Epidemiological and clinical characteristics of the chikungunya outbreak in Ruili City, Yunnan Province, China

• Published in: Journal of medical virology Vol. 94; no. 2; pp. 499 - 506
• Main Authors: Liu, Li‐Bo, Li, Man, Gao, Na, Shen, Jia‐Yuan, Sheng, Zi‐Yang, Fan, Dong‐Ying, Zhou, Hong‐Ning, Yin, Xiao‐Xiong, Mao, Jia‐Rong, Jiang, Jin‐Yong, Wang, Pei‐Gang, An, Jing
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.02.2022
• Subjects: Adult; Agglomeration; arboviruses; Arthralgia - etiology; chikungunya fever; Chikungunya Fever - epidemiology; Chikungunya Fever - physiopathology; Chikungunya virus; Chikungunya virus - genetics; Chikungunya virus - isolation & purification; Chills; China - epidemiology; Cities - epidemiology; Disease Outbreaks; Epidemics; Epidemiology; Exanthema; Female; Fever; Fever - etiology; Genome, Viral - genetics; Genotypes; Headache; Hemoglobin; Humans; Infectious diseases; Leukopenia - etiology; Lymphopenia; Male; Middle Aged; molecular epidemiology; Myanmar; Neutrophilia; Outbreaks; Pain; Patients; Phylogeny; Polymerase chain reaction; Real-Time Polymerase Chain Reaction; Strains (organisms); Thrombocytopenia; Thrombocytopenia - etiology; Vector-borne diseases; Virology; Viruses; Young Adult; Myanmar; China; Cities; Yunnan China; Myanmar (Burma); Indian Ocean; molecular epidemiology; phylogeny; chikungunya virus; chikungunya fever; arboviruses
• ISSN: 0146-6615; 1096-9071
• DOI: 10.1002/jmv.27302

Chikungunya fever is an acute infectious disease caused by the chikungunya virus (CHIKV) that is characterized by fever, rash, and joint pain. CHIKV has infected millions of people in Africa, Asia, America, and Europe since it re‐emerged in the Indian Ocean region in 2004. Here, we report an outbreak of Chikungunya fever that occurred in Ruili of Yunnan Province, a city located on the border between China and Myanmar, in September 2019. The outbreak lasted for three months from September to December. Overall, 112 cases were confirmed by a real‐time reverse‐transcription polymerase chain reaction in the Ruili People's Hospital, and they showed apparent temporal, spatial, and population aggregation. Among them, 91 were local cases distributed in 19 communities of Ruili City, and 21 were imported cases. The number of female patients was higher than that of male patients, and most patients were between 20 and 60 years old. The main clinical manifestations included joint pain (91.96%), fever (86.61%), fatigue (58.04%), chills (57.14%), rash (48.21%), headache (39.29%), and so forth. Biochemical indexes revealed increased C‐reactive protein (63.39%), lymphopenia (57.17%), increased hemoglobin (33.04%), neutrophilia (28.57%), and thrombocytopenia (16.07%). Phylogenetic analysis of the complete sequences indicated that the CHIKV strains in this outbreak belonged to the Indian Ocean clade of the East/Central/South African genotype. We speculated that this chikungunya outbreak might be caused by CHIKV‐infected persons returning from Myanmar, and provided a reference for the formulation of effective treatment and prevention measures. Highlights One of the longest CHIKV epidemics in China was described, lasting for three months. All cases showed apparent temporal, spatial and population aggregation. The CHIKV strains belonged to the Indian Ocean clade of the ECSA genotype. The first vertical transmission of CHIKV in China was recorded.