Tendencia de la mortalidad por picaduras de alacrán en México, 1979-2003 Trends in mortality from scorpion stings in Mexico, 1979-2003

OBJETIVO: Describir la tendencia de la mortalidad por picaduras de alacrán en México y sus estados federativos en el período de 1979 a 2003. MÉTODOS: Se estimaron las tasas crudas y estandarizadas de mortalidad por picaduras de alacrán y las tendencias durante el período estudiado a partir de los datos oficiales de mortalidad en México, según la 9.ª y la 10.ª revisiones de la Clasificación Internacional de Enfermedades (códigos E905.2 y X22, respectivamente). Los resultados se estratificaron por grupos de edad. Las frecuencias de muertes por picaduras de alacrán se compararon mediante el riesgo relativo (RR) y sus intervalos de confianza de 95% (IC95%). RESULTADOS: Entre 1979 y 2003, en México se registraron 6 077 muertes por picaduras de alacrán. Se observó una tendencia descendente estadísticamente significativa en la mortalidad estandarizada (beta = -0,195; P < 0,001), con una reducción total de 86,5% entre los períodos 1979-1982 y 2001-2003. La mayor mortalidad en el trienio 2001-2003 se observó en varones (0,81 por 1 000 000 de habitantes) y en los menores de 1 año (7,07 por 1 000 000 de habitantes), seguidos por los grupos de 1 a 4 años (3,78 por 1 000 000 de habitantes) y de 60 años o más (0,84 por 1 000 000 de habitantes). Las poblaciones con menos de 2 500 habitantes presentaron una mortalidad por picaduras de alacrán superior en 11,8 (IC95%: 7,86 a 17,72) veces la observada en las de más de 20 000 habitantes. Los estados con mayor mortalidad por picaduras de alacrán se encuentran en la región occidental y central del país. CONCLUSIONES: A pesar de la sostenida tendencia descendente en el número de muertes por picaduras de alacrán en los últimos 20 años en México, este sigue siendo un importante problema de salud pública. Los grupos de edad más afectados son los niños menores de 5 años y los ancianos. Se deben tomar medidas para que en todas las comunidades, principalmente en las pequeñas, se disponga de los recursos y la información adecuados para la atención oportuna de las personas que sufren una picadura de alacrán.<br>OBJECTIVE: To describe the trends in mortality from scorpion stings in Mexico as a whole and in each of its states for the period of 1979 to 2003. METHODS: We estimated the crude and standardized mortality rates due to scorpion stings and the trends during the period studied based on official mortality data for Mexico, using the codes (E905.2 and X22, respectively) from the 9th and 10th editions of the International Classification of Diseases. The results were stratified by age group. The frequencies of deaths from scorpion stings were compared using relative risk (RR), with 95% confidence intervals (CIs). RESULTS: Between 1979 and 2003 in Mexico, 6 077 deaths from scorpion stings were registered. A statistically significant downward trend was found in standardized mortality rates (beta = -0.195; P < 0.001), with a total reduction of 86.5% for the period of 2001-2003 versus 1979-1982. For the 2001-2003 period, the highest mortality rates were in children under 1 year of age (7.07 per 1 000 000), children 1 to 4 years old (3.78 per 1 000 000), persons 60 and older (0.84 per 1 000 000), and males (0.81 per 1 000 000). Persons in communities with fewer than 2 500 inhabitants had a relative risk that was 11.8 times (95% CI: 7.86 to 17.72) that found in communities with more than 20 000 inhabitants. The states with the highest mortality rates were in the central and western regions of the country. CONCLUSIONS: Despite the sustained decline in the number of deaths from scorpion stings in the last 20 years in Mexico, there is still an important public health problem. The groups that are most affected are children under 5 and the elderly. Measures should be taken so that in all communities, especially small ones, adequate resources and information are available to provide for the prompt care of persons who suffer a scorpion sting

Relationship between self-reported fish and shellfish consumption, carbon and nitrogen stable isotope values and total mercury concentrations in pregnant women (II) from Baja California Sur, Mexico

Seafood is a valuable source of nutrients important for fetal development. However, seafood consumption is the main route of exposure to monomethyl mercury (MeHg+) for humans. MeHg+ is highly bioavailable and potentially adversely affects fetal neurodevelopment. MeHg+ exposure from fish consumption varies significantly by age and trophic level of fish consumed as well as the frequency and amount of fish consumed. This study investigates total Hg concentrations ([THg]) in hair segments of pregnant Mexican women in relation to (1) self-reported frequency of fish and shellfish consumption, (2) maternal trophic level and marine diet contributions, determined using hair carbon (C) and nitrogen (N) stable isotopes, and (3) relates [THg] to various hair advisory thresholds. We also examined whether variation in C and N isotope values is explained by self-reported frequency of fish and shellfish consumption. A significant proportion of hair samples had [THg] higher than suggested agency thresholds and, for women within the range of the various advisory thresholds (1–20 μg g−1), the specific statistic used and threshold applied are important considerations for assessing and communicating risk. Individuals enriched in 15N (δ15N values) had higher [THg] as did individuals that reported consuming fish and shellfish more frequently, suggesting that variation in [THg] can be explained by both consumer reported diet and diet as determined by C and N stable isotope assessment. However, at higher reported fish consumption levels the trophic level is maintained while [THg] is paradoxically lower. This suggests that THg exposure and assimilation are more complicated in higher fish frequency consumption categories. [THg] is more variable at the higher concentrations, possibly indicating some exposure to non-dietary Hg, heritable variations affecting Hg toxicodynamics, and BMI and tobacco exposure factors as outlined in our companion paper

Marine diet and tobacco exposure affects mercury concentrations in pregnant women (I) from Baja California Sur, Mexico

Seafood provides essential polyunsaturated fatty acids (PUFA) and other nutrients to pregnant women and their fetus(es) while a diet rich in finfish can be a major pathway of monomethyl mercury (MeHg+) exposure. We measured total mercury concentration ([THg]) in hair samples provided by 75 women in Baja California Sur (BCS) to assess its relationship with age, parity, tobacco smoke exposure, and diet based on survey methodologies. Generalized linear models (GLM) were used to explain the possible association of the different variables with [THg] in hair. Median [THg] in hair was 1.52 μg g−1, ranging from 0.12 to 24.19 μg g−1 and varied significantly by segment. Approximately 72% (54/75) of those evaluated exceed 1 μg g−1 [THg] and 8% (6/75) exceed 5 μg g−1 [THg] in hair. Although frequency of fish consumption contributed significantly to explaining hair [THg], fish consumption only explained 43% of [THg] in a GLM incorporating tobacco exposure and body mass index. This study establishes possible relationships among multiple potential sources of exposure and other factors related to [THg] in hair of women in the prenatal period. A more detailed examination of other sources of exposure and factors contributing to [THg] is warranted

In silico Characterization of the Heme Oxygenase 1 From Bottlenose Dolphin (Tursiops truncatus): Evidence of Changes in the Active Site and Purifying Selection.

Cetacea is a clade well-adapted to the aquatic lifestyle, with diverse adaptations and physiological responses, as well as a robust antioxidant defense system. Serious injuries caused by boats and fishing nets are common in bottlenose dolphins (Tursiops truncatus); however, these animals do not show signs of serious infections. Evidence suggests an adaptive response to tissue damage and associated infections in cetaceans. Heme oxygenase (HO) is a cytoprotective protein that participates in the anti-inflammatory response. HO catalyzes the first step in the oxidative degradation of the heme group. Various stimuli, including inflammatory mediators, regulate the inducible HO-1 isoform. This study aims to characterize HO-1 of the bottlenose dolphin in silico and compare its structure to the terrestrial mammal protein. Upstream HO-1 sequence of the bottlenose dolphin was obtained from NCBI and Ensemble databases, and the gene structure was determined using bioinformatics tools. Five exons and four introns were identified, and proximal regulatory elements were detected in the upstream region. The presence of 10 α-helices, three 310 helices, the heme group lodged between the proximal and distal helices, and a histidine-25 in the proximal helix serving as a ligand to the heme group were inferred for T. truncatus. Amino acid sequence alignment suggests HO-1 is a conserved protein. The HO-1 "fingerprint" and histidine-25 appear to be fully conserved among all species analyzed. Evidence of positive selection within an α-helix configuration without changes in protein configuration and evidence of purifying selection were found, indicating evolutionary conservation of the coding sequence structure