A serious tick-borne infection, encephalitis, is no longer limited to eastern Poland. Recent reports indicate that the disease, previously restricted geographically, now records hospitalized patients in all areas of the country, and experts attribute this dispersion to multiple factors.
According to a survey by the National Institute of Public Health (PZH) and the General Health Inspectorate, cases of tick-borne encephalitis (TBE) have been confirmed in health units in the 16 Polish voivodeships. The study “Infectious Diseases and Poisonings in Poland in 2024” reveals that the vast majority, 99% of diagnosed patients, required hospitalization. This data highlights the high severity of the viral condition.
The largest volume of occurrences was in the Podláquia voivodeship, with 282 records. Next, Mazovia recorded 251 infections, while Warmia-Masuria had 113 diagnoses. Lublin and Lower Silesia recorded 61 and 58 cases, respectively, complementing the statistical panorama of infections reported in all regions of the country.
Influence of climate change on the spread of the disease
Compared to the previous year, 2023, the voivodeships of Lower Silesia, Mazovia and Podlachia showed the biggest jumps in the number of infections. There were also notable growths in Silesia, Lublin, Warmian-Masuria and Lesser Poland. Experts say that one of the main drivers of viral spread is climate change, which leads to both an increase in the tick population and an extension of their period of activity.
Increased mobility and the migratory flow of people also contribute to the spread of the disease, by moving pathogenic vectors to new locations. Ticks are not restricted to forests or parks; They can be found in urban environments such as gardens, squares and areas with lawns or vegetation. This exposes children and adults of all ages to the risk of bites, with reports of the disease in all age groups.
Understand the development of encephalitis and its neurological complications
Tick-borne encephalitis is characterized as an acute viral infection, often associated with serious neurological complications. Contamination occurs primarily through tick bites, but can also result from ingestion of raw milk from animals that carry the virus. In rarer situations, transmission occurs through blood transfusions or organ transplants from individuals infected during the replication of the pathogen.
The incubation period for the disease varies from 7 to 14 days. Initially, the phase may present no symptoms or simulate a flu-like illness, with fever, tiredness, nausea and headaches and muscle aches. However, in certain patients, after one or two weeks, the virus reaches the central nervous system, which can trigger meningitis, spinal cord inflammation or encephalitis. Intense headaches, neck stiffness, altered consciousness, coordination problems and paralysis are common manifestations of this stage.
Irreversible neurological consequences affect between 35% and 58% of individuals whose central nervous system is compromised by the virus. Around 1% of those infected do not survive the disease, highlighting its severity. Transmission of the virus can occur with just one bite, and the time that the tick remains attached to the skin does not change the risk, as the pathogen is present in the arachnid’s salivary glands. Nymphs, due to their small size, represent an additional danger as they are easily ignored.
The importance of vaccination as a preventive measure
The National Institute of Public Health (PZH) highlights the lack of a specific treatment for tick-borne encephalitis. This implies that health professionals do not have the resources to stop the progression of the disease in the neurological phase or to reverse its consequences. Furthermore, effective protection against bites is challenging, and it is impractical to determine which ticks carry the virus.
