[Association between malaria and anemia in an urban area with Plasmodium transmission: Mâncio Lima, Acre State, Brazil]. / Associação entre malária e anemia em área urbana de transmissão do Plasmodium: Mâncio Lima, Acre, Brasil.

The aim of this study was to analyze the prevalence of malaria-attributable anemia in the urban population of Mâncio Lima, Acre State, Brazil. This was a non-concurrent cohort study of 1,167 persons followed for the three months prior to the interview using data from the SIVEP-Malaria database. Anemia frequency and prevalence rates were calculated in patients with and without a recent history of malaria, according to target variables. 50.2% of the individuals were males, and 67.96% were 15 years or older. Overall anemia prevalence was 7.1%, higher in the 6 months to 5 years age bracket. Some 8.3% of men with a recent history of malaria presented anemia. Overall, prevalence of malaria-attributable anemia was negligible, except in men (2.4%) and the Cobal neighborhood (51.4%). The results showed that anemia prevalence was low and that malaria's contribution to anemia only existed in men and in specific geographic areas.

Associação entre malária e anemia em área urbana de transmissão do Plasmodium: Mâncio Lima, Acre, Brasil / Association between malaria and anemia in an urban area with Plasmodium transmission: Mâncio Lima, Acre State, Brazil / Asociación entre malaria y anemia en un área urbana de transmisión del Plasmodium: Mâncio Lima, Acre, Brasil

Resumo: O objetivo deste trabalho é analisar a prevalência de anemia atribuível à malária na população urbana residente no Município de Mâncio Lima, Acre, Brasil. Trata-se de um estudo de coorte não concorrente com 1.167 pessoas acompanhadas por três meses anteriores à data da entrevista mediante dados do SIVEP-Malária. Foram calculadas as medidas de frequência e a prevalência de anemia em pacientes com e sem histórico de malária recente, conforme as variáveis de interesse. Os resultados mostraram que 50,2% dos indivíduos eram do sexo masculino e 67,96% encontravam-se na faixa etária de 15 anos ou mais. A prevalência geral de anemia foi de 7,1%, sendo maior na faixa etária de 6 meses até 5 anos de idade. Com relação ao histórico de malária recente, verificou-se que 8,3% dos homens que tiveram malária apresentaram anemia. No geral, a prevalência de anemia atribuível à malária foi nulo, exceto para os homens (2,4%) e no bairro Cobal (51,4%). Os resultados demonstram que a prevalência de anemia é baixa e que a contribuição da malária para anemia existe apenas em homens e áreas geográficas específicas.

Abstract: The aim of this study was to analyze the prevalence of malaria-attributable anemia in the urban population of Mâncio Lima, Acre State, Brazil. This was a non-concurrent cohort study of 1,167 persons followed for the three months prior to the interview using data from the SIVEP-Malaria database. Anemia frequency and prevalence rates were calculated in patients with and without a recent history of malaria, according to target variables. 50.2% of the individuals were males, and 67.96% were 15 years or older. Overall anemia prevalence was 7.1%, higher in the 6 months to 5 years age bracket. Some 8.3% of men with a recent history of malaria presented anemia. Overall, prevalence of malaria-attributable anemia was negligible, except in men (2.4%) and the Cobal neighborhood (51.4%). The results showed that anemia prevalence was low and that malaria's contribution to anemia only existed in men and in specific geographic areas.

Resumen: El objetivo de este trabajo es analizar la prevalencia de anemia atribuible a la malaria en una población urbana, residente en el Municipio de Mâncio Lima, Acre, Brasil. Se trata de un estudio de cohorte no-concurrente con 1.167 personas acompañadas por tres meses anteriores a la fecha de la entrevista a través de datos del SIVEP-Malaria. Se calcularon las medidas de frecuencia y la prevalencia de anemia en pacientes con y sin historial de malaria reciente, conforme las variables de interés. Los resultados mostraron que un 50,2% de los individuos eran de sexo masculino y 67,96% se encontraban en la franja de edad de 15 años o más. La prevalencia general de anemia fue de un 7,1%, siendo mayor en la franja de edad de 6 meses hasta 5 años de edad. En relación con el historial de malaria reciente, se verificó que un 8,3% de los hombres que tuvieron malaria presentaron anemia. En general, la prevalencia de anemia atribuible a la malaria fue nula, excepto para los hombres (2,4%) y en el barrio Cobal (51,4%). Los resultados demuestran baja prevalencia de anemia y que la contribución de la malaria a la anemia existe solamente en hombres y áreas geográficas específicas.

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.