer, 1776), Dermacentor reticulatus (Fabricius, 1794), Haemaphysalis hispanica Gil Collado, 1938, Haemaphysalis inermis Birula, 1895, Haemaphysalis punctata Canestrini & Fanzago, 1878, Hyalomma lusitanicum Koch, 1844, Hyalomma marginatum Koch, 1844, Ixodes acuminatus Neumann, 1901, Ixodes bivari Dias, 1990, Ixodes canisuga Johnston, 1849, Ixodes frontalis (Panzer, 1798), Ixodes hexagonus Leach, 1815, Ixodes ricinus (Linnaeus, 1758), Ixodes simplex Neumann, 1906, Ixodes ventalloi Gil Collado, 1936, Ixodes vespertilionis Koch, 1844, Rhipicephalus (Boophilus) annulatus (Say, 1821), Rhipicephalus bursa Canestrini & Fanzago, 1878, Rhipicephalus pusillus Gil Collado, 1938, and Rhipicephalus sanguineus (Latreille, 1806).

A clear and present danger: tick-borne diseases in Europe

Ticks can transmit a variety of viruses, bacteria or parasites that can cause serious infections or conditions in humans and animals. While tick-borne diseases are becoming an increasing and serious problem in Europe, tick-borne diseases are also responsible for major depressions in livestock production and mortality in sub-Saharan Africa, Latin America and Asia. This review will focus on the most important circulating tick-transmitted pathogens in Europe (Borrelia spp., Anaplasma phagocytophilum, Babesia spp., tick-borne encephalitis virus, Rickettsia spp. and Crimean-Congo hemorrhagic fever virus).

PCR-based survey of Anaplasma phagocytophilum in Portuguese ticks (Acari: Ixodidae)

A total of two-thousand and six ticks, collected from 2002 to 2006 in areas belonging to seven districts of Mainland Portugal and also in Madeira Island, were examined by polymerase chain reaction (PCR) for the presence of Anaplasma phagocytophilum. Active infections were detected exclusively in Ixodes species, including six questing I. ricinus nymphs from Madeira Island, one questing I. ventalloi nymph from Setúbal District, and two I. ventalloi adults found parasitizing domestic cats in both Setúbal and Santarém District. These findings confirm prior observations and suggest the persistence of A. phagocytophilum on Madeira Island. Moreover, it adds I. ventalloi and domestic cats to the list of potential elements of the agent's enzootic cycles in Portugal. Molecular analysis of PCR amplicons suggests the existence of two A. phagocytophilum genotypes in Portugal, one of which is identical or very similar to North American strains implicated in human disease.