OBJECTIVES: To evaluate systemic serum cytokine and chemokine markers for inflammation and Th1/Th2 responses in relation to multiple helminth infections, parasite burden and/or nutritional status of individuals. METHODS: In a longitudinal study, stool samples from 210 individuals from an area highly endemic for Ascaris lumbricoides, Necator americanus and Schistosoma mansoni were examined before and 12 months after clearance of parasites by chemotherapy. On both occasions, the presence of mono- or multiple infections and intensities of infection were compared with nutritional parameters and with serum cytokines or chemokines as markers for inflammatory, regulatory or Th1- or Th2-type immune responses. RESULTS: Before treatment, we were not able to associate any altered nutritional parameters with increased inflammatory responses, and highest intensities of infection were found in eutrophic participants with multiple infections. In contrast, major changes in serum Th2-type chemokine levels were measured in individuals infected with intestinal helminths and/or S. mansoni, and resulted in significantly higher CCL11 and CCL17 concentrations, both before treatment and after reinfection. CONCLUSIONS: The driving force for these elevated type 2 serum chemokine concentrations was an S. mansoni infection and faecal egg counts significantly correlated with serum IL-10 concentrations.