Penicilliosis marneffei and pythiosis: emerging tropical diseases.

Penicilliosis marneffei and pythiosis insidiosi are emerging infections in subtropical, tropical, and temperate areas of the world. Penicilliosis marneffei is endemic in several Southeast Asian countries and may be carried to other areas of the world by residents of these countries or visitors. Pythiosis occurs in humans and animals who frequent the aquatic habitats that harbor Pythium insidiosum. Although early diagnosis is important because of the high morbidity or mortality associated with these two diseases, the diagnosis of these infections can be difficult because their clinical and histologic features are not pathognomonic. Prompt diagnosis is a prerequisite to their appropriate treatment. Laboratory testing, involving cultural, histologic and immunologic methods, is necessary to establish an unequivocal diagnosis. The clinical presentation, epidemiology, diagnosis and treatment of these diseases are discussed.