Worried about MERS? There's more where that came from

Drug-resistant tuberculosis

TB is one of the oldest scourges known to humankind and it spreads very easily, settling in the lungs but sometimes in the brain or spine. The bacteria that cause TB can float in the air for hours, making it very hard to trace the source of infection and making it very hard to avoid. TB is usually easy to treat with antibiotics, but drug-resistant forms have emerged that resist most of the mainline drugs and that can take months or even years to get rid of.

The World Health Organization projects that two million people will get infected with multiple drug resistant TB (MDR-TB) in 2015.

In 2007, Atlanta lawyer Andrew Speaker made headlines when he sneaked back to the United States after flying abroad after he had been diagnosed with MDR-TB and traveled anyway against CDC orders. He was arrested and forcibly isolated and treated.