CTX-M Extended-spectrum β-Lactamases, Washington State

Our study of risk factors for T. gondii infection was a case-control design to evaluate recent infection, not a cross-sectional study of T. gondii infection prevalence in a population. In our study, case-patients with recent infection were similar in age to T. gondii–negative control-patients, although among women the mean age of case-patients (33 years) differed slightly from that of control-patients (29 years) (p = 0.03, t-test). In addition, multivariate analysis comparing the case-patients with control-patients showed that age was not a significant factor. However, when we kept age in the multivariate model for women (p = 0.87 for age in the model), the odds ratio for having had children changed little, from 14.94 (95% confidence interval [CI] 3.68–60.73) to 14.01 (95% CI 2.88–68.08). Therefore, we do think that, in this study population, having had children is a risk factor for T. gondii infection among women. Dr Gomez-Marin also states that we did not evaluate drinking water–related factors. However, in our methods section (1), we indicated that our questionnaire asked about a comprehensive set of risk factors related to drinking water. Specifically, the questionnaire asked about the types of water (city, private well, and others, including bottled water); chlorination; filtering of water; and ingestion of water from streams, lakes, rivers, ponds, or other sources. Although we evaluated numerous water-related factors, we did not find them to be significant in this study, which applies to 1 area of Brazil. In other areas of Brazil, however, studies in which 1 of our authors (J.L.J.) has been involved have found water to be a risk factor or a source of infection (2,3). Again, we thank Dr GomezMarin for his letter. We sincerely appreciate his interest and work with toxoplasmosis. Jeffrey L. Jones,* Cristina Muccioli,† Rubens Belfort Jr,† Gary N. Holland,‡ Jacquelin M. Roberts,* and Claudio Silveira§ *Centers for Disease Control and Prevention, Atlanta, Georgia, USA; †Federal University of São Paulo, São Paulo, Brazil; ‡University of California, Los Angeles, California, USA; and §Clinica Silveira, Erechim, Rio Grande do Sul, Brazil