title: Use of eschar swabbing for the molecular diagnosis and genotyping of Orientia tsutsugamushi causing scrub typhus in Quang Nam province, Vietnam.
abstract: Scrub typhus is a rickettsiosis which is caused by Orientia tsutsugamushi and occurs throughout the Asia-Pacific region. Molecular diagnosis of rickettsioses using eschar swabs has recently emerged, and may be very useful for the diagnosis of these diseases in tropical settings.
  
  
  
  Quantitative polymerase chain reaction (qPCR) was used to detect O. tsutsugamushi DNA in whole blood and eschar swab specimens of 67 patients who were clinically suspected of scrub typhus in Quang Nam province, Vietnam. Among the 20 patients for whom both eschar and whole blood were obtained, 17 (85%) of the eschar specimens and 5 (25%) of the whole blood specimens tested positive for O. tsutsugamushi. Genetic analysis of the 56-kDa TSA gene sequences demonstrated that the 14 sequences obtained in this study, including 12 eschar swabs and 2 whole blood specimens, were related to 4 groups: Karp, Kawasaki, Gilliam (JG-v and TG-v) and TA716. The majority (9/14; 64.4%) of contemporary O. tsutsugamushi genotypes in Quang Nam province were related to the Karp group.
  
  
  
  These results suggest that polyclonal antigen pools used for serological testing in the future should contain at least Karp, Kawasaki, Gilliam and TA716 antigens for Vietnamese patients, as well as patients who have traveled to Vietnam. qPCR after eschar swabbing should be considered for molecular diagnosis of scrub typhus in endemic patients as well as in travelers, since it is easy to perform and appears very useful for the rapid detection of Orientia tsutsugamushi in the early phase of infection.
authors.affiliation: URMITE, Aix Marseille Université, UM63, CNRS 7278, IRD 198, INSERM 1095, IHU - Méditerranée Infection, Marseille, France.|Department of Tropical Diseases, Quang Nam Central General Hospital, Quang Nam, Vietnam.
authors.forename: Nhiem
authors.initials: N
authors.lastname: Le Viet
authors.affiliation: URMITE, Aix Marseille Université, UM63, CNRS 7278, IRD 198, INSERM 1095, IHU - Méditerranée Infection, Marseille, France.
authors.forename: Maureen
authors.initials: M
authors.lastname: Laroche
authors.affiliation: Department of Infectious Diseases, University of Medicine and Pharmacy of Ho Chi Minh City, Ho Chi Minh City, Vietnam.
authors.forename: Hoa L
authors.initials: HL
authors.lastname: Thi Pham
authors.affiliation: Department of Internal Medicine, Quang Nam Central General Hospital, Quang Nam, Vietnam.
authors.forename: Nho L
authors.initials: NL
authors.lastname: Viet
authors.affiliation: URMITE, Aix Marseille Université, UM63, CNRS 7278, IRD 198, INSERM 1095, IHU - Méditerranée Infection, Marseille, France.
authors.forename: Oleg
authors.initials: O
authors.lastname: Mediannikov
authors.affiliation: URMITE, Aix Marseille Université, UM63, CNRS 7278, IRD 198, INSERM 1095, IHU - Méditerranée Infection, Marseille, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.affiliation: URMITE, Aix Marseille Université, UM63, CNRS 7278, IRD 198, INSERM 1095, IHU - Méditerranée Infection, Marseille, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Parola
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D001769:Blood / Q000382:microbiology; D005838:Genotype; D060005:Genotyping Techniques / Q000379:methods*; D006801:Humans; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D012285:Orientia tsutsugamushi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012612:Scrub Typhus / Q000175:diagnosis* / Q000382:microbiology; D017422:Sequence Analysis, DNA; D013048:Specimen Handling / Q000379:methods*; D014744:Vietnam; D014947:Wounds and Injuries / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins