Interestingly, anemia (78.91 % Hypochromic RBCs; 232/294) and relative eosinophilia (61.90%; 182/294) have been found in thin blood films of these foreign workers. The etiology of chronic anemia is multifactorial, but asymptomatic Plasmodium parasitemia may be defined as the major cause[26]. In case of relative eosinophilia, it may be due to parasite infections which are mainly associated with the poor socioeconomic conditions, overcrowding, poor sanitation, and difficulty to access medical services among foreign workers in Thailand [27-37]. These preliminary observations highlight the importance of an active surveillance for infectious and noninfectious diseases in foreign workers.