sentences:  Likewise, the appearance of high rates of MDR-TB in New York City in the early 1990s was associated with the explosion of AIDS in that area.In New York City, a report issued by city health authorities states that fully 80 percent of all MDR-TB cases could be traced back to prisons and homeless shelters.When patients have MDR-TB, they require longer periods of treatment—about two years of multidrug regimen.