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Interview with Guillermo Arrévalo, a Shipibo urban shaman, by Roger Rumrrill. Interview by Roger Rumrrill.

Roger Rumrrill, a journalist headquartered in Lima, Peru who is a noted expert on the Peruvian Amazon, interviewed Guillermo Arrévalo, a Shipibo urban shaman in Pucallpa, who utilizes ayahuasca in curing rituals. Sr. Arrévalo comments on the phenomenon known as drug tourism, where urban men and women provide tours for foreigners, for a price, to experience drug-induced mystical experiences in urban settings like Iquitos and Pucallpa, Peru, as well as in Brazil, Bolivia and Ecuador. Arrévalo distinguishes between folkloric shamanism and touristic practices which are currently in vogue and, in his opinion, are the result of people trying to resolve personal problems. Arrévalo sees a spiritual and psychological crisis in Europe and North American society. The Shipibo shaman laments the misuse of toxic plants as additives to the ayahuasca potion and the damage that these plants cause to the unsuspecting tourist who doesn't really get his money's worth from shamans without experience, people who are liars and cheats and who don't have the capacity, the preparation or the boldness to do the work.

Banisteriopsis↗

Efficacy of a new tetravalent coryza vaccine against emerging variant type B strains.

Outbreaks of infectious coryza have been reported in vaccinated flocks in different countries, indicating that new serotype(s) of Haemophilus paragallinarum may have evolved. Several field isolates from vaccinated flocks in the US, Ecuador, Argentina and Zimbabwe were examined and, apart from one serotype C strain, all were typed as serotype B. An inactivated commercial trivalent vaccine, containing serotypes A, B and C, protected against challenge with the serotype C isolate but protection against challenge with serotype B isolates was weaker, suggesting that they might represent a new variant immunotype. An experimental tetravalent oil adjuvant vaccine, containing one of the serotype B isolates, appeared immunogenic against all isolates after one vaccination. Its efficacy and safety were further tested in layer chickens housed under field conditions. Chickens were vaccinated at 8 and 16 weeks of age while controls were unvaccinated. Vaccinates and controls were challenged with type A, B, C and variant type B at 25, 45 or 65 weeks of age. There was good protection (P<0.05) against all four immunotypes after all challenges. No systemic reactions were observed and local reactions were similar to those found with the commercial trivalent vaccine. The tetravalent vaccine may therefore be a good choice for control of new field isolates.

Animals↗

Tracing the origin of HLA-DRB1 alleles by microsatellite polymorphism.

We analyzed the origin of allelic diversity at the class II HLA-DRB1 locus, using a complex microsatellite located in intron 2, close to the polymorphic second exon. A phylogenetic analysis of human, gorilla, and chimpanzee DRB1 sequences indicated that the structure of the microsatellite has evolved, primarily by point mutations, from a putative ancestral (GT)x(GA)y-complex-dinucleotide repeat. In all contemporary DRB1 allelic lineages, with the exception of the human *04 and the gorilla *08 lineages, the (GA)y repeat is interrupted, often by a G-->C substitution. In general, the length of the 3' (GA)y repeat correlates with the allelic lineage and thus evolves more slowly than a middle (GA)z repeat, whose length correlates with specific alleles within the lineage. Comparison of the microsatellite sequence from 30 human DRB1 alleles showed the longer 5' (GT)x to be more variable than the shorter middle (GA)z and 3' (GA)y repeats. Analysis of multiple samples with the same exon sequence, derived from different continents, showed that the 5' (GT)x repeat evolves more rapidly than the middle (GA)z and the 3' (GA)y repeats, which is consistent with findings of a higher mutation rate for longer tracts. The microsatellite-repeat-length variation was used to trace the origin of new DRB1 alleles, such as the new *08 alleles found in the Cayapa people of Ecuador and the Ticuna people of Brazil.

Alleles↗

Early human infection with Onchocerca volvulus is associated with an enhanced parasite-specific cellular immune response.

The immune response after early exposure to or infection with Onchocerca volvulus was investigated in an autochthonous focus caused by the migration of infected persons to a previously unaffected area in Ecuador. Peripheral blood mononuclear cell (PBMC) proliferative and cytokine responses (interferon [IFN]-gamma and interleukin [IL]-5) to filarial antigens were measured in 14 subjects with serologic evidence of exposure and in 7 subjects with evidence of dermal microfilarial DNA and were compared with responses in 43 subjects with chronic O. volvulus infections. PBMC proliferative and cytokine responses (IFN-gamma and IL-5) to parasite antigens were elevated in the early exposure/infection group, compared with those in the chronic infection group. Addition of an IL-10-neutralizing antibody to filaria antigen-stimulated cultures resulted in significantly elevated proliferative responses in the chronic infection group. The findings suggest that early exposure and early parasite patency are associated with a vigorous cellular response, but, as infections become chronic, the cellular response becomes down-regulated, partly through an IL-10-dependent mechanism.

Adolescent↗

Assessment of the Binax NOW Streptococcus pneumoniae urinary antigen test in children with nasopharyngeal pneumococcal carriage.

We evaluated the Binax NOW Streptococcus pneumoniae urinary antigen assay by testing 210 healthy children aged 2--60 months living in urban slums of Quito, Ecuador. Healthy children with nasopharyngeal carriage of S. pneumoniae were significantly more likely to have positive urinary antigen test results than were children who were not carriers (30 of 138 vs. 3 of 71 children; chi2=10.8; P<.001). The rate of nasopharyngeal carriage of S. pneumoniae decreased with increasing age; the lowest rates were found in children with the worst nutritional status.

Antigens, Bacterial↗

Molecular systematic analysis reveals cryptic tertiary diversification of a widespread tropical rain forest tree.

The broad geographic range of many Neotropical rain forest tree species implies excellent dispersal abilities or range establishment that preceded the formation of current dispersal barriers. In order to initiate historical analyses of such widespread Neotropical trees, we sequenced the nuclear ribosomal spacer (ITS) region of Symphonia globulifera L. f. (Clusiaceae) from populations spanning the Neotropics and western Africa. This rain forest tree has left unmistakable Miocene fossils in Mesoamerica (15.5-18.2 Ma) and in South America ( approximately 15 Ma). Although marine dispersal of S. globulifera is considered improbable, our study establishes three marine dispersal events leading to the colonization of Mesoamerica, the Amazon basin, and the West Indies, thus supporting the paleontological data. Our phylogeographic analysis revealed the spatial extent of the three Neotropical S. globulifera clades, which represent trans-Andes (Mesoamerica+west Ecuador), cis-Andes (Amazonia+Guiana), and the West Indies. Strong phylogeographic structure found among trans-Andean populations of S. globulifera stands in contrast to an absence of ITS nucleotide variation across the Amazon basin and indicates profound regional differences in the demographic history of this rain forest tree. Drawing from these results, we provide a historical biogeographic hypothesis to account for differences in the patterns of beta diversity within Mesoamerican and Amazonian forests.

Africa↗

Atopic phenotype is an important determinant of immunoglobulin E-mediated inflammation and expression of T helper cell type 2 cytokines to ascaris antigens in children exposed to ascariasis.

Studies have shown a strong inverse relationship between atopy and geohelminth infection, indicating that atopy may protect against geohelminth infection. Resistance to ascariasis in atopic individuals may occur through greater immunoglobulin E-mediated responses and expression of T helper cell type 2 (Th2) cytokines to parasite antigens. To investigate the effect that atopy has on the immune response to Ascaris antigens, school-age children were recruited from rural schools in Ecuador. Immunologic variables were compared between children stratified by atopic and/or A. lumbricoides-infection status; the variables included cytokine expression by peripheral-blood mononuclear cells (PBMCs) and histamine release in response to Ascaris antigens. Atopic children had both greater frequencies of PBMCs expressing interleukin (IL)-4 and IL-5 and enhanced histamine release, compared with those in nonatopic children. Stratification by atopic and A. lumbricoides-infection status revealed the greatest histamine and Th2 cytokine responses in the stratum of atopic, noninfected children. Multivariate regression analyses showed significant effects for atopic status but not for infection status on Th2 cytokine expression and histamine release.

Adolescent↗

Serological and molecular evidence that human herpesvirus 8 is endemic among Amerindians in French Guiana.

We evaluated the presence of human herpesvirus 8 (HHV-8) infection among groups of Amerindians in French Guiana. The overall prevalence of antibodies against lytic HHV-8 antigens was 23.0% (180/781), increasing from 18.4% in children <6 years old to approximately 30% in older persons (>45 years). Seroprevalence was higher in Amerindians living in remote localities than it was in those living in the coastal region. Analysis of a 725-base pair fragment of the K1 gene amplified from DNA from a Wayampi Amerindian showed that the virus belonged to molecular subtype E, which has hitherto been found in only a few Amerindians in Brazil and Ecuador.

Adolescent↗

Documentation of subtype C HIV Type 1 strains in Argentina, Paraguay, and Uruguay.

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Adult↗

Cytoplasmic incompatibility in Drosophila simulans: dynamics and parameter estimates from natural populations.

In Drosophila simulans, cytoplasmically transmitted Wolbachia microbes cause reduced egg hatch when infected males mate with uninfected females. A Wolbachia infection and an associated mtDNA variant have spread northward through California since 1986. PCR assays show that Wolbachia infection is prevalent throughout the continental US and Central and South America, but some lines from Florida and Ecuador that are PCR-positive for Wolbachia do not cause incompatibility. We estimate from natural populations infection frequencies and the transmission and incompatibility parameter values that affect the spread of the infection. On average, infected females from nature produce 3-4% uninfected ova. Infected females with relatively low fidelity of maternal transmission show partial incompatibility with very young infected laboratory males. Nevertheless, crosses between infected flies in nature produce egg-hatch rates indistinguishable from those produced by crosses between uninfected individuals. Incompatible crosses in nature produce hatch rates 30-70% as high as those from compatible crosses. Wild-caught infected and uninfected females are equally fecund in the laboratory. Incompatibility decreases with male age, and age-specific incompatibility levels suggest that males mating in nature may often be 2 or 3 weeks old. Our parameter estimates accurately predict the frequency of Wolbachia infection in California populations.

Africa, Southern↗

Health maintenance organizations in developing countries: what can we expect?

Health maintenance organizations (HMOs) are a relatively new and alternative means of providing health care, combining a risk-sharing (insurance) function with health service provision. Their potential for lowering costs has attracted great interest in the USA and elsewhere, and has raised questions regarding their applicability to other settings. Little attention, however, has been given to critically reviewing the experience with HMOs in other countries, particularly concerning their introduction to settings other than the USA. This paper first reviews the current experience of HMOs in low- and middle-income countries, including Argentina, Bolivia, Brazil, Colombia, Ecuador, Uruguay, Chile and Indonesia. Secondly, the paper reviews the USA experience with HMOs: prerequisites for the establishment of HMOs in the USA are identified and discussed, followed by a review of the performance of HMOs in terms of cost containment, integration of care and quality of care for the elderly and poor. The analysis concludes that difficulties may arise when implementing HMOs in developing countries, and that potential adverse effects on the overall health care delivery system may occur. These should be avoided by careful analyses of a nation's health care system.

Developing Countries↗

Yaws in the Americas, 1950-1975.

Yaws was introduced into the Americas by African slaves beginning in the 16th century and may have already been present before the arrival of Columbus. In the 1950s, programs for the eradication of yaws were undertaken in almost all American countries in which yaws was endemic. By mass treatment of cases and contacts with penicillin, the programs against yaws have dramatically reduced the incidence of reported cases throughout the Western Hemisphere from greater than 44,000 cases per year during 1950-1954 to 437 cases in 1975. In Brazil, efforts against yaws reduced the number of patients treated by 99% between 1965 and 1974. By 1975, yaws apparently remained a significant public health problem in only a few communities in Brazil, Columbia, Dominica, Ecuador, Haiti, Peru, St. Lucia, and St. Vincent, and possibly in Guiana and Surinam. It may be possible to eliminate infectious yaws entirely from the Western Hemisphere within the next few years.

Humans↗

Tetanus antitoxin titers in women of childbearing age from nine diverse populations.

The proportion of women with tetanus antitoxin titers adequate to provide protection for themselves and for their newborn infants varied from 96% in New Haven, Connecticut to 19% in Santiago, Chile. Women of childbearing age in five of the nine areas (São Paulo, Recife, and Pôrto Alegre, Brazil; Ecuador; and Gazankulu, South Africa) had an average of 40% immunity to tetanus and did not differ significantly from one another. By comparison with Chile, where vaccination during pregnancy is not current policy, we estimate that 21%-34% of the women in these five areas had received toxoid recently. In general about half the women with inadequate titer had undetectable levels of antibody and may require more than one dose of vaccine to attain immunity.

Age Factors↗

Polymerase chain reaction-based diagnosis of Onchocerca volvulus infection: improved detection of patients with onchocerciasis.

Definitive diagnosis of Onchocerca volvulus (Ov) infection requires the identification of the parasite in either the skin or subcutaneous nodules. These parasitologic approaches suffer from poor sensitivity. To assess the efficacy and utility of a polymerase chain reaction (PCR)-based diagnosis for Ov infection, skin snips were examined from 94 persons in an Ov-endemic region of Ecuador, and results were compared in a blinded fashion with those of a PCR assay based on the Onchocerca-specific repetitive DNA sequence, O-150. All 60 patients microfilaria-positive on skin snip examination were positive in the PCR-based assay. In addition, 13 of 34 who were microfilaria-negative by skin snips were positive in the PCR assay. This suggests that the PCR-based assay is significantly more sensitive than current methods and overcomes many deficiencies of parasitologic and serologic methodologies in diagnosing active onchocerciasis.

Animals↗

Immunity to onchocerciasis: putative immune persons produce a Th1-like response to Onchocerca volvulus.

Immunity to Onchocerca volvulus (Ov) infection is suggested by the presence of putatively immune (PI) subjects in a region of Ecuador in which Ov is endemic. PI subjects were identified by traditional diagnostic methods combined with a polymerase chain reaction-based assay for Ov DNA in skin snips. Responses of peripheral blood mononuclear cells (PBMC) from the PI group (n = 16) were compared with those of persons with active infection (microfiladermic [MF] subjects; n = 51). PBMC of PI subjects proliferated significantly more to Ov antigen (OvAg; P < .009) than did PBMC of MF persons but less to streptolysin-O (P < .001). Cytokine analysis of PBMC culture supernatants revealed that PI subjects (n = 11) produced significantly more interferon-gamma to OvAg than did those in the MF group (n = 18; P = .018), less interleukin (IL)-5 to nonparasite antigen (P = .003) and mitogen (P = .012), and less IL-10 spontaneously (P = .016). Thus, immunity to Ov may in part be mediated by an antigen-specific Th1-type response.

Adolescent↗

Comparative egg morphology of six species of the Albimanus section of Anopheles (Nyssorhynchus) (Diptera:Culicidae).

Scanning electron micrographs were used to describe and compare structures of eggs obtained from wild-caught females of 6 species of the Albimanus section of Anopheles (Nyssorhynchus) from South America, which includes important regional vectors of human malaria. Among species from the Oswaldoi Complex, eggs of Anopheles oswaldoi (Peryassu) were not differentiated from those of its sibling Anopheles konderi Galvão & Damasceno, and eggs of the former species from Brazil, Ecuador, and Suriname showed no regionally distinguishing characteristics. Eggs of Anopheles dunhami Causey were recognized by the reticulate beadwork of outer chorion on the dorsal plastron, 1 of several egg characters separating this species from the related Anopheles trinkae Faran and Anophels nuneztovari Gabaldón. In both species examined from the Strodei Complex, Anopheles strodei Root and Anopheles benarrochi Gabaldón, Cova Garcia & Lopez, the anterior frill forms a distinctive ventral crown separated from the floats. Anopheles triannulatus (Neiva & Pinto), collected from 4 geographic sites, differed in the occurrence of perforated mounds on the dorsal plastron, but these chorionic structures and the extent of overlap of floats varied among eggs from single females. Changes among related species in the structure of the anterior frill and dorsal plastron are described for phylogenetic and developmental inferences.

Animals↗

Morphological, molecular, and chromosomal discrimination of cryptic Anopheles (Nyssorhynchus) (Diptera: Culicidae) from South America.

Based on similarity of male genitalia, the malaria vector Anopheles trinkae Faran from the eastern Andean piedmont of Colombia, Ecuador, Peru, and Bolivia was determined by Peyton (1993) to be a junior synonym of An. dunhami Causey, then known from a single locality in Amazonian Brazil. Following an appraisal of molecular, chromosomal, and morphological characters, we conclude herein that the 2 taxa are specifically distinct and remove An. trinkae from synonymy with An. dunhami. Eggs of the 2 species are distinguished easily by the anterior crown, long floats, and closed deck that occur only in An. trinkae. The X chromosome of larval polytenes is divisible into R and L arms in An. dunhami, but not in An. trinkae. A phenogram based on banding pattern scores from 18 random amplified polymorphic DNA primers separated with 100% resolution An. dunhami, An. trinkae, Anopheles nuneztovari Gabaldón and Anopheles darlingi Root. In the ITS2 region of rDNA, 25% of base sites distinguished An. trinkae from An. dunhami and 21% from the related An. nuneztovari; males of these 3 species had accessory glands of significantly different sizes. Preliminary isoenzyme screening indicated that 3 of 11 loci were diagnostic for separating An. trinkae from An. dunhami. The results indicate that An. dunhami is related more closely to An. nuneztovari than to An. trinkae and illustrate the merits of a multidisciplinary approach to mosquito systematics.

Animals↗

History of Interdepartmental Committee on Nutrition for National Defense: course of events and nutrition methodology in typical surveys.

It was my good fortune to help brief many of the survey teams on dietary methods and to serve on 2 survey teams. Dr. Arnold E. Schaefer, executive director of the International Committee on Nutrition for National Defense (ICNND), dictated his reflections, which I edited, for the symposium, "Reflections of Dr. Arnold E. Schaefer." The course of events in a typical ICNND nutrition survey were described. This included the following: 1) protocol, 2) organization of survey team, appropriate for the country, 3) briefing of team members, 4) provision of needed equipment and supplies, and 5) planning the survey with the host country. The advance mission visit usually included Dr. Frank Berry, assistant secretary of Defense for Health and the ICNND executive director, who briefed local government officials about the survey. The supply and the equipment needs included clinical and laboratory equipment, reference books and supplies needed for routine physical examinations, dietary studies, and laboratory determinations. Host countries provided 1) personnel to serve on survey teams, 2) logistical support, and 3) unbiased random population samples for clinical and dietary studies. The methods of measuring dietary intake used are described in the manual. Measuring the nutrient intake of military personnel is usually much less difficult than of civilians. The food preparation and consumption (recipe) and food composite analysis methods were most commonly used. The diet questionnaire used for civilians, recorded amounts of specific foods consumed the previous day (24-h recall). During the Ecuador survey, Combs and Wolfe obtained similar results with the recipe, the food composite, and the 24-h recall methods in the same 28 families.

Health Education↗