Background and study aim: Strongyloides stercoralis was believed to have two kinds of life cycles. One of them was an internal parthenogenetic life cycle that constituted the parasitic generation. Some authors also stated that this parasitic generation of the internal life cycle used to reproduce only by protandrogony (i.e., hermaphroditism). The second type of life cycle was the external sexual cycle, interacting among free-living worms that represented the free-living generation in soil. The key objectives of this study were to: verify the type of reproduction in the parasitic generation of S. stercoralis, and demonstrate  the complete integrated life cycles of both parasitic and free-living generations of S. stercoralis.
Patients and Methods: The major sites of stool sample collection were selected to be the elementary schools (from students) at Dilla District, because S. stercoralis was ascertained to be endemic in this region. The parasitic worms of Strongyloides stercoralis obtained from fresh stools were used to set growth culture of free-living generation of this very species and to find the free-living male and female in copulation from the growth culture. A set of parasitic male & female in copulation isolated from a fresh stool sample of a patient under medical care in a hospital was also included.   
Results: The male and female worms of S. stercoralis had been isolated from both parasitic and free-living generations while they were in the actual copulation.
Conclusion: The method of reproduction in the parasitic generation of S. stercoralis in human host was practically proved to be certainly sexual. This verified conclusion was the first practical achievement in the entire globe by solving the persistent problems (i.e., erroneous concepts of parthenogenesis and protandrogony as the types of reproduction in the parasitic generation of S. stercoralis) that had been misleading and puzzling the minds of the concerned scientists of the world until the establishment of this very achievement. Additionally, this achievement had enabled the investigator to construct the complete integrated life cycles of both parasitic and free-living generations of S. stercoralis.