title: PCR and culture identification of pathogenic Leptospira spp. from coastal soil in Leyte, Philippines, after a storm surge during Super Typhoon Haiyan (Yolanda).
abstract: Leptospirosis is a zoonosis caused by pathogenic Leptospira spp. Most of the outbreaks of leptospirosis occur after floods caused by heavy rain in countries where Leptospira spp. are endemic. It has been believed that the overflow of seawater rarely causes outbreaks of leptospirosis because the leptospires are killed by salt water. On 8 November 2013, a storm surge caused by Super Typhoon Haiyan (Yolanda) inundated the entire coastal areas of Tacloban and Palo in Leyte, Philippines. The present study was carried out in order to determine whether the environmental leptospires in soil were able to survive after the storm surge in the affected areas. We collected 23 wet soil samples along the coastal areas of Tacloban and Palo 2 months after the storm surge. The samples were suspended in HEPES buffer, and the supernatants were cultured in liquid or semisolid Korthof's medium supplemented with five antimicrobial agents to inhibit the growth of contaminants. Leptospires were isolated from primary cultures of 22 out of 23 samples. The DNA of pathogenic Leptospira species was detected in 11 samples (47.8%) by analysis of flaB by nested PCR. Eventually, two pathogenic Leptospira strains were isolated and showed the highest 16S rRNA gene sequence similarity to Leptospira kmetyi. When these isolates were experimentally mixed with soil, they were found to survive in seawater for 4 days. These results show the possibility that leptospires living in soil survived after the storm surge. Our findings may serve as a warning that when seawater inundates the land during a storm surge or a tsunami, an outbreak of leptospirosis could occur in the disaster-stricken area.
authors.affiliation: Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan msaito@bact.med.kyushu-u.ac.jp.
authors.forename: Mitsumasa
authors.initials: M
authors.lastname: Saito
authors.affiliation: Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Miyahara
authors.affiliation: Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Sharon Y A M
authors.initials: SY
authors.lastname: Villanueva
authors.affiliation: Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Natsumi
authors.initials: N
authors.lastname: Aramaki
authors.affiliation: Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Mami
authors.initials: M
authors.lastname: Ikejiri
authors.affiliation: LEPCON Project Office, College of Public Health, University of the Philippines-Manila, Ermita, Manila, Philippines.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kobayashi
authors.affiliation: Department of Health Promotion and Education, College of Public Health, University of the Philippines-Manila, Ermita, Manila, Philippines.
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Guevarra
authors.affiliation: Laboratory of Microbiology and Immunology, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, Choshi, Chiba, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Masuzawa
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Ermita, Manila, Philippines.
authors.forename: Nina G
authors.initials: NG
authors.lastname: Gloriani
authors.affiliation: Department of Medical Microbiology, College of Public Health, University of the Philippines-Manila, Ermita, Manila, Philippines Laboratory of Microbiology and Immunology, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, Choshi, Chiba, Japan.
authors.forename: Yasutake
authors.initials: Y
authors.lastname: Yanagihara
authors.affiliation: Department of Bacteriology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Yoshida
mesh_terms: D055867:Cyclonic Storms; D004190:Disasters; D006801:Humans; D007919:Leptospira / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007922:Leptospirosis / Q000382:microbiology; D010679:Philippines; D016133:Polymerase Chain Reaction; D012988:Soil Microbiology