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  • LI Shi-jie, CHEN Guo-qing, CHENG Yang-ying, ZHANG Yan, DENG Meng-meng, JI Wei, XIE Deng-long, SUO Xun
    Abstract (244) PDF (13)
    Objective To evaluate the efficacy of Compound Fipronil Spot-on Solution in repelling canine ticks. Methods A total of 140 dogs infested with ticks were randomly selected from regions in southern and northern China and assigned to four groups: southern test drug group, southern control drug group, northern test drug group, and northern control drug group. Each group comprised 35 dogs. Each dog was administered the prescribed dose.The number of ticks was counted on days 1, 7, 14, 21, and 28 following the administration. The negative conversion and average reduction rates of the tick population were then subjected to statistical analyse. Results The mean efficacy of the test drug was 100% in both the southern and northern cohorts, 28 days post-treatment. The control drug showed comparable efficacy, reaching a mean reduction of 100% in both regions by the same time point. No additional clinical manifestations or adverse events were observed across all treated dogs. Conclusions Compound Fipronil Spot-on Solutions effectively treats and prevents ticks in dogs in different regions of China. A single dose remains effective for up to 28 days, thus providing a convenient, effective solution.
  • LI Si-ying, WANG Rui, ZHOU Jin-lin
    Abstract (208) PDF (28)
    Ticks are medically significant arthropods with a global distribution and the ability to transmit a wide range of pathogens to human and animal. Their medical significance is second only to that of mosquitoes. In recent years, factors such as urbanization, international trade, and climate change have led to a notable increase in both the incidence and emergence of tick-borne diseases. Since different tick species carry or transmit different pathogens, accurate and rapid identification of tick species is essential before implementing strategies to prevent and control ticks and tick-borne diseases. This review summarizes the research progress in molecular identification technologies for tick species, providing a valuable reference for related research.
  • JIA Jia, WEI Yu-lu, ZHEN Qian, TIAN Cheng, PAN Jie, CHEN An-xi, XIONG Shu-ting, WANG Ze-min, CAO Gan, CHEN Ke-ping, XU Yan, CHU Hong-liang, LYU Xu-feng
    Abstract (202) PDF (51)
    Objective In this study, ecological monitoring data of ticks in Changzhou City (2021-2024) were analyzed to understand the composition, distribution, density, and seasonal trends of the different species and thereby provide a scientific basis for tick-borne disease control strategies. Methods Parasitic ticks were monitored via host surface examination, whereas questing ticks were monitored using the flagging method. Results In total, 1 506 ticks (636 parasitic, 870 questing), belonging to 1 family, 2 genera, and 5 species, were collected. Haemaphysalis longicornis (1 389) was the dominant species, followed by Hae. flava (111), Hae. phasiana (3), Amblyomma testudinarium (2), and Hae. hystricis (1). The parasitic tick index was 1.89 (goats as the dominant hosts), whereas the questing tick density was 0.65 individuals/(cloth flag·100 m) (forest parks as the dominant habitat). Tick activity peaked in July. Conclusions Hae. longicornis is the dominant species in Changzhou City, with activity peaking in July. As these ticks pose a significant public health risk, targeted control measures are recommended.
  • SUN Ai-juan, YANG Yang, GU Deng-an
    Abstract (195) PDF (34)
    Objective The density and species composition of cockroaches in Suzhou, China as well as their seasonal fluctuations were investigated to provide a theoretical basis for their scientific control. Methods The sticking trap method was used to survey the population of cockroaches in the city. The chi-square test was used to compare the rates of adhesion to the sticky sheets, and the Kruskal-Wallis H test was used to compare the density of cockroaches. Results From 2019 to 2023, a total of 27 576 sticky sheet traps were placed in various areas of Suzhou. Of these, 2 248 yielded positive captures of 15 963 cockroaches in total, with an adhesion rate of 8.15% and density of 0.58 insects per sheet. Blattella germanica predominated, accounting for 95.76% of the cockroach species in Suzhou. The adhesion rate and density of cockroaches decreased from 2019 to 2023, with the difference between the years being statistically significant (χ2=96.913, P<0.001). The highest adhesion rate and density (25.89% and 2.36 insects per sheet, respectively) were found in farm product markets. The adhesion rates differed significantly among different habitats (χ2=2 458.309, P < 0.001). Cockroaches were active throughout the year, and the month of peak density differed in different years, with the overall peak density being 0.66 insects per sheet in November. Additionally, the seasonal fluctuation in cockroach density differed significantly among the different years (H=23.976, P<0.001). Conclusions The survey results showed that the adhesion rate and density of cockroaches in Suzhou have been decreasing annually. Cockroaches were active throughout the year, being mainly present in farm product markets. The seasonal fluctuations in cockroach density in different years differed significantly. Therefore, the characteristics of each habitat should be considered to effectively reduce the cockroach population density.
  • JIN Xi-meng, JIANG Peng, WANG Dong-qiang, ZHAI Zong-zhen, YIN Ji-gang, ZHU Guan
    Abstract (187) PDF (43)
    Objective The aim of this study was to characterize the basic molecular and biochemical parameters for a cyclophilin protein in Cryptosporidium parvum called CpCyP1. Methods CpCyP1 expression patterns during the parasite life cycle were evaluated using qRT-PCR with total RNA isolated from different developmental stages of C. parvum. Native CpCyP1 protein in sporozoites was detected using western blot. The localization of CpCyP1 was performed using the immunofluorescence assay, with an affinity-purified rabbit polyclonal antibody against a synthetic peptide. The peptidyl-prolyl cis-trans isomerase (PPIase) activity of His-tagged recombinant CpCyP1 was evaluated using absorbance colorimetry, and the effect of cyclosporin A (CsA) on the activity of CpCyP1 was determined. Results CpCyP1 was expressed in all parasite developmental stages, whereas CpCyP1 was present mainly in the cytosol of sporozoites, meronts, and gamonts. CpCyP1 displayed Michaelis-Menten kinetics towards N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide for its PPIase activity (Km = 456.4 μmol/L; Vmax = 1.981 U). CsA inhibited PPIase activity, showing lower micromolar inhibitory activity and binding affinity (Kd = 5.122 μmol/L; IC50 = 1.004 μmol/L). Conclusions These results imply that CpCyP1 in the parasite may be the target for the previously reported anti-cryptosporidial efficacy of CsA and suggest that C. parvum cyclophilins could be evaluated as candidate drug targets.
  • CAI Zi-han, ZHOU Yu-yang, WU Qiong, ZHOU Jing, YANG Yi-mei
    Abstract (180) PDF (23)
    Objective To evaluate the efficacy of the enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and gold chromatographic strip assay (GICA) in diagnosingclonorchiasis through a meta-analysis of diagnostic tests. Methods Relevant databases, including CNKI, the Wan Fang Database, VIP, and PubMed, were searched according to inclusion and exclusion criteria. Literature quality was assessed using RevMan 5.4 and Stata 18, and funnel plots, forest plots, and SROC curves were generated. Results A total of 50 articles met the inclusion criteria. Deeks′funnel plot analysis indicated no significant publication bias among the three methods. The combined effect size analysis revealed that the sensitivity and specificity of ELISA for detecting clonorchiasis were 0.93 (0.89-0.95) and 0.94 (0.92-0.96), respectively, with an area under the SROC curve of 0.98. For PCR, the sensitivity and specificity were 0.93 (0.84-0.97) and 0.92 (0.80-0.97), respectively, yielding an area under the SROC curve of 0.97. The sensitivity and specificity of the GICA method for detecting clonorchiasis were 0.91 (0.83-0.96) and 0.95 (0.87-0.98), respectively, with an area under the SROC curve of 0.97. Conclusions In the diagnosis of clonorchiasis, ELISA, PCR and GICA have high diagnostic value, but their ranges differ from each other.
  • WANG Xin, HUANG Ying, ZHOU Xiao-qing, FENG Hao, CHEN Xi-peng, ZHU Hai-yang, LYU Meng-meng, CHEN Hao, JIANG Bao-gui, CAI Rong
    Abstract (170) PDF (32)
    Objective This study aimed to comprehensively survey the tick distribution in the natural scenic belts of various counties and districts in Huai'an City, Jiangsu Province, and to provide guidance on tick control measures. Methods From 2023 to 2024, questing ticks in 29 natural scenic belts spanning seven counties and districts of Huai'an City were collected using hand-scratching method. Further, parasitic ticks in the surrounding areas were collected using the animal search method. Collected ticks were subsequently identified to the species level in the laboratory. Results In total, 288 questing ticks were collected, all belonging to the genus Haemaphysalis of family Ixodidae. Hae. longicornis was the dominant species, accounting for 98.61%, followed by Hae. flava (1.04%) and Hae. phasiana (0.35%). The average tick density index in Lotus Lake Scenic Area (Jinhu County), All-People Fitness Theme Park (Lianshui County), Peach Blossom Valley (QingjiangpuDistrict), Huai'an Forest Park (Huai'an District), Qizu of Gaozhuang Village (Hongze District), Ancient Yellow River Sports Park (Huaiyin District), Putao Trench and (Xuyi County) was 0.022, 0.025, 0.01, 0.10, 0.22, 0.28, and 0.79ticks/flag·100 m, respectively. In total, 114 parasitic ticks were collected at the monitoring sites, with an average tick infestation rate of 69.25% in sheep and 100% in dogs at Tianquanhu Town in Xuyi County; all of these were Hae. longicornis. All parasitic ticks were from Xuyi County, and no parasitic ticks were found at the monitoring sites in Huai'an District, Hongze District, and Lianshui County. Conclusions Overall, with the advancement of eco-tourism resorts and urban greening construction in Huai'an City, the presence of ticks was confirmed by this study in previously unsurveyed areas. As the frequency of human-animal interactions increases in these areas, the potential risk of tick-borne diseases also rises. Furthermore, this study provides important clues for subsequent investigations into local tick-borne pathogens.
  • ZHOU Yang, LI Man-jin, CHENG Jin, ZOU Ya-ming, ZHU Ding, LAN Ce-jie, SHEN Yuan
    Abstract (169) PDF (69)
    Objective Aedes albopictus is the primary vector of the dengue virus. Screening and the analysis of immune-related genes in DENV2-infected Ae. albopictus provides a scientific basis for further research on blocking the extrinsic incubation period of the dengue virus. Methods Through the approach of literature mining, thirty-three potential immune-related genes were screened from species such as Aedes aegypti and Anopheles gambiae, which have a close genetic relationship with Ae. albopictus. The protein—protein interaction (PPI) analysis is employed to explore the interaction relationship of the proteins encoded by genes. The alterations in mRNA expression levels of the relevant genes in DENV2-infected Ae. albopictus midgut were detected using the qRT-PCR method. Results The PPI results indicates that TLR and Spz of Ae. albopictus; Rel1, Rel2, DefC, Spz, PIWI, Ago2, DOME and HOP of Ae. aegypti; and Rel1, Rel2, CACT, STAT and DOME of An. gambiae exhibit PPI relationships. After Ae. albopictus was infected with DENV2, 10 genes showed significant difference in expression. Ago3 (7.39, P < 0.05), DOMEa (1.63, P < 0.01), DOMEb (21.29, P < 0.001), and TLRb (1.61, P < 0.05) were significantly up-regulated. Rel1 (0.62, P < 0.001), CACTl (0.65, P < 0.001), Rel2a (0.65, P < 0.01), Rel2b (0.24, P < 0.001), GATAa (0.64, P < 0.01) and DefC (0.28, P < 0.05) were significantly down-regulated. Conclusions The concordance of Ae. albopictus with Ae. aegypti was higher than that with An. gambiae. DOMEb, Ago3, Rel2b and DefC, can serve as the preferred target genes for subsequent studies on DENV2 immune blockade.
  • ZHANG Xiao-long, XU Jia, MA Shi-liang, WANG Pi-zheng, PAN Juan, CAO Jia-yuan, SUN Zhi-wen, GUO Hui-lin, XIAO Li-li
    Abstract (168) PDF (25)
    Objective This study aimed to investigate natural infection of rodents with Ehrlichia and Neoehrlichia at major Chinese land-border ports along the "Belt and Road". Methods In 2022, rodents were monitored in 10 ports in northern and southern China and identified based on diagnostic morphological characteristics. The 16S rRNA genes of Ehrlichia and Neoehrlichia were detected by PCR using universal primers from rodent samples and phylogenetic analysis was performed based on the sequences of the detected positive pathogens. Results A total of 356 rodents were sampled, including 2 orders, 5 families, 15 genera, and 20 species. Predominantly, 73, 61, 56, and 58 were Meriones unguiculatus (20.51%), Rattus norvegicus (17.13%), Apodemus agrarius (15.73%), and Microtus gregalis (16.29%). Only one Microtus fortis from Suifenghe Port was infected with Ehrlichia sp. Moreover, 12 rodents were infected with Neoehrlichia spp. (overall positivity rate: 3.37%). Conclusions Natural infections with Ehrlichia spp. and Neoehrlichia spp. were demonstrated in rodents at important Chinese land-border ports. The positivity rate of Neoehrlichia spp. was high in some ports, indicating that surveillance for ticks and their prevention and control measures should be intensified in these regions.
  • MIAO Zhuang, LI Xi, LI Wen-jing, ZHOU Fang-fang, SUN Shu-wen, CHENG Tian-yin, LI Fen
    Abstract (157) PDF (27)
    Objective The aims of this study were to identify tick species infesting police dogs and explore their phylogenetic relationships. Methods Ticks were collected from a police dog base in Hunan Province and their diagnostic morphological characteristics and phylogenetic relationships were investigated using PCR targeting the 16S rDNA, cytochrome C oxidase subunit 1 (cox1), and NADH dehydrogenase subunit V (nad5) genes. Results Adult ticks were oval shaped with a broad and short hexagonal basis capitulum. The females had a scutum occupying the first 1/3 of the body, a U-shaped genital groove, and a comma-shaped stigmal plate, and their coxae II to IV each had short and coarse outer spurs that gradually decreased in size according to the segmental order. Males had an elongated scutum, a comma-shaped stigmal plate, and a subtriangular adanal plate. The product sizes of the amplified 16S rDNA, cox1, and nad5 gene sequences from the ticks in this study were approximately 405, 772, and 262 bp, respectively. The phylogenetic tree based on these sequences showed that this tick species clustered with Rhipicephalus sanguineus of other tropical lineages. Conclusions The tick species collected from police dogs in China is Rh. sanguineus, which belongs to the tropical lineage.
  • XU Xiu-yan, YAN Ting, ZHU Si-jie, LI Jing, LIU Mei-de, ZHANG Hong-jiang, LIU Ting, LI Qiu-hong, ZHOU Xiao-jie, TONG Ying, ZHANG Yong
    Abstract (139) PDF (14)
    Objective This study conducted molecular biological identification of the viruses carried by Culex pipiens pallens specimens collected in Shunyi District, Beijing in 2023, and observed the changes in the infection rate of the viruses carried by Cx. pipiens pallens at different collection times.Methods Cx. pipiens pallens were collected using carbon dioxide mosquito traps. The mosquito samples were ground in batches and analyzed by molecular biology technologies. The virus infection rate at different collection times was analyzed statistically.Results 17 strains of Culex pipiens pallens densovirus (CppDNV) were identified from Cx. pipiens pallens samples collected in Shunyi District, Beijing, in 2023. The nucleotide sequence analysis of the virus genome coding region showed that CppDNV was a single-stranded DNA virus with a total length of 3 335 nt, encoding 2 non-structural proteins (NS1, NS2) and 1 capsid protein (VP). The nucleotide (amino acid) sequence lengths of the three proteins were 2 376 nt (791 aa), 1 092 nt (363 aa) and 1 071 nt (356 aa), respectively. Phylogenetic analysis showed that CppDNV was located in genus Brevihamaparvovirus. Statistical analysis showed no significant difference in infection rates across collection times (χ2=4.429, P=0.194).Conclusions CppDNV was identified in Cx. pipiens pallens in Beijing, and it was stably maintained in this natural population.
  • LIN Wen-hua, DAI Zu-teng, LIN Zhi-hua, WU Rong-quan, WANG Gang, TAN Wei-long, HE Ji
    Abstract (138) PDF (39)
    Objective To monitor rodent species in the southern Fujian ports of China and investigate the natural pathogens they carry. Methods Rodents were captured using night-trapping and cage method across 17 port areas in southern Fujian in 2023. Morphological identification was performed to classify the captured specimens. Tissues from the liver, spleen, lungs, kidneys, and bladder were harvested for nucleic acid extraction. Nested and conventional PCR method were used to detect seven pathogens: Yersinia pestis, Hantavirus, pathogenic Leptospira, Borrelia burgdorferi, Bartonella, Orientia tsutsugamushi, and Anaplasma phagocytophilum. The Chi-square test was used to analyze the distribution of rodents and the status of natural pathogen infections across the study sites. Results A total of 161 rodents across five species belonging to two orders, two families, and three genera were captured. Suncus murinus was the dominant species (72.67 %), followed by Rattus tanezumi (13.04 %). Six pathogens were detected, with an overall positivity rate of 18.01%. Bartonella had the highest positivity rate (11.18%), followed by pathogenic Leptospira (4.97%), Borrelia burgdorferi (2.48%), Orientia tsutsugamushi(1.86%), Seoul virus (1.24%), and Anaplasma phagocytophilum (0.62%). Co-infections were noted in five rodents, representing 17.24% of those that tested positive, and one rodent was infected with four pathogens. No Y. pestis or Hantaan virus was detected in the captured rodents. Conclusions The rodents in the southern Fujian ports are naturally infected with multiple pathogens, including Bartonella, pathogenic Leptospira, and Seoul virus. Enhanced monitoring of rodent populations and the implementation of preventive and control measures for rodent-borne diseases are essential.
  • TIAN Rui, ZHANG Yi, TIAN Yi, ZHANG Dai-tao, HE Zhan-ying
    Abstract (138) PDF (64)
    Objective To analyze the epidemiological characteristics of confirmed malaria cases reported by hospitals in Beijing from 2014 to 2023 among individuals who traveled abroad within the previous year and to provide a scientific basis for preventing the re-transmission of imported malaria. Methods Case data were derived from the “China Information System for Disease Control and Prevention.” Imported malaria cases reported in Beijing from January 1, 2014, to December 31, 2023, were selected. Descriptive epidemiological method were applied for the analyses. The chi-square test was used to compare the infected species and the distribution of occupation and year among imported malaria cases with different onset times. The Mann-Whitney U test was used to compare the time interval from the return date to diagnosis between recurrent cases and cases diagnosed for the first time, as well as the difference between cases with disease onset before and after entry. Results A total of 334 imported malaria cases were included in this study. The cases were mainly young and middle-aged males (91.32%), and 135 cases (40.42%) were employees of large state-owned enterprises. Falciparum malaria accounted for the highest proportion (84.73%), and 94.61% of all confirmed imported malaria cases were from Africa. For the recurrent and first-diagnosed cases, the difference in the time interval from entry to diagnosis was statistically significant (U = 2129.500, P < 0.05). Among patients with disease onset over 7 days after entry, the proportion of falciparum malaria was lower than those of other types of malaria infections (χ2 = 11.180, P = 0.004). Conclusions Imported falciparum malaria from Africa remains the main challenge to maintaining and consolidating China's achievements in malaria elimination. It is recommended to further strengthen health education for outbound workers and port inspection for key inbound personnel, standardize epidemiological investigations and information notifications, and comprehensively enhance the capability for detecting and managing imported malaria cases.
  • ZHENG Xiao-ying, LIU Fei, TAO Shi-ji, WANG Dun-jia, SHEN Jia-min, CAI Yi-zhou, JIANG Le, DONG Lin-juan, ZHU Min-hui, ZHOU Yi-bin
    Abstract (136) PDF (34)
    Objective To assess the status of rodent infestation in commercial kitchens using data from the ‘Bright Kitchen, Clean Stove’ initiative. The potential use of artificial-intelligence (AI)-based surveillance systems to monitor rodent density was explored, thereby providing a scientific basis for rodent control strategies. Methods As a component of the ‘Bright Kitchen, Clean Stove’ initiative, the Minhang District Market Supervision Administration in Shanghai has installed cameras in 297 kitchens. These systems incorporate an AI-powered rodent image recognition method that automatically captures and stores the first image captured in each kitchen each day when a rodent is detected. In 2023, the system collected and stored 736 screenshots of rodents. Following manual verification, 720 of the images were confirmed to contain rodents. The images were analyzed by noting the time, location, and kitchen area, and the species were manually identified to assess the population density. Results Rodent activity was detected in 34 of the 297 monitored kitchens, with an overall infestation rate of 11.45%. Of the 720 confirmed images of rodents, Rattus norvegicus (brown rat) was the predominant species, present in 409 (56.81 %) images. Rodents were primarily concentrated in hot food preparation spaces. The density fluctuation curve had a multimodal pattern peaking in spring and autumn. The peak of daily activity was between 22:00 and 2:00. There was a significant difference in the rodent detection frequency between weekends and weekdays during peak hours and during non-peak hours (χ2 = 7.18, P < 0.01). Conclusions The ‘Bright Kitchen, Clear Stove’ smart monitoring system has been proven to be applicable to rodent density monitoring. To control rodents in commercial kitchens, greater efforts are required to address and identify the specific infesting conditions and the key points in the control process.
  • PAN Yao, ZHANG Jing, JIN Mei-jun, XIN Ling-xiang, XIAO Hai-yue, LIU Yan, YAO Wen-sheng, CHENG Chuan, HAO Li-li, LAN Lan, ZHU Liang-quan
    Abstract (135) PDF (22)
    Objective To establish a rapid, sensitive, and specific multiplex PCR detection method for the simultaneous detection of Cryptosporidium, Eimeria, and bovine parvovirus. Methods Specific primers targeting the SSU rRNA genes of Cryptosporidium and Eimeria, as well as the VP2 gene of bovine parvovirus were designed and the corresponding recombinant plasmid standards were constructed. To establish the multiplex PCR method, the reaction conditions were optimized using temperature gradient PCR and single-variable control methods. The sensitivity, specificity, reproducibility, and clinical application of the protocol were evaluated. Results The optimal annealing temperature was found to be 60.5℃, and the forward and reverse primer concentrations were determined to be 0.2 μmol/L for Eimeria, and 0.4 μmol/L for Cryptosporidium and bovine parvovirus. The assay demonstrated high sensitivity, with detection limits of 243, 260, and 3 110 copies for the recombinant plasmid standards of Cryptosporidium, Eimeria, and bovine parvovirus, respectively. Specificity testing showed no cross-reactivity with ten common bovine pathogens, including Salmonella, bovine viral diarrhea virus, and bovine rotavirus. Consistent intra- and inter-batch results confirmed the strong reproducibility of the method. Clinical application to 81 diarrhea samples from various regions in the Ganzi Prefecture, Sichuan, revealed positivity rates of 18.52% (15/81) for Cryptosporidium, 34.57% (28/81) for Eimeria, and 18.52% (15/81) for bovine parvovirus, with a mixed infection rate of 3.7% (3/81). Conclusions The multiplex PCR method established in this study offers a reliable tool for differential diagnosis and epidemiological investigation of the three common diarrheal pathogens in yaks.
  • FENG Hao, LIU Zhi-tong, QIN Tong, SUN Yi
    Abstract (133) PDF (41)
    Objective Candidatus Lariskella arthropodarum’ (CLA) is a novel intracellular alpha-proteobacterium closely related to Candidatus Midichloria mitochondrii’ (CMM), notable for its unique ability to invade and destroy mitochondria within host germline cells. CLA has been proposed as a potential pathogen, as it has occasionally been detected in blood samples from both humans and other vertebrates. However, the mechanisms of CLA infection and transmission remain poorly understood. Methods Natural CLA infection in unfed Ixodes persulcatus was investigated using meta-transcriptomic analysis of specimens collected from Zhalantun City, Hulunbuir League, Inner Mongolia Autonomous Region (IMAR), China. Results The top-matching transcript assembly was 21 917 base pairs in length and encoded genes including ccmA, mrdA, lon, ppsC, prmC, ileS, gshB, gmk, rpoC, and rpoB, all identical to CLA. These findings were further confirmed by amplification of 16S rRNA fragments (99.72% identity to CLA; GenBank accession number AB906829.1) from the DNA of the same tick specimens. A sex-biased prevalence of CLA was observed in I. persulcatus, with significantly higher infection rates in females (83.05%) compared to nymphs (46.11%) and males (36.47%). Conclusions This suggests differential adaptation of CLA across tick sexes and developmental stages.
  • ZHU Ya, ZHU Ming-chao, ZHAO Jian-zhong, SUN Li, XIA Shu-wei
    Abstract (129) PDF (1181)
    The aim of the present paper is to describe the administration of an imported Plasmodium ovale case with thrombocytopenia, and provide reference for the prevention and control of imported malaria. The patient was a 68-year-old male migrant worker who had been infected with P. ovale and had not received standard treatment. The main manifestation of this attack was thrombocytonia (platelet 81×109/L). The blood sample was tested positive by the rapid detection kit of P. ovale. The patient was treated with antimalarial therapy immediately, but platelets decreased progressively, and metabolic acidosis (bicarbonate concentration 17.2 mmol/L), acute kidney injury (creatinine 251 μmol/L) and other severe changes occurred. After active symptomatic treatment and replacement of malaria treatment regimen, the patient gradually improved. Therefore, early and adequate use of appropriate antimalarial drugs for patients with malaria infection with progressive platelet reduction is the key to curb the progression to severe disease.
  • FENG Ran, MA Tie-zheng, ZHU Si-jie, TIAN Bo, QUAN Fei, WU Zhi-lin, LIU Xiao-tao, ZHANG Fu-yuan, ZHANG Song-jian
    Abstract (126) PDF (24)
    Objective To understand mosquito density, species composition, and seasonal variations around the Beijing Capital International Airport (BCIA) and provide scientific evidence for mosquito-borne disease prevention and control.Methods Meteorological data were collected from 2016 to 2022, and mosquito density was monitored at seven surveillance sites around the BCIA from May to October each year using CO2-baited mosquito traps to analyze the relationship between mosquito density and meteorological factors.Results In total, 68 518 female mosquitoes were captured, with a mosquito density of 10.20 per light·hour. The dominant species was Culex pipiens pallens (73.90%), followed by Aedes albopictus (9.71%) and Ae. vexans (9.29%); the mosquito density was highest in 2016 (14.8 per light·hour) and lowest in 2022 (4.46 per light·hour). Significant statistical differences were observed in mosquito density among different species (F=18.118, P<0.05). The density of Cx. pipiens pallens and other mosquito species showed a mutually exclusive trend; the peak of mosquito density varied based on years and habitats, with significant statistical differences in mosquito density among different habitats (F=8.504, P<0.05). The highest mosquito density was observed near the Wenyu River (21.50 per light·hour), whereas the lowest was recorded at the BCIA construction site (2.44 per light·hour). The monthly average temperature (r=0.595), monthly average highest temperature (r=0.575), and monthly average lowest temperature (r=0.624) showed moderate positive correlations, whereas the monthly average air pressure (r=-0.484) showed a moderate negative correlation. The monthly average minimum temperature was included in the regression model (F=25.575, P<0.000), and the equation Y=1.029X4-8.181 was used. The monthly average air pressure 2 months prior (b=-2.418, β=-1.619, P<0.05) and the monthly average relative humidity (b=-0.739, β=-1.201, P<0.05) significantly negatively predicted the mosquito density. Notably, the regression equation used was y=2526.170+(-2.418)X9+(-0.739)X13. The exposure-response analysis revealed that the density of mosquitoes was not linearly related to the average monthly air pressure, rainfall, and duration of sunshine.Conclusions The dominant mosquito species around the BCIA was Cx. pipiens pallens, Ae. albopictus, and Ae. vexans. During the control of Cx. pipiens pallens, the impact on other mosquito species must also be considered. Environmental management, breeding sites, and scientific use of pesticides should be prioritized based on the activity periods of mosquitoes. Further studies on mosquitoes and meteorological factors should be conducted to provide references and novel avenues for mosquito control.
  • XIAO Long-jie, WANG Ting, YANG Yi-min, SUN Jing, LI Chun-hui, LIU Cheng-juan, ZHANG Hui-min, GUO Pei-jun**
    Abstract (122) PDF (39)
    Objective To investigate Haemaphysalis longicornis carrying Bandavirus dabieense in Yantai, Shandong Province, and provide references for the prevention and control measures of ticks and tick-borne pathogens. Methods Tick surveillance was carried out in Penglai District, Zhaoyuan City, Haiyang City, and other districts, respectively, in Yantai City from March to October in 2023 and 2024. Parasitic ticks were removed from domestic animals by hand-scratching, and questing ticks were collected using the flag-sweeping method. Real-time RT-PCR was used to detect B. dabieense in the collectedHae. longicornis specimens. SPSS22.0 software was used to perform the χ2 test or Fisher's exact test to compare the positive rates among different groups. Results A total of 7 646 Hae. longicornis were captured, including 3 232 questing ticks and 4 414 on-host ticks. Nucleic acid(both DNA and RNA) was extracted from 693 ticks grouped by source, development stage, and region. A total of 20 B. dabieense nucleic acid-positive samples were detected. The overall positive detection rate was 2.89% and the minimum infection rate (MIR) was 0.26%. Among them, 17 were from adult parasitic ticks, comprising five from dogs, six from sheep, and six from cattle, and the other three were from questing ticks. There was no significant difference in the positive rates of Hae. longicornis from different hosts or from different developmental stages (P>0.05). Significant differences were observed in the positive rate of Hae. longicornis from different geographic regions (P<0.05). Conclusions Hae. longicornalis is the dominant tick species in Yantai City, Shandong Province, with evidence from different host sources in various geographic regions. Ecological monitoring and pathogen detection in ticks should be strengthened to provide a scientific basis for the prevention and control of ticks and tick-borne diseases.
  • PAN Li-yuan, LIU Ju, ZHAO Sheng-xun
    Abstract (121) PDF (16)
    Hypereosinophilia is the term given to a group of highly heterogeneous diseases that are characterized by an increase in the absolute count of peripheral eosinophils, which can accumulate in one or more organs. Although parasitic infection is one of the common causes of eosinophilia, it is often ignored. So far, no clear diagnostic guideline for hepatic sparganosis exists worldwide, and only scattered cases have been reported. We reported a case of a patient with hypereosinophilia induced by hepatic sparganosis, with multiple organ involvement, and discussed the clinical characteristics and treatment plan. This report will help clinicians better understand the differential diagnosis of hepatic sparganosis and the diagnosis and treatment of hypereosinophilia.
  • WAN Fu-ping, JIA Cong-ying
    Abstract (119) PDF (24)
    Objective To compare and analyze malaria epidemic trends and characteristics of initial confirmed cases before and after malaria eliminating in Qingjiangpu District, Huai'an City, and to provide a scientific basis for improving strategies to prevent imported malaria retransmission.Methods Malaria case data from Qingjiangpu District were obtained from the National Infectious Disease Information Reporting System for 2010-2023. Case investigation and epidemiological data were summarized and analyzed for the pre-elimination period (2010-2016) and post-elimination period (2017-2023).Results A total of 185 malaria cases were reported between 2010 and 2023, with one locally acquired case in both 2010 and 2011; the remainder were imported, primarily falciparum malaria. Post-elimination cases decreased from 140 to 45, showing a statistically significant difference in case distribution ratios (χ2 = 9.642, P < 0.05). Seasonal peaks occurred in early January and mid-July before elimination but showed no distinct pattern afterward.Malaria cases were mainly imported from Africa countries, and most patients were young adult males. Post-elimination, the proportion of migrant workers decreased, while technical and business personnel increased significantly (χ2 = 17.855, P < 0.05). Both time-to-diagnosis and time-to-certification changed markedly after elimination, with township health centers showing improved diagnostic accuracy at initial visits. All confirmed patients were treated at designated municipal medical institutions.Conclusions After malaria elimination in Qingjiangpu District, imported malaria remains a serious concern, with cases reported each year. Therefore, it is necessary to continue strengthening the malaria monitoring system, enhance screening and evaluation of key populations, improve health education, raise diagnostic and treatment capacity across all medical institutions, and consolidate the achievements of malaria elimination.
  • LIU Yang-qing
    Abstract (116) PDF (22)
    In this article, we describe two new species of the genus Brachypogon in China: Brachypogon (B.) caelatus Liu sp. nov., found in Muchuan County, Sichuan Province; and Brachypogon (Isohelea) decus Liu sp. nov., found in Bachu County, Xinjiang Uygur Autonomous Region. Both species were collected using the sweep-net method. In the case of Brachypogon (B.) caelatus Liu, the male insect has a finger-shaped apical process on the median lobe of the aedeagus and a pair of parameres with fine and pointed ends and medial apical processes in the middle. The female has two equal-sized spermathecae, oval-shaped, sensillum pits at the end of the third segment of the palpus, and 13 fine teeth at the end of the mandible. With regard to Brachypogon (Isohelea) decus Liu, the female insect has two unequal-sized seminal vesicles, and the male has a blunt apical process on the median lobe of the aedeagus and four slender and pointed parameres. These characteristics can be clearly distinguished from those of other Brachypogon species. The examined specimens have been deposited at the Medical Insect Collection of the Academy of Military Sciences.
  • MENG Fan-jin, LIU Yong, HUANG Huan, MA Wei-bo, WU Yi-fan, TAN Wei-long
    Abstract (113) PDF (19)
    Objective This study aimed to investigate the genetic diversity, differentiation, and population structure of Aedes albopictus across different geographical regions in Shandong Province, and to explore the relationship between genetic diversity and geographical distribution.Methods Between July and August 2024, ten Ae. albopictus populations were sampled from seven cities in Shandong Province. Genomic DNA was extracted from individual mosquitoes, and the mitochondrial cytochrome c oxidase subunit I (COⅠ) gene was amplified using PCR and sequenced. The obtained sequences were verified using BLAST and analyzed with MAFFT, MEGA 11, DnaSP v6.12, Arlequin 3.5, PopART 1.7, STRUCTURE 2.3.4 and the R packages adegenet and vegan to assess genetic diversity and population structure.Results A total of 229 COⅠ sequences (662 bp) was obtained, revealing ten variable sites with no insertions or deletions. The overall base composition showed an AT bias of 67.7%. Haplotype analysis identified 11 haplotypes, with Hap2 being the dominant and most widely distributed haplotype across all populations. Neutrality tests showed significant population expansion only in the Rizhao population. Mantel testing result revealed that geographical distance does not significantly impede gene flow. Overall, genetic differentiation among populations was low, indicating frequent gene flow. When combined with additional samples from Shanghai, Fujian, Guangdong, Yunnan, Hainan and Guangxi, STRUCTURE, UPGMA and DAPC analyses revealed two primary genetic clusters of Ae. albopictus.Conclusions Ae. albopictus populations in Shandong Province exhibit frequent gene flow, low genetic differentiation, and relatively low overall genetic diversity. However, the Rizhao population showed signs of recent expansion, highlighting the need for enhanced surveillance and targeted control measures in this area.
  • YAN Ting, XU Xiu-yan, LI Jing, ZHOU Xiao-jie, ZHANG Yong, TONG Ying
    Abstract (107) PDF (10)
    Objective To investigate the species composition of mosquitoes and breeding conditions of larvae in the rice planting areas of Beijing, and to provide a scientific basis for mosquito control in rice fields.Methods Adult mosquitoes were collected using CO2-baited light traps, and mosquito larvae (including pupae) were sampled via the dipping method.Results A total of 4 genera and 6 species of adult mosquitoes were captured in the study area. The dominant species were Culex pipiens pallens, Cx. tritaeniorhynchus, and Anopheles sinensis. The average adult mosquito density was 5.11 specimens per trap-hour, with slightly lower density in July compared to August. For larvae and pupae, 3 genera and 4 species were identified, dominated byCx. tritaeniorhynchus, An. sinensis, and Aedes vexans.Conclusions The mosquito species composition in Beijing's rice planting areas is diverse. Mosquito control strategies should prioritize the management of adult mosquitoes, while density control of mosquito larvae in paddy fields can be achieved through intermittent irrigation techniques.
  • YI Rui, ZHANG Qiong, LUO Qi-lin
    Abstract (107) PDF (7)
    The child, male, 11 years old, Han nationality, student of Qiandongnan Miao Autonomous Prefecture, Guizhou Province, visited the General Hospital of Hunan Medical University on October 1, 2024 due to “cough, chest tightness for 10 days and pericardial effusion was found for 8 days.” The child has a history of eating raw crabs. Admission examination: shortness of breath, slightly cyanotic lips, mild trifoveal symptoms, low heart sound, and routine blood showed significant eosinophil elevation. Serological examination showed that pulmonary fluke antibody IgG was positive, chest and abdomen CT and cardiac ultrasound showed a large amount of pericardial effusion, medium pleural effusion on the right side with lower right lung insufficiency, small pleural effusion on the left side, small effusion on the abdominal cavity, three-point Slight reflux of the valve. Considering that it is a clinical diagnosis case of complication flukesomyces disease, the child was given a praziquantel tablet, 25 mg/kg, 3 times a day, for 3 consecutive days. The treatment was treated at the above dose for 1 week interval for 1 course of treatment, and 3 courses were given. After three months, the child recovered well after the follow-up visit. The child did not complain of special discomfort, and the CT showed a small amount of effusion.
  • WANG Chong-cai, ZHANG Yan, LU Su-ying, QIAN Jiao-jiao, XU Ya-meng, GUO Jian-bin, TAN Wei-long
    Abstract (107) PDF (31)
    Objective This study aims to understand the carriage status of Beilong virus (BeiV) in small mammals in Haikou, a city in Hainan Province, China, to provide a basis for the prevention and control of BeiV. Methods Following field sampling, a cDNA library was constructed from the tissues of small mammal specimens, including heart, liver, spleen, lung, kidney, brain, intestine, and muscle tissues. The presence of BeiV was detected using PCR, and some purified L gene fragments were subjected to Sanger sequencing. The complete genome sequences of members of the Paramyxoviridae virus family were obtained from the NCBI database using Python, using MAFFT (version 7) and MEGA-X for multiple sequence alignment and neighbor-joining method to construct a phylogenetic tree. Results A total of 38 rodent samples were collected, revealing a positive rate of 5.26%, with Rattus norvegicus exhibiting a positive rate of 7.41%. Evolutionary analysis indicated that BeiV carried by R. norvegicus in Haikou was similar to that found in R. norvegicus in Hong Kong, China, although notable genetic variations were also observed. Conclusions This study reports the first detection of BeiV in Haikou. Considering the reports of newly discovered Paramyxoviridae viruses in recent decades and the identification of BeiV in small mammals across more than a dozen provinces, it is evident that the distribution range of BeiV is much broader than previously assumed. This highlights the importance of enhancing rodent monitoring and control, as well as the screening and prevention of rodent-related pathogens.
  • LI Rui-rui, ZHOU Shu, LIU Hua, ZHOU Bo, HU Yu-zhang
    Abstract (103) PDF (11)
    In this study, there were three toxoplasmosis patients, two of whom developed symptoms in both eyes. One patient had a slight deviation of the lesion from the central fovea, which had a minor impact on vision. The diagnosis of this disease requires not only a close pet contact history and typical clinical manifestations, but also serology and the gold standard Goldmann-Witmer coefficient (GWC). However, the GWC of some patients cannot be detected at the initial stage, such as the first patient's GWC, which did not meet the standard. All three patients underwent metagenomic testing to assist with diagnosis.
  • ZHU Wen-jie, YU Hui-jun, TIAN Di, HAN Xiao-yu, WANG Ning, SHEN Shi-jing, LIN Zhe-tao, WANG Tian-hong, LIU Zhi-hong, CAO Wu-chun
    Abstract (96) PDF (88)
    Objective Spotted fever group rickettsiae (SFGR) are globally prevalent obligate intracellular bacteria that have the potential to cause severe and fatal human diseases. A study to investigate the species and genetic characteristics of SFGR was conducted in 2023 in the Ningxia region of northwestern China. Methods Tick samples were collected from Ningxia, identified, and used to isolate SFGR. The isolated strain was identified as Rickettsia raoultii through morphological observation, multi-locus sequence typing (MLST), and phylogenetic analysis. Then, it was subjected to whole-genome sequencing using next-generation technology, which revealed it to be a TIGMIC strain. Results The TIGMIC strain was demonstrated to exhibit a capacity for growth in mammalian cell lines. The complete genome sequence of the TIGMIC strain was assembled into a circular chromosome, which exhibited a length of 1 312 176 bp and comprised 1 488 genes. Functional annotation revealed that the main key genes of the TIGMIC strain were primarily associated with biosynthesis, nutrient metabolism, and cell membrane biogenesis. Apart from the rickA gene, most typical rickettsial virulence genes of the TIGMIC strain were relatively conserved. Conclusions These findings will help identify SFGR, provide etiological evidence for spotted fever in Ningxia, and emphasize the need for enhanced surveillance to prevent the spread of SFGR.
  • GONG Zheng-da, Duan Xing-de
    Abstract (95) PDF (18)
    This article describes a new species of Genus Xenodaeria Jordan (1932) (Siphonaptera: Ctenophthalmidae), collected from the southern slope of Cangshan mountain in Dali, Yunnan. The new species is similar to Xenodayia telios, Jordan 1932, and X. laxiproceria Wu, Gu et Liu, 1996, but more like X. telios. However, it can be distinguished from X. telios and other known species in the genus based on the following characteristics: The movable process of the male gripper is bent finger shaped, with a blunt end and no angular protrusion extending forward; The posterior St. VII in females has a semi-circular deep depression, with blunt rounded ends of the dorsal and ventral lobes, and the dorsal lobes are wider and longer than the ventral lobes. The type specimen was collected on November 2, 1994 from the shrubbery at an altitude of approximately 2 450 m in the southern end of Cangshan Mountain in Dali City, Yunnan Province. The host species were Anourosorex squamipes and Crocidura rapax.
  • ZHANG Lu-qian, NING Shao-qi, NIAN Yun-peng, WANG Shu, LI Xin-xin
    Abstract (89) PDF (29)
    Objective To investigate the epidemiological characteristics and changing trend of typhus in Shaanxi Province from 2005 to 2023 to provide a scientific basis for its prevention and control.Methods Excel 2007, SPSS 25.0, Joinpoint 4.9.1.0, and Geoda 1.6 were used for data collection and statistical analysis. Super Map was used for data visualization to describe the changing characteristics of the disease.Results A total of 394 typhus cases were reported in Shaanxi Province from 2005 to 2023. The average annual incidence of typhus was 0.054/100 000, showing a dynamic fluctuation trend (AAPC=-3.3, t=-0.3, P>0.05). The cases were mainly concentrated in Baoji, Hanzhong and Xi'an, accounting for 78.68%. The incidence peak was from May to October, accounting for 64.21% of annual incidence. The epidemic season was from May to October and December. The incidence of the disease was concentrated in the 40-69 age group, accounting for 58.88%, and the sex was 1.07∶1. The main occupation was farmers, accounting for 72.08%. The median time from onset to diagnosis was 7 days. Global spatial autocorrelation analysis showed that there were significant spatial autocorrelations in 11 years from 2005 to 2023 (P<0.05). Local spatial autocorrelation analysis detected a total of 43 “high-high” clustering areas, mainly concentrated in Baoji City.Conclusions The overall incidence of typhus in Shaanxi Province showed a dynamic fluctuation trend, with notable seasonal and regional aggregation. The incidence of typhus was higher in middle-aged and elderly people in rural areas. Surveillance should be strengthened in typhus endemic areas in summer and autumn, and health education should be conducted for key population to form good health habits and reduce the incidence of typhus.
  • YOU Jun-ma, ZHANG Hong-sheng, ZHENG Hui-ni
    Abstract (88) PDF (12)
    We report a case of a female farmer from the Yichang suburb, aged 68 years, who had been suffering from the infection for 3 years and had a history of seeking medical treatment at a community hospital and receiving blood transfusions. Her hemoglobin was as low as 28 g/L during this visit, and she had been ill for a long time with severe anemia. Routine stool examination revealed hookworm eggs. After active treatment, the patient recovered and was discharged from the hospital.
  • ZHANG Hong-bin, YANG Ning, BI Xiao-juan, LIN Ren-yong
    Abstract (78) PDF (10)
    Echinococcosis is categorized into alveolar echinococcosis and cystic echinococcosis, a potentially fatal zoonotic disease that seriously damages the host. MicroRNA is a type of endogenous small non-coding RNA that binds specifically to the target gene mRNA sequence to promote mRNA degradation, or combines with other non-coding RNA to regulate or inhibit translation. Echinococcus-derived microRNA participates in various biological processes in the Echinococcus lifecycle and in the interaction and pathogenesis between Echinococcus and host through extracellular vesicle transport. This article reviews the research progress of parasite-derived microRNA in regulating the growth and development of echinococcosis and cross-species regulation of hosts, providing a reference for diagnosing and treating echinococcosis.
  • CHU Qiong, DING Ping, YAO Jin-fu, WANG Xing
    Abstract (78) PDF (13)
    Objective The aim was to evaluate the effects of efforts directed toward controlling Oncomelania hupensis snails on small environmental modification projects in Anqing City to provide a reference for comprehensively controlling O. hupensis in hilly areas where schistosomiasis is endemic.Methods Field and retrospective surveys were conducted to collect data using questionnaires. The data from 35 questionnaires on small-scale environmental modification projects in Anqing City and the effects of snail obtained from monitoring forms were sorted. The data were descriptively analyzed using basic information on environmental modifications and investment costs. The Wilcoxon signed-rank test was used to compare snail status before and after environmental interventions. The Friedman test was applied to evaluate the changes in snail populations in the years after environmental intervention. Non-parametric independent sample tests were adopted to compare differences in the effects of different environmental interventions, environmental characteristics, and between project and control areas.Results A total of 35 environments altered from 2017 to 2023, including the creation of 29 ditches, 1 dry land, and 5 pond-weirs. The main environmental interventions included hardening of ditches and pond-weirs as well as tilling with intercropping. The average investment costs of mortared rubble masonry hardening and tilling with intercropping were the highest (147.10 yuan/m2) and lowest (4.62 yuan/m2), respectively. The pre-intervention snail-infested area was 78 900 m2, which decreased to 18 100 m2, a decrease of 77.06%. After environmental intervention, the density and rate of living snails significantly decreased on frames with snails (P<0.001). In ditch environments, the smoothness of the ditch walls and the presence of snails in the upper reaches did not significantly decrease the living snail density; however, the presence of cracks on the inner side of the ditches significantly impacted the decline in the rate (P<0.001). No significant difference was found in the rates at which the living snail density or snail frame occurrence decreased among different environmental modification method. The effects of brick masonry, concrete, and mortared rubble masonry on snail control were significantly stronger than those of chemical snail control (P<0.01), whereas no significant difference was found in the decline in these two rates between project areas using other modification method and control areas using chemical snail control.Conclusions Schistosomiasis-prevention-oriented environmental interventions effectively eliminate snails from hilly snail-infested areas. Cost-effective modification method should be selected based on the environmental type, and post-modification monitoring and maintenance must be strengthened to further increase snail control effectiveness.
  • CHEN Xue-ru, YAO Wen-zhen, LI Yu-hao, LI Gui-chang, MENG Tao, FENG Qun-ling, LIU Xin-hui, QIAO Li-hong, WU Xiang-ting, ZHANG Xue-feng, LI Cheng-lin, DONG Xue-cheng, WANG Da-wei, SI Xiao-yan, GUO Yu-hong
    Abstract (62) PDF (8)
    Objective This study reports on the obligatory parasitism of water mites Arrenurus sp. on Anopheles messeae at the Manzhouli Port, Inner Mongolia, China.Methods Duing July 2024, a survey on the mosquito diversity was conducted at the Manzhouli Port. Captured mosquitoes and their ectoparasites were identified to species level.Results A total of 1840 adult mosquitoes were collected, representing species from three genera: Culex (Cx. modestus, Cx. pipiens pallens), Aedes (Ae. dorsalis, Ae. flavidorsalis, Ae. flavescens), and Anopheles (An. messeae). Among all the mosqutioes specimens, 3 out of 150 captured An. messeae were found to carry ectoparasitic mites, with number of 2, 4, 27 mites separately. Morphological and molecular identification reached the same result as water mites (Hydrachnidiae, Hydracrina). COI gene sequence showed 94% similarity with the closest species Arrenurus truncatellus.Conlusions Literature review suggests water mites are host-specific parasitism of mosquito species and herein with the first record of Arrenurus sp. parasiting on An. Messeae in the most high-latitude region globally.
  • WANG Ya-yu, LI Jiang-fan, CAI Bo-qiao, LIU Guo-ping
    Abstract (60) PDF (12)
    This study reports a new species of Culicoides (Avaritia) isolated from Xunke County, Heilongjiang Province, China.The new species, Culicoides (Avaritia) dongshanensis Liu et Wang, sp. nov., was identified and illustrated based on female adults. Its diagnostic characteristics are as follows: eyes contiguous over a short distance, with short interfacetal hair, antennal ratio (AR) of 1.20, palpal ratio (PR) of 2.16, wing length of 0.83 mm, mandible with 15 teeth, one pale spot in base cell M1, one pale spot in cell M4, two pale spots in cell A, and two unequal spermathecae. Type specimens were deposited at the Center for Disease Control and Prevention of the Northern Theater Command.
  • WEI Shu-lin, QU Zhi-qiang, LUO Yuan-yuan, HUANG Yan-cui, DIAO Shu-qin, LI Xue, YANG Sheng-long, HUANG Xiao-yu, LUO Mi-fang
    Abstract (10) PDF (4)
    Objective To investigate the epidemiological characteristics of malaria and provide a basis for developing improved prevention and control measures. Methods Data were obtained from the Chinese Disease Prevention and Control Information System. Malaria surveillance data for Nanning City from January 1, 2023, to December 31, 2024, were exported from the Infectious Disease Reporting Information Management Subsystem. The characteristics of the two groups of malaria cases were compared. Results A total of 103 imported malaria cases were reported in Nanning City in 2024, representing a 38.32% decrease compared with the same period of the previous year. No statistically significant difference were observed between cases reported in 2023 and 2024 in terms of average age, gender ratio, proportion of parasite species, and monthly reporting distribution; however, statistically significant differences were found in the proportion of reporting areas and current residence areas (χ2 = 13.572 and 10.355, respectively; P = 0.001 and 0.035, respectively). The proportion of cases reported in Shanglin County and the proportion of cases residing in Shanglin County were both lower than those during the same period of the previous year. Conclusions The high aggregation of imported malaria cases in Nanning City has decreased. Medical institutions in areas other than Shanglin County should strengthen their vigilance against malaria.
  • LIU Qin-mei, WANG Jin-na, LI Tian-qi, LUO Ming-yu, GUAN Zhou, GONG Zhen-yu, SUN Ji-min
    Abstract (8) PDF (3)
    Objective In order to understand the current resistance status of Aedes albopictus (Ae. albopictus) adult population to commonly used insecticides and the resistance dynamics development in Zhejiang Province and provide a theoretical basis for the scientific and rational use of hygienic insecticides. Methods Resistance determination was carried out using the diagnostic dose method (GB/T 26347-2010) recommended by WHO in the adult mosquito contact cylinder method to monitor the resistance of Ae. albopictus field populations in 11 cities and districts in Zhejiang Province in 2024. Results The monitoring result showed that adult Ae. albopictus in 11 areas were resistant or suspected resistant populations to both cis-cypermethrin and permethrin; suspected and resistant populations to the organophosphate insecticide malathion were as high as 81.82%; while suspected resistance to the carbamate insecticide residual carbofuran accounted for 45.45%, and the rest of the monitoring sites were sensitive to it. Conclusions The result suggest that the generalized resistance of Ae. albopictus populations to pyrethroids and organophosphorus insecticides in the field in Zhejiang Province needs to be highly emphasized. In future mosquito vector and mosquito-borne disease control, insecticides should be selected based on the resistance monitoring information, while following scientific guidelines for insecticide use.
  • DU Jun, FENG Ai-min, CUI Bao-qiang, SUN Tao, YANG Yi-chuan, WANG Yan-dong
    Abstract (8) PDF (1)
    Objective To understand the epidemiological characteristics of a clustered outbreak of severe fever with thrombocytopenia syndrome (SFTS) as well as the ecological tick monitoring results for Zibo City, and to provide a scientific basis for formulating prevention and control strategies. Methods A case definition was cited before epidemic investigations were performed. Epidemiological investigations were performed on the index cases and their close contacts. Blood samples were collected from cases and close contacts, and quantitative real-time RT-PCR was used to detect SFTS virus (SFTSV) nucleic acid sequences. A retrospective cohort study was conducted to analyze risk factors and develop prevention and control strategies. Results This clustered outbreak involved two index cases and six close contacts with no deaths. Case A exhibited symptom onset on July 26. SFTS was confirmed on August 2. Case B exhibited symptom onset on August 1, and SFTS was confirmed on August 3. Patient B reported a recent history of tick bites. In both index cases, the incubation period for SFTS was inferred to be 7-12 days. The time interval from symptom onset to clinical diagnosis in the two cases ranged from 2-8 days, with an average period of 5 days. SFTSV nucleic acid test result were positive for both patients, whereas all six close contacts tested negative. All captured ticks tested negative for SFTSV using quantitative real-time RT-PCR. The densities of parasitic and free-living ticks in the emergency monitoring area around the cases were 12.60 and 4.65 ticks/(flag·100 m). In 2024, the average parasitic tick index and free-living tick density index were 4.21 and 2.43 ticks/(flag·100 m) in Yiyuan County, respectively. Conclusions No evidence of human-to-human transmission was found in the assessed SFTS clusters. The infections were likely acquired through tick bites during fieldwork, and the risk of a subsequent outbreak spreading was low.
  • WANG Gang, SHI Chun-juan, KONG Dan, ZHU Xuan, HE Ji, ZHAO Ming-hui, WANG Chong-cai
    Abstract (7) PDF (3)
    Objective Exploring genetic differences among geographic strains of Anopheles sinensis in China. Methods Based on the mitochondrial cytochrome oxidase subunit I (COⅠ) and ribosomal the second internal transcribed spacer (ITS2), genetic distance analyses were conducted onAn. sinensis samples collected nationwide. Results Genetic differentiation was observed within An. sinensis geographic strains, primarily reflected in the genetic distances of COⅠ sequences, with some distances between samples exceeding those between closely related species. However, ITS2 sequences showed relatively low levels of differentiation within geographic strains. No significant separation was observed, and gene exchange exhibited a random pattern among geographic strains. Conclusions Significant differences in genetic distance were observed among An. sinensis samples, along with evidence of interspecific continuity among sibling species. For the identification of closely related species using wild-collected Anopheles mosquitoes samples, reliance solely on commonly used barcodes such as COⅠ and ITS2 may be insufficient. Additional molecular markers, including COⅡ and D3 gene fragments, should also be considered. Caution should be exercised when using COⅠ genes to identify cryptic species, especially within Anopheles mosquitoes.
  • MA Guang-hong, DU Chun-hong
    Abstract (7) PDF (5)
    Ticks are important disease vectors that pose serious threats to human health and animal husbandry. Understanding seasonal fluctuation in tick populations and their influencing factors provides a scientific basis for population management and the prevention and control of tick-borne diseases. Tick life stages are influenced by factors including population density, activity levels, survival rates, and other biological features that exhibit periodic changes. Seasonal fluctuations in tick populations directly impact population dynamics and the risk of disease transmission. This review primarily examines the factors that influence seasonal tick population fluctuations.