Rocha Rafael, Kurum Elif, Ayhan Nazli, Charrel Rémi, Maia Carla
Global Health and Tropical Medicine (GHTM), Associate Laboratory in Translation and Innovation Towards Global Health, LA-REAL, Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa (UNL), Lisbon, Portugal.
Unité Des Virus Émergents (UVE: Aix-Marseille Univ, Università di Corsica, IRD 190, Inserm 1207, IRBA), Marseille, France.
Parasit Vectors. 2025 Mar 3;18(1):82. doi: 10.1186/s13071-025-06726-x.
Toscana virus (TOSV; Phlebovirus toscanaense), a phlebovirus transmitted by sand flies, is a growing public health concern in the Mediterranean region, with infections often being asymptomatic but potentially leading to neuroinvasive disease. Despite its presence in neighboring countries, data on TOSV seroprevalence in Portugal are limited. This study aimed to estimate the national seroprevalence of TOSV among blood donors in mainland Portugal and explore associations with sociodemographic factors and Leishmania infection.
A cross-sectional study was conducted using serum samples from 3593 blood donors across mainland Portugal, collected between February and June 2022. Anti-TOSV antibodies were detected via microneutralization assay, and anti-Leishmania antibodies had previously been tested using ELISA. Sociodemographic data were obtained from self-administered questionnaires. Seroprevalence was estimated by region, and multivariate logistic regression was used to identify factors associated with TOSV infection.
Overall, the estimated national true seroprevalence of TOSV was 2.6% (95% CI 2.1-3.1%). Regional seroprevalence varied significantly, with the highest values (up to 14.8%) in Alto Alentejo, Baixo Alentejo, Douro, Alto Tâmega e Barroso and Oeste regions. Multivariate analysis showed that age ≥ 50 years (aOR 1.70, 95% CI 1.04-2.77), residing in the Alentejo region (aOR 3.05, 95% CI 1.85-5.02) and positive/borderline Leishmania serology (aOR 2.31, 95% CI 1.29-4.15) were significantly associated with TOSV infection.
This study highlights new areas of TOSV circulation in Portugal, particularly in regions with higher Leishmania seroprevalence and visceral leishmaniasis incidence, suggesting co-circulation of these pathogens. Although a lower seroprevalence was obtained compared to neighboring countries, TOSV should still be considered in the differential diagnosis of viral meningitis and encephalitis in Portugal, especially in potentially high-risk regions. Further research is needed to better understand the ecological drivers of TOSV distribution in Portugal.
托斯卡纳病毒（TOSV；托斯卡纳白蛉病毒）是一种由白蛉传播的白蛉病毒，在地中海地区日益引起公共卫生关注，其感染通常无症状，但可能导致神经侵袭性疾病。尽管在邻国已发现该病毒，但葡萄牙关于TOSV血清流行率的数据有限。本研究旨在估计葡萄牙大陆献血者中TOSV的全国血清流行率，并探讨其与社会人口统计学因素及利什曼原虫感染的关联。
采用横断面研究，使用2022年2月至6月期间从葡萄牙大陆3593名献血者采集的血清样本。通过微量中和试验检测抗TOSV抗体，抗利什曼原虫抗体此前已用酶联免疫吸附测定法检测。社会人口统计学数据通过自行填写的问卷获得。按地区估计血清流行率，并使用多因素逻辑回归确定与TOSV感染相关的因素。
总体而言，估计TOSV的全国真实血清流行率为2.6%（95%置信区间2.1 - 3.1%）。各地区血清流行率差异显著，在阿连特茹高地、阿连特茹低地、杜罗河、上塔梅加和巴罗索以及西部等地区血清流行率最高（高达14.8%）。多因素分析显示，年龄≥50岁（调整后比值比1.70，95%置信区间1.04 - 2.77）、居住在阿连特茹地区（调整后比值比3.05，95%置信区间1.85 - 5.02）以及利什曼原虫血清学呈阳性/临界值（调整后比值比2.31，95%置信区间1.29 - 4.15）与TOSV感染显著相关。
本研究突出了葡萄牙TOSV新的传播区域，特别是在利什曼原虫血清流行率和内脏利什曼病发病率较高的地区，提示这些病原体可能共同传播。尽管与邻国相比血清流行率较低，但在葡萄牙病毒性脑膜炎和脑炎的鉴别诊断中仍应考虑TOSV，尤其是在潜在高风险地区。需要进一步研究以更好地了解葡萄牙TOSV分布的生态驱动因素。
