[Epidemiologic aspects of childhood asthma in Mexico. Asthma in the Child Study Group]. / Aspectos epidemiológicos del asma infantil en México. Groupo de Estudio del Asma en el Ninõ.

Asthma is one of the most frequent chronic diseases in children. Its epidemiological tendency is of great importance. In this study, we evaluated the statistical information available from 1987 to 1994 on childhood asthma from several medical institutions in Mexico. We found that: 1) the frequency of medical care provided to asthmatic children under the age of 15 in outpatient, emergency and within hospital settings, expressed as a percentage of the total care provided for each category, has remained unchanged in almost all of the institutions reviewed, whereas the national mortality rate due to asthma has decreased from 3.5/100,000 inhabitants in 1987 to 2.9 in 1993, 2) the frequency of healthcare provided to asthmatics decreases between the ages of 15 to 24; 3) the disease occurs more frequently among males under 15 and in females over that age, 4) from August to November there was a significant rise in care provided for asthmatics in outpatient, emergency and hospital settings in Mexico City and almost every state studied; and 5) the frequency of care for asthmatics increases according to an increase in geographical altitude levels.

[Estimate of the cost/benefit ratio of measles vaccination]. / Estimación de la razón beneficio/costo de la vacunación contra el sarampión.

Among primary health care programs, one of those that has the highest benefit/cost ratio is measles immunization. An estimate of cases, complicated cases and deaths that could have occurred if such immunization program would not have been run, and costs of medical care (hospitalization, physician's visits, medical treatment and rehabilitation), were calculated. Since population at risk has a steady-state given by those who enter -births- and releave it -when they are 15 years old-, if the program did not exist more than 2 million cases and at least 60,000 deaths from measles would have occurred annually. This hypothetical situation is compared with the actual situation of measles in Mexico during the 80's; 1) no more than 100,000 cases could have been estimated to occur in the very extreme case of notifying only one out of 10 cases. 2) The proportions of vaccinated and immune children under five reach 70 percent; this situation has produced 3) a fade out of epidemicity and has increased the critical size of community population for epidemics and doubled the interepidemic interval with the corollary of 4) increasing the average age of infection. The average cost of vaccinating a child was estimated near 1.25 dollars (US). Estimated costs of disease are related to individual losses. Taking into account these factors, benefit/cost ratio of measles immunization in Mexico is, at least, 100:1. Measles transmission patterns in Mexico are discussed since they lead to increase the benefit/cost ratio as compared to countries where the age of infection was put up before the immunization era. To expand investments on measles immunization is recommended.