title: Population-based study of Streptococcus suis infection in humans in Phayao Province in northern Thailand.
abstract: BACKGROUND
  Streptococcus suis infection in humans has received increasing worldwide recognition.
  
  
  RESULTS
  A prospective study of S. suis infection in humans was conducted in Phayao Province in northern Thailand to determine the incidence and the risk behaviors of the disease in this region in 2010. Thirty-one cases were confirmed. The case fatality rate was 16.1%, and the estimated incidence rate was 6.2 per 100,000 in the general population. The peak incidence occurred in May. The median age of the patients was 53 years and 64.5% were men. Consumption of raw pork products was confirmed in 22 cases and the median incubation period (range) was 2 days (0-11) after consumption of raw pork products. Isolates from 31 patients were confirmed as serotype 2 in 23 patients (74.2%) and serotype 14 in eight patients (25.8%). The major sequence types (STs) were ST1 (n = 20) for serotype 2 and ST105 (n = 8) for serotype 14. The epidemiological analysis suggested three possible clusters, which included 17 cases. In the largest possible cluster of 10 cases in Chiang Kham and its neighboring districts in May, the source of infection in four cases was identified as a raw pork dish served at the same restaurant in this district. Microbiological analysis confirmed that three of four cases associated with consumption of raw pork at this restaurant were attributable to an identical strain of serotype 2 with ST1 and pulsotype A2.
  
  
  CONCLUSIONS
  Our data suggest a high incidence rate of S. suis infection in the general population in Phayao Province in 2010 and confirm a cluster of three cases in 31 human cases. Food safety control should be strengthened especially for raw pork products in northern Thailand.
authors.affiliation: Laboratory for Clinical Research on Infectious Diseases, International Research Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Osaka, Japan.
authors.forename: Dan
authors.initials: D
authors.lastname: Takeuchi
authors.forename: Anusak
authors.initials: A
authors.lastname: Kerdsin
authors.forename: Anupong
authors.initials: A
authors.lastname: Pienpringam
authors.forename: Phacharaphan
authors.initials: P
authors.lastname: Loetthong
authors.forename: Sutit
authors.initials: S
authors.lastname: Samerchea
authors.forename: Pakkinee
authors.initials: P
authors.lastname: Luangsuk
authors.forename: Kasean
authors.initials: K
authors.lastname: Khamisara
authors.forename: Nithita
authors.initials: N
authors.lastname: Wongwan
authors.forename: Prasanee
authors.initials: P
authors.lastname: Areeratana
authors.forename: Piphat
authors.initials: P
authors.lastname: Chiranairadul
authors.forename: Suwat
authors.initials: S
authors.lastname: Lertchayanti
authors.forename: Sininat
authors.initials: S
authors.lastname: Petcharat
authors.forename: Amara
authors.initials: A
authors.lastname: Yowang
authors.forename: Phanupong
authors.initials: P
authors.lastname: Chaiwongsaen
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Nakayama
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Akeda
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Hamada
authors.forename: Pathom
authors.initials: P
authors.lastname: Sawanpanyalert
authors.forename: Surang
authors.initials: S
authors.lastname: Dejsirilert
authors.forename: Kazunori
authors.initials: K
authors.lastname: Oishi
mesh_terms: D000328:Adult; D000368:Aged; D016000:Cluster Analysis; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D013290:Streptococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D017011:Streptococcus suis / Q000302:isolation & purification / Q000502:physiology*; D013785:Thailand / Q000453:epidemiology