title: Loop-mediated isothermal amplification-based diagnostic assay for monkeypox virus infections.
abstract: Monkeypox virus (MPXV) causes a smallpox-like disease in non-human primates and humans. This infection is endemic to central and western Africa. MPXV is divided into two genetically different groups, Congo Basin and West African MPXV, with the former being the more virulent. A real-time quantitative MPXV genome amplification system was developed for the diagnosis of MPXV infections using loop-mediated isothermal amplification (LAMP) technology. Primers used for genome amplification of Congo Basin (C-LAMP), West African (W-LAMP), and both Congo Basin and West African (COM-LAMP) MPXV by LAMP were designed according to the nucleotide sequences of the Congo Basin-specific D14L gene, the West African-specific partial ATI gene, and the partial ATI gene that is shared by both groups, respectively. The sensitivity and specificity of the LAMP were evaluated with nested PCR using peripheral blood and throat swab specimens collected from Congo Basin MPXV or West African MPXV-infected monkeys. The sensitivity and specificity of COM-LAMP, C-LAMP, and W-LAMP were 80% (45/56) and 100% (64/64); 79% (19/24) and 100% (24/24); and 72% (23/32) and 100% (40/40), respectively. The viremia level determined by LAMP assays increased with increases in the severity of the monkeypox-associated symptoms. The newly developed LAMP assay was confirmed to be a rapid, quantifiable, and highly sensitive and specific system effective in the diagnosis of MPXV infections. The LAMP assays made it possible to discriminate between Congo Basin and West African MPXV. The LAMP developed in this study is useful not only for diagnosis of but also for the assessment of MPXV infections.
authors.affiliation: Department of Virology 1, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.
authors.forename: Itoe
authors.initials: I
authors.lastname: Iizuka
authors.forename: Masayuki
authors.initials: M
authors.lastname: Saijo
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shiota
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ami
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Suzaki
authors.forename: Noriyo
authors.initials: N
authors.lastname: Nagata
authors.forename: Hideki
authors.initials: H
authors.lastname: Hasegawa
authors.forename: Kouji
authors.initials: K
authors.lastname: Sakai
authors.forename: Shuetsu
authors.initials: S
authors.lastname: Fukushi
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Mizutani
authors.forename: Momoko
authors.initials: M
authors.lastname: Ogata
authors.forename: Mina
authors.initials: M
authors.lastname: Nakauchi
authors.forename: Ichiro
authors.initials: I
authors.lastname: Kurane
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizuguchi
authors.forename: Shigeru
authors.initials: S
authors.lastname: Morikawa
mesh_terms: D000818:Animals; D001769:Blood / Q000821:virology; D017931:DNA Primers / Q000235:genetics; D006801:Humans; D045908:Mpox, Monkeypox / Q000175:diagnosis* / Q000821:virology; D008993:Monkeypox virus / Q000235:genetics / Q000302:isolation & purification*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D010614:Pharynx / Q000821:virology; D011323:Primates; D012680:Sensitivity and Specificity; D019562:Viral Load
chemical_list: D017931:DNA Primers