Meningitis and encephalitis in Poland in 2018.

Abstract

Infectious diseases of the nervous system are most often manifested in the form of meningitis. We distinguish meningitis and/or encephalitis according to their etiology, i.e. bacterial and viral. The study discusses meningitis and encephalitis caused by: N. meningitidis, S. pneumoniae, H. influenzae and tick-borne encephalitis virus. This is due to the epidemiological surveillance of these diseases and the available prevention in the form of vaccinations against these diseases. The aim of the study is to assess the epidemiological situation of meningitis and encephalitis in Poland in 2018. The epidemiological situation of meningitis and encephalitis in Poland was assessed on data from the annual bulletin "Infectious diseases and poisoning in Poland in 2018" and "Vaccinations in Poland in 2018". In 2018, a total of 2406 cases of meningitis and/or encephalitis were registered in Poland. It is a 14.7% increase in incidence compared to 2017. An increase was recorded in the viral infections from 1212 to 1533 cases. In contrast, the number of infections with bacterial etiology decreased from 886 to 873 cases. Meningitis and/or encephalitis caused by pathogens specified in epidemiological surveillance have noticed a decreased incidence. The only exception is the increase in cases caused by S. pneumoniae, compared to 2017, from 177 to 212. This is an increase of 19.8% compared to the previous year. However, the number of cases of N. meningitidis showed a decrease of 16.4% during this period. Viral infections constituted 63.7% of all cases. Compared to 2017, it means an increase in the percentage of viral infections by 5.9 percentage points. Among laboratory confirmed cases of meningitis and/or encephalitis of known etiology, cases caused by Neisseria meningitidis (102 cases), Streptococcus pneumoniae (212 cases) and tick-borne encephalitis (197 cases) were predominant. There is a general increasing trend in the number of cases of viral meningitis and/or encephalitis. On the other hand, thanks to vaccinations, no significant increase was noted in H. influenzae, meningococcal and TBE infections. There is a chance to minimize the incidence of bacterial meningitis and/or encephalitis as in the H. influenzae infections. On the other hand, it should be seen that the problem of diagnosing cases of viral etiology should be considered. This is more related to the determination of the etiological factor than the diagnosis of viral meningitis and/or encephalitis. Difficulties in determining the etiological factor indicate that, meningitis and/or encephalitis remain a challenge for healthcare and epidemiological surveillance institutions.