Streptococcus agalactiae infections and clinical relevance in adults, Thailand.

Streptococcus agalactiae is an important pathogen that causes infections in neonates and adults; infections especially in nonpregnant adults are increasing worldwide. Of 1736 S. agalactiae isolates from individuals throughout Thailand, serotypes III (46.4%) and V (21%) were demonstrated to be the most common serotypes. Human cases (56.5% female and 43.5% male) could be found all year round, with the peak occurring more frequently during the rainy season (May-October). The mortality rate of S. agalactiae infections was 11.6%, and serotype III was the most common serotype involved. Serotype III was strongly significantly (P value <0.001) correlated with meningitis (odds ratio [OR] = 26.72), sepsis (OR = 5.56), and septic arthritis (OR = 22.79). Serotype V was more associated with urinary tract infection than other serotypes. (P value = 0.005; OR = 2.32).