High Prevalence of Sexually Transmitted Infections, and High-Risk Sexual Behaviors Among Indigenous Adolescents of the Comarca Ngäbe-Buglé, Panama.

BACKGROUND: There is scant information on sexually transmitted infection (STI) prevalence and risk factors among Latin American indigenous populations. We investigated STI prevalence and risk factors among adolescents of the Comarca Ngäbe-Buglé indigenous region of Panama. METHODS: A population-based cross-sectional study was conducted among school-going adolescents aged 14 to 19 years. Eligible consenting participants self-completed a questionnaire and provided blood and urine samples. Female participants provided additional self-administered genital swabs. Seroprevalences of human immunodeficiency virus (HIV), syphilis, hepatitis B (HBsAg, anti-HBc), and herpes simplex virus type 2 (HSV-2) were determined in all participants; genital Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) by PCR among participants who reported sexual experience or were seropositive for HIV/syphilis/HSV2/HBsAg; high-risk human papillomavirus (HPV) by qualitative DNA assay and bacterial vaginosis (BV) by Gram-stain among female participants. Risk factors were identified by estimating adjusted odds ratios (AOR) using random-effects logistic regression. RESULTS: We enrolled 700 participants (median age, 17 years [female participants]; 18 years [male participants]) from 20 schools. Sexual experience was reported by 536 participants (76.6%). The HIV/STI prevalences among females and males were: HIV 0.4% and 1.0%, high-titer active syphilis 1.3% and 6.6%, HSV-2 16.1% and 16.1%, HBsAg 1.3% and 1.4%, anti-HBc 3.2% and 1.4%, NG 1.8% and 1.7%, CT 17.5% and 10.7%; among females: BV 42.9% and HPV 33.2%. CT was independently associated with being female (AOR, 2.02; 95% confidence interval [CI], 1.20-3.41); high-titer active syphilis with being male (AOR, 4.51; 95% CI, 1.17-17.40). Bacterial vaginosis was associated with sexual behavior (≥3 lifetime sex partners: AOR, 3.81; 95% CI, 1.29-11.26), HPV with sexual experience (AOR, 4.05; 95% CI, 1.62-10.09). CONCLUSIONS: School-going indigenous adolescents in rural Panama have substantial STI burden. Targeted STI screening is required.

Phylogenetic Analysis of Hepatitis B Virus Genotypes Circulating in Different Risk Groups of Panama, Evidence of the Introduction of Genotype A2 in the Country.

The Hepatitis B Virus (HBV) can cause acute or chronic infection it is also associated with the development of liver cancer, thousands of new infections occur on a yearly basis, and many of these cases are located in certain areas of the Caribbean and Latin America. In these areas, the HBV prevalence is still high which makes this virus a serious public health concern to the entire region. Studies performed in Panama suggest a complex pattern in the distribution of HBV among the country's different risk groups. We use phylogenetic analysis in order to determine which HBV genotypes were circulating in these specific groups; for this we used a fragment of the PreS2/2 region of the HBV genome. Subsequently whole HBV genome sequences were used for Bayesian analysis of phylodynamics and phylogeography. Two main genotypes were found: genotype A (54.5%) and genotype F (45.5%). There was a difference in the distribution of genotypes according to risk groups: 72.9% of high risk groups were associated to genotype A, and 55.0% of samples of genotype F were associated to the low risk group (p<0.002). The Bayesian analysis of phylogeny-traits association revealed a statistically significant geographical association (p<0.0001) with both genotypes and different regions of the country. The Bayesian time of most recent common ancestor analysis (tMRCA) revealed a recent tMRCA for genotype A2 circulating in Panama (1997, 95% HPD: 1986-2005), when it is compared with Panamanian genotype F1c sequences (1930, 95% HPD: 1810 - 2005). These results suggest a possible change in the distribution of HBV genotypes in Panama and Latin America as a whole. They also serve to encourage the implementation of vaccination programs in high-risk groups, in order to prevent an increase in the number of new HBV cases in Latin America and worldwide.

High diversity of hepatitis B virus genotypes in Panamanian blood donors: a molecular analysis of new variants.

Hepatitis B Virus (HBV) is an infectious agent that causes more than half of the cases of liver disease and cancer in the world. Globally there are around 250 million people chronically infected with this virus. Despite 16% of the cases of liver disease in Central America are caused by HBV, the information regarding its genetic diversity, genotypes and circulation is scarce. The purpose of this study was to evaluate the genetic variability of the HBV genotypes from HBV-DNA positive samples obtained from screening blood donors at the Social Security System of Panama and to estimate its possible origin. From 59,696 blood donors tested for HBV infection during 2010-2012, there were 74 HBV-DNA positive subjects. Analysis of the partial PreS2-S region of 27 sequences shows that 21% of the infections were caused by genotype A, 3% by genotype D and 76% by genotype F. In addition, we were able to confirm circulation of six sub-genotypes A1, A2, A3, D4, F3, F1 and a proposed new sub-genotype denominated F5pan. We found a confinement of sub-genotypes F1 and F5pan to the western area of Panama. The tMRCA analysis suggests a simultaneous circulation of previously described sub-genotypes rather than recent introductions of the Panamanian sub-genotypes in the country. Moreover, these results highlight the need of more intensive research of the HBV strains circulating in the region at the molecular level. In conclusion, Panama has a high HBV genotype diversity that includes a new proposed sub-genotype, an elevated number of PreCore-Core mutations, and confinement of these variants in a specific geographical location.

Molecular characterisation of hepatitis B virus in the resident Chinese population in Panama City

Despite the effectiveness of current hepatitis B virus (HBV) vaccines, it is estimated that 350 million individuals suffer from chronic HBV infection and more than 50% of these affected individuals live on the Asian continent. Panama is a country with a great diversity of foreign groups; the Chinese community is a large example of this phenomenon. There is an urgent need to perform studies that evaluate the prevalence and the genetic diversity of HBV in this community. This study aimed to evaluate the prevalence of HBV and its genotypes and mutant variants in the Chinese population residing in Panama. In total, 320 subjects were enrolled in the study. Forty-two subjects (13.1%) were positive for HBsAg and HBV-DNA from 18 subjects revealed the presence of genotypes B2 and C1. Secondary mutations associated with drug resistance at positions rtV207L and rtN239T of the reverse transcriptase gene were identified. Additionally, the mutation pair A1762T/G1764A was found in three samples and the mutation G1896A was detected in an HBeAg-negative subject. In conclusion, to our knowledge, this is the first study to report high HBV prevalence rates in resident ethnic Chinese in Central America and the presence of genotypes B2 and C1 in this region.

Mifepristone 2.5 mg versus 5 mg daily in the treatment of leiomyoma before surgery.

OBJECTIVES: To evaluate the efficacy and safety of 2.5 mg and 5 mg mifepristone during 3 months for the treatment of uterine fibroids before surgery. DESIGN: Multicenter randomized clinical trial. LOCATIONS: Eusebio Hernández Hospital, Havana, Cuba and the Alemán Hospital, Managua, Nicaragua. SUBJECTS: Included in the study were 146 women with symptomatic uterine fibroids. TREATMENT: GROUP I: half a tablet of 5 mg (2.5 mg) mifepristone taken orally every 24 hours, and Group II: one tablet of 5 mg mifepristone taken orally every 24 hours over a period of 3 months in both groups. Two endometrial biopsies were performed. VARIABLES TO EVALUATE EFFICACY: Increase in average hemoglobin, changes in fibroid and uterine volume, and symptomatic improvement. RESULTS: The average hemoglobin at the end of treatment was 0.6 g/dL greater in the 5 mg mifepristone group (P = 0.033). In both groups there were similar reductions in fibroid volumes. Clinical improvement was more significant in the 5 mg group. CONCLUSION: The dose to be used should be 5 mg.

Evaluation of the efficacy of albendazole sulphoxide and praziquantel in combination on Taenia crassiceps cysts: in vitro studies.

OBJECTIVES: Praziquantel and albendazole are currently used for chemotherapeutic treatment of neurocysticercosis. Albendazole has been found to be more effective than praziquantel; however, it is well known that not all patients will show a complete resolution of cysts. Searching for more effective treatments, this study was designed to evaluate the effect of the combination of praziquantel and albendazole sulphoxide in a Taenia crassiceps in vitro model as well as the kind of interaction between both drugs. METHODS: In order to determine the concentration that produced 50% effect (EC50), T. crassiceps cysts were incubated in culture medium containing praziquantel (0.005-0.04 microg/mL), albendazole sulphoxide (0.021-0.16 microg/mL) or the combination of praziquantel and albendazole sulphoxide in a fixed-dose ratio (1:1). The experimental concentration (EC50Exp) of the combination was determined from the concentration-response curve constructed from the combined drug treatment. Isobolographic analyses were used to define the nature of the interaction between praziquantel and albendazole sulphoxide. Morphological and ultrastuctural alterations after different treatments over the parasite tissue were observed by light and transmission electron microscopy. RESULTS: The changes in ultrastructure were more marked with the praziquantel and albendazole sulphoxide combination. Also the cysticidal effect of the combination was observed earlier than that of each drug alone. When isobolographic analysis was employed, we found that the experimental EC50 value (0.042 microg/mL) was not significantly different from the theoretical EC50 value (0.035 microg/mL), which indicates an additive interaction between praziquantel and albendazole sulphoxide. CONCLUSIONS: Our study suggests that the combination of praziquantel and albendazole sulphoxide could potentially improve the current neurocysticercosis treatment.

Predictors of smoking cessation success.

PURPOSE: To evaluate Smoking Cessation Clinic success rate and attitudes toward smoking among current and quitters enrolled at the clinic. METHODS: Telephone survey among a random sample of 61 subjects enrolled at the Smoking Cessation Clinic in the San Juan Veterans Affairs Hospital. The questionnaire was validated and standardized for Hispanic subjects. RESULTS: Twenty eight percent of the subjects interviewed referred they had quit smoking. Quitters used to smoke more cigarettes than current smokers do. Quitters perceived their general health to be worse than current smoker's perception. Even though Quitters were concerned about weight gain after quitting, it was not a negative outcome for smoking cessation. No association was found between active smoking and use of ethanol, neither socializing with friends nor feeling anxious. CONCLUSION: The Smoking Cessation Clinic at the San Juan Veterans Affairs Hospital has a success rate similar to other clinics reported in the literature. Poor health perception and consumption of more than one pack per day predicted smoking cessation. There was no single strong factor associated to smoking cessation. The idiosyncrasy of targeted population should be taken in account when designing smoking cessation program.

Limits of variation of fiber distribution in the sural nerve of man

Although the sural nerve is the most extensively studied nerve in man, there is a dearth of data regarding the normal variations in the size-frequency distribution of axons in normal subjects; criteria for assessing the normality of a given individual are not available. Therefore, in everyday practice, the surgical pathologist may meet with difficulty in interpretit the biopsy of one particular individual, in whom the distribution is slightly different from the curves published. The object of this work is to detect the normal limits of variation in the distribution of diameters of muelinated and unmyelinated fibers in normal subjects and to establish the criteria that permit the calculated curves to be used in veryday clinical practice. Normal sural nerves of 19 patients were analyzed. Ages ranged between 18 months and 55 years. Morphometric analysis was performed with the Histoscan X automatic image processing analyzer, and , for statistical analysis, mixtures of lognormal distributions were fitted and tested with Pearson's statistics. Nerves of three diabetic patients were used for testing the method. They were clearly classified as abnormal. The curves, therefore, have been proven useful for everyday surgical pathology practice