Trajetorias: a dataset of environmental, epidemiological, and economic indicators for the Brazilian Amazon.

The Trajetorias dataset is a harmonized set of environmental, epidemiological, and poverty indicators for all municipalities of the Brazilian Legal Amazon (BLA). This dataset is the result of a scientific synthesis research initiative conducted by scientists from several natural and social sciences fields, consolidating multidisciplinary indicators into a coherent dataset for integrated and interdisciplinary studies of the Brazilian Amazon. The dataset allows the investigation of the association between the Amazonian agrarian systems and their impacts on environmental and epidemiological changes, furthermore enhancing the possibilities for understanding, in a more integrated and consistent way, the scenarios that affect the Amazonian biome and its inhabitants.

Time Trend of Overweight and Obesity in Adults from Rio Branco, Acre, Western Brazilian Amazon (2006-2020).

This study aimed to analyze overweight trend and obesity in adults from Rio Branco, Acre, Western Brazilian Amazon, from 2006 to 2020. This is a time series study, with data from Surveillance System for Risk and Protective Factors for Chronic Diseases by Telephone Survey (VIGITEL). To estimate annual percentage change (APC) and 95% confidence intervals, the software Jointpoint Regression Analysis v.4.6.0.0., was used. In Rio Branco, overweight prevalence ranged from 44.0% in 2006 to 58.9% in 2020, with a bigger frequency among men than that among women. Obesity prevalence has increased from 12.5% in 2006 to 21.4% in 2020, similar between both sexes. From 2006 to 2020, overweight APC was 5.2% (95% CI: 1.4; 9.1) by 2010, and decreased to 1.3% by 2020. Public policies to control obesity and its risks must be both, implemented as strengthened.

Correction to: Socioeconomic and demographic characterization of an endemic malaria region in Brazil by multiple correspondence analysis.

After publication of the article [1], it has been brought to our attention that the y-axis of Fig. 6 has been labeled incorrectly. It should read "linear predictor". This has now been corrected in the original article.

Socioeconomic and demographic characterization of an endemic malaria region in Brazil by multiple correspondence analysis.

BACKGROUND: In the process of geographical retraction of malaria, some important endemicity pockets remain. Here, we report results from a study developed to obtain detailed community data from an important malaria hotspot in Latin America (Alto Juruá, Acre, Brazil), to investigate the association of malaria with socioeconomic, demographic and living conditions. METHODS: A household survey was conducted in 40 localities (n = 520) of Mâncio Lima and Rodrigues Alves municipalities, Acre state. Information on previous malaria, schooling, age, gender, income, occupation, household structure, habits and behaviors related to malaria exposure was collected. Multiple correspondence analysis (MCA) was applied to characterize similarities between households and identify gradients. The association of these gradients with malaria was assessed using regression. RESULTS: The first three dimensions of MCA accounted for almost 50% of the variability between households. The first dimension defined an urban/rurality gradient, where urbanization was associated with the presence of roads, basic services as garbage collection, water treatment, power grid energy, and less contact with the forest. There is a significant association between this axis and the probability of malaria at the household level, OR = 1.92 (1.23-3.02). The second dimension described a gradient from rural settlements in agricultural areas to those in forested areas. Access via dirt road or river, access to electricity power-grid services and aquaculture were important variables. Malaria was at lower risk at the forested area, OR = 0.55 (1.23-1.12). The third axis detected intraurban differences and did not correlate with malaria. CONCLUSIONS: Living conditions in the study area are strongly geographically structured. Although malaria is found throughout all the landscapes, household traits can explain part of the variation found in the odds of having malaria. It is expected these results stimulate further discussions on modelling approaches targeting a more systemic and multi-level view of malaria dynamics.

Prenatal care and childbirth assistance in Amazonian women before and after the Pacific Highway Construction (2003-2011): a cross-sectional study.

BACKGROUND: Attention to prenatal care and child delivery is important for the health of women and children, but in the Amazon these indicators tend to be historically unfavorable, in part by geographical and political isolation. In 2003 both Brazilian and Peru governments have finished paving an international road connecting remotes areas in the Brazilian Amazon to the Pacific coast in Peru. METHODS: The situation of prenatal care and child delivery with mothers of children under 5 years old living in the urban area of Assis Brasil, Acre was assessed in two cross-sectional studies performed in 2003 and 2011, corresponding to the period before and after the Pacific highway construction. RESULTS: In 2003, most mothers were of black/Afro-American ethnicity, or "pardos" (the offspring of a Caucasian with a African descendant) (77.69 %), had more than 4 years of schooling (73.40 %) and had a mean age of 22.18 years. In 2011, the number of as a migration of indigenous women increased from 0 to 14.40 % of the respondents, because of migration from communities along the rivers to urban areas, with no other significant changes in maternal characteristics. No significant improvement in childbirth assistance was noticed between 1997 and 2011; only the percentage of in-hospital vaginal deliveries performed by doctors increased from 17.89 to 66.26 % (p <0.001) during this period. Access to prenatal care was associated with white ethnicity in 2003, and higher socioeconomic level and white ethnicity in 2011, while the higher number of prenatal visits was associated with higher maternal education and higher socioeconomic levels in 2011. Vaginal child delivery at a hospital facility was associated with maternal age in 2003, and year of birth, being of white ethnicity and higher level of education in 2011. CONCLUSIONS: The indicators of prenatal care and child delivery were below the national average, showing that geographical isolation still affects women's health care in the Amazon, despite the construction of the highway and governmental health protocols adopted during this period.

Stunting in children under five years old is still a health problem in the Western Brazilian Amazon: a population-based study in Assis Brasil, Acre, Brazil.

Despite the process of nutritional transition in Brazil, in some places, such as the Amazon region, stunting is still an important public health problem. We identified the prevalence and factors associated with stunting in children under five years old residing in the urban area of Assis Brasil. A survey was conducted in which a questionnaire on socioeconomic, maternal and children's conditions was applied, and height or length was measured. The children with height for age index below -2 Z-scores were considered stunted, according to the criteria by the World Health Organization. Four hundred and twenty-eight children were evaluated. Of these, 62 were stunted. Factors associated with stunting, according to adjusted models, were: the presence of open sewer, the wealth index for households, the receipt of governmental financial aid and the mother's height, age and education. Therefore, it was observed that family and the mother's characteristics as well as environmental and socioeconomic factors were closely related to the occurrence of stunting in the population studied, and such nutritional disturbance is still a health problem in the Brazilian Amazon.

Hepatitis A seroprevalence in preschool children in Assis Brazil, Acre, Brazil, in 2003 and 2010.

BACKGROUND: The Amazon region has the highest seroprevalence of hepatitis A virus (HAV) in Brazil. METHODS: In the present study, the seroprevalence of total HAV antibodies in two groups, composed of 147 and 254 children between 1 and 5 years old in Assis Brasil, Acre, was measured in 2003 and 2010, respectively, and compared with socio-economic changes in the city. RESULTS: In 2003, the HAV seroprevalence rate was 26.5%, while in 2010, it was 22.4%. There was an overall improvement in socio-economic and sanitary conditions, with the exception of open sewage. In 2003, factors associated with positive serology were child age (aOR [adjusted odds ratio] 1.84; 95% CI: 1.28-2.64), having a latrine or not having a toilet at home (aOR 4.73; 95% CI: 1.06-21.17) and the treatment of drinking water with chlorine (aOR 0.26; 95% CI: 0.07-0.92). In 2010, the main factors associated with positive serology were using rivers, streams and rainwater as sources of water for domestic purposes (aOR 24.36; 95% CI: 3.69-160.85); having a wooden or ground floor at home (OR 2.51; 95% CI: 1.11-5.69) and child age (aOR 2.33; 95% CI: 1.66-3.28). CONCLUSIONS: In the Brazilian Amazon, sanitation and water treatment still require improvement and socio-economic development is warranted in order to decrease hepatitis A transmission.

Child Health in the Peruvian Amazon: Prevalence and Factors Associated with Referred Morbidity and Health Care Access in the City of Iñapari.

Introduction. Children under 5 years of age are more susceptible to developing morbidities such as diarrhea, respiratory infections, anemia, and malnutrition. The objective of the study is to evaluate the prevalence of reported morbidities in this age group in the city of Iñapari (Peru) and the access to health services in this municipality. Methods. Data collection using interviews that assessed socioeconomic and demographic conditions, child morbidity, and access to health services was performed in 2011. Statistical analysis was performed using SPSS 13.0. Results. Regarding morbidities that occurred during lifetime, 39.8% reported previous anemia and intestinal parasite infection. About 53.7% of the children reported any type of morbidities in the last 15 days before interview, being most frequent respiratory symptoms (38.9%), diarrhea (23,4%), and fever (23,1%). Only 63.1% of those reporting recent morbidities sought health care. These morbidities were associated with precarious sanitation and lack of infrastructure, the presence of other comorbidities, and poor access to health services. Conclusion. The main referred morbidities in Amazonian Peruvian children were diarrhea, respiratory symptoms, anemia, and vomiting. Incentives and improvements in the health and sanitation conditions would be important measures to improve the quality of life of the Amazonian child population.

Clustering symptoms of non-severe malaria in semi-immune Amazonian patients.

Malaria is a disease that generates a broad spectrum of clinical features. The purpose of this study was to evaluate the clinical spectrum of malaria in semi-immune populations. Patients were recruited in Mâncio Lima, a city situated in the Brazilian Amazon region. The study included 171 malaria cases, which were diagnosed via the use of a thick blood smear and confirmed by molecular methods. A questionnaire addressing 19 common symptoms was administered to all patients. Multiple correspondence analysis and hierarchical cluster analysis were performed to identify clusters of symptoms, and logistic regression was used to identify factors associated with the occurrence of symptoms. The cluster analysis revealed five groups of symptoms: the first cluster, which included algic- and fever-related symptoms, occurred in up to 95.3% of the cases. The second cluster, which comprised gastric symptoms (nausea, abdominal pain, inappetence, and bitter mouth), occurred in frequencies that ranged between 35.1% and 42.7%, and at least one of these symptoms was observed in 71.9% of the subjects. All respiratory symptoms were clustered and occurred in 42.7% of the malaria cases, and diarrhea occurred in 9.9% of the cases. Symptoms constituting the fifth cluster were vomiting and pallor, with a 14.6% and 11.7% of prevalence, respectively. A higher parasitemia count (more than 300 parasites/mm(3)) was associated with the presence of fever, vomiting, dizziness, and weakness (P < 0.05). Arthralgia and myalgia were associated with patients over the age of 14 years (P < 0.001). Having experienced at least eight malaria episodes prior to the study was associated with a decreased risk of chills and fever and an increased risk of sore throat (P < 0.05). None of the symptoms showed an association with gender or with species of Plasmodium. The clinical spectrum of malaria in semi-immune individuals can have a broad range of symptoms, the frequency and intensity of which are associated with age, past exposure to malaria, and parasitemia. Understanding the full spectrum of nonsevere malaria is important in endemic areas to guide both passive and active case detection, for the diagnosis of malaria in travelers returning to non-endemic areas, and for the development of vaccines aimed to decrease symptom severity.

Socioeconomic inequities and hepatitis A virus infection in Western Brazilian Amazonian children: spatial distribution and associated factors.

BACKGROUND: Hepatitis A is still a neglected health problem in the world. The most affected areas are the ones with disadvantaged socioeconomic conditions. In Brazil, seroprevalence studies showed that 64.7 % of the general population has antibodies against HAV (hepatitis A virus), and the Amazon region has the highest seroprevalence in the country. METHODS: In the present study the seroprevalence of total HAV antibodies in children between 1 and 5 years old residing in the urban area of Assis Brasil, Acre was measured and spatial distribution of several socioeconomic inequities was evaluated. RESULTS: In the year of 2011, seroprevalence rate was 16.66 %. Factors associated with having a positive serology identified by multivariate analysis were being of indigenous ethnicity [adjusted Odds Ratio (aOR) = 3.27, CI 1.45-7.28], usage of water from the public system (aOR = 8.18, CI 1.07-62.53), living in a house not located in a street (aOR = 3.48, CI 1.54-7.87), and child age over 4 years old (aOR = 2.43, CI 1.23-4.79). The distribution of seropositive children was clustered in the eastern part of the city, where several socioeconomic inequities (lack of flushed toilets, lack of piped water inside the household and susceptibility of the household to flooding during rain, low maternal education, having wood or ground floor at home, and not owning a house, lack of piped water at home, and type of drinking water) also clustered. CONCLUSIONS: The findings highlight that sanitation and water treatment still need improvement in the Brazilian Amazon, and that socioeconomic development is warranted in order to decrease this and other infectious diseases.

Side Effects of Chloroquine and Primaquine and Symptom Reduction in Malaria Endemic Area (Mâncio Lima, Acre, Brazil).

Side effects of antimalarial drug can overlap with malaria symptoms. We evaluated 50 patients with vivax malaria in Mâncio Lima, Acre, treated with chloroquine and primaquine. Patients were evaluated for the presence of 21 symptoms before and after treatment and for reported side effects of these drugs after treatment was started. The most frequent symptoms before medication were headache, fever, chills, sweating, arthralgia, back pain, and weakness, which were present in between 40% and 76% of respondents. The treatment reduced the occurrence of these symptoms and reduced the lack of appetite, but gastrointestinal symptoms and choluria increased in frequency. There were no reports of pale stools before medication, but 12% reported the occurrence of this symptom after treatment started. Other symptoms such as blurred vision (54%), pruritus (22%), paresthesia (6%), insomnia (46%), and "stings" into the skin (22%) were reported after chloroquine was taken. The antimalarial drugs used to treat P. vivax malaria reduce much of the systemic and algic symptoms but cause mainly gastrointestinal side effects that may lead to lack of adherence to drug treatment. It is important to guide the patient for the appearance and the transience of such side effects in order to avoid abandoning treatment.

Epidemic and Endemic Malaria Transmission Related to Fish Farming Ponds in the Amazon Frontier.

Fish farming in the Amazon has been stimulated as a solution to increase economic development. However, poorly managed fish ponds have been sometimes associated with the presence of Anopheles spp. and consequently, with malaria transmission. In this study, we analyzed the spatial and temporal dynamics of malaria in the state of Acre (and more closely within a single county) to investigate the potential links between aquaculture and malaria transmission in this region. At the state level, we classified the 22 counties into three malaria endemicity patterns, based on the correlation between notification time series. Furthermore, the study period (2003-2013) was divided into two phases (epidemic and post-epidemic). Higher fish pond construction coincided both spatially and temporally with increased rate of malaria notification. Within one malaria endemic county, we investigated the relationship between the geolocation of malaria cases (2011-2012) and their distance to fish ponds. Entomological surveys carried out in these ponds provided measurements of anopheline abundance that were significantly associated with the abundance of malaria cases within 100 m of the ponds (P < 0.005; r = 0.39). These results taken together suggest that fish farming contributes to the maintenance of high transmission levels of malaria in this region.

Isolation and characterization of Mayaro virus from a human in Acre, Brazil.

Mayaro virus (MAYV) is widely distributed throughout South America and is the etiologic agent of Mayaro fever, an acute febrile illness often presenting with arthralgic manifestations. The true incidence of MAYV infection is likely grossly underestimated because the symptomatic presentation is very similar to that of dengue fever and other acute febrile tropical diseases. We report the complete genome sequence of a MAYV isolate detected from an Acrelândia patient presenting with fever, chills, and sweating, but with no arthralgia. Results show that this isolate belongs to genotype D and is closely related to Bolivian strains. Our results suggest that the Acre/Mayaro strain is closely related to the progenitor of these Bolivian strains that were isolated between 2002 and 2006.

Seroprevalence and seroconversion of dengue and implications for clinical diagnosis in amazonian children.

This study aimed to evaluate the prevalence of serum IgG dengue in children in an Amazonian population, to assess the seroconversion rate in 12 months, and to estimate how many seropositive children had a prior clinical diagnosis of dengue. We conducted a population-based study between 2010 and 2011, with children aged 6 months to 12 years that were living in the urban area of a small town in the Brazilian Amazon. The prevalence of IgG antibodies against dengue antigens was determined by indirect ELISA technique, and seronegative children were reexamined after 12 months to determine seroconversion rates. Results showed seroprevalence of IgG antibodies against dengue type of 2.9%, with no significant association between age, race, and sex. In seropositive children, only 8.4% had received a clinical diagnosis of dengue, and the ratio of clinically diagnosed cases and subclinical cases was 1 : 11. The seroconversion rate between 2010 and 2011 was 1.4% (CI 3.8% to 35.1%). The seroprevalence of dengue in this pediatric population was low, and the vast majority of cases were not clinically detected, suggesting a difficulty in making the clinical diagnosis in children and a high frequency of asymptomatic infections.

Socioeconomic inequalities are still a barrier to full child vaccine coverage in the Brazilian Amazon: a cross-sectional study in Assis Brasil, Acre, Brazil.

INTRODUCTION: Vaccines are very important to reduce morbidity and mortality by preventable infectious diseases, especially during childhood. Optimal coverage is not always achieved, for several reasons. Here we assessed vaccine coverage for the first 12 months of age in children between 12 and 59 months old, residing in the urban area of a small Amazonian city, and factors associated with incomplete vaccination. METHODS: A census was performed in the urban area of Assis Brasil, in the Brazilian Amazon, in January 2010, with mothers of 282 children aged 12 to 59 months old, using structured interviews and data from vaccination cards. Mixed logistic regression was used to determine factors associated with incomplete vaccination schemes. RESULTS: Only 82.6% of all children had a completed the basic vaccine scheme for the first year of life. Vaccine coverage ranged from 52.7% coverage (oral rotavirus vaccine) to 99.7% coverage (for Bacille Calmette-Guérin). The major deficiencies occurred in doses administered after the first six months of life. Incomplete vaccination was associated with not having enough income to buy a house (aOR = 2.12, 95% CI 1.06-4.21), low maternal schooling (aOR = 2.60, 95% CI 1.28 - 5.29) , and time of residence of the child in the urban area of the city (aOR = 0.73, 95% CI 0.55 - 0.95). CONCLUSIONS: This study showed that vaccine coverage in the first twelve months of life in Assis Brasil is similar to other areas in the Amazon and it is below the coverage postulated by the Brazilian Ministry of Health. Low vaccine coverage was associated with socioeconomic inequities that still prevail in the Brazilian Amazon. Short and long-term strategies must be taken to update child vaccines and increase vaccine coverage in the Amazon.

Epidemiology of disappearing Plasmodium vivax malaria: a case study in rural Amazonia.

BACKGROUND: New frontier settlements across the Amazon Basin pose a major challenge for malaria elimination in Brazil. Here we describe the epidemiology of malaria during the early phases of occupation of farming settlements in Remansinho area, Brazilian Amazonia. We examine the relative contribution of low-density and asymptomatic parasitemias to the overall Plasmodium vivax burden over a period of declining transmission and discuss potential hurdles for malaria elimination in Remansinho and similar settings. METHODS: Eight community-wide cross-sectional surveys, involving 584 subjects, were carried out in Remansinho over 3 years and complemented by active and passive surveillance of febrile illnesses between the surveys. We used quantitative PCR to detect low-density asexual parasitemias and gametocytemias missed by conventional microscopy. Mixed-effects multiple logistic regression models were used to characterize independent risk factors for P. vivax infection and disease. PRINCIPAL FINDINGS/CONCLUSIONS: P. vivax prevalence decreased from 23.8% (March-April 2010) to 3.0% (April-May 2013), with no P. falciparum infections diagnosed after March-April 2011. Although migrants from malaria-free areas were at increased risk of malaria, their odds of having P. vivax infection and disease decreased by 2-3% with each year of residence in Amazonia. Several findings indicate that low-density and asymptomatic P. vivax parasitemias may complicate residual malaria elimination in Remansinho: (a) the proportion of subpatent infections (i.e. missed by microscopy) increased from 43.8% to 73.1% as P. vivax transmission declined; (b) most (56.6%) P. vivax infections were asymptomatic and 32.8% of them were both subpatent and asymptomatic; (c) asymptomatic parasite carriers accounted for 54.4% of the total P. vivax biomass in the host population; (d) over 90% subpatent and asymptomatic P. vivax had PCR-detectable gametocytemias; and (e) few (17.0%) asymptomatic and subpatent P. vivax infections that were left untreated progressed to clinical disease over 6 weeks of follow-up and became detectable by routine malaria surveillance.

Hepatitis A and E seroprevalence and associated risk factors: a community-based cross-sectional survey in rural Amazonia.

BACKGROUND: Hepatitis A virus (HAV) and hepatitis E virus (HEV) are both transmitted by the faecal-oral route, and represent common causes of acute hepatitis in developing countries. The endemicity of HAV infection has shifted from high to moderate in Brazil. Human cases of HEV infection seem to be rare, although the virus has been detected in swine livestock and effluents of slaughterhouses. This study was to determine the epidemiology of hepatitis A and E in one of the largest agricultural settlements in the Amazon Basin of Brazil. METHODS: Serum samples collected from 397 individuals aged between 5 and 90 years during a population-based cross-sectional survey were tested for anti-HAV and anti-HEV antibodies. Associated risk factors and spatial clustering of HAV and HEV seropositivity were also analyzed. RESULTS: The overall rate of HAV seropositivity was 82.9% (95% confidence interval (CI), 79.2-86.6%). Multilevel logistic regression analysis identified increasing age (in years; odds ratio (OR), 1.097; 95% CI, 1.050-1.147; P < 0.001) and crowding (OR, 1.603; 95% CI, 1.054-2.440; P = 0.028) as significant risk factors for HAV seropositivity. Anti-HEV IgG was detected in 50/388 settlers (12.9%, 95% CI, 9.5-16.2%). Anti-HEV IgM was detected in 7/43 (16.3%) anti-IgG positive samples, and 4 of them had a confirmed result by immunoblot. Increasing age was the only significant determinant of HEV seropositivity (OR, 1.033; 95% CI, 1.016-1.050; P < 0.001). No significant spatial clustering of HAV and HEV seropositivity was detected in the area. CONCLUSIONS: Both HAV and HEV are endemic, with differing rates of infection in children and adults in this rural setting of the Brazilian Amazon. Anti-HEV prevalence was considerably higher than those previously reported in Brazil. The detection of HEV- specific IgM antibodies in four asymptomatic individuals is highly suggestive of the circulation of HEV in this rural population.

Epidemiology and control of child toxocariasis in the western Brazilian Amazon - a population-based study.

Toxocara spp. infection and the seroconversion rate in the Amazon have been poorly investigated. This study analyzed individual and household-level risk factors for the presence of IgG antibodies to Toxocara spp. in urban Amazonian children over a period of 7 years and evaluated the seroconversion rates over a 1-year follow-up. In children < 59 months of age, the overall prevalence rate was 28.08% in 2003 and 23.35% in 2010. The 2010-2011 seroconversion rates were 13.90% for children 6-59 months of age and 12.30% for children 84-143 months of age. Multilevel logistic regression analysis identified child age, previous wheezing, and current infection with hookworm as significant associated factors for Toxocara spp. seropositivity in 2003. In 2010, age, previous helminthiasis, and having a dog were associated with seropositivity, whereas having piped water inside the household was a protective factor. Control programs mainly need to target at-risk children, water quality control, and animal deworming strategies.

Vivax malaria in an Amazonian child with dilated cardiomyopathy.

A child living in the Brazilian Amazon region who had had vivax malaria at the age of 11 months was admitted three months later with a history of progressive dyspnoea and fever, which culminated in respiratory distress and severe dilated cardiomyopathy at hospital admission in a malaria-free area. She received treatment for cardiac insufficiency and was tested for malaria with two thick blood smears, which were negative. There was general improvement of cardiorespiratory function in the next two weeks, but in the third week of hospital admission, there was re-appearance of fever, severe anaemia, severe plaquetopaenia, and respiratory distress. A third thick blood smear was positive for Plasmodium vivax mono-infection, which was confirmed by molecular methods. A serological panel with the most prevalent infectious agents known to cause myocarditis was performed, and specific anti-cytomegalovirus (CMV) IgM and elevated levels of anti-CMV IgG were also detected in the serum. After treatment for malaria, there was improvement of respiratory distress, although cardiac function did not recover. She was discharged home with drugs for cardiac insufficiency and is currently under follow-up with a paediatric cardiologist as an outpatient. This report presents a young child with several episodes of vivax malaria who suffers from cardiac insufficiency, probably related to CMV-induced myocarditis.