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[Molecular and serological diagnosis of a dengue outbreak in Coro, Falcón state, Venezuela].

Dengue virus (DV) is responsible for a spectrum of diseases, from a self-limited fever disease (DF, dengue fever) to the more severe forms of hemorrhagic fever/dengue shock syndrome (DHF/DSS). The aim of this study was the serological and molecular confirmation of an outbreak of dengue in Falcon state, Venezuela. A total of 54 sera from patients with clinical diagnosis of DV infection were analyzed by an enzyme immunoassays developed in Venezuela (ELISA -IgM e -IgG) and by PCR. From them, 78% exhibited DV infection (PCR+ y/o IgM+), 48% exhibited viremia by PCR and 57% were positive to IgM. An interesting observation was the high percent (76%) of patients with past or secondary infection (IgG positive), which included all the patients exhibiting clinical symptoms of DHF (n = 8). From the PCR positive sera, serotype 1 was found in 27%, serotype 2 in 54% and serotype 4 in 19%. No serotype 3 was found circulating in this population, although this serotype was already circulating in the nearby island of Aruba. The combination of serological and molecular methods allow us to obtain a fairly precise information of this outbreak.

Adolescent↗

Environmental factors in Helicobacter pylori-related gastric precancerous lesions in Venezuela.

Although Helicobacter pylori (HP) infection has been acknowledged to play an etiological role in gastric carcinogenesis, its relatively weak association particularly in developing countries suggests critical roles of cofactors. Among a population with an extremely high prevalence of HP infection ( approximately 95%) in Venezuela, we examined the relationship of household characteristics, smoking, alcohol drinking, dietary consumption, and plasma nutrient levels with the prevalence of three different stages of gastric precancerous lesions, chronic atrophic gastritis (AG; n = 337), intestinal metaplasia (IM; n = 551), and dysplasia (n = 157), in comparison with those without any of these lesions (n = 1154). Length of refrigerator use was marginally inversely associated with the prevalence of the precursor lesions studied. The association was most pronounced for AG followed by dysplasia. On the other hand, smoking status was a significant predictor for IM and dysplasia. Those smoking >/=>10 cigarettes/day had 1.8-fold risk of IM and 3.6-fold risk of dysplasia compared with never smokers. There were no associations with alcohol consumption. When six food groups known to be associated with stomach cancer risk in Venezuela were tested, the prevalence of these lesions progressively increased with increasing starchy vegetable consumption and decreasing fresh fruit/fruit juice consumption. The association with fruits was more evident for dysplasia and AG and that with starchy vegetables for IM and AG. However, there were no inverse associations with plasma antioxidant vitamins. These findings offer important public health implications in preventing progression of HP-associated gastric precancerous lesions in high-risk populations.

Adult↗

[Centipede (Scolopendra sp.) envenomation in a rural village of semi-arid region from Falcon State, Venezuela].

INTRODUCTION: Centipedes are invertebrate animals belonging to Phylum Arthropoda, Class Chilopoda, with a first pair of front legs that has been modified to form large, poisonous fangs connected to venomous glands. Likely, due to relatively benignity of the clinical manifestations, in Venezuela studies and research on centipede envenomation are virtually scarse. AIM: The objective of this work was to study, biological, clinical, epidemiological and treatment profiles of envenomation caused by centipedes from Río Seco town, semi-arid area of Falcon State, Venezuelan north-western region. METHODS: Between August 2001 and July 2002, patients who referred centipede attack were attended in ambulatory emergency. These were clinically examined, and by means of anamnesis the site and time of bite were recorded. The centipede was collected for identification. Ringer solution and non steroid analgesic plus hidrocortisone (500 mg, one doses) were administered parenterally and intravenously, respectively. In one case with abscess, the patient received intravenously antibiotic therapy for 3 days plus orally for 4 days (500 mg every 6 hours). RESULTS: It was registered 17 cases bitten by Scolopendra sp., aged 3-52 years, 9 females and 8 males, with an estimated Incidence Density (ID) of 1.34/100 persons/year. The majority of the accidents prevailed in the dry season (100%), inside the home (70.59%), during the night (52.94%) and on the hands (29.41%). Most clinical manifestations were local: hyperthermia (100%), pain (64.7%) and paresthesias (52.94%). The majority of the patients resolved symptoms quickly between 2-24 hours after cessation of the treatment (analgesic + hydrocortisone). CONCLUSION: Due to be expected an ID between 1.28 x 10(-12) and 0.010 (X = 0.0021)/100 persons/year, thus envenomation rate at Rio Seco, Falcon State, Venezuela, can be considered of "very high" or epidemic. Sinanthropic and domestic habits of scolopendromorphae centipedes increase the frequency of stings. Only symptomatic therapeutical treatment was required.

Adolescent↗

Male sex pheromones and the phylogeographic structure of the Lutzomyia longipalpis species complex (Diptera: Psychodidae) from Brazil and Venezuela.

Lutzomyia longipalpis, a sibling complex, is the main vector of Leishmania chagasi/infantum. Discriminating between siblings is important as they may differ in vectorial capacity. Lutzomyia longipalpis populations display distinct male sex pheromone chemotypes. We investigated the phylogeographic pattern of variation at microsatellite loci from 11 populations from Brazil and Venezuela related to their male pheromone. Temporal genetic differentiation was mostly not significant at the same site. Spatial genetic differentiation was, however, strong, although there was only a weak relationship between genetic differentiation and the geographic distance separating the samples (r2 < 0.10); geographic separation explained a much greater (54-97%) percentage of the genetic differences among populations when samples with the same pheromone type were analyzed separately. A cluster analysis showed five groups: Lu. cruzi (Brazil) and Lu. pseudolongipalpis (Venezuela) as separate species, two (mostly 9-methyl-germacrene-B) Venezuelan and Brazilian groups, and a very distinct cluster of Brazilian cembrene populations.

Animals↗

[Seroprevalence of Hepatitis C Virus (HCV) in patients of the Regional Viral Reference Laboratory (Maracaibo, Venezuela)].

PURPOSE: Collect and analyze information regarding seroprevalence of Hepatitis C Virus (HCV) in a population of 722 patients that visited the Regional Viral Reference Laboratory (Maracaibo, Venezuela) during the years 2000-2003. MATERIAL AND METHODS: An immunoenzymatic test INNOTEST HCV Ab IV of Innogenetics was used to evaluate the presence of IgG type antibodies against the Hepatitis C Virus (HCV) in the serum of the patients studied. Results obtained with respect to seroprevalence and other epidemiological variables, were organized and analyzed using SPSS 10.0 (Chicago, USA) and Origin Pro 7.5 (Northampton, USA) software. RESULTS: A seroprevalence of 2.63% (19,322) was found, higher than that reported in Venezuela for the general population (0.9%) and other groups. The infection was more frequent in men than in women. The most common symptoms in the infected patients were jaundice and cephalalgia (31.58%). CONCLUSION: The data reported shall update previous research in the zone and indicates the need to develop epidemiological control for Hepatitis C Virus (HCV) in the State of Zulia.

Adolescent↗

[Homocysteinemia and its relationship with the methylentetrahydrofolate reductase polymorphism in various ethnic groups from western Venezuela].

The prevalence of hyperhomocysteinemia and C677T MTHFR polymorphism was studied in various ethnic groups from Western Venezuela (60 Wayuu Indians, 42 italian immigrants and 77 Venezuelan mestizos) in relation with the prevalence of hyperhomocysteinemia and the C677T MTHFR polymorphism. Homocysteinemia was determined by polarized fluorescence immunoassay in an IMX system, serum folate was measured by radioimmunoanalysis and the MTHFR genotype was determined by PCR and restriction analysis. Hyperhomocysteinemia was defined as a value over 2 SD above the mean value for normal MTHFR (CC677) in each group. The prevalence of MTHFR variants (C677T and 677TT) was elevated in all ethnic groups (78% among the wayuu, 76% among Italians and 63% among mestizos) with a significant association between the concentrations of homocysteine and the levels of serum folate among the wayuu (p < 0.0001) and the mestizos (p < 0.001) only. Hyperhomocysteinemia was associated with MTHFR variants in 23% of the wayuu (OR: 6.17, CI 95: 0.74-51.36), 9.5% of the Italians (OR: 0.93, CI 95: 0.085-10.10) and 20.7 of the Venezuelans mestizos (OR: 5.2, CI 95: 1.08-24.90, p > 0.03). There was no relationship between hyperhomocysteinemia and folate deficiency in any of the groups studied. In conclusion, despite a high prevalence of C677T MTHFR variants in these ethnic groups of western Venezuela, the lack of no evidence of hyperhomocysteinemia combined with folate deficiency may imply that the nutritional status of these groups plays an important role in the control of hyperhomocysteinemia as a risk factor for cardiovascular disease.

Adolescent↗

[Basal insulin levels in a Zulia State population in Venezuela].

This study examines the basal insulin levels in a population from Zulia state (Venezuela). A total of 1703 subjects (1175 women and 528 men) from five different sanitary regions (Maracaibo, La Guajira, Perijá, Sur del Lago de Maracaibo, y Costa Oriental del Lago de Maracaibo) were studied. Weight, height, waist and hip circumferences, and blood pressure were determined. A blood sample was taken after a 12-h overnight fast to determine serum glucose, triglycerides, total cholesterol and HDL-C using enzymatic methods and insulin by radioimmunoassay. According to ATP III criteria two groups were established: a group without metabolic abnormalities (138 subjects) and a group with some metabolic abnormalities 84.8% of subjects of the non metabolic alteration groups and 80.4% of the group with some metabolic alteration were of mixed race. Non metabolic altered lean subjects (BMI <25 Kg/m2) had the lowest (p < 0.0001) basal insulin levels compared to the ones with overweight from the same group and the obese with metabolic abnormalities. This study proposes to consider a cutoff basal insulin levels of 13 microU/mL for women and 11 microU/mL for men, over 20 years of age, in the Zulia state region of Venezuela.

Adult↗

[Trypanosomatidae of public health importance occurring in wild and synanthropic animals of rural Venezuela].

INTRODUCTION: Chagas disease and leishmaniasis are important public health problems due to their high frequency and broad distribution in Latin America. Understanding of the roles of reservoir animals is crucial for a global assessment of the epidemiology of these diseases. OBJECTIVE: To identify parasites classed as Trypanosomatidae as they occurred in sylvatic animals, and to establish rates of coinfection. MATERIALS AND METHODS: Sylvatic animals were systematically captured in the rural area of El Carrizal, Merida State, Venezuela, betweenJuly, 1998 and February, 2000. The captures were made in Tomahawk type homemade traps, placed 15 nights per month throughout the study period. Blood was extracted from each captured and anesthetized animal by means of cardiac puncture. The search for trypanosomatids was undertaken by fresh blood examination, Giemsa stained blood smears and by means of blood-agar culture. Occasional xenodiagnoses were made to check diagnostic accuracy. The isolates obtained in culture media were identified by restriction fragment analysis and hybridization with specific probes. RESULTS: Three species of sylvatic animals (n = 215) were captured: Rattus spp. (135), Sigmodon hispidus (73) and Didelphis marsupialis (7). From them, three species of Trypanosomatidae were identified: Leishmania (Viannia) guyanensis, Trypanosoma cruzi and Trypanosoma lewisi. Trypanosoma. cruzi was identified in D. marsupialis (4/7), S. hispidus (1/73) and Rattus spp. (1/ 135), whereas L. (V.) guyanensis and T. lewisi were identified only in Rattus spp., 1/135 and 12/ 135, respectively. CONCLUSIONS: The coexistence of these genetically related hemoflagellates in sylvatic hosts was important for understanding the immunological interactions that may be established in reservoir animals, and the possible implications that this may have for the susceptible host. Finally, the identification of L. (V.) guyanensis in Rattus spp and T. cruzi in S. hispidus constituted the first reports of this relationship in Venezuela.

Animals↗

IgM antibodies to native phenolic glycolipid-I in contacts of leprosy patients in Venezuela: epidemiological observations and a prospective study of the risk of leprosy.

In a randomized, double-blind vaccine trial in Venezuela, about 29,000 contacts of leprosy patients have been vaccinated with either a mixture of heat-killed Mycobacterium leprae and BCG or BCG alone, and are being re-surveyed annually to detect new cases of leprosy. All contacts had a serum sample collected at the time of entry into the trial, and 13,020 of these sera have been analyzed for antibodies to phenolic glycolipid-I (PGL-I). Antibody levels have been related to various characteristics of the contacts and to their risk of developing leprosy in the following 4 years. A strong association was found between PGL-I antibody level and the risk of developing leprosy, in spite of possible modification of the incidence rate induced by vaccination. Antibody levels were higher in females than in males, and declined progressively with age. Household contacts had higher levels than did non-household contacts, and levels were higher in individuals from the state in Venezuela which has the highest incidence of the disease. No substantial differences were found in antibody levels between contacts of multibacillary and paucibacillary patients, which may in part reflect the influence of treatment, and there was no clear association with the presence of BCG or lepromin scars or with skin-test responses to PPD and leprosy soluble antigen. The assay of antibodies to PGL-I seems unlikely to provide a sensitive or specific test for infection with M. leprae, and measuring PGL-I antibody levels as a screening procedure to identify those at high risk of developing leprosy is unlikely to be particularly useful in most leprosy control programs. Such assays may be useful for the epidemiological monitoring of changes in the intensity of infection with M. leprae in a community and for the study of carefully defined groups of contacts during some phases of control programs.

Adolescent↗

A genetic study of the malaria vector Anopheles nuneztovari from western Venezuela.

A photomap of larval polytene chromosomes of Anopheles nuneztovari (population B) from western Venezuela is presented. Samples of An. nuneztovari B taken from 4 study sites in the states of Barinas and Táchira comprise a single panmictic population, which is chromosomally identical to the cytotype identified by Kitzmiller et al. (1973) from western Venezuela and Colombia. The frequency of polymorphism 2La has increased significantly in the 16 years that have elapsed since the 1973 study. In addition, inversion 2La does not conform to Hardy-Weinberg equilibrium. These 2 changes are most likely due to environmental alterations which have resulted in the heterozygous condition becoming more locally adaptive.

Animals↗

Soft contact lens damage: a one-year study in Caracas, Venezuela.

We reviewed 424 requests for soft contact lens cleaning that had been sent to a service laboratory in Caracas, Venezuela in the course of a year. We believe that this sample represents a cross-section of problem lenses in a tropical country (Venezuela). Among the cases for which data were available, there were more extended wear lenses than daily wear lenses sent for cleaning. A majority of the lens wearers were females and/or over age 20. The wearers were experienced handling their lenses. A relatively high percentage of them (52 of 184; 28%) used homemade solutions (unpreserved saline, distilled water, tap water, and/or baby shampoo) for the care and cleaning of their lenses. Although the reasons for referral were similar to those reported from temperate zones, we found a much higher incidence of combined deposits (protein-lipid-inorganic) than reported in studies carried out in other countries. Fungal invasion seemed more prevalent in our area than in temperate zones. From our results, the need for better education of wearers is obvious. In addition, special measures for the control of fungal growth may be required locally. The high incidence of this type of growth may be partly related to tropical conditions that favor the dispersal of fungal spores.

Adolescent↗

Epidemiological aspects of porcine rotavirus infection in Venezuela.

The prevalence of porcine rotavirus infection in Venezuela was studied from November 1980 to November 1981. Rotaviruses were identified in 21.3 per cent of 286 diarrhoeic samples analysed by electron microscopy and in none of the 48 controls. Rotaviruses were readily detected throughout the year, which may correspond to the absence of seasonal climatic variations in a tropical country such as Venezuela. Rotavirus infection was frequently observed in pigs that were two to six weeks old and was rare in younger animals. The age distribution of rotavirus infection correlated well with the presence of circulating antibodies, as measured by the complement fixation test. Sucking pigs less than two weeks old appeared to be protected from the infection by passive immunity; no antibodies were detected in the two- to three-week-old group, coinciding with an increased susceptibility to rotavirus infection. The antigenic specificity of the rotavirus isolates was confirmed by enzyme-linked immunosorbent assay test, using antibodies directed against the group-specific antigen of human rotavirus. Polyacrylamide gel electrophoresis of viral double-stranded RNA revealed an heterogeneity on the electropherotype of selected samples obtained at different times during the study period.

Age Factors↗

Air sampling studies in tropical America (Venezuela). Frequency and periodicity of pollen and spores.

Updated information on airborne particles is not currently available in Venezuela. Thus the diagnosis and treatment of respiratory allergy in this country is by necessity based on imported data and allergens. We have therefore carried out air-sampling studies in Caracas, the capital of Venezuela, a city with a tropical climate. A numerically constant pollen load was encountered in the air throughout the year. Most pollen was contributed by trees and by foreign species. A seasonal grass peak was observed in November which may be the cause of true pollinosis or hay fever. Pollen of the ragweed family was rarely observed. A great diversity of molds contributed to the annual spore count. The contribution of individual molds was rather low, thus casting some doubt on the potential role of airborne molds as allergens in the tropics. As in the case of pollen a rather constant load of mold spores was present in the air throughout the whole year.

Air Microbiology↗

Occupational medicine in a developing society: a case study of Venezuela.

Recent activities of the World Health Organization and other international agencies have placed new emphasis on occupational health in developing nations. Venezuela is a nation in transition from a developing society dominated economically by petroleum and agriculture to an economically-diversified industrialized urban society. It provides a case study which illuminates the problems of extending occupational health services in developing economies and questions of public policy regarding utilization of medical resources and the priority that occupational health should hold in such a society. Occupational health has become a serious problem in the developing world as new industries and accelerating ecnomic development occur without adequate resources for worker protection. The study of cases such as that of Venezuela may provide guidance for anticipating and preventing problems in other nations. This paper should be considered a pilot study to explore a social aspect of occupational health that has not received adequate attention.

Developing Countries↗

[Program for the production of mollusks in Venezuela].

This paper discusses an integrated project in Venezuela, planned and designed to ascertain the best procedures required for production of large quantities of shellfish, including: selection and maintenance of pollution-free growing areas; the best harvesting methods; and the safest and most economical marketing procedures. The major problems involved in producing safe, wholesome and nutritious shellfish are primarily those of sanitation and adequate preservation of the foods until they finally reach the consumer. Therefore, it is essential that these products be produced and handled in a sanitary manner on a continuous basis. There are numerous codes of recommended handling practices for shellfish, most developed only after many technical conferences were organized to evaluate all of the available scientific evidence. Therefore, for producing safe shellfish in Venezuela, this publication recommends the adoption of these sanitary and handling practices, designed and tested by the faculty and staff personnel of Universidad Simón Bolívar.

Animals↗

[Hepatitis C in hemophiliac patients in Maracaibo, Venezuela].

Infection with the hepatitis C virus is one of the risks of transfusion therapy. Considering that in Venezuela, there are not enough data that permit one to establish the frequency of hepatitis C in transfused patients, the purpose of this work was to investigate the presence of anti hepatitis C virus (HCV) antibodies in 56 hemophilic patients from Zulia State, Venezuela. Thirty six (64%) had received fresh frozen plasma and/or cryoprecipitate. Another fourteen (25%) also received lyophilized F VIII or prothrombin complex; six patients (10%) were never transfused. The positive samples (EIA 2nd. generation) were reconfirmed by RIBA-2. Twenty two of the patients were positive for HCV. The presence of anti-HCV antibodies was mainly detected in patients that received more than 10.000 U of the deficient factor. Four of the patients with HCV were also positive for the Human Immunodeficiency Virus (HIV). The results suggest that although the transfusion of blood derivatives carries the risk of HCV transmission, our patients show a low prevalence of this disease, probably due to the infrequent use of clotting factors lyophilizates.

Adolescent↗

Very low frequency of latex and fruit allergy in patients with spina bifida from Venezuela: influence of socioeconomic factors.

BACKGROUND: The prevalence of latex allergy appears to be substantially higher in certain high risk groups, particularly in children with spina bifida. The source of this increase is presently unknown and may be due either to increased infantile exposure or to an intrinsic predilection for atopy in this condition. OBJECTIVE: We attempted to ascertain the prevalence of latex and tropical fruit allergy in children of lower socioeconomic strata with spina bifida from Caracas, Venezuela, who have limited operative and other medical exposure to latex. METHODS: Ninety-three unselected patients with spina bifida from clinic and hospital populations were prick tested with commercial (Stallergenes-Pasteur) latex extract and crude glove (Baxter-Triflex, 1/5 wt/vol) latex extract as well as with standardized mite and cockroach, 1/10 wt/vol, extracts (Hollister-Stier). An array of tropical fruits were also included in the battery of skin test materials, using the prick by prick method. Careful family and personal history for allergy as well as any reactions to rubber products were noted, placing emphasis on intraoperative anaphylaxis, number of operations and use of bladder catheters. RESULTS: Only four patients of the 93 skin tested (4.3%) were positive to latex. Atopy was not a predisposing factor for latex allergy and neither was the number of surgical interventions. No fruit allergy was found in this population and three of the four skin test-positive patients had facial angioedema when exposed to balloons. CONCLUSIONS: The very low incidence of latex allergy found in our patients with spina bifida could very well be due to a low level of rubber exposure as best exemplified in the use of nonlatex bladder catheters, frequently washed and resterilized surgeon's gloves, and low number of operations per patient. The fact that atopy was no more prevalent in children with spina bifida than in the general population in Venezuela strongly supports exposure level as the major factor determining latex sensitization.

Adolescent↗