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Objective To identify the temporal-spatial distribution patterns and changing of hotspot areas of malaria importations, and high-risk importation areas for imported malaria in Jiangsu Province, in order to provide the scientific evidence for prevention of malaria reintroduction in China. Methods Cases with imported malaria in Jiangsu Province from 2016 to 2022 were accessed from the National Notifiable Disease Report System and the Information Management System for Parasitic Disease Control in China. The county-level vector map of Jiangsu Province was obtained from the National Fundamental Geographic Information System, China. ArcGIS 10.7 software was utilized to create a thematic map depicting the distribution of imported malaria cases in Jiangsu Province at the county level. Global and local autocorrelation analysis was then conducted to investigate the spatiotemporal changes in malaria import hotspot counties. Results There were a total of 1 189 cases with imported malaria reported in 77 counties (81.05%, 77/95) of Jiangsu Province from 2016 to 2022. The global spatial autocorrelation analysis showed that a global spatial cluster of imported malaria in Jiangsu was only identified in 2020 ( Moran's I=0.46, Z=4.37, P<0.01), but local spatial autocorrelation analysis found that a total 60 hotspot counties existed from 2016 to 2022. There are 23 counties in central Jiangsu (38.33%), and 20 counties in southern Jiangsu (33.33%), 17 counties in northern Jiangsu (28.33%). The distribution of hotspot counties exhibits continuity. For instance, Chongchuan District, which falls under the jurisdiction of Nantong City, has consistently emerged as a hotspot county for 2016-2021. Since 2020, two recurring hotspot counties emerged in northern Jiangsu and southern Jiangsu. These counties are Ganyu District, under the jurisdiction of Lianyungang City, and Lishui District, under the jurisdiction of Nanjing City. Conclusions The spatial-temporal cluster of cases with imported malaria was identified at the county level in Jiangsu, that hotspot counties were consistently detected. It is essential to maintain the sustainability of malaria surveillance and response in hotspot counties which were new detected, and strengthen the capacity of surveillance and response in hotspot counties which were continually detected based on the spatial-temporal distribution characteristics and changing rules of imported malaria. [ABSTRACT FROM AUTHOR]

Objective To investigate the effects of capsaicin on gut microbiota and antimicrobial peptide expression of Anopheles stephensi, providing experimental references for the application of capsaicin in mosquito-borne disease prevention and control. Methods Anopheles stephensi were continuously fed with sugary water containing capsaicin or DMSO for the capsaicin-treated group and the control, respectively. The DNA of the female mosquito's midguts and gut bacteria was extracted. Bacterial 16S rDNA high-throughput sequencing and real-time fluorescence quantitative PCR were used to analyze and compare the bacteria diversity, gut flora composition, relative abundance, and total bacterial load in female mosquitoes' midgut between the control and capsaicin treatment groups. Total RNA was extracted from the midguts of the two groups of Anopheles mosquitoes, and the transcriptional levels of important antimicrobial peptides were detected and compared by reverse transcription and real-time fluorescence quantitative PCR. Results A total of 10 phyla, 11 classes, 28 orders, 43 families, and 62 genera were identified in the two groups. The capsaicin-treated group had fewer taxa, with significantly reduced bacterial diversity, and different community composition and relative abundance of the flora compared to the control group. At the phylum level, Bacteroidota, Proteobacteria, and Firmicutes predominated in both two groups. At the order level, Flavobacteriales, Acetobacterales, Pseudomonadales, and Lactobacillales were the dominant bacteria, with reduced relative abundance of Pseudomonadales and Acetobacterales and increased relative abundance of Flavobacteriales and Lactobacillales in the capsaicin-treated group. At the genus level, Elizabethkingia was predominantly abundant in both samples, with higher relative abundance of Elizabethkingia, Leuconostoc, and Gluconobacter in the capsaicin-treated group, while Asaia and Acinetobacter had significantly lower relative abundance compared to the control group. In addition to these changes, the total bacterial load was increased and the transcriptional levels of attacin C, cecropin A, and defensin were significantly decreased by capsaicin treatment. Conclusions Capsaicin treatment significantly affects the composition of the gut flora in Anopheles stephensi and increases the total bacterial load while inhibiting the expression of antimicrobial peptides. Based on the analysis, it indicates that capsaicin might affect the fecundity and vector competence of Anopheles by changing the energy metabolism and immune-related bacteria. [ABSTRACT FROM AUTHOR]