If current efforts to combat the effects of HIV/AIDS are not stepped up, Nigeria's economy will shrink by 20 percent, an expert has warned. Health economist Dr. Reginald Chima made the submission at a session on the socio-economic impact of HIV/AIDS in Nigeria during the ongoing 4th National conference on HIV/AIDS in Nigeria. After two decades of HIV devastation, Nigeria's economy will have lost 20 percent of her gross domestic product, he said.