Chigger mites are the vector of scrub typhus. This study estimates the infestation status and ecological characteristics of chiggers on the chestnut white-bellied rat Niviventer fulvescens in Southwest China between 2001 and 2019. Chiggers were identified under the microscope, and infestation indices were calculated. The Preston’s log-normal model was used to fit the curve of species abundance distribution. A total of 6,557 chiggers were collected in 136 of 342 N. fulvescens rats, showing high overall infestation indices (prevalence=39.8%, mean abundance=19.2, mean intensity=48.2) and high species diversity (S=100, H’=3.0). Leptotrombidium cangjiangense, Neotrombicula japonica, and Ascoschoengastia sifanga were the three dominant chigger species (constituent ratio=42.9%; 2,736/6,384) and exhibited an aggregated distribution among different rat individuals. We identified 100 chigger species, with 3 of them (Leptotrombidium scutellare, Leptotrombidium wenense, and Leptotrombidium deliense) as the main vectors of scrub typhus in China and nine species as potential vectors of this disease. Disease vector occurrence on N. fulvescens may increase the risk of spreading scrub typhus from rats to humans. Chigger infestation on N. fulvescens varied significantly in different environments. The species abundance distribution showed a log-normal distribution pattern. The estimated number of chigger species on N. fulvescens was 126 species.
Balamuthia mandrillaris amebic encephalitis (BAE) can cause a fatal condition if diagnosis is delayed or effective treatment is lacking. Patients with BAE have been previously reported in 12 provinces of China, with skin lesions being the primary symptom and encephalitis developing after several years. However, a significantly lower number of cases has been reported in Southwest China. Here we report an aggressive BAE case of a 64-year-old woman farmer with a history of skin lesions on her left hand. She was admitted to our hospital due to symptoms of dizziness, headache, cough, vomiting, and gait instability. She was initially diagnosed with syphilitic meningoencephalitis and received a variety of empirical treatment that failed to improve her symptoms. Finally, she was diagnosed with BAE combined with amebic pneumonia using next-generation sequencing (NGS), qRT-PCR, sequence analysis, and imaging studies. She died approximately 3 weeks after the onset. This case highlights that the rapid development of encephalitis can be a prominent clinical manifestation of Balamuthia mandrillaris infection.
Citations
Citations to this article as recorded by
The role of plasma metagenomic sequencing in identification of Balamuthia mandrillaris encephalitis Sarah Y. Edminster, Ryan W. Rebbe, Christopher Khatchadourian, Kyle M. Hurth, Anna J. Mathew, Julie Huss-Bawab, Mark S. Shiroishi, Devin Clark, Andrew P. Norgan, Susan M. Butler-Wu, Annie Hiniker Acta Neuropathologica Communications.2025;[Epub] CrossRef
Balamuthia amoebic encephalitis directly causing intracranial infection: A case report Yuhan Liang, Yanhong Liu, Zelong Chen, Jiayi Sun, Xuemeng Zhang, Yulin Wang Radiology Case Reports.2025; 20(6): 2820. CrossRef
Pulmonary infection due to
Balamuthia mandrillaris
in the southwestern United States: not all miliary disease is tuberculosis and coccidioidomycosis
N. B. Price, H. Pariury, J. Papic, M. R. Anthony, W. Lainhart, K. W. Shehab, Carey-Ann D. Burnham ASM Case Reports.2025;[Epub] CrossRef
Applications of the powerful next-generation sequencing tool for detecting parasitic infections: towards a smart laboratory platform Bahareh Basirpour, Rabeeh Tabaripour, Farzane Jafarian, Mahdi Fakhar, Hajar Ziaei Hezarjaribi, Shirzad Gholami Microbial Pathogenesis.2025; 206: 107746. CrossRef
Next-Generation Sequencing for Diagnosis of Fatal Balamuthia Amoebic Encephalitis: A Case Report Yuanyuan Feng, Huiyu Feng, Xuegao Yu, Jing Zhao, Hongyan Zhou, Jiaoxing Li, Peisong Chen, Li Feng Diagnostics.2025; 15(20): 2590. CrossRef
Based on the field investigations in 91 investigation sites (counties) in southwest China between 2001 and 2019, the present paper reported the chigger mites on A. agrarius mice in southwest China for the first time by using a series of statistical methods. From 715 striped field mice captured in 28 of 91 investigated sites, only 255 chiggers were collected, and they were identified as 14 species, 6 genera in 3 subfamilies under 2 families. Of 715 A. agrarius mice, only 24 of them were infested with chigger mites with low overall prevalence (PM=3.4%), overall mean abundance (MA=0.36 mites/host) and overall mean intensity (MI=10.63 mites/host). The species diversity and infestation of chiggers on A. agrarius were much lower than those previously reported on some other rodents in southwest China. On a certain species of rodent, A. agrarius mouse in southwest China seems to have a very low susceptibility to chigger infestations than in other geographical regions. Of 14 chigger species, there were 3 dominant species, Leptotrombidium sialkotense, L. rupestre and Schoengastiella novoconfuciana, which were of aggregated distribution among different individuals of A. agrarius hosts. L. sialkotense, one of 6 main vectors of scrub typhus in China, was the first dominant on A. agrarius. The species similarity of chigger mites on male and female hosts was low with CSS=0.25, and this reflects the sex-bias of different genders of A. agrarius mice in harboring different chigger species.
Citations
Citations to this article as recorded by
Infestation, community structure, seasonal fluctuation and climate-driven dynamics of mites on small mammals at a focus of scrub typhus in southwest China Peng-Wu Yin, Yan Lv, Xian-Guo Guo, Wen-Yu Song, Rong Fan, Cheng-Fu Zhao, Zhi-Wei Zhang, Ya-Fei Zhao, Wen-Ge Dong, Dao-Chao Jin Frontiers in Veterinary Science.2025;[Epub] CrossRef
The Distribution and Host-Association of the Vector Chigger Species Leptotrombidium imphalum in Southwest China Qiao-Yi Liu, Rong Fan, Wen-Yu Song, Pei-Ying Peng, Ya-Fei Zhao, Dao-Chao Jin, Xian-Guo Guo Insects.2024; 15(7): 504. CrossRef
Clinical and epidemiological investigation of human infection with zoonotic parasite Trypanosoma dionisii in China Nannan Xu, Xiaoai Zhang, Hui Liu, Yintao Xu, Huixia Lu, Lianhui Zhao, Yishan He, Meiqi Zhang, Jingtao Zhang, Guangqian Si, Ziyi Wang, Muxin Chen, Yuchun Cai, Yi Zhang, Qiang Wang, Yuwan Hao, Yuanyuan Li, Zhengbin Zhou, Yunhai Guo, Caiyun Chang, Ming Liu, Journal of Infection.2024; 89(5): 106290. CrossRef
A Retrospective Report on the Infestation and Distribution of Chiggers on an Endemic Rodent Species (Apodemus latronum) in Southwest China Qiao-Yi Liu, Xian-Guo Guo, Rong Fan, Wen-Yu Song, Pei-Ying Peng, Ya-Fei Zhao, Dao-Chao Jin Veterinary Sciences.2024; 11(11): 547. CrossRef
Disease vector occurrence and ecological characteristics of chiggers on the chestnut white-bellied rat Niviventer fulvescens in Southwest China between 2001 and 2019 Yan-Ling Chen, Xian-Guo Guo, Wen-Yu Song, Tian-Guang Ren, Lei Zhang, Rong Fan, Cheng-Fu Zhao, Zhi-Wei Zhang, Wen-Ge Dong, Xiao-Bin Huang, Dao-Chao Jin Parasites, Hosts and Diseases.2023; 61(3): 272. CrossRef
Infestation of Oriental House Rat (Rattus tanezumi) with Chigger Mites Varies along Environmental Gradients across Five Provincial Regions of Southwest China Yan-Ling Chen, Xian-Guo Guo, Fan Ding, Yan Lv, Peng-Wu Yin, Wen-Yu Song, Cheng-Fu Zhao, Zhi-Wei Zhang, Rong Fan, Pei-Ying Peng, Bei Li, Ting Chen, Dao-Chao Jin International Journal of Environmental Research and Public Health.2023; 20(3): 2203. CrossRef
Analysis on infestation and related ecology of chigger mites on large Chinese voles (Eothenomys miletus) in five provincial regions of Southwest China Bei Li, Xian-Guo Guo, Tian-Guang Ren, Pei-Ying Peng, Wen-Yu Song, Yan Lv, Peng-Wu Yin, Zhe Liu, Xin-Hang Liu, Ti-Jun Qian International Journal for Parasitology: Parasites and Wildlife.2022; 19: 169. CrossRef
Infestation and distribution of chigger mites on Confucian white-bellied rat (Niviventer confucianus) in Southwest China Yan-Ling Chen, Xian-Guo Guo, Wen-Yu Song, Tian-Guang Ren, Lei Zhang, Rong Fan, Cheng-Fu Zhao, Zhi-Wei Zhang, Wen-Ge Dong, Xiao-Bin Huang Biologia.2022; 78(3): 727. CrossRef
First
Prev
