 Some clinical trials have been able to confirm this detrimental effect of helminths on HIV infection, while other trials failed to do so. A recent Cochrane review on clinical trials with HIV and helminth co-infection found an overall slight reduction of HIV viral load if helminth infection was treated. However there was no measurable effect on CD4 count or clinical staging of HIV. This might be explained by the fact that these trials were very heterogeneous in their set-up and were run for too short a time max 6 months to allow sufficient answers to these questions. 