Department of Civil Engineering Architecture Land and Environment and Mathematics, University of Brescia, Brescia, Italy.
Institute Zooprofilattico Sperimentale Della Lombardia E Dell'Emilia Romagna, Brescia, Italy.
Parasit Vectors. 2024 Mar 6;17(1):109. doi: 10.1186/s13071-024-06208-6.
In Italy, malaria was endemic until the 1970s, when it was declared eradicated by WHO. Nowadays, with the persistence of competent mosquito populations, the effect of climate change, and increased possibility of importing malaria parasites from endemic counties due to growing migration, a malaria resurgence in Italy has become more likely. Hence, enhancing the understanding of the current distribution of the Anopheles maculipennis complex and the factors that influence the presence of this malaria vector is crucial, especially in Northern Italy, characterised by a high density of both human population and livestock.
To assess the presence and abundance of malaria vectors, a 4-year field survey in the plain areas of Lombardy and Emilia-Romagna region in Italy was conducted. Every sampling point was characterised in space by the land use in a 500-m radius and in time considering meteorological data collected in the short and long time periods before sampling. We combined the results of a linear regression model with a random forest analysis to understand the relative importance of the investigated niche dimensions in determining Anopheles mosquito presence and abundance.
The estimated normalised variable importance indicates that rice fields were the most important land use class explaining the presence of Anopheles, followed by transitional woodlands and shrubland. Farm buildings were the third variable in terms of importance, likely because of the presence of animal shelters, followed by urbanised land. The two most important meteorological variables influencing the abundance of Anopheles in our study area were mean temperature in the 24 h before the sampling date and the sum of degree-days with temperature between 18 °C and 30 °C in the 14 days before the sampling date.
The results obtained in this study could be helpful in predicting the risk of autochthonous malaria transmission, based on local information on land cover classes that might facilitate the presence of malaria vectors and presence of short- and medium-term meteorological conditions favourable to mosquito development and activity. The results can support the design of vector control measures through environmental management.
在意大利，疟疾曾流行至 20 世纪 70 年代，后被世界卫生组织宣布根除。如今，由于具有传播能力的蚊虫种群持续存在、气候变化的影响以及由于移民增加而导致从流行地区输入疟原虫的可能性增加，意大利疟疾再次出现的可能性更大。因此，加强对冈比亚按蚊复合体当前分布及其影响这种疟疾媒介存在的因素的了解至关重要，尤其是在意大利北部，该地区人口和牲畜密度均较高。
为了评估疟疾媒介的存在和丰度，在意大利伦巴第和艾米利亚-罗马涅地区的平原地区进行了为期 4 年的实地调查。每个采样点在空间上都以 500 米半径内的土地利用情况为特征，在时间上考虑了在采样前短期和长期收集的气象数据。我们将线性回归模型的结果与随机森林分析相结合，以了解所研究的生态位维度在确定疟蚊存在和丰度方面的相对重要性。
估计的归一化变量重要性表明，稻田是解释疟蚊存在的最重要的土地利用类型，其次是过渡性林地和灌木林地。农场建筑是重要性排名第三的变量，可能是因为存在动物庇护所，其次是城市化土地。在我们的研究区域内，影响疟蚊丰度的两个最重要的气象变量是采样日期前 24 小时的平均温度以及采样日期前 14 天内 18-30°C 之间的温度度日总和。
本研究获得的结果有助于根据可能有助于疟蚊存在的土地覆盖类别的本地信息以及有利于蚊子发育和活动的短期和中期气象条件，预测本地疟疾传播的风险。结果可以通过环境管理来支持设计控制措施。
