da Silva Anderson Coutinho, Duarte Elisabeth Carmem, Marchesini Paola Barbosa, Viana Giselle Maria Rachid, Ramalho Walter Massa, Garcia Klauss K S
Center of Tropical Medicine, University of Brasilia, Brasília, 70904-970, Brazil.
Health Secretariat of Health and Environmental Surveillance, Ministry of Health, Brasilia, 70719-040, Brazil.
Malar J. 2025 Jul 12;24(1):227. doi: 10.1186/s12936-025-05357-y.
Malaria is infectious disease with low occurrence in Brazil extra-Amazon Region. Despite this, higher lethality is observed in this region compared to the country's endemic area. Therefore, this study aimed to analyse factors associated with malaria hospitalizations (severe malaria) in the extra-Amazon Region, in order to prevent deaths.
A case-control design was used, utilizing data from the Brazilian Notifiable Diseases Information System (Sinan) and hospitalization records from the Unified Health System (SIH/SUS) from 2011 to 2019. Cases comprised hospitalized malaria patients, while controls included reported malaria notifications without hospitalization. Probabilistic record linkage techniques were employed, and associations were analysed using multiple logistic regression with a 0.05 significance level.
The main risk factors identified were: Black or mixed-race ethnicity (OR = 1.22; 95% CI 1.04-1.43), low education (elementary school OR = 2.21; 95% CI 1.78-2.75 or high school OR = 1.72; 95% CI 1.39-2.13), infection outside the extra-Amazon Region (Amazon Region OR = 1.50; 95% CI 1.15-1.96 or abroad OR = 1.72; 95% CI 1.28-2.32), high parasite count (501 to 10,000/mm OR = 1.51; 95% CI 1.27-1.80, 10,001 to 100,000/mm OR = 1.77; 95% CI 2.87-1.96 or higher than 100,000/mm OR = 3.15; 95% CI 2.20-4.50) and delayed treatment (after 3-7 days symptoms onset OR = 1.74; 95% CI 1.36-2.24 or 8 days or more OR = 2.08; 95% CI 1.62-2.66). Active case detection was a protective factor (OR = 0.65; 95% CI 0.54-0.78).
Delayed treatment remains a key factor in the occurrence of severe malaria, leading to high parasitaemia and revealing inequalities in access to healthcare based on socioeconomic differences. Travel to the Amazon Region or other countries also poses a challenge, requiring strengthened traveller health strategies and increased surveillance awareness to promptly suspect and identify cases.
疟疾是巴西亚马逊地区以外发病率较低的传染病。尽管如此，与该国疟疾流行地区相比，该地区的致死率更高。因此，本研究旨在分析亚马逊地区以外与疟疾住院（重症疟疾）相关的因素，以预防死亡。
采用病例对照设计，利用巴西法定传染病信息系统（Sinan）的数据以及2011年至2019年统一卫生系统（SIH/SUS）的住院记录。病例包括住院的疟疾患者，而对照包括报告的未住院的疟疾病例。采用概率记录链接技术，并使用显著性水平为0.05的多元逻辑回归分析相关性。
确定的主要危险因素为：黑人或混血种族（比值比[OR]=1.22；95%置信区间[CI]1.04-1.43）、低教育水平（小学学历OR=2.21；95%CI 1.78-2.75或高中学历OR=1.72；95%CI 1.39-2.13）、在亚马逊地区以外感染（亚马逊地区OR=1.50；95%CI 1.15-1.96或国外OR=1.72；95%CI 1.28-2.32）、寄生虫计数高（501至10000/立方毫米OR=1.51；95%CI 1.27-1.80，10001至100000/立方毫米OR=1.77；95%CI 1.87-1.96或高于100000/立方毫米OR=3.15；95%CI 2.20-4.50）以及治疗延迟（症状出现后3至7天OR=1.74；95%CI 1.36-2.24或8天及以上OR=2.08；95%CI 1.62-2.66）。主动病例检测是一个保护因素（OR=0.65；95%CI 0.54-0.78）。
治疗延迟仍然是重症疟疾发生的关键因素，导致高寄生虫血症，并揭示了基于社会经济差异在获得医疗保健方面的不平等。前往亚马逊地区或其他国家旅行也带来了挑战，需要加强旅行者健康策略并提高监测意识，以便及时怀疑和识别病例。
