The incidence of poliomyelitis in the Czech Republic shows four epidemiologically different phases recorded during a lifetime of one human generation: endemicity (until 1938), epidemicity (1939 to 1956), repression (1957 to 1960) and elimination (1961 till now). The phase of the endemic incidence of poliomyelitis studied in this paper finished in 1938. Since 1919 when poliomyelitis notification was started, three waves of increasing though low mortality were observed: in 1926, 1932 and 1936 (0.27, 0.43 and 0.38 per 100,000, respectively). Between 1919 and 1938 the mortality increased in children over one year but it remained relatively highest in infants under one year of age. The poliomyelitis death rates were high between 1928 and 1938, 23.6% on the average. Such high rates might be attributable to the underrated morbidity cases in comparison with a rather reliably notified polio mortality. The period between 1919 and 1938 represented the end of the endemic incidence of poliomyelitis in the Czech countries, and it could be considered as preepidemic.

The first large epidemic of poliomyelitis in (previous) Czechoslovakia was recorded in 1939. It affected only the western part of the state, Bohemia, with a relatively high morbidity and mortality, 25.42 and 2.05 per 100,000, respectively, the death rate being 8.1%. In Prague, children aged between 5 and 9 years represented 41.5% and those up to 14 years 84% of all cases of poliomyelitis. Other epidemics followed in 1943, 1948 and 1953 affected Moravia and Slovakia as well. The highest death rates were in the interepidemic periods, the lowest ones were recorded in the epidemics. During the "epidemic phase" between 1939 and 1956, 12,868 cases of poliomyelitis and 1,159 deaths from poliomyelitis were reported, the mean death rate value being 9.0%. General hygiene measures, passive immunization with specific convalescent human sera and intranasal "chemoprophylaxis" tried then on a large scale, did not show any demonstrable antiepidemic effect.

The "repression phase" of paralytic poliomyelitis in the Czech Republic (and in the Slovak Republic as well) between 1957 and 1960 was characterized by controlled, short term, mass vaccination campaigns. In spring 1957, at the very beginning of a polio epidemic, about 87% of all children aged 1 to 7 years and about 40% of those aged 8 to 15 years were intradermally vaccinated with IPV. The protective effect in population given two IPV doses was 66% (in Slovakia 74%). The starting epidemic of 1957 was stopped. Morbidity and mortality from poliomyelitis markedly decreased in 1958. Nevertheless, about 39%, 13% and 41% of children aged under 8 years (given three IPV doses) had not specific virus-neutralizing antibodies against polioviruses types 1, 2 and 3 respectively. A field trial with OPV started in winter 1958-59. Over 110,000 children aged 2 to 6 years were vaccinated with Sabin OPV, which proved to be safe, highly immunogenic and protective. In spring 1960 about 93% of children were vaccinated in the former Czechoslovakia with OPV in a mass, countrywide campaign. No case of paralytic poliomyelitis was reported during the second half of 1960. The same was true for all year 1961, the first year of the historical period of poliomyelitis elimination in our country.

Global eradication of poliomyelitis launched and coordinated by the World Health Organization since 1988 is close to being achieved: the main objective is to discontinue the circulation of the wild, neurovirulent, endemic virus of poliomyelitis. Although this objective has been within the reach, there are two other risks, lower but existing and posing possible threat to the eradication, that need to be controlled: 1) wild polioviruses stored in laboratories should be destroyed or reliably contained and 2) emergence and epidemic role of neurovirulent polioviruses potentially derived from attenuated oral polio vaccine should be prevented. After all these global eradication objectives are met and three years relapse from its certification, under intensive and sensitive surveillance, it will be possible to consider whether or not to stop vaccination against poliomyelitis in the world. The global eradication of poliomyelitis is a complex issue that will require further efforts in the field of both the biomedical research and organizational, economic and political approaches. In the Czech Republic, poliomyelitis has been eradicated since 1960. The former Czechoslovakia was the first country in the world to achieve and to scientifically demonstrate nationwide eradication of poliomyelitis. The current post-eradication surveillance of poliomyelitis in the Czech Republic is managed by the Centre of Epidemiology and Microbiology of the National Institute of Public Health in cooperation with the Ministry of Health of the Czech Republic, WHO Regional Office for Europe in Copenhagen and National Certification Committee for Poliomyelitis Eradication.