Epidemiology of AIDS and tuberculosis.

This article reviews literature on the epidemiology, pathogenicity, and control of HIV and Mycobacterium tuberculosis coinfection. Regarding pathogenicity, immune system deterioration makes HIV-infected people more likely to develop active tuberculosis on primary or secondary exposure to the bacillus or to suffer reactivation of latent infections, and to experience considerably higher rates of extrapulmonary manifestations, relapses, and death. Regarding epidemiology, as of 1990 there were an estimated 3 million people coinfected with HIV and M. tuberculosis, with some 300,000 active tuberculosis cases and 120,000-150,000 tuberculosis deaths occurring annually among those coinfected. Over 500,000 coinfected people are thought to reside in the Americas, over 400,000 of them in Latin America. In general, the impact of coinfection is evident. Relatively high and increasing prevalences of HIV infection have been detected among tuberculosis patients around the world, and tuberculosis has become a frequent complication of AIDS cases. Moreover, there is no longer any doubt that coinfection obstructs tuberculosis prevention and control. Among other things, it affects BCG vaccination policies, suggests the need to administer preventive chemoprophylaxis to HIV-infected individuals at high risk of harboring or contracting tuberculosis infections, and complicates both detection and treatment of active tuberculosis cases. The recent proliferation of M. tuberculosis strains resistant to multiple drugs, most notably in the United States, compounds the problem. Tuberculosis prevention and control are still technically and economically feasible. However, more must be done to establish surveillance programs with laboratory support. More research is needed to determine what case prevention measures are best-suited to current circumstances and the HIV/AIDS presence. More effective preventive treatment regimens that are well tolerated, well complied with, and do not pose the risk of multiresistance need to be devised. More health workers need to be trained to suspect tuberculosis and to conduct timely and appropriate tests confirming this diagnosis. And finally, more must be done to standardize the types and durations of the various curative treatment regimens employed.

[Ionizing radiation at low doses and cancer: epidemiological controversy]. / Radiación ionizante a dosis bajas y cáncer: controversia epidemiológica.

The carcinogenic effects of ionizing radiation at high doses are un questionable. On the other hand, the deleterious exposure effects to low doses have not been totally proven, mainly due to methodological problems and difficulty in measuring reliable dose exposure. In this paper, some recent studies examining the effects of ionizing radiation in some occupational groups are reviewed and discussed. Also, the main areas of epidemiologic controversy are stressed. For future experiences, prospective, longitudinal studies with occupational cohorts, measuring radiation exposure with adequate registry and follow-up, are suggested.

[Evaluation of epidemiological articles published in 2 journals in the area of public health]. / Una evaluación de los artículos epidemiológicos publicados en dos revistas del área de la salud pública.

The main aim of this study was to assess the quality and quantity of the Mexican epidemiologic production published in two journals: Salud Pública de México (SPM) and Boletín de la Oficina Sanitaria Panamericana (BOSP). A previously accepted criterion was used to qualify a paper as an epidemiologic work. The period of study was eleven years (1975-1985) with 89 classified paper as "epidemiologic reports" (36 of BOSP and 53 of SPM). The variables included: original or revision's report; epidemiologic design; measures employed (frequency, association or potential impact); condition (contagious diseases, chronic-degenerative diseases or physiologic status); use of prevalent cases, incident cases or deaths; internal and external validity; bias' recognition; and number of references. Among the results that stand out are the proportion of cross-sectional designs (51.75), the weight for communicable diseases (36%), the detection of potential bias (65.7%) and the reports without references (30%). The discussion is centered in the main implications of these results when they are used to make decisions in the planning, operation and assessment of health services and in the generation of new epidemiologic knowledge.

[Differential mortality by sex. Causes and behavior of respiratory and gastroenteric infections in Mexico]. / Mortalidad diferencial por sexo. Causas y comportamiento de las infecciones respiratorias y gastroenterales en México.

The differential in mortality by sex has not been broadly studied in Mexico. In this work mortality by sex in under one year old children and infants by federal entity for the main infectious diseases during 1980-1982 was analyzed. The results showed that the rate of mortality by sex (RMS) for under one year old children was higher than one, which means that there is a male over-mortality for that group of age. In the one to four year old children group, there were three entities that showed over-mortality among women. The analysis of the proportional mortality revealed that 40 to 50 percent of deaths in under one year old children were due to gastroenteral and respiratory infections. The probable causes of the male over-mortality observed and the need to determine the regional patterns of mortality are also discussed.