Athos Muniz Braña

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.

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.

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.

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.

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 childrens 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 mothers height, age and education. Therefore, it was observed that family and the mothers 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.

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.