Epidemiology of Streptococcus suis Infection: Patients of Chiang Kham Hospital, 2009 - 2011 - ระบาดวิทยาโรคสเตร็บโตตอกตัส ซูอิส ผู้ป่วยโรงพยาบาลเชียงคำ ปี 2552-2554

Abstract

           Streptococcus suis is a major porcine pathogen, which can be transmitted to human beings by close contact with either infected or carrier pigs. There were many outbreaks in many provinces in the North of Thailand also Chiang Kham district Phayao province continuously. In this descriptive study a screening tool was developed between January 2009 and December 2011 and could be applied for the disease screening and control. This research data were collected by using disease surveillance during the 3 year study period. The 618 patients with diagnosis of sepsis, acute meningitis, infective endocarditis, severe pneumonia and/or septic arthritis were screened and examined. The finding of surveillance revealed that there were 31 patients infected with the bacteria, 8, 15, and 8 patients in 2009, 2010 and 2011 respectively. The signs and symptoms of the patients were fever (93.5%), headache (77.4%), myalgia (64.5%) stiff neck (51.6%), hearing loss (48.8%) and nausea vomiting (48.4 %). Leukocytosis was seen as there were, on averge, 13,344 cell/mcl (4,000-11,000 cell/mcl). Neutrophil was found to be 82.2 (40-74%). An increase in number of white blood cells to 1,071.9 cell/microlitre (0-5) and protein level 260.7mg/dl (12-60) were reported in cerebrospinal fluid (CSF) analysis whereas, the sugar level of 25.4mg/dl was found and still below normal level (40-80). Hemo-culture and CSF-culture demonstrated S. suis infection to be 9.7 percent. There were 25 males (80.6 %) and 6 females (19.4 %), male patients were about 4 time of female patients. All infection patients aged over 25 years. The 71.0 percent of S. suis infected patients had an experience of consuming raw pork or under- cooked pork products or coming into contact with raw pork meat or raw internal organs or blood (71.0 percent). Reportedly 90.3 percent of S. suis infected patients did not know about infection status of the origin. In all, 83.9 percent of the S. suis infected patients found to be under the influence of alcohol. The following risk factors associated with S. suis infection were history of consuming raw pork, no recollection, contact or exposure to raw pork, internal organs or pork blood as well as alcohol consumption and age ranging over 25 to 70 years, can be used to develop screening tool for S. suis infection. The result of testing the tool showed accuracy of 90.61 percent, precision 32.56 percent, sensitivity 90.36 percent, specificity 90.63 percent, positive predictive value 33.73 percent, and negative predictive value 99.44 percent. The specificity will increase if the patients have signs and symptoms such as fever, headache, myalgia, nausea vomiting, stiff neck or hearing loss as well as laboratory findings showing evidence of bacterial infection even bacterial infection in cerebrospinal fluid (CSF). It is highly recommended that the public should be informed educated about the safety and danger of eating raw pork. However, changing attitude and behavior of the risk groups by supporting social measures and law enforcement are  required in order to provide protection from S. suis infection.

Key words: epidemiology, Streptococcus suis, Chiang Kham Hospital