Circulating proinflammatory mediators have not been found in studies on typhoid fever, although the patients suffer from a systemic disease with characteristic protracted fever. The 14-kDa group II extracellular phospholipase A2 (PLA2) is induced by interleukin-1 and tumor necrosis factor and may mediate some of the effects of these cytokines. Circulating PLA2 concentrations were measured in 12 typhoid fever patients on various days after admission and after recovery. On admission, mean concentrations of PLA2 were elevated (1444 +/- 1560 ng/mL) and decreased gradually and significantly to day 14 (55 +/- 48 ng/mL). patients with complicated disease had significantly higher PLA2 levels on admission. PLA2 was not produced in a lipopolysaccharide-stimulated whole blood culture, indicating that PLA2 originates from other types of cells. These data indicate that PLA2 may be a mediator of disease in protracted inflammatory diseases such as thyroid fever.