Epidemiological characteristics of the deaths related to Streptococcus suis infection in Thailand between 2016 and 2020

Abstract

Introduction: Streptococcus suis infection is caused by the bacterium. It can penetrate body through the consumption of raw. Improper or delayed treatment might result in serious complications or even death.
Methods: The descriptive study was conducted by reviewing the data of all Streptococcus suis deaths reported to the R506, Event based surveillance database (EBS), as well as disease investigation reports during 2016 to 2020
Results: During 2016 to 2020, there were 1,656 reported cases and 102 deaths related to Streptococcus suis infection were documented with the highest number in 2019 (31 cases), accounting for a case fatality proportion of 6.13%. The male–to–female ratio was 3.25 to 1, the median age was 59.5 years, (minimum 32 years and maximum 95 years), highest among age group was “50–59 years old” (29.41%). Among the deaths, 73.77% had underlying diseases, the largest proportion was hypertension (24.59%). The death cases were found all year round, the majority were found between March and July. The death cases were found in northern, northeastern, and central regions of Thailand, distributed across 16 provinces where the deaths have occurred previously. Among these, the highest deaths reported from Nakhon Ratchasima Province (26 cases). Fever was the most common symptom (63.93%), other important symptoms were diarrhea (37.70%), headache (13.11%), dizziness (6.56%), inability to balance (6.56%), loss of hearing ability (1.64%) and hearing loss (1.64%). The most common food that causes the infection was raw pork spicy salad (Larb-Dib) accounting for 32.8% which the deaths had consumed with families (63.93%). The most common direct contact history was butchering (16.39%). The history of alcohol consumption was discovered in 44% of the deaths. The most common source of pork and offal was from fresh market (36.07%). Only 22 cases (36.07%) had initial diagnosis as Streptococcus suis infection.
Summary and Recommendations: In order to reduce the chance of death, proper knowledge of the severity of eating raw pork should be provided, especially in risk groups including those with underlying diseases. Patients who have a history of drinking alcohol while eating raw pork or of slaughtering pork, should seek treatment in a hospital promptly and submit their risk history to the doctor in order to receive a prompt and correct diagnosis.