Epidemiological characteristics of human Streptococcus suis infection in the southern region, Vietnam, from 2013 to 2022

Abstract

A case-series study of human Streptococcus suis cases (clinical or confirmed cases) was conducted in the Southern region of Vietnam from 2013 to 2022. A total of 317 cases of S.s infection were reported across 19 out of 20 cities and/or provinces in the region, with 18 fatalities, resulting in a case fatality rate (CFR) of 5.6%. - Cases were sporadically distributed - through out the region during the 10-year periodwith Ho Chi Minh City (HCMC) recording the highest number (72 cases or 22.7% of the Region). More cases were detected in the Western provinces compared to the Southern ones. The incidence rate was higher among males (75%) compared to females (25%). Of the reported cases, 61% of were diagnosed as purulent meningitis, followed by septic shock and the combination of both clinical conditions. Most of the cases were detected and treated at tertiary hospitals, accounting for 89.5% of cases in the Southern region. Cases were frequently observed in the age group 50-59 (33%), followed the 40-49 age group (28%)with no cases reported in people under 20 years old. Farmers and livestock raisers accounted for 30%, 10.1% of whom engaged in activities such as pig transportation, pig-slaughtering procedures without proper handling. Case investigations showed that 68.8% of the 317 cases reported having reliable epidemiological links to human S.suis infection such as inappropriately handling pigs, pork or consuming unprocessed pork meat within two weeks before symptom onset and notably, 84% of cases recovered within 3 weeks - of hospital admission. Most cases of S.suis infections were attributed to serotype 2 strains. It is crutical to avoid direct contact with pigs, pigs suspicious of contract S.suis, consuming porks or pigs-related products having not been safely prepared or uncooked. Early case detection through diagnosis in both state and private hospitals is crucial to mitigate the risk of potential outbreak spreading thus reducing the S.suis infection burden in the Southern Region, Vietnam.