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PubMed1992

Prevalence of Entamoeba histolytica and other intestinal parasites in a community from Maracaibo, Venezuela.

The prevalences of Entamoeba histolytica and other intestinal parasites were assessed in a suburban community of Maracaibo, Venezuela, by examination of a stool specimen from each of 342 individuals, using iron-haematoxylin stained faecal smears and formalin-ether concentration. The overall parasitic infection rate was 80.4%, and 65.8% of the population had multiple infections. The overall amoebic infection rate, which was highest in female adults, averaged 39.7%. The E. histolytica infection rate was 8.7% and most of those infected were passing cysts. Entamoeba polecki was observed in two samples. Amongst the protozoa, Entamoeba coli was observed most frequently (24.8%) and Giardia lamblia was the predominant pathogen (13.0%). Trichuris trichiura (71.9%) and Ascaris lumbricoides (54%) were the most common parasites, particularly in school-children. The high rates of parasitic and multiple infections reflect the low socio-economic status of the community studied.

Adolescent↗
PubMed1992

Didelphis marsupialis: a primary reservoir of Trypanosoma cruzi in urban areas of Caracas, Venezuela.

Direct blood examination and xenodiagnosis of 45 sylvatic, peridomestic or domestic mammals from the Caracas valley, Venezuela, revealed trypanosome infection in six of the 24 opossums, Didelphis marsupialis, collected in urban areas. Isolates were successfully made of trypanosomes from four of the opossums, using the parasites which developed in Rhodnius prolixus fed on the infected opossums to infect NMRI mice. The prepatent period, course of parasitaemia, morphology of bloodstream trypomastigotes, tissue tropism of parasites in the opossums and/or mice, host mortality, morphology of parasites in the bugs, and infectivity to mice of parasites in the faeces of infected bugs, were all characteristic of Trypanosoma (Schizotrypanum) cruzi. In mice, the parasites showed marked myotropism; the heart, skeletal muscle and the smooth muscle of the urinary bladder, penis, prostate, seminal vesicle, lung, stomach, jejunum and colon were frequently invaded, and pseudocyts were also occasionally found in the liver, brain and pancreas. The significance of the invasion of the genito-urinary structures as a possible alternative parasite transmission route is discussed. The possible role of D. marsupialis, as a primary reservoir of T. cruzi, in the establishment of foci of Chagas' disease in Caracas and other Latin American cities, is emphasized.

Animals↗
PubMed1994

Cutaneous leishmaniasis in Tachira State, Venezuela.

Cutaneous and mucocutaneous leishmaniases are widely spread in the mountainous Andean regions of South America. In Venezuela, these regions consist of the coffee-growing states of Trujillo, Merida and Tachira. Entomological and parasitological investigations in three geographically different climatic zones (Lomas Bajas, Delicias and La Grita) in Tachira state have shown a predominance of the sandfly species Lutzomyia spinicrassa (verrucarum group) and two Leishmania species, Leishmania mexicana and Leishmania braziliensis. Two transmission cycles appear to occur: a peridomestic cycle in Lomas Bajas and a sylvatic one in Delicias and La Grita.

Adolescent↗
PubMed1994

Epidemiology of cutaneous leishmaniasis in Merida, Venezuela. III. Altitudinal distribution, age structure, natural infection and feeding behaviour of sandflies and their relation to the risk of transmission.

An entomological survey revealed that the distribution of the Lutzomyia species in Merida, Venezuela, varies with altitude. Of the 21 species encountered, 12 (57%) are known to be anthropophilic. The significance of the predominant man-biting species at any altitude is discussed in terms of the risk of transmission of cutaneous leishmaniasis. The general parous rate (and perhaps the ability of a female sandfly to survive oviposition and transmit Leishmania parasites during a second or subsequent bloodmeal) was found to be related to rainfall and altitude. The finding of Leishmania infections in wild-caught parous females of anthropophilic species indicates the high risk of acquiring leishmaniasis in the study area. Observations on the feeding habits of the sandflies indicate that some species are opportunistic feeders, attracted to a variety of hosts, including man.

Altitude↗
PubMed1995

Phlebotomine sandflies in Venezuela. IV. Review of the Lutzomyia subgenus Micropygomyia (Diptera:Psychodidae), with a description of L. absonodonta n. sp. and the male of L. lewisi.

The subgenus Micropygomyia, of the genus Lutzomyia, is reviewed. A new species, Lutzomyia absonodonta, previously misidentified as L. micropyga, and the male of L. lewisi are described. Illustrated keys for identifying male and female flies of the Micropygomyia species in Venezuela, distribution maps and notes on the ecology of each species are also provided.

Animals↗
PubMedDate not supplied

Snuff synergy: preparation, use and pharmacology of yopo and Banisteriopsis caapi among the Piaroa of southern Venezuela.

Current understanding of the preparation and use of yopo, a hallucinogenic snuff made from the ground seeds of the Anadenanthera peregrina tree, has departed little from the accounts of scientists and travelers made over a century ago. Schultes and others have made refinements to these early accounts. While several scholars have drawn attention to the fact that little ethnographic work has been conducted to assess the ethnobotanical diversity and cultural framework of the snuff hallucinogen complex, few subsequent studies deal with botanical variations in preparation and use. This article contrasts historical accounts of yopo preparation with ethnographic data I have recently collected among the Piaroa of southern Venezuela to demonstrate one way in which yopo preparation and use deviates from the basic model established by Humboldt, Spruce and Safford. Piaroa shamans include B. caapi cuttings in the preparation of yopo and consume doses of B. caapi prior to snuff inhalation concomitant with the strength of visions desired for particular tasks. I argue that the combined use of yopo and B. caapi by Piaroa shamans is pharmacologically and ethnobotanically significant, and substantiates claims of the use of admixtures in snuff; further ethnographic investigation of the snuff hallucinogen complex is necessary.

Alkaloids↗
PubMedDate not supplied

The age at menarche in Carabobo, Venezuela with a note on the secular trend.

A study of the age at menarche was conducted in the state of Carabobo as part of Project Venezuela, a National Human Growth, Nutrition and Family Survey. The study was performed during 1978 on a cross-sectional random stratified sample which included 955 girls between the ages of 9 and 20 years. Data were collected using the status quo method. The median age at menarche was estimated by logits at 12.68 0.08 for all socio-economic groups. Sexual maturation occurred earlier in girls from stratum III and later in those from strata IV and V; 12.34 0.11, 12.59 0.11, and 12.86 0.12, respectively. Small sample size did not permit comparisons with strata I and II girls. The results indicate a secular trend in the age of menarche when compared with previous Venezuelan studies. Median age for all Carabobo girls is comparable and often slightly lower than recent data from European and American studies.

Adolescent↗
PubMed2006

Chromoblastomycosis in children and adolescents in the endemic area of the Falcón State, Venezuela.

The present paper describes 22 cases of chromoblastomycosis (CBM) caused by Cladophialophora carrionii in children and adolescents (2-19 years old). The patients were seen between 1992 and 2004 and all resided in a CBM endemic area in the semi-arid zone of the Falcón state, Venezuela. Twelve of the 22 patients (54.55%) had close relatives who also had CBM and 19 (86.36%) were male. Lesions consisted of erythematous papules with desquamation or squamous plaques (0.12-14.19 cm in diameter), located primarily on the upper limbs (77.27% of patients). Thirteen of the patients were treated with topical 5-fluorouracil (5-FU; 1% cream), seven with topical ajoene (0.5% gel) and two had electrodesiccation and/or fulguration. Two patients who did not respond to 5-FU were treated with oral itraconazole (100 mg/day for 1 month). Complete clinical and mycological remission was achieved in 17/20 (85%) of the patients treated with 5-FC, ajoene and electrodesiccation and/or fulguration. In addition, similar results were obtained with the two patients who received itraconazole therapy. These cases emphasize the importance of early diagnosis in difficult-to-treat mycotic diseases such as CBM. By early intervention we were able to employ topical treatment with a minimum of adverse effects to achieve a high percentage of favorable therapeutic responses. The patients were thus able to avoid the evolution of the chronic, deforming and incapacitation clinical manifestations associated with CBM.

Administration, Oral↗
PubMedDate not supplied

Sex ratio at birth deviations in modern Venezuela: the Trivers-Willard effect.

This study evaluates the impact of the Trivers-Willard (T-W) effect on human populations, using demographic data collected from vital registration data in Venezuela. The evaluation of the sex ratio at birth (SRB) and of fetal and infant deaths supports the existence of T-W effect in the Venezuelan population in extreme conditions. This T-W effect was observable in the SRB but not at later ages and is related to the marital status of the mother. The results indicate that the investment in females associated with environmental adversity is greater than the investment in males associated with good environmental conditions.

Bias↗
PubMedDate not supplied

Women's roles and family formation in Venezuela: new forms of consensual unions?

This paper assesses the effects of changes in women's education and labor force participation on nuptiality patterns and their implications for fertility decline in Venezuela. Results show that together with delays in union formation, changes in women's education and labor force participation produced a different, more "modern" type of consensual union, which coexists with "traditional" consensual unions. "Traditional" consensual unions remain a substitute for formal marriage among women from rural origins with low levels of education and higher levels of work experience. "Modern" consensual unions appear to be an option for well-educated women of urban origins. As in developed countries, these unions assume the form of a trial period before marriage or an alternative to singlehood. "Modern" consensual unions are more unstable than "traditional" consensual unions and they are associated with lower fertility.

Adult↗
PubMed2003

Horizontal transmission of rhesus monkey rotavirus-based quadrivalent vaccine during a phase 3 clinical trial in Caracas, Venezuela.

During a phase 3 clinical trial of rhesus monkey rotavirus-based quadrivalent vaccine in Venezuela, 2207 infants received 3 oral doses of vaccine (4 x 105 plaque-forming units/dose) or placebo at ages approximately 2, 3, and 4 months; 219 (14%) of 1537 stools obtained during 1550 diarrheal episodes in postvaccination surveillance were rotavirus-positive by enzyme-linked immunosorbent assay. With the use of various VP7 and VP4 primers for genotyping purposes, 213 of 219 rotavirus-positive stools were analyzed by reverse-transcription polymerase chain reaction. Twenty-nine (14%) of 213 rotavirus-positive stools contained at least 2 distinct rotavirus strains: a low-titered vaccine strain(s) and a second strain that, when possible, was studied further and found to be a wild-type rotavirus strain. The titer of vaccine viruses in 19 stools that plaqued directly in cell cultures ranged from 10(1) to 10(3) plaque-forming units/0.5 mL of a 10% stool suspension. Reassortants of vaccine virus and wild-type human rotavirus were not detected.

Animals↗
PubMedDate not supplied

Human T cell leukemia virus type I and Epstein-Barr virus antibodies in homosexuals and hemophilia patients from Venezuela.

The presence of serum antibodies to human T-cell leukemia/lymphoma Virus-I (HTLV-I) and to Epstein-Barr Virus (EBV) was studied in homosexuals and hemophilia patients from the State of Zulia (Venezuela), a highly endemic area for HTLV-I infection. No serum antibodies to HTLV-I were detected despite the presence of alterations in peripheral blood lymphocyte subsets. Anti-EBV antibodies in homosexuals were indicative of persistent infection with this virus. Our results suggest that HTLV-I does not play a role in the immunological alterations in homosexuals or hemophiliacs in an area of high prevalence for this virus.

Antibodies, Monoclonal↗
PubMed2006

Antimicrobial resistance of Pseudomonas aeruginosa strains isolated from surgical infections in a 7-year period at a general hospital in Venezuela.

BACKGROUND: By definition, the term "surgical infection" implies that surgery plays the major role in therapy, whereas antimicrobial chemotherapy is only supplementary. Despite this view, the efficacy of such drugs is relevant, and for this reason, drug activity surveillance is necessary, especially for opportunistic and nosocomial pathogens such as Pseudomonas aeruginosa. We evaluated bacterial isolates from patients with suspected surgical infections in a hospital of Caracas, Venezuela (West General Hospital) between 1997 and 2003. METHODS: Clinical samples were processed and identified with standard cultures and biochemical tests. The antimicrobial susceptibility of the isolates in vitro was assessed by an agar disk diffusion method using Mueller-Hinton agar, as recommended by the National Committee for Clinical Laboratory Standards (now the Clinical and Laboratory Standards Institute). Isolates were tested against 22 drugs, including piperacillin, ceftazidime, cefoperazone, amikacin, gentamicin, ciprofloxacin, meropenem, and imipenem. RESULTS: From a total of 16,287 bacterial strains isolated from surgical infections during the study period, 243 (1.5%) were P. aeruginosa. Of this total, 30.9% were resistant to gentamicin, 26.3% to tobramicin, 23.0% to cefoperazone, 22.8% to piperacillin, 22.5% to ciprofloxacin, 17.6% to amikacin, 13.6% to imipenem, and 12.9% to meropenem. The best antimicrobial activity was observed with cefepime (90.1% susceptible strains, 1.9% intermediate resistance, and 8.0% resistant strains) and aztreonam (77.7% susceptible strains, 15.2% intermediate resistance, and 7.1% resistant strains). CONCLUSIONS: In our setting, cefepime is most active against strains of P. aeruginosa. In comparison with third-generation cephalosporins, cefepime may be less likely to induce resistance. Surveillance of antimicrobial activity should be done periodically to guide therapy of surgical infections.

Adolescent↗
PubMed1994

A population-based clinical trial with the SPf66 synthetic Plasmodium falciparum malaria vaccine in Venezuela.

A phase III malaria vaccine trial in 13 villages in an endemic area, South Venezuela, compared incidence rates of Plasmodium falciparum and Plasmodium vivax infections in 1422 vaccinated and 938 nonvaccinated subjects over 18 months. The SPf66 vaccine was given in three doses, on days 0, 20, and 112. Vaccination was complete in 976 subjects (68.7%). Minor side effects requiring no treatment were reported by 123 (12.6%), with an apparent increase in frequency from the first to the third vaccine dose. No autoimmune evidence was observed in a sample of subjects. Antibodies against SPf66 were present at low titers in 24.7% of tested subjects before vaccination, increasing to 53.6% after the second dose and to 73.6% after the third dose; 26.4% of subjects initially seronegative never seroconverted. The SPf66 malaria vaccine showed a protective efficacy of 55% (95% confidence interval, 21%-75%) against P. falciparum and of 41% (19%-57%) against P. vivax malaria.

Adolescent↗
PubMed1996

The impact of rotavirus disease in Venezuela.

Information concerning the disease burden of rotavirus, particularly in developing countries, has important implications for the use and for monitoring the impact of rotavirus vaccines. Although rotavirus has been recognized as the most frequent cause of hospitalization in the world, national estimates and specific information about the incidence of hospitalization for rotavirus gastroenteritis are very limited. Consequently, estimates of the incidence of hospitalization among children during the first 2 years of life in Venezuela were determined by extrapolation of data from a community-based study carried out in Caracas.

Child, Preschool↗
PubMed1992

Phlebotomine sandflies in Venezuela: review of the verrucarum species group (in part) of Lutzomyia (Diptera: Psychodidae) with description of a new species from Lara.

The series townsendi and verrucarum of the verrucarum species group of the phlebotomine genus Lutzomyia França are reviewed. Lutzomyia nadiae, new species, from the mountains of Yacambú, Lara State, is described. Distribution maps, illustrated keys, notes on medical importance, taxonomy, and ecology are presented for species in these series known from Venezuela.

Animals↗
PubMed1997

Hourly activity of Lutzomyia ovallesi and L. gomezi (Diptera:Psychodidae), Vectors of cutaneous leishmaniasis in northcentral Venezuela.

The comparative hourly activity of Lutzomyia ovallesi (Ortiz) and L. gomezi (Nitzulescu), vectors of cutaneous leishmaniasis in Miranda State, Venezuela, was studied between November and March during 1991-1994 using a Shannon trap with a fluorescent light. Female abundance of L. ovallesi increased from 1800 to 2000 hours, plateaued from 2000 to 2400 hours, then decreased progressively. L. gomezi always exhibited maximum activity between 1900 and 2000 hours, then declined abruptly. The importance of these activity patterns in Leishmania transmission is discussed.

Animals↗
PubMed2005

Ecological characterization of the aquatic habitats of mosquitoes (Diptera: Culicidae) in enzootic foci of Venezuelan equine encephalitis virus in western Venezuela.

We studied the aquatic mosquito habitats in and around enzootic foci of Venezuelan Equine Encephalitis virus (VEE) in western Venezuela. Specimens were sampled for 5 mo in three types of vegetation: tall lowland tropical forests, short inundated/secondary growth forests, and pastures/herbaceous vegetation around forests. Ground pools, flooded pastures, swamps, ponds, and canals predominated. We used a multivariate statistical approach to quantitatively assess the relationships of mosquito species with broad categories of the landscape, and with environmental variables within each aquatic habitat. Twenty-four mosquito species in the genera Aedes, Psorophora, Culex, Mansonia, and Uranotaenia were collected. Species richness was higher in the tall forests than in other types of vegetation. Discriminant Function Analysis showed a strong association between landscape category and mosquito species assemblage and identified Culex erraticus Dyar & Knab and Mansonia titillans Walker as indicator species of open areas, and Aedes serratus Theobald as an indicator of tall forests. M. titillans, Uranotaenia geometrica Theobald, Cx. erraticus, and Culex dunni Dyar were associated with unshaded, warm, vegetated waters in flooded pastures and swamps, whereas Ae. serratus, Aedes fulvus (Wiedemann), Psorophora albipes Theobald, Psorophora ferox (Humboldt), Culex caudelli Dyar & Knab, and Culex pedroi Sirivanakarn & Belkin were associated with small, shaded ground pools within the tall forests. Culex coronator Dyar & Knab was associated with partially exposed sites within short forests. These results allowed us to interpret better our previous studies on mosquito adult spread in the study area and their possible role as VEEV disseminators.

Animals↗