Matono Takashi, Izumiya Hidemasa, Koga Hidenobu, Kaku Mitsuo, Ohnishi Makoto, Morita Masatomo
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan; Department of Infection Control and Laboratory Diagnostics, Internal Medicine, Tohoku University Graduate School of Medicine, Sendai, Japan; Department of Infectious Diseases, Aso Iizuka Hospital, Iizuka, Japan.
Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo, Japan.
Int J Infect Dis. 2022 Dec;125:170-176. doi: 10.1016/j.ijid.2022.10.034. Epub 2022 Oct 29.
An unusual increase in Salmonella enterica serovar Paratyphi A infection rate in Japanese travelers returning from Myanmar was observed in 2015.
We analyzed epidemiologic data of returned travelers with enteric fever from 2005-2019. We also analyzed 193 Salmonella Paratyphi A isolates, including 121 isolates with published genomes.
Annual notification trends showed a rapid increase in Salmonella Paratyphi A infection in travelers returning from Myanmar in 2015: 2-4 cases/100,000 travelers in 2012-2014 and 13 cases/100,000 travelers in 2015 (P <0.001). The genomic analyses revealed that 11 Myanmar-related isolates in 2015 formed a tight cluster in clade 3 with a single nucleotide variant (SNV) distance of 0-11 (primarily 0-7), yielding a wider SNV range than outbreak-associated isolates from Cambodia in 2013 (0-6 SNVs) or China in 2010 (0-5 SNVs). Although all Cambodia-related isolates in 2013 harbored the wild-type gyrA sequence, all Myanmar-related isolates in 2015 had a single, identical mutation (Ser83Phe) in the gyrA gene.
The epidemiologic and molecular investigations suggested an increase in the infection rate with genetically closely related Salmonella Paratyphi A in travelers returning from Myanmar in 2015. Careful monitoring of the infection in Myanmar as an endemic country is warranted, considering the resumption of cross-border travel during the COVID-19 pandemic.
2015年观察到从缅甸返回的日本旅行者中甲型副伤寒沙门氏菌感染率异常上升。
我们分析了2005年至2019年回国的伤寒热旅行者的流行病学数据。我们还分析了193株甲型副伤寒沙门氏菌分离株，其中121株具有已发表的基因组。
年度通报趋势显示，2015年从缅甸返回的旅行者中甲型副伤寒沙门氏菌感染迅速增加：2012年至2014年为每10万名旅行者中有2 - 4例，2015年为每10万名旅行者中有13例（P <0.001）。基因组分析显示，2015年的11株与缅甸相关的分离株在进化枝3中形成了一个紧密的簇，单核苷酸变异（SNV）距离为0 - 11（主要为0 - 7），其SNV范围比2013年柬埔寨（0 - 6个SNV）或2010年中国（0 - 5个SNV）的与疫情相关的分离株更广。尽管2013年所有与柬埔寨相关的分离株都含有野生型gyrA序列，但2015年所有与缅甸相关的分离株在gyrA基因中都有一个相同的单一突变（Ser83Phe）。
流行病学和分子调查表明，2015年从缅甸返回的旅行者中，与甲型副伤寒沙门氏菌基因密切相关的感染率有所增加。考虑到在COVID - 19大流行期间跨境旅行的恢复，有必要对作为流行国家的缅甸的感染情况进行仔细监测。
