Objective. To describe the methodology, the research designs used, the estimation and sample selection, variable definitions, collection instruments, and operative design and analytical procedures for the National Survey Violence Against Women in Mexico. Material and Methods. A complex (two-step) cross-sectional study was designed and the qualitative design was carried out using in-depth interviews and participant observation in health care units. Results. We obtained for the quantitative study a total of 26 240 interviews in women users of health services and 2 636 questionnaires for health workers; the survey is representative of the 32 Mexican states. For the qualitative study 26 in-depth interviews were conducted with female users and 60 interviews with health workers in the States of Quintana Roo, Coahuila and the Federal District.Key words: family violence; health workers; sampling design; Mexico ResumenObjetivo. Describir la metodología utilizada en la Encuesta Nacional sobre Violencia contra las Mujeres 2003 (ENVIM 2003) en México, junto con el diseño de investigación, la estimación y la selección de muestras, la definición de variables, los instrumentos de recolección, el diseño operativo para su instrumentación y los procedimientos de análisis. Material y métodos. En la parte cuantitativa se recurrió a un diseño transversal en dos etapas. En el componente cualitativo se realizaron entrevistas en profundidad y observación participante en unidades médicas. Resultados. Se obtuvo un total de 26 240 entrevistas, aplicadas a usuarias de los servicios de salud; y 2 636 cuestionarios correspondientes a proveedores, que abarcaron los 32 estados de la República. En el estudio cualitativo se llevó a cabo un total de 26 entrevistas de profundidad a usuarias y 60 entrevistas de profundidad a prestadores de servicios de salud en los estados de Quintana Roo, Coahuila y el Distrito Federal.Palabras clave: violencia de pareja; prestadores de servicios de salud; diseño muestral; México L a violencia de pareja es un problema social que debe ser reconocido por toda la población. Ocuparse de ella es darle la debida importancia a uno de los problemas de salud pública que más se ha mantenido oculto a lo largo de la historia. De aquí la importancia de romper con la idea de que es un problema "privado" y hacer públicas estas situaciones que dañan la salud de millones de personas. La violencia de pareja constituye un delito que afecta y deteriora los aspectos más valiosos del ser humano, y puede llegar a costarle la vida.1,2 Desde la perspectiva de salud pública, la violencia de pareja es un problema que ocasiona daño psi-

The results show that violence during pregnancy is a regular event in the impoverished context and that its expression is more severe. These results point to the importance of continued study of the problem of violence against pregnant women in Mexico and the importance of identifying battered women in prenatal care.

Objective. Hepatitis C Virus (HCV) infection is becoming a chronic disease in 60-85% of individuals and is a cause of hepatic cirrhosis and hepatocellular carcinoma. The objective of this study was to report the seroprevalence of HCV infection in a probabilistic sample of the Mexican population. Material and Methods. This study is based on information obtained from the National Health Survey conducted in 2000. A total of 21 271 sera randomly selected for anti-HCV and RNA of HCV was studied. It was performed at the National Institute of Public Health in 2005. Results. Seroprevalence of HCV antibodies was 1.4% (IC95% 1.1%-1.6%), of which 35.7% had active infection. Risk factors for infection were using heroine (RM= 9.8, IC: 2.1-41.4), being separated from his/her spouse (RM= 2.6, IC: 1.1-5.9), being a widower (RM= 2.2, IC: 1.1-4.3) and living in the northern states in the country (RM= 1.9, IC: 1.1-3.2). Conclusion. Results from this study indicate that HCV is an emerging public health problem in Mexico. Risk factors indicate that the main route of transmission is through transfusion of blood products (previous to 1996) and the second route is through usage of intravenous drugs and sexual practices.

Objective. To estimate the prevalence of chronic hepatitis B infection and carrier status in Mexico; to analyze the frequency and distribution of hepatitis B markers in relation to the demographic and geographic variables and to identify risk factors. Materials and Methods. A total of 12 014 sera samples from the 2000 National Health Survey that were randomly selected for Anti-HB c and HBsAg were studied. The sera were collected between November 1999 and June 2000 on a national level. Results. Seroprevalence for anti-HB c and HBsAg were 3.3% (CI 95%: 2.8-3.9) and 0.21% (0.11-0.37), respectively. Odds ratios adjusted by age for anti-HB c were: 15.3 for subjects 50 to 59 years old as compared with adults less than 29 years of age; 2.6 for residents in the southern region of the country as compared with residents in the central region; 4.6 for laborers as compared with business owners; 2.1 for women having had stillbirths; and 1.7 for adults having initiated sexual relations before 25 years of age. Conclusion. The epidemiological pattern for hepatitis B in Mexico is lower than the data worldwide. Nevertheless, it is of concern that 1.7 million Mexicans have suffered from the infection caused by this virus and 107 000 suffer from a chronic carrier status.

In response to the Latin American cholera epidemic, El Salvador began a prevention programme in April 1991. The first case was confirmed in August, and 700 cases were reported within 3 months. A matched case-control study was conducted in rural La Libertad Department in November 1991. Illness was associated with eating cold cooked or raw seafood (odds ratio [OR] = 7.0; 95% confidence limits [CL] = 1.4, 35.0) and with drinking water outside the home (OR = 8.8; 95% CL = 1.7, 44.6). Assertion of knowledge about how to prevent cholera (OR = 0.2; 95% CL = 0.1, 0.8) and eating rice (OR = 0.2; 95% CL = 0.1, 0.8) were protective. More controls than patients regularly used soap (OR = 0.3; 95% CL = 0.1, 1.0). This study demonstrated three important points for cholera prevention: (1) seafood should be eaten cooked and hot; (2) populations at risk should be taught to treat household drinking water and to avoid drinking water outside the home unless it is known to be treated; and (3) education about hygiene can be an important tool in preventing cholera.