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Objectives: To assess the susceptibility status of 13 natural populations of Aedes aegypti (collected from sites in Colombia where dengue is a serious public health problem) to the pyrethroids, deltamethrin and lambda-cyhalothrin, and to the organochlorine, DDT, and to identify any biochemical mechanisms associated with resistance., Methods: Immature forms of the vector were collected from natural breeding spots at each site and then raised under controlled conditions. Using the F2 generation, bioassays were performed using the World Health Organization's 1981 methodology (impregnated paper) and United States Centers for Disease Control and Prevention's 1998 methodology (impregnated bottles). In populations where mortality rates were consistent with decreased susceptibility, levels of nonspecific esterases (NSE), mixed-function oxidases (MFO), and acetylcholinesterase (AChE) were measured using colorimetric tests., Results: All of the mosquito populations that were tested showed resistance to the organochlorine DDT. In the case of the pyrethroids, widespread resistance to lambda-cyhalothrin was found, but not to deltamethrin. Assessing the biochemical resistance mechanisms showed that 7 of the 11 populations had elevated NSE, and one population, increased MFO., Conclusions: Physiological cross-resistance between DDT and lambda-cyhalothrin in the A. aegypti populations tested was dismissed. Physiological resistance to lambda-cyhalothrin appears to be associated with increased NSE. The differences in susceptibility levels and enzyme values among the populations were associated with genetic variations and chemicals in use locally.

Objective: The annual risk of infection (ARI) for tuberculosis is the probability that an individual without previous contact with the tubercle bacillus has of being infected during the course of a year. The ARI is the most appropriate indicator for estimating the degree of tuberculosis infection in a population. The objective of this paper was to estimate the ARI and its trends in the city of Cali, Colombia, using data provided by the Municipal Secretariat of Health., Methods: We used a deterministic model of the dynamics of pulmonary tuberculosis. The flows among the population subgroups were based on the natural history of the disease, taking vaccination into account. Using the data from the Municipal Secretariat of Health, we estimated the initial conditions and the values of the parameters., Results: The mean ARI values were 1.24% in the 1970s, 0.93% in the 1980s, and 0.85% in the 1990s. In order to assess trends, we attempted to predict the annual risk, utilizing a nonlinear least-squares adjustment of the data on the overall percentage for each year. With that approach, we projected that the ARI in 2003 would be 1.3%, indicating a return to the patterns found in the 1970s., Conclusions: The estimated risk of tuberculosis infection in Cali during the decades of the 1970s, the 1980s, and the 1990s was very high in comparison with the risk in countries such as the Netherlands, which in 1985 had an ARI of 0.012%. However, the ARI in Cali is not so high in comparison to indices for other countries of South America, which range from 0.5% to 1.5%. This model and the simulation it produced showed a rising trend in the ARI for Cali, as well as demonstrated that the ARI will tend to continue to rise if control measures are not improved.

It is a documented fact that teenage mothers have worse maternal and child health indicators than older ones. Thus, the purpose of this paper was to investigate some maternal characteristics (biological and behavioral) that could affect their childrens' health. With information derived from the 1990 Prevalence, Demographic, and Health survey, we studied all children under 5 (n = 4,971) and their respective mothers. Independent variables were age (at the time of the survey), marital status, urban or rural residence, socioeconomic bracket, and parity; dependent variables were low birth weight, prenatal care, early prenatal care, and having a vaccination card. We found that in Colombia most pregnant women were receiving prenatal care from a physician or no prenatal care; very few were under care by a traditional birth attendant, nurse, or other type of health worker. The odds of having a low birth weight infant were higher among pregnant teenagers than among women between the ages of 20 and 24 years. Notwithstanding, these two groups of women showed similar results in terms of behavioral variables (prenatal care, early prenatal care, and having a vaccination card). On the other hand, these indicators were better among married mothers as opposed to those who were unwed, widowed, separated, living with a partner out of wedlock, or divorced. In short, teenage pregnancy should be viewed as high risk not only because of the poor development of the reproductive organs, but also because of behavioral considerations. The risk is even higher when the future mother is legally married, has two or more children, does not live in an urban environment, has a low income, and has little formal education.

During the past several years, there has been an increase in the cases of urban malaria in Buenaventura, Colombia, from 576 in 1987 to 3296 in 1991 and 2017 in 1992; therefore, an epidemiological study to identify transmission patterns was carried out in this municipality on Colombia's Pacific coast. This paper describes the entomological findings regarding vectors, potential breeding sites and behavior of Anopheles species during the period from June 1993 to May 1994. Of the 469 potential breeding sites identified in the urban area, 28 were positive for anophelines, while in the neighboring rural zone, 20 out of 80 potential breeding sites were positive for the immature forms of Anopheles. Mining excavations, lakes and breeding ponds for fish or shrimp were the places where A. albimanus was more frequently found. For A. nuñeztovari, the breeding sites were rain puddles and ponds for breeding fish or shrimp. A. neivai was also identified in the urban area and larvae were collected from bromeliaceous plants. Both inside and outside the households mosquito collections were carried out, and 90% of the collected mosquitoes were identified as A. albimanus. Of the female A. albimanus 54.8% were parous. This species was found to have peak peridomiciliary activity between 6 p.m. and 10 p.m. The highest biting rate in the peridomiciliary area was 7.1 and was observed during March. It is expected that this entomological information will permit the launching of a strong community participation process and the implementation of control measures in accordance with the entomological findings related to malaria in the urban area of Buenaventura.

The production of articles resulting from biomedical, clinical, and public health studies that originated in Argentina, Brazil, Chile, Cuba, Mexico, and Venezuela from 1973 through 1992 was analyzed to discover trends in health research in Latin America. From the database of the Institute for Scientific Information (ISI), 41,238 articles with first authors who resided in those countries were extracted. These articles were analyzed by subject area, type of study, country, number of authors and institutions that participated in the investigation, and citations received by each article. Also analyzed were 95 articles in epidemiology selected from a pool of 570 published by authors from the six countries in 11 public health journals that enjoy international prestige. The results showed that the number of published works increased by 117% between the first and last five-year periods within the study period. Clinical research was distributed the most evenly among the countries, and public health research was the most concentrated (60.7% originated in Brazil). The numbers of biomedical and public health research articles showed relatively more growth than those reporting on clinical research throughout the period. A relative decrease was found in articles by only one author, which suggests a greater frequency of team efforts, and an increase was seen in articles with authors tied to two or more national or foreign institutions, which indicates greater cooperation between institutions and countries. The average number of citations received by each article was 3, which was less than half the number received by the articles in the ISI database (7.78). Regarding the subset of 95 articles in epidemiology, the great majority (96%) dealt with infectious diseases or maternal and child health, while in the international literature 78% of such articles were about chronic diseases. This group of articles gave evidence of more cooperation with international institutions and had a citation index of 4.36 per article. It is concluded that, despite the inherent limitations, this type of study reveals some general trends in the development of research in the six Latin American countries with the greatest scientific production and makes it possible to formulate hypotheses on the factors that influence these trends. Taken with the paper caution, the results of studies like this one can be of great value in defining health science and technology policies.

This paper describes the "health history", a method for obtaining data on patients, families and groups developed by the Nursing Department of Valle University, in Cali, Colombia. According to the authors, the method can be used by all health professionals and serve as a basis for nurse training. It discusses the obstacles that have arisen with the application of different concepts in nursing instruction and the difficulties that are sometimes caused when the nurse is insufficiently trained. It also dwells on the need for coordination between teaching and service institutions. The paper gives the sequence of steps to be followed in compiling the health history, as follows: collection of the information, statement of the problems, diagnosis, the plan to be followed, and progress and observation of the patient. Specimen health histories, one for an individual and family and the other for a group, are included to illustrate the theoretical aspects. To promote the use of the health history by the entire health team it is recommended that collective learning exercises be conducted to help define the roles of its different members.