BRING BACK DDT: America faces a resurgence of tropical diseases. “For half a day each week, one wing of the Smith Clinic’s third floor in Houston is transformed into a tropical medicine clinic, treating all manner of infectious diseases for anyone who walks through the door. Since it opened in 2011, Woc-Colburn and her colleagues have treated everything from dengue and chikungunya to river blindness and cutaneous leishmaniasis. Their patients are not globetrotting travellers, bringing exotic diseases back home. The Smith Clinic is a safety net provider, the last resort for healthcare for people on low incomes and without insurance. Many of their patients haven’t left the Houston area for years. This suggests that what Woc-Colburn sees in the clinic may be just the leading edge of a gathering crisis. Diseases once associated with ‘elsewhere’ are increasingly being found in the southern states of the USA.”