[The prevalence of intestinal parasitism in native villages of the Tembé tribe, the Brazilian eastern Amazon]

Epidemiology of soil-transmitted helminthiases-related mortality in Brazil

Soil-transmitted helminth (STH) infections are widely distributed in tropical and subtropical areas, including Brazil. We performed a nationwide population-based study including all deaths in Brazil from 2000 to 2011, in which STHs (ascariasis, trichuriasis and/or hookworm infection) were mentioned on death certificates, either as underlying or as associated causes of death. Epidemiological characteristics, time trends and spatial analysis of STH-related mortality were analysed. STHs was identified on 853/12 491 280 death certificates: 827 (97·0%) deaths related to ascariasis, 25 (2·9%) to hookworm infections, and 1 (0·1%) to trichuriasis. The average annual age-adjusted mortality rate was 0·34/1 000 000 inhabitants (95% confidence interval: 0·27-0·44). Females, children <10 years of age, indigenous ethnic groups and residents in the Northeast region had highest STH-related mortality rates. Nationwide mortality decreased significantly over time (annual percent change: -5·7%; 95% CI: -6·9 to -4·4), with regional differences. We identified spatial high-risk clusters for STH-related mortality mainly in the North, Northeast and South regions. Diseases of the digestive system and infectious/parasitic diseases were the most commonly associated causes of death mentioned in the STH-related deaths. Despite decreasing mortality in Brazil, a considerable number of deaths is caused by STHs, with ascariasis responsible for the vast majority. There were marked regional differences, affecting mainly children and vulnerable populations.

Evolution of Socioeconomic Conditions and Its Relation to Spatial-Temporal Changes of Giardiasis and Helminthiasis in Amazonian Children

This study analyzed the evolution of socioeconomic, sanitary, and personal factors as well as spatiotemporal changes in the prevalence of helminthiasis and giardiasis in urban Amazonian children between 2003 and 2011. Child age, lack of sanitation, and lack of access to bottled water were identified as significant associated factors for helminthiasis and giardiasis. There was an overall improvement in socioeconomic and sanitary conditions in the city resulting in decreased helminth prevalences from 12.42 to 9.63% between 2003 and 2010, but the prevalence increased to 15.03% in 2011 due to migratory movement and unstable sanitary conditions. As for Giardiasis, socioeconomic and environmental changes were not enough to reduce prevalence (16% in 2003 and 23% in 2011). Spatial analysis identified a significant cluster for helminthiasis in an area of poor housing conditions. Control programs in the Amazon need to target high-risk areas focusing changes in sanitation, water usage, and health education.

Prevalence of soil-transmitted helminths after mass albendazole administration in an indigenous community of the Manu jungle in Peru

Few data are available on the epidemiology of soil-transmitted helminths (STHs) in indigenous populations of the Peruvian Amazon. While albendazole is being increasingly used in deworming campaigns, few data exist on the impact of mass drug administration in isolated populations. We studied the prevalence of STHs, anemia, and malnutrition in a Matsigenka ethnic group from the Peruvian Amazon. Participants had received two doses of albendazole on consecutive days, 3 months before and again 2 weeks before data collection. Overall, 290 subjects were included. Most were female (53.7%) and 63.9% were ≤19 years old. Half of the participants had helminth infections. Trichiuris (30.2%), hookworm (19.1%), Ascaris (17.7%), and Strongyloides (5.6%) were the most common helminths. Other helminth ova included Capillaria hepatica and Fasciola-like eggs. Subjects of 5-19 years (51.8 %) and 20-35 years (68.6 %) old had helminths more often than those under 5 years (38%) and older than 35 years (41.5%) (P  =  0.02). Anemia was detected in 41% of children and this was more common in children under 5 years that in those of 5-19 years [odd ratio (OR) = 5.68; 95% CI: 2.71-11.88]. Overall, 72.1% of children were malnourished. Stunting was common in children (70.7%), but wasting was not (2.9%). Despite repeated albendazole administration, this population continued to have a high prevalence of STHs, anemia, and malnutrition. In addition, we detected unusual organisms and organisms that do not respond to albendazole. Further studies are needed to assess the rationale and efficacy of mass chemotherapy for STHs in the Amazon.

Intestinal protozoa and helminths among Terena Indians in the State of Mato Grosso do Sul: high prevalence of Blastocystis hominis

A parasitological survey was carried out among Terena Indians living in the Tereré settlement in the municipality of Sidrolândia, State of Mato Grosso do Sul, Brazil. Single samples of feces from 313 Indians were processed by means of the spontaneous sedimentation method. In the population studied, 73.5% were infected with at least one intestinal parasite or commensal. Protozoa predominated. Blastocystis hominis (40.9%), Entamoeba coli (33.2%) and Entamoeba histolytica/Entamoeba dispar (31.6%) were the most common. Bivariate analysis showed that females were generally more infected and presented higher rates of infection by Entamoeba histolytica/Entamoeba dispar and Entamoeba coli. Males were more infected by hookworms and Strongyloides stercoralis than females. The precarious sanitary conditions of the Tereré settlement are probably a contributory factor towards the high prevalence of intestinal protozoa.

Parasitosis intestinales en poblaciones Mbyá-Guaraní de la Provincia de Misiones, Argentina: aspectos epidemiológicos y nutricionales

Se describieron las enteroparasitosis más frecuentes en dos comunidades Mbyá-Guaraní de Misiones, Argentina: Kaaguy Poty e Yvy Pytá. Las parasitosis intestinales se asociaron con el estado nutricional de los individuos infectados y los factores ambientales y culturales que caracterizan a las poblaciones estudiadas. Los resultados se compararon con los obtenidos en una población aborigen vecina, Takuapí, y la población urbana más cercana: Aristóbulo del Valle. Se utilizaron las técnicas de Ritchie, Willis y Kato Katz para las muestras fecales. Se analizaron los parámetros antropométricos y se procesaron muestras de tierra. De un total 296 individuos en las cuarto poblaciones, 100 (87,7%), 63 (88,7%), 49 (96,1%) y 50 (82%) estuvieron parasitados en Kaaguy Poty, Yvy Pytá, Takuapí, y Aristóbulo del Valle respectivamente. El 84% de los individuos parasitados estuvieron poliparasitados. El 43% de los individuos medidos presentaron desnutrición y el 87% de ellos estaban parasitados. Hubo asociación entre el uso de letrinas y Giardia lamblia (p < 0,01); defecación a cielo abierto, ausencia de calzado y ancilostomídeos (p < 0,01); el tipo de vivienda y los helmintos en general (p < 0,01). En el suelo se hallaron formas parasitarias, sugiriendo la relación entre la contaminación del entorno ambiental y la elevada prevalencia de parasitosis intestinales en las poblaciones estudiadas.

HUMAN RIGHTS, BIOMEDICAL SCIENCE, AND INFECTIOUS DISEASES AMONG SOUTH AMERICAN INDIGENOUS GROUPS

Despite the efforts of international health agencies to reduce global health inequalities, indigenous populations around the world remain largely unaffected by such initiatives. This chapter reviews the biomedical literature indexed by the PubMed database published between 1963 and 2003 on South American indigenous populations, a total of 1864 studies that include 63,563 study participants. Some language family groupings are better represented than are others, and lowland groups are better represented than are highland groups. Very few studies focus on major health threats (e.g., tuberculosis, influenza), public health interventions, or mestizo-indigenous epidemiological comparisons. The prevalence rates of three frequently studied infections—parasitism, human T-cell lymphotropic viral infection (HTLV), and hepatitis—are extraordinarily high, but these facts have been overlooked by national and international health agencies. This review underscores the urgent need for interventions based on known disease prevalence rates to reduce the burden of infectious diseases in indigenous communities.

Risk factors for infection by the Entamoeba histolytica/E. dispar complex: An epidemiological study conducted in outpatient clinics in the city of Manaus, Amazon Region, Brazil

An epidemiological study was conducted on a population attending outpatient clinics in Manaus, Amazon, Brazil to determine the prevalences of infection by the Entamoeba histolytica/E. dispar complex and by E. histolytica alone, as well as to identify the risk factors involved in transmission. The study was conducted in two phases: survey and case-control. Face-to-face interviews were carried out and faecal samples collected from 1578 individuals. Faeces were examined by optical microscopy and tested for the pathogenic E. histolytica specific antigen. Positivity to E. histolytica/E. dispar was 21.5% (340 cases). Cases were compared with 340 control samples, negative for the E. histolytica/E. dispar complex based on examination by optical microscopy. The analysis was conducted by logistic regression. The risk factors identified were: place of residence, age, ingestion of raw vegetables, quality of water consumed, number of rooms and bedrooms per house, and having other protozoan infections. Specific antigen detection tests identified 22 participants infected by E. histolytica (6.8%) among those positive for E. histolytica/E. dispar. There was a higher proportion of males among participants infected by E. histolytica than among those with E. dispar infections. The study population was asymptomatic or presented non-specific symptoms that could be attributed to amoebiasis.