Human mixed infections of Leishmania spp. and Leishmania-Trypanosoma cruzi in a sub Andean Bolivian area: identification by polymerase chain reaction/hybridization and isoenzyme.
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Parasites belonging to Leishmania braziliensis, Leishmania donovani, Leishmania mexicana complexes and Trypanosoma cruzi (clones 20 and 39) were searched in blood, lesions and strains collected from 28 patients with active cutaneous leishmaniasis and one patient with visceral leishmaniasis. PCR-hybridization with specific probes of Leishmania complexes (L. braziliensis, L. donovani and L. mexicana) and T. cruzi clones was applied to the different DNA samples. Over 29 patients, 8 (27.6%) presented a mixed infection Leishmania complex species, 17 (58.6%) a mixed infection Leishmania-T. cruzi, and 4 (13.8%) a multi Leishmania-T. cruzi infection. Several patients were infected by the two Bolivian major clones 20 and 39 of T. cruzi (44.8%). The L. braziliensis complex was more frequently detected in lesions than in blood and a reverse result was observed for L. mexicana complex. The polymerase chain reaction-hybridization design offers new arguments supporting the idea of an underestimated rate of visceral leishmanisis in Bolivia. Parasites were isolated by culture from the blood of two patients and lesions of 10 patients. The UPGMA (unweighted pair-group method with arithmetic averages) dendrogram computed from Jaccard's distances obtained from 11 isoenzyme loci data confirmed the presence of the three Leishmania complexes and undoubtedly identified human infections by L. (V.) braziliensis, L. (L.) chagasi and L. (L.) mexicana species. Additional evidence of parasite mixtures was visualized through mixed isoenzyme profiles, L. (V.) braziliensis-L. (L.) mexicana and Leishmania spp.-T. cruzi. The epidemiological profile in the studied area appeared more complex than currently known. This is the first report of parasitological evidence of Bolivian patients with trypanosomatidae multi infections and consequences on the diseases' control and patient treatments are discussed. (+info)
Breastfeeding in Bolivia - information and attitudes.
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BACKGROUND: The main objective of the present study was to investigate the relationship between the attitudes of the mother and her family towards breastfeeding and the actual feeding pattern in a Bolivian population. A second objective was to study the relationship between breastfeeding information, specified according to source and timing, and feeding pattern. METHODS: Cross-sectional interviews with 420-502 Bolivian mothers with an infant less than or equal to 1 year of age. Duration of exclusive breastfeeding, use of prelacteal food and/or colostrum were the main outcome measures. RESULTS: The attitudes of the mother, her partner (the infant's father) and the infant's grandmother towards breastfeeding did not influence the infant feeding pattern. Women who had received breastfeeding information from health care personnel before birth or on the maternity ward breastfed exclusively for a longer duration (adjusted p = 0.0233) and avoided prelacteal food to a greater extent (adjusted odds ratio (AOR) = 0.42; 95% confidence interval for adjusted odds ratio (95% CI AOR) = 0.23-0.72). Information from a doctor before birth or on the maternity ward was associated with less use of prelacteal food (AOR = 0.53; 95% CI AOR = 0.31-0.93), an increased use of colostrum (AOR = 3.30; 95% CI AOR = 1.16-9.37), but was not linked to the duration of exclusive breastfeeding (p = 0.1767). CONCLUSION: The current study indicates that breastfeeding information delivered by health care personnel in a non-trial setting may affect the infant feeding pattern including the use of prelacteal foods and colostrum. There was no evidence that the attitudes of the mother, or the infant's father or grandmother influenced actual feeding behavior. The lack of a "negative or neutral attitude" towards breastfeeding in the participants of the current study does, however, diminish the chances to link attitude to feeding behavior. (+info)
Breastfeeding intentions, patterns, and determinants in infants visiting hospitals in La Paz, Bolivia.
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BACKGROUND: Recent ecological research from Latin America has shown that infant health could be promoted through exclusive breastfeeding in infants aged 0-3 months and partial breastfeeding throughout the remainder of infancy. METHODS: In a cross-sectional study in 1995, the author interviewed 518 mothers with infants leq; 1 year in La Paz, Bolivia, to describe the breastfeeding pattern and its determinants including socio-economic, religious and ethnic background. RESULTS: The rate of any breastfeeding remained above 85% during the first year. Exclusive breastfeeding rates fell from 89% at one week of age to 45% as early as one month of age, and then gradually declined to 20-25% in 6-month-old infants. The overall exclusive breastfeeding rate in infants < 4 months was 46% (n = 246). The use of prelacteal feeds (p < 0.0001, n = 436), not feeding the infant colostrum (p = 0.0008, n = 436), and Latin ethnicity (p = 0.0091, n = 436) were associated with a shorter duration of exclusive breastfeeding. Rural mothers were four times more likely to discard the colostrum than urban mothers (p = 0.0110, n = 501). Actual exclusive breastfeeding duration was shorter than what the mothers reported to be the ideal duration of exclusive breastfeeding for the infant. CONCLUSIONS: The rate of exclusive breastfeeding in Bolivian infants fell rapidly during the first months of life. Avoidance of prelacteal feeding and use of colostrum were associated with improved breastfeeding patterns. (+info)
Prevalence of human papillomavirus infection in rural villages of the Bolivian Amazon.
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Cervical cancer constitutes a major health problem in developing countries like Bolivia. The roles of certain genotypes of human papillomaviruses (HPVs) in the pathogenesis of cervical cancer is well established. The prevalence of HPV infection among sexually active women varies greatly. Information regarding HPV infection in Bolivia is very much scarce, specially in regions like the Amazonian lowland. We studied 135 healthy women living in four rural localities of the Bolivian Amazon. Presence of HPV in DNA extracted from cervical swabs was analyzed using a reverse line hybridization assay. The estimated overall HPV infection prevalence among the studied rural localities was 5.9% (ranging from 0-16.6%). These values were unexpectedly low considering Bolivia has a high incidence of cervical cancer. The fact that Amazonian people seem to be less exposed to HPV, makes it likely that some other risk factors including host lifestyle behaviors and genetic background may be involved in the development of cervical cancer in this population. (+info)
Practical aspects of in vivo antimalarial drug efficacy testing in the Americas.
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The World Health Organization (WHO) has developed guidelines for in vivo antimalarial drug efficacy testing for Plasmodium falciparum and Plasmodium vivax in areas with low-to-moderate transmission, such as the Americas. These guidelines are used widely by ministries of health and national malaria control programs to assess the efficacy of their first-line and second-line drugs for the treatment of malaria and to provide the information necessary to update national malaria treatment policies. Following the WHO guidelines, we have conducted in vivo efficacy trials with a variety of drugs and drug combinations against P. falciparum and P. vivax at 13 sites in Peru, Bolivia, and Ecuador. Based on these experiences, we have identified several modifications that we believe should be made in the WHO recommendations to make them more suitable to the relatively low levels of P. falciparum transmission in the Americas and to the logistic challenges of carrying out such studies in sparsely populated areas, such as the Amazon Basin. These include changes in inclusion and exclusion criteria, in enrollment and follow-up procedures, and in the measurement of study outcomes. (+info)
Reduced oxygen at high altitude limits maximum size.
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The trend towards large size in marine animals with latitude, and the existence of giant marine species in polar regions have long been recognized, but remained enigmatic until a recent study showed it to be an effect of increased oxygen availability in sea water of a low temperature. The effect was apparent in data from 12 sites worldwide because of variations in water oxygen content controlled by differences in temperature and salinity. Another major physical factor affecting oxygen content in aquatic environments is reduced pressure at high altitude. Suitable data from high-altitude sites are very scarce. However, an exceptionally rich crustacean collection, which remains largely undescribed, was obtained by the British 1937 expedition from Lake Titicaca on the border between Peru and Bolivia in the Andes at an altitude of 3809 m. We show that in Lake Titicaca the maximum length of amphipods is 2-4 times smaller than other low-salinity sites (Caspian Sea and Lake Baikal). (+info)
Demographic threats to the sustainability of Brazil nut exploitation.
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A comparative analysis of 23 populations of the Brazil nut tree (Bertholletia excelsa) across the Brazilian, Peruvian, and Bolivian Amazon shows that the history and intensity of Brazil nut exploitation are major determinants of population size structure. Populations subjected to persistent levels of harvest lack juvenile trees less than 60 centimeters in diameter at breast height; only populations with a history of either light or recent exploitation contain large numbers of juvenile trees. A harvesting model confirms that intensive exploitation levels over the past century are such that juvenile recruitment is insufficient to maintain populations over the long term. Without management, intensively harvested populations will succumb to a process of senescence and demographic collapse, threatening this cornerstone of the Amazonian extractive economy. (+info)
Introduced Plasmodium vivax malaria in a Bolivian community at an elevation of 2,300 meters.
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Tuntunani, Bolivia, a community of 199 persons situated at an elevation of 2,300 meters, experienced its first malaria outbreak in 1998. Blood smears from 63 of 183 symptomatic residents were examined, and 52 showed Plasmodium vivax. An investigation two years later indicated that the epidemic resulted from introduced transmission, since persons of all ages and both sexes were infected, and there had been no travel to low-lying endemic areas in the five months preceding the epidemic. Treatment became available only two months into the epidemic, at which time 58% of the people had been ill for three weeks or longer. This outbreak demonstrates the vulnerability of highland populations with poor access to health care to introduced malaria. (+info)