Successful seroresponses to measles and rubella following aerosolized Triviraten vaccine, but poor response to aerosolized mumps (Rubini) component: comparisons with injected MMR.

Seroresponses to measles, rubella and mumps were evaluated following the injection of MMR II and injection or aerosol administration of Triviraten in young adults. Response to aerosolized Rubini mumps strain was a focus of interest, given robust responses to aerosolized mumps vaccine (Leningrad-Zagreb strain) in a prior study using aerosolized MMR vaccine. The aerosolized Edmonston-Zagreb (EZ) measles vaccine was significantly more immunogenic than injected EZ vaccine, and comparable to results following injected Moraten measles vaccine having twice the dosage. Responses to rubella were comparable in the three MMR study groups. Aerosolized Rubini vaccine was very highly and unexpectedly less immunogenic than either injected Rubini or Jeryl-Lyn strains. The high attenuation of Rubini vaccine appears to have limited its affinity for respiratory tract receptors, which may underlie its lack of clinical effectiveness.

Partial protection of seasonal trivalent inactivated vaccine against novel pandemic influenza A/H1N1 2009: case-control study in Mexico City.

OBJECTIVE: To evaluate the association of 2008-9 seasonal trivalent inactivated vaccine with cases of influenza A/H1N1 during the epidemic in Mexico. DESIGN: Frequency matched case-control study. SETTING: Specialty hospital in Mexico City, March to May 2009. PARTICIPANTS: 60 patients with laboratory confirmed influenza A/H1N1 and 180 controls with other diseases (not influenza-like illness or pneumonia) living in Mexico City or the State of Mexico and matched for age and socioeconomic status. MAIN OUTCOME MEASURES: Odds ratio and effectiveness of trivalent inactivated vaccine against influenza A/H1N1. RESULTS: Cases were more likely than controls to be admitted to hospital, undergo invasive mechanical ventilation, and die. Controls were more likely than cases to have chronic conditions that conferred a higher risk of influenza related complications. In the multivariate model, influenza A/H1N1 was independently associated with trivalent inactivated vaccine (odds ratio 0.27, 95% confidence interval 0.11 to 0.66) and underlying conditions (0.15, 0.08 to 0.30). Vaccine effectiveness was 73% (95% confidence interval 34% to 89%). None of the eight vaccinated cases died. CONCLUSIONS: Preliminary evidence suggests some protection from the 2008-9 trivalent inactivated vaccine against pandemic influenza A/H1N1 2009, particularly severe forms of the disease, diagnosed in a specialty hospital during the influenza epidemic in Mexico City.

Vaccines against influenza A (H1N1) pandemic.

BACKGROUND AND AIMS: The World Health Organization (WHO) has reported, as of September 2009, that the influenza A (H1N1) influenza pandemic has originated >300,000 laboratory-confirmed cases and 3917 deaths in 191 countries. It is recognized that pandemic vaccines have their greatest impact as a preventive strategy when administered before or near the peak incidence of cases in an outbreak. Therefore, vaccination campaigns should be in place when influenza A (H1N1) 2009 vaccines are available. We undertook this study to provide updated information on clinical evaluation of influenza A (H1N1) vaccines and review recommendations for influenza A (H1N1) vaccination campaigns and public health policy. METHODS: The following methods were used: 1) review of registry at ClinicalTrials.gov. 2) search of PubMed Central (PMC) for influenza A (H1N1) vaccine. 3) review of recommendations of WHO, Mexican Health Secretariat (SSA) and Advisory Committee on Immunization Practices (ACIP) on influenza A (H1N1) vaccination campaigns. RESULTS: Until October 1, 2009 there were 11 available influenza A (H1N1) candidate strains provided by WHO Global Influenza Surveillance Network. ClinicalTrials.gov registers 45 phase I and II clinical trials evaluating immunogenicity and safety of influenza A (H1N1) vaccines. Preliminary results support administration of a single dose and use of adjuvants. Main recommendations of WHO, SSA and ACIP include epidemiologic considerations, objectives, definition of target groups and reinforcement of other mitigation measures. CONCLUSIONS: The present pandemic of influenza A (H1N1) has shown mild to moderate severity. Vaccination strategies in Mexico will have the objective of decreasing severe outcomes, slowing transmission, protecting groups at increased risk of infection, complications, or death, and preventing overload of health services. Control of the pandemic should include reinforcement of other non-pharmacologic measures of mitigation and, importantly, an adequate strategy of social communication.

Immunogenicity of aerosol measles vaccine given as the primary measles immunization to nine-month-old Mexican children.

UNLABELLED: Aerosol measles vaccination has been found to be more immunogenic than subcutaneous administration as a booster in school aged children, and immunogenic in 12-month-old children as a primary dose. The objective of the study was to evaluate immunogenicity to aerosol measles vaccine in 9-month-old children. METHODS: Nine-months-old infants received Edmonston-Zagreb measles vaccine by aerosol (10(3.58) CCID50/0.1 mL, estimated retained dose 10(2.81) CCID50 or subcutaneous route (10(4.28) CCID50/0.5 mL); cellular and humoral immunity and adverse events were assessed. RESULTS: Measles-specific T cell proliferative responses developed in 42% of children given aerosolized vaccine compared with 67% of those who received subcutaneous vaccine (p = 0.01); the mean stimulation index (SI) was 4.4+/-0.7 versus 6.9+/-1, respectively, (p = 0.05). Seroconversion rates were 33 and 92% after aerosol or subcutaneous immunization (p < 0.001). Among infants who developed serologic responses, measles geometric mean titers (GMT; 95% CI) by neutralizing antibody assay were 215 mIU/mL (115-400) in aerosol vaccine recipients and 411 mIU/mL (345-490) in those given subcutaneous vaccine (p = 0.06). CONCLUSIONS: The proportion of 9-month-old infants who developed cellular and/or humoral immunity to measles was lower in the aerosol group but measles antibody and T cell responses were comparable among those who developed measles immunity. Differences in response rates are attributable to the lower aerosol dose. Improving aerosol delivery or increasing the dose may enhance immunogenicity of primary aerosol measles vaccination in this age group.

Tuberculosis and diabetes in southern Mexico.

OBJECTIVE: To determine the impact of diabetes on the rates of tuberculosis in a region where both diseases are prevalent. RESEARCH DESIGN AND METHODS: Data from a population-based cohort of patients with pulmonary tuberculosis undergoing clinical and mycobacteriologic evaluation (isolation, identification, drug-susceptibility testing, and IS6110-based genotyping and spoligotyping) were linked to the 2000 National Health Survey (ENSA2000), a national probabilistic, polystage, stratified, cluster household survey of the civilian, noninstitutionalized population of Mexico. RESULTS: From March 1995 to March 2003, 581 patients with Mycobacterium tuberculosis culture and fingerprint were diagnosed, 29.6% of whom had been diagnosed previously with diabetes by a physician. According to the ENSA2000, the estimated prevalence of diabetes in the study area was 5.3% (95% CI 4.1-6.5). The estimated rates of tuberculosis for the study area were greater for patients with diabetes than for nondiabetic individuals (209.5 vs. 30.7 per 100000 person-years, P < 0.0001). CONCLUSIONS: In this setting, the rate of tuberculosis was increased 6.8-fold (95% CI 5.7-8.2, P < 0.0001) in patients with diabetes due to increases in both reactivated and recently transmitted infection. Comorbidity with diabetes may increase tuberculosis rates as much as coinfection with human immunodeficiency virus (HIV), with important implications for the allocation of health care resources.

Induction of cellular and humoral immunity after aerosol or subcutaneous administration of Edmonston-Zagreb measles vaccine as a primary dose to 12-month-old children.

Infants were immunized by aerosol (10(3.6) plaque-forming units [pfu]/dose) or subcutaneous (sc) (10(4.27) pfu/dose) administration of Edmonston-Zagreb measles vaccine. Measles-specific T cell proliferative responses with a stimulation index of > or =3 developed in 72% of children given aerosol-administered vaccine, compared with 87% given s.c.-administered vaccine (P =.06). Seroconversion rates were 90% after aerosol-administered vaccine and 100% after s.c.-administered vaccine (P=.01), and measles geometric mean titers were 237 milli-international units (mIU) (95% confidence interval [CI], 146-385 mIU) and 487 mIU (95% CI, 390-609 mIU) in each group, respectively (P=.01). Measles-specific T and B cell responses were weaker after aerosol than after sc vaccination, indicating a need to use a higher aerosol dose to achieve optimal immunogenicity.

Aerosolized measles and measles-rubella vaccines induce better measles antibody booster responses than injected vaccines: randomized trials in Mexican schoolchildren.

OBJECTIVE: To compare antibody responses and side-effects of aerosolized and injected measles vaccines after revaccination of children enrolling in elementary schools. METHODS: Vaccines for measles (Edmonston-Zagreb) or measles-rubella (Edmonston-Zagreb with RA27/3) were given by aerosol or injection to four groups of children. An additional group received Schwarz measles vaccine by injection. These five groups received vaccines in usual standard titre doses. A sixth group received only 1000 plaque-forming units of Edmonston-Zagreb vaccine by aerosol. The groups were randomized by school. Concentrations of neutralizing antibodies were determined in blood specimens taken at baseline and four months after vaccination from randomized subgroups (n = 28-31) of children in each group. FINDINGS: After baseline antibody titres were controlled for, the frequencies of fourfold or greater increases in neutralizing antibodies did not differ significantly between the three groups that received vaccine by aerosol (range 52%-64%), but they were significantly higher than those for the three groups that received injected vaccine (range 4%-23%). Mean increases in titres and post-vaccination geometric mean titres paralleled these findings. Fewer side-effects were noted after aerosol than injection administration of vaccine. CONCLUSION: Immunogenicity of measles vaccine when administered by aerosol is superior to that when the vaccine is given by injection. This advantage persists with aerosolized doses less than or equal to one-fifth of usual injected doses. The efficacy and cost-effectiveness of measles vaccination by aerosol should be further evaluated in mass campaigns.

A randomized trial demonstrating successful boosting responses following simultaneous aerosols of measles and rubella (MR) vaccines in school age children.

The reactogenicity and immunogenicity of combined measles and rubella (MR) booster vaccination, via aerosol and subcutaneous routes, was assessed in 562 healthy children. Rates of rubella seroconversion and geometric mean titers (GMT) were similar for both routes. Rates of measles PN seroconversion, GMT and measles ELISA post-vaccination seropositivity and seroconversion rate were each higher for aerosol vaccine (54%, 3928 IU/l, 99.6 and 98.8%), than for subcutaneous vaccine (7%, 866 IU/l, 92.2 and 82.4%) (P<0.01). Reactogenicity was higher for subcutaneous vaccine (P<0.05). This study demonstrates that aerosol vaccine was more immunogenic for measles antibodies, and equally immunogenic for rubella antibodies. Aerosol vaccine was less reactogenic.

El A, B, C, sobre ántrax para personal de salud / The A, B, C, of Anthrax for health care personnel

El propósito de esta serie artículos es presentar al personal de salud un resumen actualizado sobre los agentes asociados al bioterrorismo; en éste se entrega un resumen, puesto al día, sobre ántrax, con énfasis en las características de los casos ocurridos en el mes de octubre en los Estados Unidos de América, (EUA) y la experiencia de las oficinas gubernamentales de ese país para atender esa emergencia. Asimismo, se describen las medidas que se han implantado en México. Los autores están convencidos de que ante el terror la mejor arma es la información oportuna y actualizada. El texto completo en inglés de este artículo está disponible en: http://www.insp.mx/salud/index.html

La vacunación antisarampionosa en México por el método de aerosol / Anti-measles vaccination by aerosol in Mexico

En este trabajo se describen las acciones de vacunación contra el sarampión por el método de aerosol inhaladado llevada a cabo en la República Mexicana entre 1988 y 1990. Se hace mención pormenorizada del equipo simplificado que se empleó, del personal, de su adiestramiento, de la promoción y de la estructura de las campañas correspondientes. También se precisa la vacuna usada: cepa Edmonston-Zagreb cultivada en células diploides, del Instituto Nacional de Virología de la Secretaría de Salud en México, con un título que varió, de 10 4.5 unidades formadoras de placa/ml (PFU/ml) a 10 4.8 PFU/ml, administrada en 30 segundos de inhalación, con un descarga del nebulizados, durante este lapso, de 2 800 a 4 000 PFU por niño, estimándose la dosis retenida en 25 por ciento , por ejemplo, 700 a 1 000 PFU. En total se tiene documentada la vacunación de 3 760 684 niños prescolares y escolares en 13 de las 32 entidades federativas del país. No se observaron efectos indeseables de gravedad y los estudios limitados que se realizaron, tanto serológicos como de campo, avalan la efectividad y seguridad de este método que es, por otra parte, mucho más barato, rápido y aceptable por la población que el de inyección subcutánea.

Tuberculosis y SIDA en México / Tuberculosis and AIDS in Mexico

La tuberculosis continúa representando un problema importante en México y de acuerdo con las cifras notificadas ha ocurrido un exceso en el número de casos esperados en los últimos años, principalemente en adultos jóvenes de ambos sexos; se estima la tasa en 51.7 casos por 100 000 habitantes. En los pacientes con SIDA ocupa el tercer lugar como entidad infecciosa, depués de candidiasis y neumonía por P. carinii. De los 19 352 casos de SIDA notificados hasta julio de 1994, 8.3 por ciento de los pacientes presentó tuberculosis como manifestación inicial. De acuerdo con las encuestas centinela llevadas a cabo entre 1990-1994 en 17 entidades federativas en pacientes tuberculosos, la prevalencia de infección por VIH es de 3.1 por ciento (rango = 0 a 6.5 por ciento) en 1 187 pacientes del sexo masculino y de 1 por ciento (rango = 0 a 2.3 por ciento) en 886 del sexo femenino. Se describen los resultados de los estudios de investigación epidemiológica llevados a cabo en el campo de la prevención de la tuberculosis, así como las características de drogosusceptibilidad de las cepas de M. tuberculosis aisladas en estos pacientes. Finalmente se discuten las perspectivas de prevención y control

La tuberculosis continúa representando un problema importante en México y de acuerdo con las cifras notificadas ha ocurrido un exceso en el número de casos esperados en los últimos años, principalmente en adultos jóvenes de ambos sexos; se estima la tasa en 51.7 casos por 100 000 habitantes. En los pacientes con SIDA ocupa el tercer lugar como entidad infecciosa, después de candidiasis y neumonía por P. carinii. De los 19 352 casos de SIDA notificados hasta julio de 1994, 8.3% de los pacientes presentó tuberculosis como manifestación inicial. De acuerdo con las encuestas centinela llevadas a cabo entre 1990-1994 en 17 entidades federativas en pacientes tuberculosos, la prevalencia de infección por VIH es de 3.1% (rango=0 a 6.5%) en 1 187 pacientes del sexo masculino y de 1% (rango=0 a 2.3%) en 886 del sexo femenino. Se describen los resultados de los estudios de investigación epidemiológica llevados a cabo en el campo de la prevención de la tuberculosis, así como las características de drogosusceptibilidad de las cepas de M. tuberculosis aisladas en estos pacientes. Finalmente se discuten las perspectivas de prevención y control.

Las enfermedades de transmisión sexual y la epidemia de VIH/SIDA / Sexually transmitted diseases and the AIDS epidemic in Mexico

Se refieren las actividades llevadas a cabo en el campo de las enfermedades de transmisión sexual (ETS) durante los últimos años. Las fuentes de información fueron: a) Encuestas en mujeres dedicadas a la prostitución. A partir de 1990 se han estudiado 1 386 mujeres en cuatro estados de la República Mexicana mediante cuestionario estructurado y exámenes de laboratorio. La prevalencia de las diferentes ETS han sido considerables para sífilis (VDRL, FTA-abs), 23.7 por ciento; clamidiasis (Ag IF), 12.9 por ciento; gonorrea (Ag, ELISA), 11.5 por ciento; anti-HBS, 11.0 por ciento; herpes 1, 2 (IgM), 9.3 por ciento; HBSAg, 5.7 por ciento; sin embargo, ha sido baja para VIH(ELISA, Western blot), 0.5 por ciento. En 1994 se estudiaron en la Ciudad de México 662 mujeres con técnicas de laboratorio diferentes para clamidiasis y gonorrea (cultivo), hepatitis B (anticuerpo anticore) y herpes (anticuepos totales) con los resultados siguientes; sífilis 1.5 a 12 por ciento, clamidiasis 10.8 a 11.7 por ciento, gonorrea 0 a 5.9 por ciento, hepatitis B 0 a 7.1 por ciento, herpes 44.7 a 78 por ciento y VIH 0 a 1.4 por ciento. b) Encuesta en hombres con práctica homosexuales y bisexuales. Con la metodología mencionada se han estudiado 325 sujetos en tres estados. A diferencia de los resultados en mujeres, la prevalencia de VIH ha sido alta (18.8 por ciento), y significativa para el resto de las ETS: anti HBSAg 5.0 por ciento; clamidiasis (Ag, IF) 4.3 por ciento; herpes simplex 1 y 2 (Ag, IF) 4.7 por ciento; gonorrea (Ag, ELISA) 2.8 por ciento. c) Estudios clínicos de pacientes. Se ha estudiado la interrelación clínica entre las diferentes ETS y la infección por VIH, en particular se describen las diferencias clínicas de pacientes infectados por VIH con condilomatosis o sífilis en comparación con los no coinfectados. Se discuten las implicaciones de la interrelación entre las diferentes ETS y la infección por VIH en la prevención y control de este tipo de enfermedades

Studies on sexually transmitted diseases (STD) during the previous years in Mexico are discussed. The information sources were: a) Surveys among commercial sex workers. Since 1990, 1386 women have been studied in four federal states through structured questionnaires and laboratory tests. Prevalence of different STD's has been significant (syphilis (VDRL, FTA-abs) 23.7%; chlamydiasis (Ag IF) 12.9%; gonorrhea (Ag, ELISA) 11.5%; anti-Hss 11.0%; herpes 1,2 (IgM) 9.3%, HBsAg 5.7%. Frequency of HIV (ELISA, Western blot) has been low; 0.5%. In 1994, 662 women were studied in Mexico City, with different laboratory techniques for chlamydiasis and gonorrhea (culture), hepatitis B (anticore antibodies) and herpes (total antibodies) with the following results: syphilis 1.5-12%; chlamydiasis 10.8-11.7%; gonorrhea 0-5.9%, hepatitis B 0-7.1%; herpes 44.7-78%; and HIV 0-1.4%. b) Surveys among men with homosexual and bisexual practices. 325 subjects have been studied in three federal states using methods similar to those of the 1990 survey. Contrasting with results among women, HIV prevalence was found to be high; (18.8%), and considerable for other STD s: anti-HBsAg 28.6%, syphilis 34.9%, recent herpes 10.9%, HBsAg 5.0%, chlamydiasis (Ag, IF) 4.3%, herpes simplex 1, 2 (Ag, IF) 4.7%, gonorrhea (Ag, ELISA) 2.8%. c) Patient clinical studies. The clinical interrelationship between different STD and HIV infection has been studied: clinical differences are described between patients with condylomata or syphilis depending on HIV serostatus. Implications of the interrelationship between different STD s and HIV infection for the prevention and control of these diseases are discussed.

Epidemiología del SIDA/VIH en México; de 1983 a marzo de 1995 / Epidemiology of AIDS-VIH in Mexico, 1983-march 1995

El objetivo de este artículo fue analizar la magnitud, distribución, frecuencia, patrones, tendencias, factores de riesgo, grupos en riesgo, predicciones y evaluación de las intervenciones del SIDA/VIH en México, en los últimos doce años. Se presentan los resultados del Registro Nacional de Casos de SIDA, encuestas centinelas de VIH en 18 ciudades del país, análisis de los certificados de defunción, estudios transversales y longitudinales, observacionales y de intervención. Hasta el primer trimestre de 1995 se han estimado 34 230 casos de SIDA, 120 000 infectados por VIH y 21 000 muertes por SIDA. La tendencia es de crecimiento amortiguado con periodos de 18 meses de duplicación de los casos. El patrón epidemiológico es de transmisión, principalmente en hombres homosexuales y bisexuales, y con una relación hombre-mujer de 6 a 1. En 1992, en México el SIDA constituyó la décimo novena causa de muerte en población general. Existen por lo menos dos patrones de transmisión, uno urbano-occidental que contribuye con más del 90 por ciento de los casos, y uno rural-caribeño, de más reciente aparición. La transmisión sanguínea del SIDA tiene una tendencia descendente, de la heterosexual y la perinatal son moderadamente ascendentes. La seroprevalencia en la población general adulta es de 0.06 por ciento; en cambio en grupos con prácticas de riesgo se encuentran tasas hasta del 50 por ciento. Los factores de riesgo identificados son semejantes a los descritos en otros países y han servido para el diseño de intervenciones. Se han realizado evaluaciones de las intervenciones con resultados positivos en la prevención de la transmisión sanguínea y por vía sexual en prostitutas; los resultados en homosexuales no han sido satisfactorios. Para el año 2000 se calcula la cifra de 77 000 a 88 000 casos acumulados de SIDA en México

The purpose of this study is to analyze the HIV/AIDS magnitude, distribution, frequency, patterns, trends, risk factors, risk groups, estimation and evaluation of interventions in Mexico during the last twelve years. Results of a summary of statistics and results from several sources are presented including the National Registr of AIDS cases, HIV sentinel surveillance in 18 cities of the country, analysis of death certificates, cross-sectional, longitudinal, observational, and intervention studies. As of March 1995, 34 230 AIDS cases, 120 000 HIV infections and 21 000 AIDS deaths are estimated. A damaged exponential growth with duplication of AIDS cases every 18 months can be seen. Epidemiological patterns of transmission are found primarily among men with homosexual and bisexual practices. The male: female ratio is 6 to 1. In 1992 AIDS was the 19th cause of death among the general population. At least two patterns of transmission have been identified: one is the western-urban pattern which contributes with more than 90% of cases and the other, more recent, has been described as Caribbeanrural. Blood transmission of AIDS shows a downward trend, and heterosexual and perinatal transmission is slightly increasing. Seroprevalence among adults is 0.06%: however, among groups with risk practices, rates up to 50% have been found. Risk factors are similar to those described in the literature in other countries, and have been used for designing interventions. Evaluation of interventions has been accomplished by demonstrating positive results in the prevention of blood transmission and sexual transmission among female commercial sex workers; prevention efforts directed to men with homosexual practices have not been successful. Between 77 000 and 88 000 cumulated AIDS cases are estimated in Mexico for the year 2000.

La epidemia de VIH/SIDA y la mujer en México / The HIV/AIDS epidemic and women in Mexico

Este trabajo presenta un análisis de evolución de los casos de SIDA y la seroprevalencia de infección por VIH en mujeres de México, desde el inicio de la epidemia hasta el primer semestre de 1994, así como de los factores sociales y culturales que ponen en particular desventaja a la mujer mexicana respecto de la adopción de medidas preventivas de esta enfermedad. Desde 1985 en que se presentaron los primeros casos de SIDA en mujeres y hasta el 1 de junio de 1994, se había acumulado un total de 2 767 casos de SIDA en mujeres, que corresponden al 14.8 por ciento del total acumulado. Los primeros casos se asociaron a transfusiones de sangre contaminada; sin embargo, a partir de 1986 empezaron a aparecer casos asociados a transmisión heterosexual. Actualmente, sólo el 35 por ciento de los casos nuevos de SIDA reportados en mujeres son atribuibles a transfusiones, mientras que el 64 por ciento corresponde a transmisión sexual, coexistiendo dos epidemias: la de transmisión sanguínea, con una velocidad de duplicación de 45 meses y una tendencia hacia la disminución, y la transmitida por contacto sexual, que presenta una mayor velocidad de crecimiento (periodo de duplicación de meses) y cuya tendencia es ascendente. En general la mujer presenta mayor vulnerabilidad, tanto biológica como social y cultural, a la transmisión del VIH/SIDA. Las condiciones de desigualdad económica, social y cultural de las mujeres respecto de sus parejas sexuales, desemboca en relaciones de dependencia y falta de poder social desde las cuales es muy difícil evaluar objetivamente el riesgo de infectarse y, aún más, negociar la adopción de medidas preventivas. En situación particularmente desventajosa se encuentran las mujeres de áreas rurales, a lo cual se agrega la tendencia a la ruralización de la epidemia asociada a la migración interna y sobre todo internacional (de trabajadores temporales hacia los EUA), que puede resultar en efectos demográficos y sociales de gran impacto. Se concluye que es necesario profundizar en el diseño y evaluación de estrategias de prevención bajo control de las mujeres que les permitan protegerse, aun sin el conocimiento de su pareja sexual; simultáneamente deben realizarse estrategias educativas dirigidas a parejas heterosexuales (especialmente jóvenes), que les permitan negociar la adopción de medidas preventivas eficaces

This study presents an analysis of AIDS cases and seroprevalence of HIV infection among Mexican women, from the onset of the epidemic through June 1994, as well as the analysis of the social and cultural factors that put women in a powerless situation regarding the adoption of preventive measures. Since 1985, when the first AIDS cases among women were reported in Mexico and until June 1, 1994, a total of 2 767 cases have been reported, representing 14.8% of the total number of cases. The first cases of AIDS among women were associated to infected blood transfusions; however, in 1986, heterosexually transmitted cases began to appear. Currently, only 35% of newly reported AIDS cases are associated to blood transfusions while 64% of them are related to heterosexual transmission. In fact, two epidemics are evident: one transmitted through blood, showing a downward trend (duplication time 45 months), and a second one, heterosexually transmitted, increasing twice as fast (duplication time 27 months). The latter is expected to dominate AIDS epidemiology among women in the future. In general, women are more vulnerable to HIV/AIDS biologically, but also socially and culturally. Women is economic, social and cultural subordination to their sexual partners results in a situation that makes it difficult for them to assess their infection risk and even more, to negotiate taking preventive measures. This situation is even more disadvantageous to rural women and, together with the recent trend of the AIDS epidemic to ruralization and with internal and international migration (temporary work force migration to the USA), can result in deep demographic and social effects. We conclude that it is necessary to work on the design and assessment of preventive measures under women's control, that empower them to protect themselves even without their partner's awareness. Also, it is necessary to promote sexual education among young heterosexual couples on how to talk about sexual issues and negotiate the use of preventive measure according to their actual sexual practices.

Casos de SIDA en el área rural en México / AIDS cases in the rural areas of Mexico

El objetivo de este trabajo es describir el desarrollo de la epidemia de SIDA en el área rural de México. Para cumplir con este propósito se utilizó el Registro Nacional de Casos de SIDA, además de un listado de localidades por habitantes obtenido del XI Censo de Población y Vivienda realizado en 1990. Los casos rurales fueron comparados con aquéllos procedentes de áreas urbanas, en cuanto a fecha de notificación distribución por sexo, categorías de riesgo e historia de migración. De los 19 090 casos de SIDA reportados en México hasta el primero de julio de 1994, 699 (3.7 por ciento) correspondían a residentes en localidades con menos de 2500 habitantes. El primer caso rural se conoció en 1986, tres años después del primer caso de SIDA informado en la Ciudad de México; en ese año se notificaron cinco casos. Estos han continuado aumentando cada año a partir de esta fecha salvo para 1991, cuando hubo menos casos que el año anterior. Se han reportado casos rurarles en todos los estados del país. El estado con la tasa de prevalencia más alta fue Nayarit con 102 por millón de habitantes, seguido de Morelos con 99, Jalisco con 90, y Colima y Tlaxcala con 84. Una proporción de 25 por ciento de los casos rurales tienen antecedentes de migración temporal a los Estados Unidos (EUA), contra 6.1 por ciento de los casos urbanos. La distribución global por sexo muestra importantes diferencias significativas, con una proporción de 21.3 por ciento casos femeninos en áreas rurales, comparado con una proporción de 14.4 por ciento mujeres de áreas urbanas (p<0.05). Existe una mujer por cada cuatro hombres en el área rural y seis hombres por cada mujer en el medio urbano con SIDA. Las tasas de prevalencia en hombres son en promedio casi tres veces y medio más altas que las tasas en mujeres. El patrón de transmisión rural en este momento no representa un problema significativo por el número de enfermos, pero es importante señalar que es un patrón diferente del que México ha enfrentado en los últimos 10 años. Tiene la posibilidad de ganar importancia en el futuro, ya que no se prevé que disminuya su principal componente: la migración a los EUA. La epidemia de SIDA en el área rural es más reciente que la urbana y presenta un crecimiento exponencial que, a diferencia del que se conoce para las ciudades, todavía no amortiguó su crecimiento y se da en un grupo social con condiciones de vida más precarias

The objective of this paper is to describe the AIDS epidemic in rural areas of Mexico. Information from the National AIDS Registry and the 1990 XI National Census was used. Rural AIDS cases and urban cases were compared regarding notification time ser risk categories and migration information. Of the 19 090 AIDS cases reported to the first of July 1994 699 (3.7%) were rural cases. The first five of these cases were reported in 1986 three years after the first cases had been reported in Mexico. The number of AIDS cases has been growing each year but in 1991. Cases have been reported by all Mexican states. The state with the highest prevalence was Nayarit with 102 cases per million inhabitants followed by Morelos with 99 Jalisco with 90 and Colima and Tlaxcala with 84. A total of 25% of the rural cases are migrants who have been to the US against 6.1% of cases from urban areas. The distribution by sex shows 21.3% of women affected against 14.4% of urban cases (p < 0.05). The rural female to male ratio is 1:4 while the urban ratio is 1:6. The prevalence rates are almost three times greater in men than in women. The rural AIDS pattern represents a problem not because of the number of people affected but because of the heterosexual way of transmission. We do not think that migration to the US is going to change. The rural AIDS epidemic is more recent and growing faster than that occurring in the urban setting