[The new epidemiologic situation in the Czech Republic caused by the C:2a:P1.2 (P1.5) strain of meningococci].

: A new epidemiological situation for invasive meningococcal disease developed in the Czech Republic in 1993. The investigation of meningococcal noncapsular antigens revealed that the new strain Neisseria meningitidis C:2a:P1.2 (P1.5) is the causative agent. This strain has never been found in the Czech Republic before, at least not since 1973 (Czech meningococci have been sero/subtyped since). The investigation of the relationships by ET-typing revealed that this Neisseria meningitidis C:2a:P1.2 (P1.5) belongs to the ET-37 clone. In spring 1993 this new meningococcal clone caused an unusual increase of morbidity in two districts in one region of the Czech Republic and during the next winter/spring season (1993/1994) it spread to all regions of the country. This new strain causes severe and frequently atypical clinical manifestations, with the highest morbidity and fatality rates in the age group of 15-19 years (20% fatality in 1993).