Chiang Kham General Hospital
Chiang Kham General Hospital
Takeuchi D.,Osaka University |
Kerdsin A.,Kasetsart University |
Akeda Y.,Osaka University |
Chiranairadul P.,Phayao Provincial Hospital |
And 15 more authors.
American Journal of Tropical Medicine and Hygiene | Year: 2017
Streptococcus suis is an important zoonotic pathogen in swine and humans that causes sepsis and meningitis. Our previous study in Thailand showed that the prevalence of S. suis infection in humans, especially in northern areas of Thailand, and the transmission of the pathogen occurred mainly through the consumption of traditional raw pork products. Considering the high incidence proportion and mortality rate of the disease as an important public health problem, we implemented a food safety campaign in the Phayao Province in northern Thailand in 2011. We evaluated the effects of a food safety campaign by comparing the sociodemographic, clinical, and bacteriological characteristics of cases before and after the campaign. The follow-up study showed a marked decrease of the incidence proportion in the first 2 years, indicating the effectiveness of the campaign. In the third year, however, the incidence proportion slightly increased again, indicating the existence of deep-rooted cultural behaviors and the necessity of continuous public health intervention. Furthermore, epidemiological analysis of the cases made it possible to estimate the infectivity of the pathogen via the oral route of infection. In the present study, we showed the effectiveness of the food safety campaign for controlling the S. suis infection, and we present a role model public health intervention for prevalent areas affected by S. suis infection in humans. Copyright © 2017 by The American Society of Tropical Medicine and Hygiene.
Maneerat K.,Thammasat University |
Yongkiettrakul S.,National Center for Genetic Engineering and Biotechnology |
Kramomtong I.,Chulalongkorn University |
Tongtawe P.,Thammasat University |
And 6 more authors.
Transboundary and Emerging Diseases | Year: 2013
Summary: Isolates of Streptococcus suis from different Western countries as well as those from China and Vietnam have been previously well characterized. So far, the genetic characteristics and relationship between S. suis strains isolated from both humans and pigs in Thailand are unknown. In this study, a total of 245 S. suis isolates were collected from both human cases (epidemic and sporadic) and pigs (diseased and asymptomatic) in Thailand. Bacterial strains were identified by biochemical tests and PCR targeting both, the 16S rRNA and gdh genes. Thirty-six isolates were identified as serotype 2 based on serotyping and the cps2-PCR. These isolates were tested for the presence of six virulence-associated genes: an arginine deiminase (arcA), a 38-kDa protein and protective antigen (bay046), an extracellular factor (epf), an hyaluronidase (hyl), a muramidase-released protein (mrp) and a suilysin (sly). In addition, the genetic diversities of these isolates were studied by RAPD PCR and multilocus sequence typing (MLST) analysis. Four virulence-associated gene patterns (VAGP 1 to 4) were obtained, and the majority of isolates (32/36) carried all genes tested (VAGP1). Each of the three OPB primers used provided 4 patterns designated RAPD-A to RAPD-D. Furthermore, MLST analysis could also distinguish the 36 isolates into four sequence types (STs): ST1 (n = 32), ST104 (n = 2), ST233 (n = 1) and a newly identified ST, ST336 (n = 1). Dendrogram constructions based on RAPD patterns indicated that S. suis serotype 2 isolates from Thailand could be divided into four groups and that the characteristics of the individual groups were in complete agreement with the virulence gene profiles and STs. The majority (32/36) of isolates recovered from diseased pigs, slaughterhouse pigs or human patients could be classified into a single group (VAGP1, RAPD-A and ST1). This genetic information strongly suggests the transmission of S. suis isolates from pigs to humans in Thailand. Our findings are the first to report genetic characteristics of strains from Thailand and to elucidate the genetic relationship among S. suis isolates from human and pig origins. © 2013 Blackwell Verlag GmbH.
Takeuchi D.,Osaka University |
Kerdsin A.,National Institute of Health |
Pienpringam A.,Chiang Kham General Hospital |
Loetthong P.,Phayao Provincial Hospital |
And 16 more authors.
PLoS ONE | Year: 2012
Background: Streptococcus suis infection in humans has received increasing worldwide recognition. Methods and Findings: 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. © 2012 Takeuchi et al.
Sripan P.,Chiang Mai University |
Sripan P.,Institute Of Recherche Pour Le D Veloppement Ird Umi 174 |
Ngo-Giang-Huong N.,Institute Of Recherche Pour Le D Veloppement Ird Umi 174 |
Ngo-Giang-Huong N.,Chiang Mai University |
And 20 more authors.
Chiang Mai Journal of Science | Year: 2012
Exposure to single dose nevirapine during labor (SD-NVP) to prevent mother to child transmission of HIV (PMTCT) is associated with a lower likelihood of virologic suppression at six months of a nevirapine based antiretroviral therapy but long-term consequences of SD-NVP have not been studied. We analyzed data from women who received SD-NVP in the PHPT-2 PMTCT clinical trial. Following delivery, women initiated a regimen composed of nevirapine, lamivudine, and stavudine or zidovudine when their CD4 level declined to less than 250 cells/mm3. HIV RNA load and CD4 cell counts were evaluated every six months. Failure was defined as a confirmed HIV RNA load >400 copies/mL at least 6 months after therapy initiation, or death, and observations were censored at time of drop out or switch to a protease inhibitor based regimen. Survival analysis was performed using Kaplan-Meier estimates and Cox regression models. The 221 SD-NVP exposed women and 48 unexposed women had similar characteristics at baseline, except the time spent between delivery and initiation of therapy (6.1 and 14.9 months, respectively). At four years, 35% of the SD-NVP exposed and 14% of the unexposed women met the failure criteria (P=0.02). In the multivariable analysis, factors contributing to the failure consisted of exposure to SD-NVP (HR: 2.63, P=0.03), plasma HIV-1 RNA level above median (HR: 2.53, P<0.001), stage C of the CDC HIV clinical staging (HR: 2.12, P=0.04), platelets cell count above median (HR: 1.65, P=0.04) and early initiation of therapy after delivery (HR: 1.64, P=0.04). In this cohort, the impact of SD-NVP on further antiretroviral therapy was still significant after four years of therapy, justifying the use of strategies to prevent resistance mutations after exposure to SD-NVP.