Prevalence of skin reactivity to coccidioidin and associated risks factorsin subjects living in a northern city of Mexico

Background. Coccidioidomycosis is a reemerging fungal disease seen mainly i n the states located at the Mexican-U.S. border. The finding of advanced ca ses of the disease are now more frequent. Methods. A cross-sectional study was conducted to determine the prevalence of skin reactivity to coccidioidin in the city of Torreon, Coahuila, Mexico , located in the northern region of the country. A multifactorial associati on of environmental, social, and health conditions was analyzed. A total of 1,653 coccidioidin skin tests was applied in male and female subjects olde r than 8 years of age. Results. The overall rate of positive reactivity in this city was 40.2%, wi th a 95% confidence interval of 37.8-42.5. This was related to time/life ex posure risk and to the habitat of unpaved streets. No statistically signifi cant difference regarding gender, socioeconomic level, and working activiti es was found. The highest reactivity was observed in subjects between 30 an d 65 years of age. Conclusion. Positive results were related to exposure risk and habitat, pri ncipally in the southeast region of the city. These results were applied bo th to residents and outsiders with no differences between the groups. Of th e total, 87.5% were considered high-risk subjects. It is recommended that f uture surveys be carried out in other northern cities of Mexico to obtain m ore useful data concerning the extent of the infection and mainly to establ ish preventive measures, such as appropriate reforestation and urbanization procedures. (C) 1999 IMSS. Published by Elsevier Science Inc.