[Pertussis: its evolution in Argentina at the end of the twentieth century]

The objective of this study was to analize data of pertussis morbidity and mortality in Argentina and vaccination coverage with combined pertussis vaccine (DwPT), which was available from 1969 until 2000 inclusive, and to investigate their interrelation. A retrospective study was performed based on National Registers. Notification and mortality annual mean variation rates and geometric mean rates, by periods, were analyzed, and correlation coefficients between each one of them and with vaccination coverage were calculated. Notification annual mean variation rates for 1969-2000 were -14.34 and for 1980-2000 -17.26; mortality annual mean variation rates for 1980-2000 was -10.41. Vaccination coverage in infants up to one year of age (3 doses) was 44.4% in 1980; less than 60% until 1982 and higher than 80% after 1990. A highly significant inverse correlation was observed, between (a) vaccine implementation, increase in its coverage, introduction of a fifth vaccine dose, and (b) notification and mortality rates. It was observed during the study, that in our country there is a relatively little knowledge about disease occurrence in adults, and an apparent absence of population-based studies performed on the efficacy of erythromycin chemo prophylaxis in epidemics outbreaks. Based on these data, strategies for a better surveillance and control of pertussis, are exposed.