Seroprevalence of hepatitis A virus in a cross-sectional study in Mexico: Implications for hepatitis A vaccination

Hepatitis A virus (HAV) remains a public health concern worldwide contributing to significant morbidity in developed and developing countries. This cross-sectional database study estimated the overall HAV seroprevalence and the seroprevalence by gender, age, region and socioeconomic status in Mexico. Between January and October 2010, serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1-95 y. Subjects' gender, age, geographical region and socioeconomic status were extracted from the survey and compiled into a subset database by the Mexican National Institute of Public Health. Anti-HAV antibodies were measured using a chemiluminescent immunoassay. A total of 3658 subjects were included in the according-to-protocol cohort. Overall, the HAV seroprevalence was 84.2%. The HAV seroprevalence rates were similar between females (86.1%) and males (82.2%). The percentage of subjects seropositive for anti-HAV antibodies was highest in adults aged ≥ 20 y (96.9%), followed by adolescents aged 10-19 y (80.1%) and lowest in children aged 1-9 y (45.0%) (p < 0.0001). Regionally, the highest HAV seroprevalence rate was observed in the South (88.8%) followed by Central and Northern Mexico and Mexico City (p = 0.02). The HAV seroprevalence was similar between subjects of high socioeconomic (90.1%) status and of low socioeconomic status (86.6%). This study confirms the intermediate HAV endemicity in Mexico. Cost-effectiveness studies are necessary to evaluate the inclusion of an effective hepatitis A vaccine from a population-based perspective in addition to continuous efforts to improve hygiene and sanitation that have a substantial impact on the disease burden.

Cervical cancer screening in the US-Mexico border region: a binational analysis

Cervical cancer mortality is high along the US-Mexico border. We describe the prevalence of a recent Papanicolaou screening test (Pap) among US and Mexican border women. We analyzed 2006 cross-sectional data from Mexico's National Survey of Health and Nutrition and the US Behavioral Risk Factor Surveillance System. Women aged 20-77 years in 44 US border counties (n = 1,724) and 80 Mexican border municipios (n = 1,454) were studied. We computed weighted proportions for a Pap within the past year by age, education, employment, marital status, health insurance, health status, risk behaviors, and ethnicity and adjusted prevalence ratios (APR) for the US, Mexico, and the region overall. Sixty-five percent (95 %CI 60.3-68.6) of US women and 32 % (95 %CI 28.7-35.2) of Mexican women had a recent Pap. US residence (APR = 2.01, 95 %CI 1.74-2.33), marriage (APR = 1.31, 95 %CI 1.17-1.47) and insurance (APR = 1.38, 95 %CI 1.22-1.56) were positively associated with a Pap test. Among US women, insurance and marriage were associated (APR = 1.21, 95 %CI 1.05-1.38 and 1.33, 95 %CI 1.10-1.61, respectively), and women aged 20-34 years were about 25 % more likely to have received a test than older women. Insurance and marriage were also positively associated with Pap testing among Mexican women (APR = 1.39, 95 %CI 1.17-1.64 and 1.50; 95 %CI 1.23-1.82, respectively), as were lower levels of education (≤8th grade or 9th-12th grade versus some college) (APR = 1.74; 95 %CI 1.21-2.52 and 1.60; 95 %CI 1.03-2.49, respectively). Marriage and insurance were associated with a recent Pap test on both sides of the border. Binational insurance coverage increases and/or cost reductions might bolster testing among unmarried and uninsured women, leading to earlier cervical cancer diagnosis and potentially lower mortality.

Prevalence and socioeconomic differences of risk factors of cardiovascular disease in Ecuadorian adolescents

PURPOSE

The aim of this paper is to report the prevalence of cardiovascular risk factors and socioeconomic differences in school-going Ecuadorian adolescents.

METHODS

A cross-sectional study was performed from January 2008 until April 2009 in 770 adolescents aged 10 to 16 years old, who attend secondary schools in an urban (Cuenca), and rural area (Nabón) in Ecuador. Data collected for the overall sample included anthropometric variables (weight, height and waist circumference), blood pressure and socio-demographic characteristics. Fasting blood glucose and lipid profile determinations were collected in a subsample of 334 adolescents.

RESULTS

The most prevalent cardiovascular risk factors were dyslipidemia (34.2%), abdominal obesity (19.7%) and overweight (18.0%). The prevalence of the remaining cardiovascular risk factors were high levels of blood pressure (6.2%) and obesity (2.1%). Boys were 3.3 times (P < 0.001) more likely to have risk levels of blood pressure. Compared to their peers from lower socioeconomic groups, children from better off socioeconomic strata were 1.5 times (P = 0.048) more likely to be overweight/obese and 1.5 times (P = 0.046) more likely to have abdominal obesity. Overweight and obese children were 4.4 times more likely to have dyslipidemia (P < 0.001). Children living in the rural area were 2.8 times (P = 0.002) more likely to have dyslipidemia than those from the urban area.

CONCLUSIONS

Our results demonstrate the advanced levels of the nutrition transition in this Ecuadorian adolescent population. Primary health care should monitor and take actions to address this public health problem in adolescents.

Study of nanoscale structures in hydrated biomaterials using small-angle neutron scattering

Distribution of water in three classes of biomedically relevant and degradable polymers was investigated using small-angle neutron scattering. In semicrystalline polymers, such as poly(lactic acid) and poly(glycolic acid), water was found to diffuse preferentially into the non-crystalline regions. In amorphous polymers, such as poly(d,l-lactic acid) and poly(lactic-co-glycolic acid), the scattering after 7 days of incubation was attributed to water in microvoids that form following the hydrolytic degradation of the polymer. In amorphous copolymers containing hydrophobic segments (desaminotyrosyl-tyrosine ethyl ester) and hydrophilic blocks (poly(ethylene glycol) (PEG)), a sequence of distinct regimes of hydration were observed: homogeneous distribution (∼10Å length scales) at <13 wt.% PEG (∼1 water per EG), clusters of hydrated domains (∼50Å radius) separated at 24 wt.% PEG (1-2 water per EG), uniformly distributed hydrated domains at 41 wt.% PEG (∼4 water per EG) and phase inversion at >50 wt.% PEG (>6 water per EG). Increasing the PEG content increased the number of these domains with only a small decrease in distance between the domains. These discrete domains appeared to coalesce to form submicron droplets at ∼60°C, above the melting temperature of crystalline PEG. The significance of such observations on the evolution of micrometer-size channels that form during hydrolytic erosion is discussed.

Antileishmanial sesquiterpene lactones from Pseudelephantopus spicatus, a traditional remedy from the Chayahuita Amerindians (Peru). Part III

ETHNOPHARMACOLOGICAL RELEVANCE

The study of traditional remedies used by the Chayahuita, an ethnic group from the Peruvian Amazonia, has prompted us to investigate in detail the ethanolic extract of Pseudelephantopus spicatus (Juss. ex Aubl.) C.F. Baker, which has demonstrated strong biological activity towards Leishmania amazonensis. Our goal was to discover the active compound of this plant-based remedy.

MATERIALS AND METHODS

A bioguided fractionation of the crude extract was undertaken based on the biological activity recorded against Leishmania amazonensis axenic amastigotes in in vitro bioassays.

RESULTS

Three strongly to moderately active compounds were isolated: two hirsutinolides (the 8,13-diacetyl-piptocarphol and the 8-acetyl-13-O-ethyl-piptocarphol) and ursolic acid. IC(50) against Leishmania amazonensis axenic amastigotes are respectively 0.2, 0.37 and 0.99 μM (while IC(50) of amphotericin B is 0.41 μM). These compounds have never been isolated from this plant species, and germacranolides have never been identified as potential antileishmanial agents.

CONCLUSIONS

The compounds isolated from Pseudelephantopus spicatus account for the antileishmanial activity of the plant, thus giving support to its use by the Chayahuita in Peru.

Molecular characterization of Staphylococcus aureus from outpatients in the Caribbean reveals the presence of pandemic clones

Staphylococcus aureus infections continue to pose a global public health problem. Frequently, this epidemic is driven by the successful spread of single S. aureus clones within a geographic region, but international travel has been recognized as a potential risk factor for S. aureus infections. To study the molecular epidemiology of S. aureus infections in the Caribbean, a major international tourist destination, we collected methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) isolates from community-onset infections in the Dominican Republic (n = 112) and Martinique (n = 143). Isolates were characterized by a combination of pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing (MLST) typing. In Martinique, MRSA infections (n = 56) were mainly caused by t304-ST8 strains (n = 44), whereas MSSA isolates were derived from genetically diverse backgrounds. Among MRSA strains (n = 22) from the Dominican Republic, ST5, ST30, and ST72 predominated, while ST30 t665-PVL+ (30/90) accounted for a substantial number of MSSA infections. Despite epidemiological differences in sample collections from both countries, a considerable number of MSSA infections (~10%) were caused by ST5 and ST398 isolates at each site. Further phylogenetic analysis suggests the presence of lineages shared by the two countries, followed by recent genetic diversification unique to each site. Our findings also imply the frequent import and exchange of international S. aureus strains in the Caribbean.

Prevalence and distribution of type 2 diabetes mellitus in Mexican adult population: a probabilistic survey

OBJECTIVE

To describe the prevalence, distribution and degree of control of type 2 diabetes (T2D) in Mexican population.

MATERIAL AND METHODS

Subjects were classified as previously diagnosed T2D (PD); or as "finding of the survey" (FS) (glucose >or=126 mg/dL). Hemoglobin A1c was measured in PD-subjects.

RESULTS

The prevalence for PD-T2D was 7.34% (95%CI 6.3, 8.5) and for FS 7.07% (95%CI 6.1, 8.1), summing 14.42%; (7.3 million diabetics). 5.3% of PD-T2D were in good, 38.4% in poor and 56.2% very poor control. Older age (OR=0.96, 95%CI 0.94, 0.97), lower BMI (OR=0.95, 95%CI 0.91, 1.0), were protective for poor control. Affiliation to private services (OR=1.77, 95%CI 0.98, 3.13), larger T2D duration (OR=1.05, 95%CI 1.01, 1.08), and combining oral medication and insulin (OR=16.1, 95%CI 1.61, 161) were riskier.

CONCLUSIONS

We found an alarming prevalence of T2D in Mexican population; the majority of PD diabetics are in poor control. Research on the latter is warranted.

Prevalence of dyslipidemias in the Mexican National Health and Nutrition Survey 2006

OBJECTIVE

To describe the prevalence of lipid abnormalities found in the Mexican National Health and Nutrition Survey 2006 (ENSANut 2006).

MATERIAL AND METHODS

Information was obtained from 4 040 subjects aged 20 to 69 years, studied after a 9- to 12-hour fast.

RESULTS

Median lipid concentrations were: cholesterol 198.5 mg/dl, triglycerides 139.6 mg/dl, HDL-cholesterol 39.0 mg/dl, non-HDL-cholesterol 159.5 mg/dl and LDL-cholesterol 131.5 mg/dl. The most frequent abnormality was HDL-cholesterol below 40 mg/dl with a prevalence of 60.5% (95%CI 58.2-62.8%). Hypercholesterolemia (> 200 mg/dl) had a frequency of abnormality of 43.6% (95%CI 41.4-46.0%). Only 8.6% of the hypercholesterolemic subjects knew their diagnosis. Hypertriglyceridemia (>or= 150 mg/dl) was observed in 31.5% (IC 95% 29.3-33.9%) of the population.

CONCLUSIONS

The ENSANUT 2006 data confirm that the prevalence of hypoalphalipoproteinemia and other forms of dyslipidemia in Mexican adults is very high.

Trends for type 2 diabetes and other cardiovascular risk factors in Mexico from 1993-2006

OBJECTIVE

To describe the trends in the prevalence of type 2 diabetes (T2D), and other cardiovascular risk factors in three national health surveys (1993, 2000 and 2006).

MATERIALS AND METHODS

The databases of three surveys: ENEC 1993, ENSA 2000 and ENSANUT 2006 were gathered. Calculations of published data were reprocessed to do appropriate adjustments to assure comparability among surveys.

RESULTS

From 1993 to 2006 the prevalence of type 2 diabetes (6.7-14.4%), metabolic syndrome (26.6-36.8%), hypertension (23.8-30.7%), hypercholesterolemia (27-43.6%), and high LDL-cholesterol (31.6-46%) increased rapidly. The prevalence of low HDL cholesterol was very high (60.5-63%) in all surveys and remained remarkably unchanged among surveys.

CONCLUSIONS

This increasing trends for the prevalence of T2D and cardiovascular risk factors predicts larger increments in the near future for T2D and cardiovascular morbidity and mortality. Intensification of the preventive and remedy strategies is mandatory in order curve the foreseen dramatic increment in the disease burden.

Confined displacement algorithm determines true and random colocalization in fluorescence microscopy

The quantification of colocalizing signals in multichannel fluorescence microscopy images depends on the reliable segmentation of corresponding regions of interest, on the selection of appropriate colocalization coefficients, and on a robust statistical criterion to discriminate true from random colocalization. Here, we introduce a confined displacement algorithm based on image correlation spectroscopy in combination with Manders colocalization coefficients M1(ROI) and M2(ROI) to quantify true and random colocalization of a given florescence pattern. We show that existing algorithms based on block scrambling exaggerate the randomization of fluorescent patterns with resulting inappropriately narrow probability density functions and false significance of true colocalization in terms of p values. We further confine our approach to subcellular compartments and show that true and random colocalization can be analysed for model dendrites and for GABA(B) receptor subunits GABA(B)R1/2 in cultured hippocampal neurons. Together, we demonstrate that the confined displacement algorithm detects true colocalization of specific fluorescence patterns down to subcellular levels.

Metabolic syndrome in Mexican adults: results from the National Health and Nutrition Survey 2006

OBJECTIVE

To examine the prevalence of metabolic syndrome (MS) and its associated risk factors in Mexican adults aged 20 years or older, using data derived from the National Health and Nutrition Survey 2006 (ENSANUT 2006).

MATERIAL AND METHODS

The ENSANUT 2006 was conducted between October 2005 and May 2006. Questionnaires were administered to 45 446 adult subjects aged 20 years or older who were residents from urban and rural areas. Anthropometric and blood pressure measurements were obtained from all subjects and fasting blood specimens were provided by 30% of participants. We randomly selected a sub-sample of 6 613 from which laboratory measurements were carried out for glucose, insulin, triglycerides, total cholesterol and HDL-cholesterol. For this analysis, we included only results from eight or more hours of fasting samples (n=6 021). We used individual weighted factors in the statistical analysis and considered the survey's complex sampling design to obtain variances and confidence intervals. All analyses were done using SPSS 15.0.

RESULTS

In accordance with definitions by the National Cholesterol Education Program Adult Treatment Panel III (ATP III), the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI), and the International Diabetes Federation (IDF), the prevalence of MS in Mexican adults aged 20 years or older was 36.8, 41.6 and 49.8%, respectively. Women were more affected than men due to the higher prevalence of central obesity among females. Prevalence of MS increased with age and was higher among populations living in metropolitan areas, in the west-central region, and those with lower education.

DISCUSSION

Regardless of the MS definition, a large proportion of Mexican adults has the condition, so preventive measures are needed to decrease the prevalence of the MS components in this population. MS can predict type 2 diabetes and cardiovascular disease, two of the main causes of death in the adult population in Mexico. The intentional search of MS components allows stratifying the population according to risk levels. Treatment for each component should be implemented properly to prevent or delay onset of type 2 diabetes and cardiovascular disease.

Prevention of cardiovascular disease based on lipid lowering treatment: a challenge for the Mexican health system

OBJECTIVE

To estimate the percentage of Mexican adults that may require lipid-lowering treatment according to National Cholesterol Education Program-III guidelines, using data from the National Health and Nutrition Survey 2006 (ENSANut 2006).

MATERIAL AND METHODS

Information was obtained from 4 040 subjects aged 20 to 69 years, studied after a 9 to 12 hours fast.

RESULTS

A cardiovascular risk equivalent was found in 13.8% and >or=2 risk factors were present in 31.5% of the population. LDL-C concentrations were above the treatment goal in 70% of the high-risk group and in 38.6% of subjects with >or=2 risk factors. Nearly 12 million Mexicans should be taught how to change their lifestyles and close to 8 million individuals require drug therapy to decrease their cardiovascular risk.

CONCLUSIONS

Thirty percent of Mexican adults require some form of lipid-lowering treatment (lifestyle modifications in 36.25%, drug therapy in 24.19%).

Methodology for the analysis of type 2 diabetes, metabolic syndrome and cardiovascular disease risk indicators in the ENSANUT 2006

OBJECTIVE

To describe: a) the methods used to quantify biochemical indicators of Type 2 Diabetes (T2D), and other cardiovascular risk indicators in the Mexican National Health and Nutrition Survey 2006 (ENSANUT 2006) and b) compare the sub-sample with the non-selected participants in diverse socio-demographic, anthropometric and health characteristics.

MATERIAL AND METHODS

A sub-sample of 6 021 fasting adult participants was randomly selected from the total fasting participants (n=39 425). We compared diverse socio-demographic, anthropometric and health parameters between this sub-sample and the rest of the participants.

RESULTS

No differences were found in sociodemographics characteristics, except age, between the sub-sample and from the rest of the fasting adults. In addition no difference were found between prevalences of overweight and obesity, central obesity, and previously diagnosed high blood pressure, T2D or hypertrigliceridemia.

CONCLUSIONS

The randomly selected sub-sample was not essentially different from the rest of the fasting subjects. Thus, no bias is expected in the interpretation of cardiovascular risk indicators derived from these data.

[Obesity in Mexico: epidemiology and health policies for its control and prevention]

Obesity is a major risk factor for developing type 2 diabetes, cardiovascular disease, hypertension, dyslipidemias, musculoskeletal diseases, and certain types of cancer. In Mexico the prevalence of overweight and obesity is 16.7% in preschool children, 26.2% in school children, and 30.9% in adolescents. For adults, the prevalence of overweight and obesity is 39.7 and 29.9%, respectively (ENSANUT 2006). Based on an analysis of the situation in Mexico, the need for a comprehensive, multisectoral, multilevel policy and an effective coordination policy have been clearly identified to achieve changes in eating patterns and physical activity to enable the prevention of chronic diseases and to reduce the prevalence of overweight and obesity The combination of strategies and actions of the Mexican National Agreement for Healthy Nutrition proposed by the federal government proposes among its aims for 2012: a reversal in the prevalence of overweight and obesity for children aged 2-5 years in comparison with ENSANUT to stop the increasing prevalence in this condition for school children and adolescents (aged 5-19 years), and to slow down the increasing prevalence of overweight and obesity in adults. This challenge will require important regulatory actions, efficient and adaptable implementation, and participation of all sectors of society.

Knowledge and adoption of community mitigation efforts in Mexico during the 2009 H1N1 pandemic

BACKGROUND

The public's ability and willingness to adopt community mitigation efforts during a pandemic are debated in the literature.

PURPOSE

Awareness and adoption of community mitigation efforts in Mexico during the 2009 pandemic influenza A (H1N1) (pH1N1) outbreak were measured to evaluate if the population received, understood, and acted on public health messages.

METHODS

A cross-sectional representative household survey in Mexico City; San Luis Potosi (high case ratio); and Queretaro (low case ratio) was conducted in May and June 2009. Accounting for the complex survey design, percentages and 95% CI for answers to all questions were generated and compared based on living inside or outside Mexico City, high versus low prevalence of infection in the community, and perceived severity and knowledge of the virus.

RESULTS

Greater than 90% of respondents received community mitigation messages and adopted one or more community mitigation efforts. There were few differences among cities. Respondents reported high cost of masks, soaps, and gels as barriers to community mitigation-effort adoption. Nearly one fifth of respondents, disproportionally from the lower socioeconomic tertile, found some messages confusing. Half of all households reported a negative economic impact resulting from the outbreak.

CONCLUSIONS

Mexico's community mitigation campaign reached the majority of the population in three surveyed cities. Confusion regarding messages and economic barriers to community mitigation-effort adoption were sometimes reported.

Ta'ta', Huayani: perception of leishmaniasis and evaluation of medicinal plants used by the Chayahuita in Peru. Part II

AIM OF THE STUDY

A knowledge attitude and practice study centred on leishmaniasis and its treatment was performed among the Chayahuita, an Amazonian Peruvian ethnic group living in an endemic area. This study documents traditional Chayahuita plant's use and disease concepts. Also, activity of some medicinal plants used by the Chayahuita is highlighted and discussed.

MATERIALS AND METHODS

Ninety-three Chayahuita people were interviewed, following a semi-structured questionnaire focussed on disease knowledge and perception, personal attitude and healing practices. Simultaneously, a collection of plants was performed in different ecotopes, in order to make an extensive inventory of the pharmacopoeia.

RESULTS

For the Chayahuita, cutaneous (CL) and muco-cutaneous leishmaniasis (MCL) are considered as diseases of their own, with specific names, aetiologies, mode of transmission. Regarding CL, Chayahuita people consider that the humid characteristic of the skin ulcer is a discriminative fact orienting the diagnostic forTa'ta' (leishmaniasis). Forty-six different species were designated useful against LC and /or MCL (29 species by means of the questionnaire and 27 species when collecting in different ecotopes). Thirty-seven extracts corresponding to 31 species used medicinally were screened in vitro against Leishmania amazonensis axenic amastigotes, assessing their viability by the reduction of tetrazolium salt (MTT). Six species displayed a good activity (10 microg/ml<IC50<20 microg/ml): an undetermined hemi-epiphytic Clusiaceae, Cybianthus anthuriophyllus Pipoly (Myrsinaceae), two Piper, Piper sanguineispicum Trel., and Piper loretoanum Trel. (Piperaceae), Desmodium axillare Sw. DC. (Fabaceae), and Clibadium sylvestre (Aubl.) Baill. (Asteraceae).

CONCLUSION

Perception of leishmaniasis, attitude, treatments and diet prohibitions still largely reflects traditional Chayahuita cosmovision, even if some tentative of bio-medical re-interpretation is arising.