Poliomyelitis and its elimination in Cuba: An historical overview. Author reply.

INTRODUCTION Polio was first detected in Cuba in the late 19th century among residents of the US community on the Isla de Pinos (Isle of Pines, now Isle of Youth), apparently introduced through migration from the USA. The first outbreak was reported in 1906 on the Isle, with the first epidemic reported in the former province of Las Villas in 1909. The epidemics subsequently intensified, by 1934 becoming periodic every four to five years, and accompanied by high morbidity, mortality and crippling sequelae, primarily among children. OBJECTIVE To review and analyze the history of polio and its control in Cuba, from the disease's first appearance in 1898 until WHO/PAHO certification of elimination in 1994. METHODS The historiological method was used; archival documents, medical records, and available polio morbidity and mortality statistics from the Ministry of Public Health's National Statistics Division before 1959 and from 1959 through 2000 were reviewed. Crude morbidity and mortality rates were calculated using population estimates at mid-period. Reports and scientific publications describing polio vaccination campaigns and their results were also reviewed, and key informants were interviewed. RESULTS After initial introduction of polio in Cuba, five major epidemics occurred between 1932 and 1958: in 1934 (434 cases, 82 deaths); 1942 (494 cases, 58 deaths); 1946 (239 cases, 33 deaths), 1952 (492 cases, 15 deaths) and 1955 (267 cases, 8 deaths). Between 1957 and 1961 the disease's endemicity reached epidemic levels, with the last outbreak occurring in 1961, with 342 cases, 30% of them in children aged >4 years. In 1962, Cuba launched a nationwide polio vaccination campaign, the first of annual campaigns thereafter carried out in the framework of a coherent national program aimed at polio elimination. Using the Sabin oral vaccine and targeting the entire pediatric population in a single time period, five million doses were administered in the first campaign, reaching 87.5% of the target population aged 1 month through 14 years, constituting 109.4% of planned coverage. Since that year, no deaths from polio have been recorded (there were ten cases between 1963 and 1989) and WHO/PAHO certified polio elimination in Cuba in 1994. CONCLUSIONS Cuba controlled polio with effective vaccination strategies and appropriate epidemiological measures, in the context of social, financial and political support. KEYWORDS History, poliomyelitis, epidemiology, disease control, vaccination, Sabin vaccine, Cuba.