<qa>  What is the three-way interaction between HIV and helminth infections?Previous studies on the interaction between HIV and helminth infections have indicated that HIV may have a negative impact on helminth infections and vice versa, and there is evidence that treatment of chronic helminth infections in HIV infected individuals can delay the progression of HIV. These interactions may be related to changes in the immunological responsiveness or through an effect on reactive oxygen compounds resulting in oxidative stress. Oxidative stress may be a neglected determinant for progression of lymphatic filariasis and may also impair immune functions and lead to increased HIV replication through activation of nuclear transcription factors. The present study examines the three-way interaction between HIV infection, lymphatic filariasis caused by the helminth parasite W. bancrofti and the drug diethylcarbamazine DEC. DEC is an important drug for treatment of lymphatic filariasis and previous findings indicate that DEC may also have an effect on retroviral infections. 