Risk Factors of Streptococcus suis Infection in Vietnam. A Case-Control Study
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Author(s)
Type
Journal Article
Abstract
Background: Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East
Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors
underlying the disease.
Methods and Findings: A case-control study with appropriate hospital and matched community controls for each patient
was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire
and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of
swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By
multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating ‘‘high
risk’’ dishes, including such dishes as undercooked pig blood and pig intestine (OR1 = 2.22; 95%CI = [1.15–4.28] and
OR2 = 4.44; 95%CI = [2.15–9.15]), occupations related to pigs (OR1 = 3.84; 95%CI = [1.32–11.11] and OR2 = 5.52; 95%CI = [1.49–
20.39]), and exposures to pigs or pork in the presence of skin injuries (OR1 = 7.48; 95%CI = [1.97–28.44] and OR2 = 15.96;
95%CI = [2.97–85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2
rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection.
Conclusions: This case control study, the largest prospective epidemiological assessment of this disease, has identified the
most important risk factors associated with S. suis bacterial meningitis to be eating ‘high risk’ dishes popular in parts of Asia,
occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors
can be addressed in public health campaigns aimed at preventing S. suis infection.
Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors
underlying the disease.
Methods and Findings: A case-control study with appropriate hospital and matched community controls for each patient
was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire
and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of
swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By
multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating ‘‘high
risk’’ dishes, including such dishes as undercooked pig blood and pig intestine (OR1 = 2.22; 95%CI = [1.15–4.28] and
OR2 = 4.44; 95%CI = [2.15–9.15]), occupations related to pigs (OR1 = 3.84; 95%CI = [1.32–11.11] and OR2 = 5.52; 95%CI = [1.49–
20.39]), and exposures to pigs or pork in the presence of skin injuries (OR1 = 7.48; 95%CI = [1.97–28.44] and OR2 = 15.96;
95%CI = [2.97–85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2
rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection.
Conclusions: This case control study, the largest prospective epidemiological assessment of this disease, has identified the
most important risk factors associated with S. suis bacterial meningitis to be eating ‘high risk’ dishes popular in parts of Asia,
occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors
can be addressed in public health campaigns aimed at preventing S. suis infection.
Date Issued
2011-03-08
Date Acceptance
2011-01-31
Citation
PLOS One, 2011, 6 (3)
ISSN
1932-6203
Publisher
Public Library of Science
Journal / Book Title
PLOS One
Volume
6
Issue
3
Copyright Statement
© 2011 Ho et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted
use, distribution, and reproduction in any medium, provided the original author and source are credited.
use, distribution, and reproduction in any medium, provided the original author and source are credited.
License URL
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
MULTIDISCIPLINARY SCIENCES
HONG-KONG
MENINGITIS
CHINA
PCR
Publication Status
Published
Article Number
e17604