There also was a similar drop in the amount of field outreach staff. Patient visits dropped to twenty-one thousand. The number of physicians went from three to essentially nobody. The number of clinicians went from seventeen to ten. 'Then the city decided to gradually cut back because of budgetary problems. 'In 1990–91, we had thirty-six thousand patient visits at the city's sexually transmitted disease clinics,' Zenilman says. John Zenilman of Johns Hopkins University in Baltimore, an expert on sexually transmitted diseases, has another explanation: the breakdown of medical services in the city's poorest neighborhoods. Crack, the CDC said, was the little push that the syphilis problem needed to turn into a raging epidemic. It changes the patterns of social connections between neighborhoods. It brings far more people into poor areas to buy drugs, which then increases the likelihood that they will take an infection home with them to their own neighborhood. Crack is known to cause a dramatic increase in the kind of risky sexual behavior that leads to the spread of things like HIV and syphilis. What caused Baltimore's syphilis problem to tip? According to the Centers for Disease Control, the problem was crack cocaine. If you look at Baltimore's syphilis rates on a graph, the line runs straight for years and then, when it hits 1995, rises almost at a right angle.

In the space of a year, from 1995 to 1996, the number of children born with the disease increased by 500 percent. In the mid-1990s, the city of Baltimore was attacked by an epidemic of syphilis.

The tipping point novel