income concentration with about 40% of income In the highest 10% income group and from 1% to 4% of income in the lowest 20% Income group.

Social conditlons also show similarities and disparities. All three countries share similar proportions of population in poverty ranging from 37 % in Mexico to 45 % in Brazil. But other social conditions, such as access to safe water, sanitation facilities and education are quite different. In Brazil, there Is a very high illiteracy rate (22 % of adult population) while In Colombia and Mexico these rates are 12 % and 10 **%,** respectively. Access to safe water and sanitation facilities In Mexico are limited to 69 % and 45 %, respectively, whereas In Brazil and Colombia at least 75 % of the population has access to piped water and more that 65 % has access to adequa. sanitation facilitles.

Finally, it is interesting to note that with the lowest GNP per capta. Colombia's social and health Indicators are not far below those of Mexico and Brazil and even for some of these indicators such as mortality under five and life expectancy, Colombia is in better or similar position. Several hypothesis could explain these differences and certainly this is not our purpose in this paper. Nevertheless it is important to stress that investments In prevention and primary health care In Brazil and Mexico have been relatively small in the past three decades and only in the mid-1980's this situation started to change. Colombia, on the contrary, has concentrated national efforts In population-based activities to control communicable diseases.

# _2. Population_ **_Dynamis_**

In the past 30 years, the three selected countries have experienced substantial reductions In their total fertility rate, giving place to a profound change in the age structure of their populations. Table I shows the total fertility rate registered for the years 1965, 1989 and projected for the year 2000. From levels between 5.6 and 6.7, total fertility dropped to about 3 and it is estimated that by the year 2000 these countries will report rates around 2.2. This has been achieved to a large extent as a consequence of the greater utilization of contraceptives by childbearing age women, that in 1987 reached levels of 53% In Mexico, 63% in Colombia and 65% in Brazil. The main changes in the population structure involve an important growth of the relative population of adults and elderly, as shown in Table II. By the year 2000 almost 70 % of the population of these countries will be 15 to 64 years old.

# _3. HeaIt1i Status_

The health status of the populations of Brazil, Colomhia and Mexico has, according to information on mortality levels, improved considerably over the past sixty years. Life expectancy at birth is 69 years for Mexico and Colombia and 66 years In Brazil. The childhood mortality rates are lower for Colombia and Mexico, (45 and 47 per 1,000 children under 5 respectively) and 58 for Brazil. See Table I. Although these indicators show a considerably better health status than many developing countries, they are quite unsatisfactory when compared with countries that have similar or lower annual income per capita such as Costa Rica and Chile.

The epidemiological profile in the three countries shows that, according to mortality statistics, infectious and parasitic diseases are no longer responsible for the majority of the deaths, but rather cardiovascular disease, cancer and injury explain between 45 and 58 percent of the total deaths. Table IlIl shows the distribution of deaths by major causes of death. Mexico has a larger share of deaths due to infectious and parasitic disease and malnutrition, and Colombia has more deaths due 4