Urban Rodent Surveillance, Climatic Association, and Genomic Characterization of Seoul Virus Collected at U.S. Army Garrison, Seoul, Republic of Korea, 2006–2010

Abstract

Rodent-borne pathogens pose a critical public health threat in urban areas. An epidemiological survey of urban rodents was conducted from 2006 to 2010 at the U.S. Army Garrison (USAG), Seoul, Republic of Korea (ROK), to determine the prevalence of Seoul virus (SEOV), a rodent-borne hantavirus. A total of 1,950 rodents were captured at USAG, Yongsan, near/in 19.4% (234/1,206) of the numbered buildings. Annual mean rodent infestation rates were the highest for food service facilities, e.g., the Dragon Hill Lodge complex (38.0 rodents) and the Hartell House (18.8 rodents). The brown rat, , accounted for 99.4% (1,939/1,950) of all the rodents captured in the urban area, whereas only 0.6% (11/1,950) of the rodents was house mice (). In November 2006, higher numbers of rats captured were likely associated with climatic factors, e.g., rainfall and temperatures as rats sought harborage in and around buildings. Only 4.7% (34/718) of the rodents assayed for hantaviruses was serologically positive for SEOV. A total of 8.8% (3/34) were positive for SEOV RNA by reverse transcription polymerase chain reaction, of which two SEOV strains were completely sequenced and characterized. The 3' and 5' terminal sequences revealed incomplete complementary genomic configuration. Seoul virus strains Rn10-134 and Rn10-145 formed a monophyletic lineage with the prototype SEOV strain 80-39. Seoul virus Medium segment showed the highest evolutionary rates compared with the Large and Small segments. In conclusion, this report provides significant insights into continued rodent-borne disease surveillance programs that identify hantaviruses for analysis of disease risk assessments and development of mitigation strategies.

Synanthropic rodents as virus reservoirs and transmitters

“…The Orthohantavirus genus includes the greatest number of pathogenic species of public health importance 60 . Its presence is associated with the geographic distribution of rodents (Murinae, Avicolinae, and Sigmodontinae families), which can harbor distinct forms of the disease.…”

“…Seoul virus usually causes mild infections and without medical care the mortality rates reach 1%. The host of this virus (R. norvegicus) is found in urban areas, leading to a cosmopolitan distribution of the disease, in contrast to those caused by other Old World hantaviruses 60,70 . The incubation period varies from 2-3 weeks, and the endothelial cell tropism of the virus 71 produces nonspecific symptomatology (fever, headaches, muscle pain, nausea, vomiting), in addition to respiratory problems, dizziness, and diarrhea.…”

Human infection with Seoul orthohantavirus in Korea, 2019

“…The NGS approach allowed us to determine the cause of the HFRS symptoms in our patient. It also provided us with the molecular epidemiologic history of the complete SEOV gene segments [ 15 , 18 ]. Indeed, based on the evolutionary relationships reconstructed ( Fig 2 ), we were able to track potential genetic reassortment events between different rodent and/or human SEOV strains.…”

“…This suggests the possibility of HFRS misdiagnosis, and HTNV-like viruses, but not SEOV, have been considered the agents responsible for most cases [ 5 , 14 ]. An epidemiological history might also affect the diagnostic approaches used for HFRS patients [ 15 ], as occurred in our case. In this regard, we here emphasized that SEOV, as well as HTNV-like viruses, should be prioritized as one of the pathogenic agent of HFRS and investigated molecular evolution patterns of rodent and human SEOV strains including the complete genomic sequences of SEOV isolated from the HFRS patient specimen using a next-generation sequencing (NGS) method.…”

Phylogeographic diversity and hybrid zone of Hantaan orthohantavirus collected in Gangwon Province, Republic of Korea

“…Emerging orthohantavirus infections may occur at any time through contaminated urine, feces, or saliva in rodent-infested areas. To ascertain geographic prevalence and disease risk assessment of orthohantavirus in HFRS-endemic areas, ROK, genetic and molecular epidemiological studies on small mammals have consistently been conducted for decades [ 8 , 10 – 17 ]. Most studies have demonstrated the serological prevalence and genetic diversity of orthohantaviruses collected from HFRS patients or rodents in Gyeonggi Province [ 11 – 16 ].…”