Factors related to road system organisation and its association with mortality due to motor vehicle-pedestrian collisions in Guadalajara Metropolitan Area.

INTRODUCTION: Traffic events are one of the five leading causes of mortality in Mexico. Pedestrians are one of the main road users involved in such incidents and have the highest mortality rate, which is regularly analysed in relation to vehicles and pedestrians, but not the built environment. The purpose of this study was to analyse the elements of the road system organisation that influences the mortality rate of pedestrians hit by motor vehicles in the Guadalajara Metropolitan Area. METHOD: We designed a case and control study in which the cases were sites where a pedestrian died during 2012. The controls were sites close to where the death occurred, as well as those with road infrastructure characteristics similar to those where the events took place. We obtained the pedestrian data from the death certificates and assessed some of the environmental elements of the road sites. A logistic regression analysis was used to estimate OR; 95% CI. RESULTS: Road system factors related with pedestrian mortality in close locations were: the presence of bus stops on intersections in one street or both, and road system features, such as the presence of traffic islands, vehicle flow and pedestrian flow. CONCLUSIONS: According to the urban network theory and multiple theory, the final elements resulted as risk factors due to a fault in connectivity between the nodes. A temporal analysis of urban features will help urban planners make decisions regarding the safety of pedestrians and other road users.

Prognostic Factors for Permanent Work Disability in Patients With Rheumatoid Arthritis Who Received Combination Therapy of Conventional Synthetic Disease-Modifying Antirheumatic Drugs: A Retrospective Cohort Study.

BACKGROUND: There is limited information about the factors related with the development of long-term permanent work disability (PWD) in rheumatoid arthritis (RA) treated with a combination of conventional synthetic disease-modifying antirheumatic drugs (cs-DMARDs). OBJECTIVE: The aim of this study was to evaluate incidence and factors associated with the development of PWD in RA treated with combination therapy using conventional synthetic cs-DMARDs. METHODS: We assessed in multivariate models the effect of clinical and demographic factors in the development of PWD in a long-term retrospective cohort of 180 workers with RA who were treated with a combination of cs-DMARDs. RESULTS: Incidence rates of PWD were 2.2% at 1 year, 7.7% at 5 years, 24.9% at 10 years, 34.9% at 15 years, and 45% at 20 years. In the adjusted Cox regression analysis, factors associated with PWD development were the first failure with combination of cs-DMARDs (hazard ratio [HR], 2.4; 95% confidence interval [CI], 1.05-5.46; P = 0.03), poor functioning at time of cohort onset (HR, 2.2; 95% CI, 1.05-4.70; P = 0.03), and requirement for joint replacement (HR, 3.3; 95% CI, 1.28-8.79; P = 0.01). CONCLUSIONS: Around 25% of workers with combination therapy with cs-DMARDs developed PWD in 10 years following the diagnosis of RA. Some factors increase the risk of disability. Permanent work disability generates a relevant society burden and increases health care costs. Therefore, indicators predicting failure of combination therapies with cs-DMARDs might provide clinicians of useful tools for modifying treatments avoiding the disease progression.

At 10 years of chlormadinone use in Latin America: a review.

Chlormadinone acetate (CMA) is a progesterone derivative (17α-acetoxy-6-chloro-4,6-pregnadiene-3,20-dione), first synthesized in 1961. It was used as progestin-based hormone replacement therapy; since 1999 it was first used for oral contraception combined with ethinyl estradiol (EE). CMA exerts a potent progestagenic effect, about one third higher than that observed with endogenous progesterone. CMA is also an anti-estrogen, showing no androgenic effects (at birth control dose). Unlike progesterone, it has a mild glucosteroidal effect with no anti-mineralocorticoid effect at all. These biological actions have allowed CMA to have a role for therapeutic use in dysmenorrhea, hyperandrogenism, and as a contraceptive agent. In addition, CMA has exhibited beneficial neuroendocrine effects on women's mood. CMA-EE combination has shown excellent contraceptive efficacy, high tolerability, and compliance due to its risk-benefit profile, having additional benefits on skin and hair, such as reduction of seborrhea and acne. Metabolic tolerance of CMA has been demonstrated in several clinical studies. Currently, CMA is formulated to be taken as oral caplets in a 21 caplets package containing 0.03 mg/EE and 2 mg CMA per pill with/without seven placebo additional pills. Another presentation has 24 caplets containing 0.02 mg/EE and 2 mg CMA plus four placebo pills.

[Drowning risk factors into cistern for children 1 to 4 years old]. / Factores de riesgo en la asfixia por inmersión en aljibe en niños de uno a cuartro años.

OBJECTIVE: Analyze risk factors for drowning deaths in tanks, from home, for children between one and four years, residents of the metropolitan area of Guadalajara and the neighboring municipalities in the period 2009-2011. MATERIAL AND METHODS: Case-control study, 28 children (cases) between one and four years old, whose cause of death was drowning in the well of your home, from 2009-2011, in the metropolitan zone of Guadalajara and the neighboring municipalities, and 113 children (controls) of the same age, if neighbors whose homes had cistern. Deaths were classified with W73 and W74 codes from International Statistical Classification of Diseases and Related Health Problems (ICD 10th). A questionnaire for variables: age and sex of child; age, marital status, occupation and education of the household head and mother; housing conditions; and location, type and segurity cistern lid, and forms the removal of water therefrom. RESULTS: The rate of drowning deaths, age-specific, was 2.7 deaths per 100,000 children between one and four years of age during the study period. The ages of two and three years had the greatest risk of drowning. Sex had a predominance of children, two girls one over. The heads of families and mothers of cases were younger (< 29 years), with maximum secondary schooling. Most of the houses had not finished complete. The characteristics of de well, as metal lid,foil or plastic, the lack of assurance of the tank and the location of the cover, crossing sites, showed association with death by drowning. The absence of a pump to draw water in cases the proved statistically more significant with p = 0.002. CONCLUSION: The results of our study show the presence of drowning deaths in children between one and four years associated with the type of cistern cover, the locking mechanism, a way of extracting the water and the location of the well, and thus the need to implement preventive measures in education and engineering, to reduce or avoid the risk of death by suffocation in the study group.

Factors influencing sick leave episodes in Mexican workers with rheumatoid arthritis and its impact on working days lost.

To evaluate impact of working days lost and factors for developing sick leave episodes in Mexicans workers with rheumatoid arthritis (RA). A prospective cohort of 123 patients with RA was followed for 1 year. Factors evaluated for sick leave episodes included: demographics, job characteristics, comorbidity, depressive symptoms, and clinical/therapeutic variables. Rates of sick leave episodes, working days lost, and permanent work disability (PWD) were identified. Statistical analysis included Cox regression models estimating hazard risks (HR) and their 95 % confidence intervals (95% CI). Cumulative time of follow-up for the cohort was 43,380 days, 24 % of workers had at least one episode of sick leave, with a mean of working days lost per patient-year of 18.36; 4.1 % developed PWD. Development of sick leave in the Kaplan-Meier analysis was associated with: age ≥40 years (p = 0.04), having a couple (p = 0.04), performing manual work (p = 0.03), suffering depressive symptoms (p = 0.04), limitations in functioning (p = 0.01), and poor global functional status ≥ III (p = 0.01). Cox regression models identified HAQ-Di ≥ 0.6 as the stronger predictor for sick leave (HR = 4.04, 95 % CI 1.41-11.58, p = 0.009) followed by age (HR = 1.05, 95 % CI 1.01-1.11, p = 0.04), ≥4 risk factors had a HR to 9.4 (95 % CI: 2.1-42.7) for sick leave. In this prospective cohort of Mexican workers with RA, we identified several factors associated with sick leave episodes and working days lost that should be potentially addressed by a multidisciplinary approach, being required to revaluate these strategies with the aim of increasing the work permanence of these patients.

Association of the STAT4 Gene rs7574865 Polymorphism with IFN-γ Levels in Patients with Systemic Lupus Erythematosus.

STAT4 plays an important role in disease activity in SLE patients. STAT4 particles have the capacity to activate the transcription of genes associated with the production of TH1 and Th17 lymphocytes, with a greater predominance on the production of IFN-γ and IL-17A. The presence of variants in STAT4 genes has a major impact on the generation of autoimmunity. However, there are few studies evaluating the impact of these variants on the production of proinflammatory cytokines such as IFN-γ and IL-17A. Methods-A case-control study was carried out with 206 Mexican mestizo patients residing in Western Mexico with a diagnosis of SLE and a group of 80 patients without autoimmune diseases was captured to determine the cut-off point for high IFN-γ levels. In this study, SLE patients with high IFN-γ levels were considered as cases (cut-off > 15.6 pg/mL), and SLE patients with normal IFN-γ levels were considered as controls (cut-off ≤ 15.6 pg/mL). Disease activity was identified from the systemic lupus erythematosus disease activity index (SLEDAI). For the determination of levels of cytokines IFN-γ, IL-12, and IL17A, commercial ELISA kits were used. Genotyping of STAT4 rs7574865 (G > T) was performed by quantitative polymerase chain reaction (qPCR) using TaqMan probes. Results-The patients with SLE had a median age of 45 years with a range of disease duration from 4 years to 18 years; 45.6% were identified as having disease activity. In this sample, we identified a high IFN-γ prevalence of 35.4%. The levels of IFN-γ were higher in the patients with genotype TT than GG. We found that TT genotype conferred a higher risk of high IFN-γ when compared to the GG and GT genotypes. Conclusions-In this study, we identified that the polymorphic genotype TT of the STAT4 gene rs7574865 polymorphism is associated with increased levels of IFN-γ. However, its strength of association was weak, so complementary studies are needed to evaluate its impact on SLE patients.

-383 A/C tumor necrosis factor receptor 1 polymorphism and ankylosing spondylitis in Mexicans: a preliminary study.

The objective of this study was to evaluate the differences in allele and genotype frequencies of -383 tumor necrosis factor receptor 1 (TNFR1) polymorphism between ankylosing spondylitis (AS) and controls. Mexican Mestizos with AS were matched by gender, age, and ethnicity with healthy controls and compared in allele and genotype frequencies of the -383 TNFR1 polymorphism. Polymorphisms were genotyped using PCR-RFLP. The AA genotype occurred at a higher frequency in the AS group (92%) compared with controls (79%, P = 0.03). A allele was increased in AS (96% vs. 88%, P = 0.015) and was associated with genetic susceptibility for AS (odds ratio = 3.48, 95% CI = 1.23-10.61). This preliminary study is the first assessing the association of the -383 A/C TNFR1 polymorphism with AS, although it has the limitation of a small sample size. These data are of interest for the genetic epidemiology of AS in the Mexican population, requiring further investigation in other countries.

Mortality trend by dengue in Mexico 1980 to 2009.

OBJECTIVE: To describe the mortality of dengue in Mexico during 1980 to 2009. MATERIAL AND METHODS: Dengue mortality data for Mexico were obtained from Instituto Nacional de Estadistica, Geografía e Informática. We used standardized and non-standardized dengue mortality rates per 1,000,000 people and determined the mortality trend. The groups were based on International Classification of Diseases coding criteria (ICD-9 E061 and ICD-10 A91X). The results were stratified by age groups and the frequencies of dengue deaths were compared using relative risk (RR) with its 95% confidence interval. RESULTS: During 1980 to 2009 in Mexico, 549 deaths due to dengue were reported. We found an important variation in the mortality rates during the years studied. We were able to identify three periods: 1980 to 1992, 1994 to 2000, and 2001 to 2009. The mortality rates found are from 0.88/1,000,000 through 0.00/1,000,000. The average mortality rates by decade: 1980 to 1989: 0.53/1,000,000; 1990 to 1999: 0.06/1,000,000; 2000 to 2009: 0.12/1,000,000. In the analysis of mortality by community size during 2000 to 2009, we observed in the small communities with < 2,499 people, the risk is 1.25 times higher than in those with more than 20,000 people. CONCLUSIONS: We found, in general, a sustained decline in the number of deaths by dengue over the last 30 years in Mexico. However, a slow increase was observed since 1994, which may be related to the circulation of DENV2 and DENV3, among other factors. We need to strengthen prevention programs in smaller communities (< 2,499) where we found a higher risk of mortality due to dengue.

[Drowning mortality trends in children younger than 5 years old in Mexico, 1979-2008]. / Tendencia de la mortalidad de la asfixia por inmersión en niños menores de cinco años en México de 1979 a 2008.

OBJECTIVE: To describe mortality trends from drowning in children younger than 5 years old. MATERIALS AND METHODS: Mortality records of children younger than 5 years old were obtained from the National Health Information (SINAIS) system of Mexico from 1979 to 2008. Cause of death by asphyxia was established according to the International Classification of Diseases (ICD 9th and 10th). We analyzed age, sex, federal state, year and place where the event occurred. RESULTS: Fatal drowning diminished from 7.64 in 1979 to 3.59 deaths per 100,000 in 2008. This trend was observed throughout the assessment period and in all federal states. Children younger than 2 years showed the highest rate of death. Mortality was higher in males than females (1.7:1). A great proportion of events happen at home. CONCLUSION: Drowning mortality among children less than 5 years old in Mexico shows a downward trend in all states.

[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.

[Trends in mortality by burns in Mexico, 1979-2009]. / Tendencia de mortalidad por quemaduras en México, 1979-2009.

OBJECTIVE: To describe the trends in burn-related mortality rates in Mexico from 1979-2009. METHODS: Burn-related mortality standardized rates and trends were estimated from official mortality data in Mexico. Variables included were:age, sex, federal state and year of death. RESULTS: From 1979-2009, 33,333 burn-related deaths were registered. During this period, the burn-mortality rate decreased, stating from a rate of 2.32/100,000 in 1979 and dropping to 0.72/100,000 in 2007, but in 2008 and 2009 the mortality rates occurred in the states of Baja California, Chihuahua, Baja California Sur,Sonora and Durango, all of these states in the northwest of Mexico. Men were twice as likely as women to die from burns. CONCLUSIONS: Mortality caused by burns in Mexico presents a descendent tendency in most of the states of the Country, with the exception of the northwest region, which may be related to the lack of specialized units in the treatment of burn distance between the population centers and the specialized attention units.

Myostatin Levels and the Risk of Myopenia and Rheumatoid Cachexia in Women with Rheumatoid Arthritis.

Background: Myostatin is a regulator of muscle size. To date, there have been no published studies focusing on the relation between myostin levels and myopenia in rheumatoid arthritis (RA). Objective: Evaluate the value of serum myostatin as a biomarker of cachexia and low skeletal muscle mass (LSMM) in RA patients, along with whether high serum myostatin is associated to these conditions after adjusting for potential confounders. Methods: This cross-sectional study included 161 female RA patients and 72 female controls. In the RA group, we assessed several potential risk factors for LSMM and rheumatoid cachexia. Dual-energy X-ray absorptiometry was used to quantify the skeletal muscle mass index (SMMI) (considering LSMM ≤ 5.5 kg/m2) and the presence of rheumatoid cachexia (a fat-free mass index ≤ 10 percentile and fat mass index ≥ 25 percentile of the reference population). Serum myostatin concentrations were determined by ELISA. To identify a cut-off for high serum myostatin levels, we performed ROC curve analysis. Multivariable logistic regression analysis was used to identify the risk factors for LSMM and rheumatoid cachexia. The risk was expressed as odds ratios (ORs) and their 95% confidence intervals (95% CIs). Results: Compared to the controls, the RA group had a higher proportion of LSMM and exhibited high serum myostatin levels (p < 0.001). ROC curve analysis showed that a myostatin level ≥ 17 ng/mL was the most efficient cut-off for identifying rheumatoid cachexia (sensitivity: 53%, specificity: 71%) and LSMM (sensitivity: 43%, specificity: 77%). In the multivariable logistic regression, RA with high myostatin levels (≥17 ng/mL) was found to increase the risk of cachexia (OR = 2.79, 95% CI: 1.24-6.29; p = 0.01) and LSMM (OR = 3.04, 95% CI: 1.17-7.89; p = 0.02). Conclusions: High serum myostatin levels increase the risk of LSMM and rheumatoid cachexia. We propose that high myostatin levels are useful biomarkers for the identification of patients in risk of rheumatoid cachexia and myopenia.

Economic impact of fatal and non-fatal road traffic injuries in Guadalajara Metropolitan Area and Jalisco, Mexico.

OBJECTIVE: To estimate the economic cost of fatal and non-fatal road traffic injuries (RTI) in Guadalajara metropolitan area (GMA) and Jalisco, Mexico during 2007. MATERIALS AND METHODS: Using an incidence-based cost of illness analysis from a household perspective employing a bottom-up approach all direct medical and non-medical costs, and indirect costs were estimated for a sample of RTI people who sought care during 1 month in four different medical facilities. Individuals were surveyed just before discharge from emergency rooms (ER) and hospitalisation services. Hospitalised individuals were followed up at 8 weeks after discharge. Productivity loss was estimated with the human capital approach. Using estimated costs and administrative records of mortality and morbidity, the economic costs were dimensioned for GMA and for Jalisco. A multivariate and probabilistic sensitivity analysis was conducted to evaluate variations resulting from assumptions used. RESULTS: 297 injured were included in the study, 20% were hospitalised and 237 only received care at ER. A total cost of US$21190 was estimated in all injured receiving care at ER and $83309 for those hospitalised. Direct cost represents more than 30% of reported income in 8% of the ER users and 80% of hospitalised. Total economic cost was US$329,061,813 for GMA (discount rate of 3%), nearly 51% of the state total (US$650,908,924 or 1.3% of State GNP). CONCLUSIONS: This estimation shows the high cost (both, direct and indirect) RTI impose in households affecting their economy and leading families to lose wealth assets, get in debt or impoverished.

[Safe blood in the absence of viral infections due to HBV, HCV and HIV in serological window period in donors]. / Sangre segura en ausencia de infecciones virales por VHB, VHC y VIH en período de ventana serológica de donadores.

OBJECTIVE: To determine the prevalence of viral infections (HBV, HCV and HIV) in serological window period in blood donors screened with nucleic acid testing (NAT). MATERIALS AND METHODS: We assessed all blood donors from July 2008 to June 2009 at the Central Blood Bank of the Mexican Institute of Social Security. Medical history was made and provided an information brochure and self-exclusion questionnaire. All blood donors were tested with serological tests (Ag-HBVs, Anti-HCV and Anti-HIV) and molecular testing with NAT for HBV, HCV and HIV. The window period was defined with the positive NAT and negative serological test. RESULTS: During one year, we evaluated 47 847 blood donors. None subject was identified with viral infection (HBV, HCV and HIV) in serological window period. Positive serological testing were found for HBV in 78 (0.2%), 318 (0.7%) for HCV and 155 (0.3%) for HIV. Positive NAT was demonstrated only in donors with positive serology: 26 of 78 with HBV, 56 of 318 with HCV and 16 of 155 with HIV. CONCLUSION: This is the first study in México showed no viral infections (HBV, HCV and HIV) during serological window period in blood donors; The medical history and the self-exclusion questionnaire help to improve blood transfusion safety.

[Nosocomial transmission of hepatitis C associated with anesthesia procedures: a case-control study]. / Transmisión nosocomial de la hepatitis C asociada a procedimientos anestésicos: un estudio de casos y controles.

OBJECTIVE: Nosocomial transmission of hepatitis C virus (HCV) infection had been related with anesthesia procedures. The study aim was to measure the association between anesthesia procedures in cases with previous surgery and HCV infection. MATERIAL AND METHODS: In a case-control study were included subjects that attended to the Central Blood Bank of the West Medical National Center, Mexican Institute of the Social Security in Guadalajara, Jalisco between july 2005 and september 2007. Cases were patients with positive hepatitis C antibody (anti-HCV) confirmed by recombinant immunoblot assay (RIBA) and/or nucleic acid test (HCV RNA); the control group was blood donors with negative antibody. An exhaustive questionnaire about risk factors for hepatitis C, was applied. The risk of HCV infection was determined with the Odds Ratio (OR) and multivariate analysis was made by logistic regression. RESULTS: We included 362 subjects, 211 cases and 151 controls; in 70 (33.2%) cases were found significant association between the anesthesia procedures and HCV infection in patients with previous surgery (OR adjusted 2.44, CI 95% 1.44 - 4.11) CONCLUSION: This is the first study in México that demonstrate association between history of anesthesia procedures and HCV infection in cases with previous surgery.

Functional disability is related to serum chemerin levels in rheumatoid arthritis.

Adipokines, especially chemerin, can interact with cytokines and other molecules in inflammation. To date, there is insufficient information regarding a possible correlation between functional disability and chemerin and other pro-inflammatory molecules in rheumatoid arthritis (RA). To identify the association of functional disability with serum chemerin and other pro-inflammatory molecules, including other adipokines, cytokines and E-selectin, in patients with RA. Cross-sectional study. Assessment: disease activity (DAS28-ESR) and functional disability (HAQ-DI). We compared the adipokines (chemerin, leptin, adiponectin, resistin, and visfatin), cytokines (TNF-α, IL-6, IL-1ß, and IL-18) and E-selectin levels between RA with functional disability and RA non-disabled patients. Of 82 patients with RA, 43 (52%) had functional disability. The RA with functional disability group had higher chemerin (140 vs. 112 ng/mL, p = 0.007) than the non-disabled RA group. Chemerin correlated with the HAQ-DI (rho = 0.27, p = 0.02) and DAS28-ESR (rho = 0.21, p = 0.05). Severe activity correlated with IL-6 (rho = 0.33, p = 0.003) and E-selectin (rho = 0.23, p = 0.03) but not with disability. No other pro-inflammatory molecules correlated with HAQ-DI. High chemerin levels were associated with functional disability in RA, whereas no other molecules correlated with loss of function. These results encourage further studies assessing new roles of chemerin as a marker of impairment in RA.

High antibody level: an accurate serologic marker of viremia in asymptomatic people with hepatitis C infection.

BACKGROUND: The screening and diagnosis of hepatitis C virus (HCV) infection is initiated by testing for antibody to HCV (anti-HCV). A positive anti-HCV test in blood donors represents ongoing infection in only a variable proportion of individuals. Because a high anti-HCV level has been associated with viremia, a study was conducted to determine whether a high antibody level is an accurate serologic marker for viremia in asymptomatic anti-HCV-positive persons. STUDY DESIGN AND METHODS: In a diagnostic test study, we included 856 anti-HCV-positive blood donors in a blood bank at Guadalajara, Jalisco, Mexico, between 2002 and 2007. A third-generation amplified chemiluminescence assay (ChLIA HCV) was used to detect anti-HCV. A positive result of the qualitative nucleic acid test (HCV RNA) was considered the gold standard for viremia. RESULTS: By receiver operating characteristic analysis, the signal-to-cutoff (S/CO) ratio of 20 or more was chosen as optimal to identify viremia and so was defined as high anti-HCV level. There was a significant difference in the proportion of viremia between subjects with high antibody level and those with lower levels (93.7% vs. 1.8%, respectively; p < 0.001). A high antibody level showed a sensitivity for viremia of 96.6% (95% confidence interval [CI], 93.8%-98.1%), a specificity of 96.6% (95% CI, 94.8%-97.8%), and a likelihood ratio of 28.6 (95% CI, 18.4%-44.6%). CONCLUSION: A high antibody level (S/CO ratio >/=20 by ChLIA HCV) clearly divides the viremic from the nonviremic blood donors and functions as an accurate serologic marker to guide the use of routine HCV RNA testing to confirm hepatitis C infection.

Risk factors associated with horizontal transmission of hepatitis B viral infection from parents to children in Mexico.

INTRODUCTION: Hepatitis B virus (HBV) infection in children is a health problem worldwide. In Mexico, a high prevalence rate of HBV infection and occult HBV infection have been reported in high-risk adults and children. However, studies regarding HBV infection transmitted from HBV-infected parents to children are limited. This study aimed to determine the risk factors associated with HBV transmission of HBV from parents to children in Mexico. METHODOLOGY: A retrospective case-control study was carried out in 24 pediatric patients with clinical HBV infection and 48 healthy controls. Bivariate and forward conditional logistic regression analysis was used to compare demographic variables, the status of HBV vaccination, and risk factors for HBV infection transmission among children and their parents. RESULTS: No newborns were diagnosed with HBV infection, and no significant differences were found in age (p = 0.209) or gender (p = 0.612) compared to the control group. The independent risk factor associated with HBV transmission was the presence of a parent with a history of promiscuity (OR = 30.95, 95%CI = 3.382-283.326; p = 0.002), whereas having completed the HBV vaccination schedule for their age was a protective factor against HBV infection in the children (OR = 0.245, 95%CI = 0.079-0.764; p = 0.015). CONCLUSIONS: HBV infection in Mexican children is associated with close interpersonal contact with a parent engaged in high-risk sexual practices suggesting that the horizontal route could be the primary mode of infection. Child and adult vaccination campaigns should be reinforced to avoid HBV infection in Mexico.

Very low hepatitis C antibody levels predict false-positive results and avoid supplemental testing.

BACKGROUND: False-positive results for hepatitis C virus antibody (anti-HCV) occur with unacceptable frequency in low-prevalence populations. The purpose of the study was to determine whether signal-to-cutoff (S/CO) ratios of anti-HCV assay-reactive samples could be used to discriminate false-positive from true-positive anti-HCV results and avoid the need for supplemental testing. STUDY DESIGN AND METHODS: Using receiver-operating characteristic curve, the cutoff point that identifies the major proportion (>/=95%) of false-positive results, with a minor proportion (<5%) of true-positive anti-HCV results, was determined. An anti-HCV assay (VITROS, Ortho Clinical Diagnostics) was used to detect the antibodies. The third-generation recombinant immunoblot assay and HCV RNA tests were performed on all included donors. Third-generation RIBA is the gold standard for identifying false-positive antibody results. RESULTS: A total of 649 anti-HCV-positive blood donors were identified. A S/CO ratio of less than 4.5, defining very low levels in this value, was the optimal cutoff point to identify false-positive results; 315 of 322 samples with very low levels were false-positive anti-HCV results (97.8%; 95% confidence interval [CI], 95.8%-99.0%) and 7 were true-positive (2.2%; 95% CI, 1.0%-4.3%). Viremia was detected in none of them. A direct relationship was observed between positive supplemental testing and increased antibody levels in the other 327 samples. CONCLUSION: The high prediction rate of false-positive anti-HCV results using very low levels by the Ortho VITROS anti-HCV assay safely avoids the need for supplemental testing.

Genetic polymorphisms of the renin-angiotensin system in preterm delivery and premature rupture of membranes.

INTRODUCTION: Premature rupture of membranes (PRM) is a late pregnancy complication commonly associated with preterm delivery (PD). Although several markers related to the renin-angiotensin system (RAS) have been evaluated in certain pregnancy complications, only the angiotensin-converting enzyme (ACE) I/D variant has been studied in PD-PRM. The aim of this survey was to investigate the association of the polymorphisms (angiotensin II type 1 [AT1] receptor T174M and M235T, renin G2805A, ACE I/D and AT1-receptor A1166C) of the genes of RAS in women with PD-PRM. DESIGN: Deoxyribonucleic acid samples from 89 Mexican Mestizo women with PD and PRM and 224-288 controls were studied. Polymorphisms were analysed by polymerase chain reaction-restricted fragment length polymorphism or sequence specific primer assays. RESULTS: For all loci, genotype distribution was in agreement with Hardy-Weinberg expectations in the control group. Significant intergroup difference (case vs. control) was seen for angiotensinogen (AGT) M235T polymorphism, with an increased allele M235 in affected cases (50% vs. 40% in controls). Analysis of two-locus haplotype agrees with an independent segregation of physically unlinked genes. Haplotype AGT 174T-235M was also increased (50% vs. 40% in controls). CONCLUSIONS: Physically unlinked genes involved in RAS segregate independently. The AGT 174-235 region is associated with PD-PRM in this population.