There were approximately 2 million deaths worldwide from tuberculosis in 1997, 98% of them in developing countries. Factors implicated in the resurgence of tuberculosis in the United States in the late 80s and early 90s included increased immigration from countries with high prevalence, HIV infection, emergence of resistant strains, poverty, homelessness, drug abuse, and a decline in tuberculosis-related health services. With better control programs, cases began to decrease in 1993. In 1998, 18,361 cases of tuberculosis (6.8 per 100,000 population) were reported to the US Centers for Disease Control and Prevention (CDC), a 31% decrease from 1992. Pregnancy is not thought to change the course of tuberculosis; however, tuberculosis poses a risk to the pregnant woman and her fetus.