[Decrease of HCV seroprevalence in Mexico: Results from the National Health and Nutrition Survey 2012]. / Disminución de la seroprevalencia de hepatitis C en México: resultados de la Ensanut 2012.

OBJECTIVE: To estimate seroprevalence of hepatitis C virus (HCV) among 15-49 years old Mexicans living in households and to describe the profile of seroreactive individuals. MATERIALS AND METHODS: Cross-sectional study implemented in 2012 using a national probabilistic sample with behavioral data from face-to-face interviews at households and HCV antibodies screening using capillary blood from same individuals. RESULTS: HCV seroprevalence in Mexico was estimated at 0.27% (IC95% 0.12-0.60), representing 161 000 persons. Seroprevalence was significantly higher among males (0.45% CI95% 0.01-0.89) than females (0.10% CI95% 0.00-0.22). Multivariate analysis suggests a higher possibility of HCV reactivity among men, increasing with age and higher among those sexually active, and lower for higher socioeconomic level. CONCLUSION: HCV seroprevalence in Mexico by 2012 seems significantly lower than the estimation from 2000 of 1.2% for the same age-group. Evidence of infection among individuals 15-19 years old suggests the need to strength preventive actions, particularly in subjects with risky behaviors.

Disminución de la seroprevalencia de hepatitis C en México: resultados de la Ensanut 2012 / Decrease of HCV seroprevalence in Mexico: Results from the National Health and Nutrition Survey 2012

Objetivo. Estimar la seroprevalencia del virus de la hepatitis C (VHC) en población mexicana en viviendas particulares y explorar aspectos del perfil poblacional de serorreactividad. Material y métodos. Estudio transversal con una muestra probabilística de la población del país entre 15 y 49 años en el año 2012, con información sociodemográfica obtenida por entrevista en los hogares y determinación de anticuerpos al VHC por inmunoensayo de micropartículas en sangre capilar. Resultados. La seroprevalencia de VHC en México se estimó en 0.27% (IC95% 0.12-0.60), equivalente a 161 000 personas en el país, y fue mayor entre hombres (0.45% IC95% 0.01-0.89) en comparación con mujeres (0.10% IC95% 0.00-0.22). El análisis multivariado señala que la posibilidad de un resultado positivo a VHC es mayor entre hombres, aumenta con la edad y entre los sexualmente activos, y es menor en la población de mayor nivel socioeconómico. Conclusiones. La seroprevalencia observada de VHC resulta significativamente menor que la estimada en el año 2000 (1.2%) para el mismo grupo de edad. La evidencia de casos entre individuos de 15 a 19 años sugiere la necesidad de fortalecer acciones preventivas recomendadas internacionalmente, con énfasis en la población expuesta al VHC por prácticas de riesgo.

Objective. To estimate seroprevalence of hepatitis C virus (HCV) among 15-49 years old Mexicans living in households and to describe the profile of seroreactive individuals. Materials and methods. Cross-sectional study implemented in 2012 using a national probabilistic sample with behavioral data from face-to-face interviews at households and HCV antibodies screening using capillary blood from same individuals. Results. HCV seroprevalence in Mexico was estimated at 0.27% (IC95% 0.12-0.60), representing 161 000 persons. Seroprevalence was significantly higher among males (0.45% CI95% 0.01-0.89) than females (0.10% CI95% 0.00-0.22). Multivariate analysis suggests a higher possibility of HCV reactivity among men, increasing with age and higher among those sexually active, and lower for higher socioeconomic level. Conclusion. HCV seroprevalence in Mexico by 2012 seems significantly lower than the estimation from 2000 of 1.2% for the same age-group. Evidence of infection among individuals 15-19 years old suggests the need to strength preventive actions, particularly in subjects with risky behaviors.

Seroprevalencia de VIH en población mexicana de entre 15 y 49 años: resultados de la Ensanut 2012 / HIV seroprevalence among Mexicans age 15 to 49: results from the National Health & Nutrition Survey 2012

Objetivo. Estimar la seroprevalencia de VIH en población mexicana no institucionalizada de 15 a 49 años, y aspectos selectos del perfil de la población serorreactiva. Material y métodos. Estudio transversal con una muestra probabilística de la población del país de 15 a 49 años, con información sobre comportamientos obtenida por entrevista directa en los hogares y determinación de anticuerpos para VIH en sangre capilar. Resultados. Se identificó una seroprevalencia de 0.15% (IC95% 0.09-0.21) en la población de 15 a 49 años; de 0.07% (IC95% 0.03-0.11) en mujeres, y de 0.24% (IC95% 0.11-0.36) en hombres. La población serorreactiva a VIH son hombres jóvenes, de mayor nivel socioeconómico en relación con la población general y con información que sugiere una mayor cobertura por la seguridad social (49.9% en serorreactivos contra 34.5% en no serorreactivos). El 49.4% de los serorreactivos contra 18.5% de los no serorreactivos se había realizado al menos una prueba de detección de VIH. Conclusiones. La seroprevalencia de VIH estimada en la Encuesta Nacional de Salud y Nutrición (Ensanut) 2012 sugiere que ésta se ha mantenido relativamente estable desde 2000. La estimación representa alrededor de 104000 personas (rango de entre 53000 y 126000) de 15 a 49 años que viven con VIH en México (75% de los cuales son hombres), de los que 50.6% desconocería su estatus serológico. Implementando un modelo de corrección de sesgo y agregando a los estimados en hogar, los casos estimados entre población de hombres que tienen sexo con hombres (tanto homosexual como bisexual), la estimación de la seroprevalencia alcanzaría 0.23%, con un total de 140000 personas de 15 a 49 años viviendo con VIH (con un intervalo estimado de entre 92000 y 201000 personas).

Objective. To estimate the HIV seroprevalence among Mexicans aged 15 to 49 years old and living in households, and to describe the profile of serorreactive individuals. Materials and methods. Cross-sectional study with a national probabilistic sample of individuals aged 15 to 49 years with behavioral data from direct interview (face-to-face) at households and HIV screening using capillary blood collected from the same individuals. Results. A seroprevalence of 0.15% (95%CI 0.09-0.21) was estimated for Mexicans aged 15 to 49; seroprevalence among women was 0.07% (95%CI 0.03-0.11) and 0.24% (95%CI 0.11-0.36) for men. HIV serorreactive population is composed of younger men, with a higher socioeconomic level compared to the general population, and with a higher insurance coverage-social protection on health in general and social security in particular. Only 50% of the serorreactive individuals may be aware of their status as living with HIV. Conclusions. The estimated HIV seroprevalence in the NHNS 2012 suggests a stable pattern since 2000. The estimated prevalence among individuals 15 to 49 years was adjusted both for selection bias correction and to include MSM estimations (under the assumption that MSM is a population hard to reach in a household survey), resulting in a total seroprevalence of 0.23% and an estimated number of people with HIV of 140000.

[HIV seroprevalence among Mexicans age 15 to 49: results from the National Health & Nutrition Survey 2012]. / Seroprevalencia de VIH en población mexicana de entre 15 y 49 años: resultados de la Ensanut 2012.

OBJECTIVE: To estimate the HIV seroprevalence among Mexicans aged 15 to 49 years old and living in households, and to describe the profile of serorreactive individuals. MATERIALS AND METHODS: Cross-sectional study with a national probabilistic sample of individuals aged 15 to 49 years with behavioral data from direct interview (face-to-face) at households and HIV screening using capillary blood collected from the same individuals. RESULTS: A seroprevalence of 0.15% (95%CI 0.09-0.21) was estimated for Mexicans aged 15 to 49; seroprevalence among women was 0.07% (95%CI 0.03-0.11) and 0.24% (95%CI 0.11-0.36) for men. HIV serorreactive population is composed of younger men, with a higher socioeconomic level compared to the general population, and with a higher insurance coverage-social protection on health in general and social security in particular. Only 50% of the serorreactive individuals may be aware of their status as living with HIV. CONCLUSIONS: The estimated HIV seroprevalence in the NHNS 2012 suggests a stable pattern since 2000. The estimated prevalence among individuals 15 to 49 years was adjusted both for selection bias correction and to include MSM estimations (under the assumption that MSM is a population hard to reach in a household survey), resulting in a total seroprevalence of 0.23% and an estimated number of people with HIV of 140,000.

Maternal/child seroprevalence of antibodies against Treponema pallidum at four general hospitals in the state of Morelos, Mexico.

BACKGROUND AND AIMS: Treponema pallidum can cause syphilis in pregnant women and congenital syphilis in the newborn. In Latin America, 330,000 pregnant women are diagnosed with syphilis every year. Adequate prenatal care to detect syphilis reduces maternal morbidity and fetal and neonatal mortality and morbidity. We undertook this study to determine T. pallidum seroprevalence among pregnant and puerperal women from Morelos, Mexico, as well as to evaluate the sexual behavior, demographic and clinical variables associated with the infection. METHODS: A cross-sectional study was carried out among pregnant and puerperal women from four general hospitals from Morelos, Mexico during 2005-2009. Women answered a questionnaire and provided a blood sample to detect antibodies against T. pallidum. RESULTS: A total of 2331 women were analyzed with 0.26% of T. pallidum seroprevalence. There were four cases with active syphilis and two cases with latent syphilis, as well as two cases of congenital syphilis. Illiterate women had 6.7 times higher risk of being infected. Women who did not undergo a urine test had a 5.3 times higher risk for infection and women who do not have piped water inside their household had a 5.0-fold higher risk of having anti-T. pallidum antibodies. All seropositive cases were from the same hospital (Cuautla General Hospital) with demographic, sexual behavior and medical care characteristics different from the other three hospitals. CONCLUSIONS: Syphilis during pregnancy and congenital syphilis are still present in Mexico. It may be that the more urban a population the higher the chance of the prevalence of maternal syphilis. It would be beneficial to reinforce the observance of the Official Mexican Norm and to implement rapid diagnostics tests to contend with this public health problem.

[Guideline for interpretation and report of the antibody to hepatitis C virus. Grupo de Desarrollo de la Guía ]. / Guía de interpretación y reporte del anticuerpo a hepatitis C.

Patients with hepatitis C virus (HCV) infection are detected by testing for the presence of antibodies to HCV (Anti-HCV). A positive Anti-HCV test represents a true positive result only in a variable proportion of subjects (35 to 95%). The qualitative interpretation as positive or negative Anti-HCV report is associated with a general lack of understanding regarding the interpretation of results, when more specific testing should be performed, and which tests should be considered for this purpose. Therefore, a substantial variation in supplemental testing practices exists among laboratories and physicians. This guideline was developed on the basis of the best available evidence to classify positive antibody in two (low and high) or three levels (very low, low and high) according to the signal to cutoff (S/CO) ratio: the very low level of the Anti-HCV identifies false-positive results and further diagnostic testing is not necessary. The low antibody level is frequently related with false-positive results and testing with Immunoblot is recommended; only Immunoblot-positive subjects require HCV RNA testing because of a low possibility of being viremic. The high Anti-HCV level is an accurate serological marker for predicting viremia and denotes the need of routine HCV RNA testing in order to efficiently confirm hepatitis C. Cost-effectiveness analysis, based on the Anti-HCV level, recommends the use of the two or three-levels to choose the confirmatory test of positive antibody. This approach can be implemented without increasing test costs because the S/CO ratio is automatically generated in most laboratory analyzers and would provide health care professionals with useful information for counseling and evaluating patients, to eliminate unwarranted notifications in cases of false antibody reactivity, and correctly identifying those Anti-HCV-positive patients who are infected and need antiviral treatment. The written report should include the antibody level (S/CO ratio), the type of the immunoassay applied and interpretation guideline. Anti-HCV testing is performed in multiple settings including blood banks or health department facilities; adoption of this Guideline for interpretation and report of the antibody to hepatitis C virus by laboratories and its implementation by clinicians will improve the accuracy for interpreting antibody result to determine the next step on hepatitis C diagnosis.

Hepatitis C seroprevalence and correlation between viral load and viral genotype among primary care clients in Mexico.

OBJECTIVE: To measure hepatitis C virus (HCV) sero-prevalence, prevalence, hepatitis risk characteristics frequency, and genotype correlation with viral load among clients attending health care clinics. MATERIAL AND METHODS: Venous blood samples from l12 226 consecutive consenting adults were collected from January 2006 through December 2009. HCV antibodies were detected by immunoassay. HCV RNA was detected by qRT-PCR and viral genotype was performed by PCR and LIPA test. RESULTS: The HCV seroprevalence observed was l.5 % (C.I. 95% l.3-l.7), from seropositive individuals 60.9 % reported previous blood transfusion, 28.3% declared to have relatives with cirrhosis, 25.2% had tattoos or piercings, and 6.9% referred to have used drugs. Male gender and transfusion (p<0.001) were the most frequent hepatitis risk characteristics in the HCV seropositive group. Among seropositive subjects 48.3% presented HCV RNA.The most frequent genotype detected in all geographic areas of Mexico was l (subtype lA, 33%; subtype lB, 21.4%) followed by genotype 2 (subtype 2A, 8.50%). Subjects with genotype 1 had a significant correlation with the highest viral load. CONCLUSIONS: Our results show that nearly half of seropositive individuals are chronically infected. HCV infection has been shown in this study to be an emerging health problem in Mexico.

Hepatitis C seroprevalence and correlation between viral load and viral genotype among primary care clients in Mexico

OBJECTIVE: To measure hepatitis C virus (HCV) sero-prevalence, prevalence, hepatitis risk characteristics frequency, and genotype correlation with viral load among clients attending health care clinics. MATERIAL AND METHODS: Venous blood samples from l12 226 consecutive consenting adults were collected from January 2006 through December 2009. HCV antibodies were detected by immunoassay. HCV RNA was detected by qRT-PCR and viral genotype was performed by PCR and LIPA test. RESULTS: The HCV seroprevalence observed was l.5 percent (C.I. 95 percent l.3-l.7), from seropositive individuals 60.9 percent reported previous blood transfusion, 28.3 percent declared to have relatives with cirrhosis, 25.2 percent had tattoos or piercings, and 6.9 percent referred to have used drugs. Male gender and transfusion (p<0.00l) were the most frequent hepatitis risk characteristics in the HCV seropositive group. Among seropositive subjects 48.3 percent presented HCV RNA.The most frequent genotype detected in all geographic areas of Mexico was l (subtype lA, 33 percent; subtype lB, 21.4 percent) followed by genotype 2 (subtype 2A, 8.50 percent). Subjects with genotype 1 had a significant correlation with the highest viral load. CONCLUSIONS: Our results show that nearly half of seropositive individuals are chronically infected. HCV infection has been shown in this study to be an emerging health problem in Mexico.

OBJETIVO: Medir la seroprevalencia y prevalencia del virus de hepatitis C (VHC), la frecuencia de caracteristicas de riesgo y la correlacion genotipica con la carga viral en sujetos asistentes a clinicas de medicina familiar. MATERIAL Y METODOS: muestras de sangre venosa se colectaron de l12 226 adultos, previo consentimiento informado, de enero 2006 hasta diciembre 2009, para la deteccion de anticuerpos contra VHC por ELISA. La deteccion de RNA-VHC y el genotipo viral se realizo mediante qRT-PCR. RESULTADOS: La seroprevalencia de VHC fue l.5 por ciento (C.I. 95 por ciento l.3-l.7), 60.9 por ciento reportaron transfusion sanguinea previa, 28.3 por ciento dijo tener familiares cercanos con cirrosis, 25.2 por ciento tenian tatuajes o piercing y 6.9 por ciento refirio ser usuario de drogas intravenosas. El ser hombre, el antecedente de transfusiones y el uso de drogas (p<0.00l), fueron los factores con mayor frecuencia en el grupo VHC seropositivo. La prevalencia del RNA-VHC en seropositivos fue de 48.3 por ciento. El genotipo mas frecuente en todas las areas geograficas de Mexico fue el l (subtipo lA, 33 por ciento; subtipo lB, 21.4 por ciento) seguido por el genotipo 2 (subtipo 2A, 8.50 por ciento). Se observó una correlación positiva de 51 por ciento con la carga viral más alta y el genotipo viral 1A. CONCLUSIONES: Nuestros resultados muestran que cerca de la mitad de individuos seropositivos están infectados crónicamente. Esta infección debe considerarse como un problema emergente de salud pública en México.

Sífilis materna y congénita en cuatro provincias de Bolivia / Maternal and congenital syphilis in four provinces in Bolivia

OBJETIVO: Calcular las frecuencias de sífilis materna y congénita, transmisión del agente etiológico de la madre al recién nacido, y variables asociadas con la enfermedad, en seis hospitales públicos en Bolivia. MATERIAL Y MÉTODOS: Se realizó un estudio transversal de mayo a septiembre de 2004. Se administró la prueba rápida para sífilis Determine-TP y RPR cuantitativo a mujeres postparto sin RPR previo. Se incluyeron antecedentes demográficos y de atención prenatal de embarazos previos. A los recién nacidos de madres con sífilis se les practicó Western Blot IgM p47 y ELISA IgM. Las pruebas serológicas se procesaron en el Laboratorio Nacional de Referencia (INLASA). Se realizó un análisis estadístico bivariado y multivariado para establecer asociaciones con el diagnóstico positivo a T. pallidum. RESULTADOS: La prevalencia de sífilis entre 1 594 mujeres postparto fue de 7.2 por ciento, con una proporción de transmisión de infección de madres a recién nacidos de 15.7 por ciento. La prevalencia de sífilis congénita por serología fue de 1.1 por ciento; 94 por ciento de estos neonatos no presentaron sintomatología. A pesar de una cobertura de control prenatal de 70.5 por ciento en Bolivia, aún existen mujeres que acuden directamente al parto institucional sin contar con tamizaje previo para sífilis con pruebas de rutina. El bajo nivel de instrucción formal (< 8 años) en ambos padres y no asistir a control prenatal se asociaron con sífilis congénita. CONCLUSIONES: Es importante fortalecer las estrategias de diagnóstico temprano de sífilis durante el embarazo, utilizando pruebas rápidas para contribuir a la prevención de la sífilis congénita y materna.

OBJECTIVE: Assess frequencies of maternal and congenital syphilis, mother-child transmission and variables associated with syphilis in six urban hospitals in Bolivia. MATERIAL AND METHODS: A cross-sectional study was performed between May and September 2004. We administered the Abbot Determine-TP rapid test and quantitative RPR to postpartum women without prior RPR. Sociodemographic variables and prior prenatal care visits were studied. Newborns of syphilis positive mothers were studied with Western Blot IgM p47 and ELISA IgM. Serum samples were analyzed at the Central Reference Laboratory (INLASA). Statistical analysis included bivariate and multivariate analyses to establish association with positive diagnosis of T. pallidum. RESULTS: Syphilis prevalence among 1 594 postpartum women was 7.2 percent. Mother to child transmission was 15.7 percent. Congenital syphilis prevalence by serology was 1.1 percent and 94 percent of these newborns displayed no symptoms. Despite 70.5 percent prenatal care coverage in Bolivia some women still go directly to a facility to give birth without prior routine tests for syphilis. Low education levels in both parents (< 8 years) and failure to attend prenatal care were strong predictors of congenital syphilis. CONCLUSIONS: Rapid syphilis tests constitute an important tool to strengthen early diagnosis of syphilis during pregnancy. Preventing congenital and maternal syphilis in Bolivia remains a public health priority.

Herpes simplex virus type 2 among Mexican high school adolescents: prevalence and association with community characteristics.

BACKGROUND: We undertook this study to estimate the prevalence and correlates of herpes simplex virus type 2 (HSV-2) among Mexican adolescents in high school. METHODS: This was a cross-sectional analysis using data that had been collected to evaluate a school-based HIV prevention intervention. As part of the final round of evaluation, capillary blood samples were taken from volunteers to test for antibodies to HSV-2. The effect of each school's seroprevalence on the probability of an individual being seropositive was estimated, and the results were grouped by town to evaluate the association between characteristics of the locality and student HSV-2 seroprevalence. RESULTS: Dried blood spots were collected for 80% of the 1607 participants in the survey who reported that they were sexually active. Of these samples, 21% tested positive for HSV-2 antibodies, with no significant difference in prevalence between men and women. Seroprevalence among schools ranged from 0 to 57%. The number of sex workers registered in the locality was the most important covariate of seroprevalence, with each additional female sex worker (FSW) per 1000 women between 18 and 45 years of age in the town associated with an increase of 1% in the seroprevalence of HSV-2. CONCLUSIONS: Characteristics of adolescents' micro-environments that influence their pool of potential sexual partners and the likelihood that these partners are HSV-2 positive may be more important predictors of the risk of STI infection than self-reported condom use.

[Maternal and congenital syphilis in four provinces in Bolivia]. / Sífilis materna y congénita en cuatro provincias de Bolivia.

OBJECTIVE: Assess frequencies of maternal and congenital syphilis, mother-child transmission and variables associated with syphilis in six urban hospitals in Bolivia. MATERIAL AND METHODS: A cross-sectional study was performed between May and September 2004. We administered the Abbot Determine-TP rapid test and quantitative RPR to postpartum women without prior RPR. Sociodemographic variables and prior prenatal care visits were studied. Newborns of syphilis positive mothers were studied with Western Blot IgM p47 and ELISA IgM. Serum samples were analyzed at the Central Reference Laboratory (INLASA). Statistical analysis included bivariate and multivariate analyses to establish association with positive diagnosis of T. pallidum. RESULTS: Syphilis prevalence among 1 594 postpartum women was 7.2%. Mother to child transmission was 15.7%. Congenital syphilis prevalence by serology was 1.1% and 94% of these newborns displayed no symptoms. Despite 70.5% prenatal care coverage in Bolivia some women still go directly to a facility to give birth without prior routine tests for syphilis. Low education levels in both parents (< 8 years) and failure to attend prenatal care were strong predictors of congenital syphilis. CONCLUSIONS: Rapid syphilis tests constitute an important tool to strengthen early diagnosis of syphilis during pregnancy. Preventing congenital and maternal syphilis in Bolivia remains a public health priority.

Seroepidemiología de la hepatitis A en México: sensor de inequidad social e indicador de políticas de vacunación / Seroepidemiology of hepatitis A in Mexico: a detector of social inequity and monitor of immunization policies

OBJETIVO: Estudiar la distribución y frecuencia de los anticuerpos contra el virus de la hepatitis A en una muestra probabilística en México con representatividad estatal, así como analizar los factores de riesgo y los patrones epidemiológicos. MATERIAL Y MÉTODOS: A partir de la Encuesta Nacional de Salud se estudiaron 4 907 sueros seleccionados de forma aleatoria para anticuerpos contra VHA mediante ensayo inmunoenzimático. Los sueros se recolectaron de noviembre de 1999 a junio del 2000 a nivel nacional. RESULTADOS: Se encontró seroprevalencia general de 81.3 por ciento (IC 78.6-84.2), y los resultados expandidos permiten inferir que existen 78.7 millones de mexicanos infectados. Los factores de riesgo en menores de nueve años incluyen residir en entidades sureñas (RM= 5.3), localidades rurales (RM= 3.1), provenir de familia con bajos ingresos (RM= 2.4) y habitar viviendas con acceso limitado a servicios sanitarios (agua, RM= 2.5; drenaje, RM= 2.7). CONCLUSIONES: Los patrones de transmisión heterogéneos y las diferencias en las pre-valencias de infección indican inequidad en las poblaciones estudiadas, explicables por diferencias en las condiciones sanitarias y sociales. Se discuten las ventajas de intervenciones poblacionales tales como la vacunación y el fortalecimiento de las condiciones sanitarias y socioeconómicas.

OBJECTIVE: Hepatitis A Virus (HAV) in Mexico has traditionally been considered a disease with a homogeneous pattern of transmission, high rates of infection at early ages, and infrequent complication rates. The purpose of this study was to take advantage of the 2000 NHS, a probabilistic population-based survey, in order to describe the seroepidemiology of HAV infection in Mexico. MATERIAL AND METHODS: This study is based on information obtained from the National Health Survey that was conducted in 2000. The present report is based on 4 907 randomly selected samples that were studied to determine the prevalence of HAV antibodies using immunoenzymatic assay. Sera were collected from November 1999 to June 2000. RESULTS: Seroprevalence among the general population was 81.3 percent (CI95 percent: 78.6-84.2); expanded results allow the inference that 78.7 million Mexicans have been infected by this agent. Risk factors for HAV among children younger than nine years of age are the following: residence in southern states OR=5.3, residence in rural communities OR= 3.1, low-income family OR= 2.4 and living in households with limited access to sanitary facilities (water OR= 2.5 and sewage OR= 2.7). CONCLUSIONS: Results of this study demonstrate that HAV transmission patterns are heterogeneous and that differentials in the prevalence of infection are due to sanitary and social inequity among studied populations. Finally, the advantages of adopting public health measures such as vaccination and improvement of sanitary and socioeconomic conditions are discussed.

Prevalencia de infección por VIH en la población adulta en México: una epidemia en ascenso y expansión / Prevalence of HIV infection among adult population in Mexico: an increasingly expanding epidemic

OBJETIVO: ONUSIDA ha reconocido que calcular la magnitud de la infección por VIH en los planos nacional o regional es importante desde el punto de vista de la evaluación, planeación de programas y supervisión. Al adoptar esta recomendación, el propósito de este trabajo fue cuantificar la magnitud de la infección en la población general adulta mexicana a partir de los datos consignados en la ENSA 2000, la cual permitió determinar la prevalencia de infección por VIH en la población general y los principales factores relacionados. La disponibilidad de datos de la Encuesta Seroepidemiológica proveyó además la oportunidad de conocer las tendencias en el periodo entre las dos encuestas (1987-2000). MATERIAL Y MÉTODOS: Se seleccionó de manera aleatoria a 21 271 individuos de 20 años de edad o mayores, de ambos sexos, estudiados en la ENSA 2000 para IgG anti-VIH1/2 (ELISA), confirmados por inmunoelectrotransferencia, y los principales factores relacionados con seropositividad. Las muestras se procesaron en el Instituto Nacional de Salud Pública en 2005. RESULTADOS: La prevalencia para anticuerpos anti-VIH-1 fue de 0.25 por ciento. Los principales factores vinculados con la infección fueron las edades más jóvenes, sexo masculino, vivir en el Distrito Federal, escolaridad de licenciatura o mayor y ser soltero, divorciado o separado. CONCLUSIONES: La seroprevalencia en hombres adultos muestra un incremento de 10 veces en comparación con la encuesta nacional de 1987. Si bien la epidemia continúa concentrada en hombres que tienen relaciones sexuales con hombres, existe evidencia de diseminación a la población heterosexual.

OBJECTIVE: UNAIDS has recognized that estimating HIV infection at a national or regional level is important for evaluation, program planning and advocacy. Following this recommendation, the purpose of this study was to estimate the magnitude of HIV infection prevalence among adults from the general population using information from the National Health Survey (ENSA 2000), a probabilistic, multi-stage, stratified, cluster household survey conducted by the Mexican Ministry of Health between November 1999 and June 2000. Availability of information from the Seroepidemiological Survey conducted in 1987 allowed for the estimation of trends between the two surveys (1987-2000). MATERIAL AND METHODS: A total of 21 271 males and females 20 years or older included in the ENSA 2000 were randomly selected and studied for anti-HIV 1/2 IgG (ELISA), confirmed by immunoelectrotransference (WB), and for risk factors associated with HIV infection. Samples were processed in the National Institute of Public Health in 2005. RESULTS: Prevalence for HIV infection was 0.25 percent. The main factors associated with infection were younger ages, male gender, residence in the Federal District, college education or higher, and being single or divorced. CONCLUSIONS: Seroprevalence among adults shows a ten-fold increase as compared with the results of the national seroprevalence survey of 1987. Although the epidemic continues to be concentrated among men who have sex with men, results provide evidence of dissemination towards the heterosexual population.

Seroprevalencia de la hepatitis C en adultos de México: ¿un problema de salud pública emergente? / Seroprevalence of hepatitis C among Mexican adults: an emerging public health problem?

OBJETIVO: La infección por virus de la hepatitis (VHC) evoluciona hacia la cronicidad en 60 a 85 por ciento de los sujetos que la sufren y ocasiona cirrosis hepática y cáncer primario de hígado. El objetivo de este estudio fue notificar la seroprevalencia de infección por VHC en una muestra probabilística de la población en el plano nacional. MATERIAL Y MÉTODOS: Se estudiaron 21 271 sueros seleccionados de manera aleatoria de la Encuesta Nacional de Salud 2000, para anti-VHC y RNA de VHC. El estudio se realizó en el Instituto Nacional de Salud Pública en el año 2005. RESULTADOS: La seroprevalencia de los anticuerpos VHC fue de 1.4 por ciento (IC95 por ciento 1.1-1.6) y 35.7 por ciento tenía infección activa. Los factores de riesgo de infección de VHC detectados son el antecedente de consumo de heroína (RM=9.8, IC: 2.1-41.4), estar separado (RM=2.6, IC: 1.1-5.9) o ser viudo (RM=2.2, IC: 1.1-4.3) y residir en la región norte del país (RM=1.9, IC: 1.1-3.2). CONCLUSIONES: Los datos indican que la hepatitis C es un problema de salud pública emergente en México. Los factores de riesgo de infección indican que la transmisión más frecuente de los infectados ocurre en receptores de sangre y hemoderivados (antes de 1996) y, de manera secundaria, por drogadicción intravenosa y de tipo sexual.

OBJECTIVE: Hepatitis C Virus (HCV) infection is becoming a chronic disease in 60-85 percent 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 percent (IC95 percent 1.1 percent-1.6 percent), of which 35.7 percent 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.

Prevalencia en México de la infección y el estado de portador de la hepatitis B en adultos / Prevalence of hepatitis B infection and carrier status among adults in Mexico

OBJETIVO: Calcular la prevalencia de infección y estado de portador crónico de la hepatitis B en México. Analizar la frecuencia y distribución de estos marcadores en relación con variables poblacionales y geográficas e identificar los factores de riesgo. MATERIAL Y MÉTODOS: Se estudiaron 12 014 sueros seleccionados de forma aleatoria para anti-VHBc y Ag VHBs de la Encuesta Nacional de Salud 2000. Los sueros se recolectaron entre noviembre de 1999 y junio de 2000 a nivel nacional. RESULTADOS: Las seroprevalencias de anti-HBc y Ag VHBs fueron de 3.3 por ciento (IC95 por ciento 2.8-3.9) y 0.21 por ciento (0.11-0.37). Las RM ajustadas por edad para anti-VHBc son: 15.3 para sujetos de 50 a 59 años en comparación con adultos menores de 29 años; 2.6 para los habitantes del sur del país respecto de los del centro; 4.6 en peones en comparación con patrones; 2.1 en mujeres con antecedente de hijos nacidos muertos; 1.7 en adultos con inicio de relaciones sexuales antes de los 25 años. CONCLUSIONES: El patrón epidemiológico de la hepatitis B en México es bajo según las cifras mundiales. Sin embargo, es preocupante que 1.7 millones de mexicanos han sufrido la infección por este virus y 107 000 padecen del estado de portador crónico.

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-HBc and HBsAg were studied. The sera were collected between November 1999 and June 2000 on a national level. RESULTS: Seroprevalence for anti-HBc and HBsAg were 3.3 percent (CI 95 percent: 2.8-3.9) and 0.21 percent (0.11-0.37), respectively. Odds ratios adjusted by age for anti-HBc 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.

Prevalencia de anticuerpos antitreponémicos y características sociodemográficas de la población mexicana adulta en el año 2000 / Anti-Treponema pallidum seroprevalence and sociodemographic characteristics in Mexican adult population, 2000

OBJETIVO: Determinar la frecuencia de anticuerpos antitreponémicos en mexicanos adultos de ambos sexos y las características de la población relacionadas con la infección sifilítica. MATERIAL Y MÉTODOS: Se analizaron para anti-Treponema pallidum 12 010 sueros seleccionados de forma aleatoria de la Encuesta Nacional de Salud 2000, con aplicación de un algoritmo conformado por técnicas serológicas treponémicas y no treponémicas, de tamizaje y confirmatorias, y se realizó un análisis estadístico para identificar los factores vinculados con la seropositividad. RESULTADOS: La seroprevalencia de anticuerpos antitreponémicos fue de 3.1 por ciento (IC95 por ciento 2.5-3.7). Las características relacionadas de modo significativo con la exposición a la infección fueron la mayor edad (RM 3.3), sexo masculino (RM 1.3), residencia en la región geográfica sur del país (RM 1.7), vivir en unión libre (RM 2.7) o ser viudo (RM 1.8), inicio de relaciones sexuales a edad temprana (RM 6.3) y, en las mujeres en particular, se identificó el antecedente de mortinatos (RM 1.8) y el informe de falta de uso del condón como método anticonceptivo (RM 14.1). CONCLUSIONES: Los hallazgos del estudio demuestran que la magnitud del antecedente de la infección por el treponema en la población mexicana adulta es considerablemente mayor respecto del que permite calcular la notificación oficial de casos de la enfermedad. Como sucede con otras infecciones de transmisión sexual, aspectos sociodemográficos, de género y las prácticas sexuales no seguras incrementan la transmisión del agente etiológico. En México existe la necesidad de reforzar la vigilancia de la infección sifilítica a través de un diagnóstico oportuno y eficaz de los casos, más su adecuado tratamiento, para coadyuvar al control del padecimiento.

OBJECTIVE: To measure for the first time in a population based study the prevalence of antibodies against Treponema pallidum among the Mexican adult population and correlates of infection. MATERIALS AND METHODS: This study was derived from the Mexican National Health Survey carried out in 2000. Anti-T. pallidum seroprevalence was determined according to an algorithm based on a set of treponemic and non-treponemic serological tests for 12 010 sera randomly selected from participating women and men 20 years and older. A statistical analysis was applied to identify seropositivity associated variables. RESULTS: Anti-T. pallidum seroprevalence was 3.1 percent (CI95 percent 2.5-3.7). Population characteristics significantly related to infection exposure were: older age (OR 3.3), being male (OR 1.3), inhabiting the southern region of the country (OR 1.7), having a regular partner not being married (OR 2.7) or being a widow (OR 1.8), early age at sexual debut (OR 6.3), and for women, having had still births (OR 1.8) and not using the condom as a contraceptive measure (OR 14.1). CONCLUSIONS: Results obtained show that exposure to T. pallidum infection among Mexican adults is at present a true public health problem, unknown until now. Factors associated with seropositivity were those expected considering the epidemiology of sexually transmitted infections. Health authorities must reinforce the surveillance and diagnosis of syphilis in Mexico to help prevent and control the transmission of the etiologic agent.

Diseño y metodología de la Encuesta Nacional de Salud 2000 / National Health Survey 2000: design and methodology

OBJETIVO: Como parte del Sistema de Encuestas Nacionales de Salud, durante los últimos meses de 1999 y los primeros tres del año 2000 se realizó la Encuesta Nacional de Salud de México (ENSA 2000). Se estudió la accesibilidad, calidad, utilización y cobertura de los Servicios de Salud; de modo adicional se actualizaron los marcadores serológicos de enfermedades infecciosas prevenibles por vacunación, infecciones de transmisión sexual y hepatitis. MATERIAL Y MÉTODOS: Para la ENSA 2000 se seleccionaron tres grupos etarios y a los utilizadores de los servicios de salud. Se captó la información mediante entrevista directa y se tomaron muestras biológicas para análisis clínicos y medidas de parámetros biológicos y somatométricos. El diseño muestral de la ENSA 2000 fue probabilístico, polietápico, estratificado y de conglomerados. El tamaño de la muestra fue de 1 470 viviendas por estado, para un total de 47 040 viviendas a nivel nacional; los factores de expansión se modificaron por la falta de respuesta y la posestratificación. El personal operativo se capacitó y estandarizó para mantener una alta respuesta, en especial para las muestras de sangre. RESULTADOS: En total se obtuvieron 83 157 muestras de sangre de las 94 000 esperadas (respuesta de 88 por ciento) que se mantuvieron refrigeradas en tanto se ubicaron en el laboratorio del Instituto Nacional de Salud Pública donde se prepararon cuatro alícuotas y se congelaron a -150° C hasta el análisis.

OBJECTIVE: The 2000 Mexican National Health Survey (NHS) was created as part of the System for National Health Surveys conducted during the last months of 1999 and the first three of 2000. The 2000 NHS is a probabilistic survey of households from which users of health services were selected according to three age groups. Information was gathered through direct interviews with appropriate informants. Biological samples were taken for clinical tests as well as for measuring biological and somatometric parameters. MATERIAL AND METHODS: The sample design of the 2000 NHS was stratified and clustered. Sample size was 1 470 households per state for a total of 47 040 households nationwide (there are 32 states in México). Sample weights were calculated and modified according to the non-response and post-stratified to calibrate for population distribution. Interviewers were trained in order to maintain a high response rate, especially for biological samples. RESULTS: A total of 83 157 blood samples were collected from the 94 000 expected (88 percent response rate). All samples were refrigerated immediately after collection and divided in four vials for storage at the National Institute for Public Health's laboratory. Samples were frozen at -150° Celsius until further analysis.

[Maternal and congenital syphilis in two Mexican hospitals: evaluation of a rapid diagnostic test]. / Sífilis matema y congénita en dos hospitales mexicanos: evaluación de una prueba diagnóstica rápida.

OBJECTIVE: To estimate the prevalence of maternal and neonatal syphilis, to assess the usefulness of a rapid treponemic diagnostic test, and to evaluate the frequency of screening for syphilis during prenatal care in Mexican women. MATERIAL AND METHODS: This was a cross-sectional study that included 1,322 women interviewed in two hospitals (Hospital General in Cuernavaca, Morelos, and Hospital de la Mujer in Mexico City). Women answered a questionnaire on reproductive background, exposure to sexually transmitted infections and prenatal care. In order to diagnose syphilis, a rapid Determine TP test and a latex-VDRL test were used among all participating women. Positive cases were confirmed using FTA-ABS test. RESULTS: Prevalence of serologically active syphilis was 0.3% (4/1322). Using as comparison standard a combination of VDRL and FTA-ABS tests, the Determine TP test had a sensitivity and specificity of 100%. Two newborns with positive FTA-ABS IgM, one negative with FTA-ABS IgM and one first-trimester abortion were found from seropositive women. Prenatal serum screening for syphilis was conducted in only 6.9% of women included in the study. CONCLUSIONS: Although the prevalence of maternal syphilis is relatively low, results show that if the situation found in the hospitals studied is shared by other hospitals in Mexico, a systematic screening for maternal syphilis would help to diagnose more cases of this infection than the number reported in official figures. Screening of syphilis in pregnant women using rapid tests may help in the prevention of congenital syphilis.