An outbreak of the mosquito-borne Zika virus has led to travel warnings for U.S. women who are or may become pregnant. Zika has been linked to major birth defects and has already had a devastating impact in Brazil. On Jan. 16, the first U.S. case of a baby infected in the womb with Zika was reported in Hawaii. The baby’s mother had traveled to Brazil while pregnant. The Centers for Disease Control is now advising pregnant women to avoid travel to 14 countries and territories in Latin America and the Caribbean, including Puerto Rico, Mexico and Haiti.

Zika joins an unhappy collection of diseases making the jump from tropical regions, where some of the world’s poorest people reside, to temperate zones of affluence. Global warming may be making previously hostile geography more amenable to the major vector for these illnesses, the humble mosquito.

Like the Ebola panic of 2014, Zika reminds the complacent of the affluent world of a kind of enforced solidarity with folks in poorer regions, an impoverished and sometimes cruel imposter of the true solidarity we are called to embrace. There is no such thing as an isolated illness in the era of continent-hopping travel—no problem of “theirs” that cannot quickly become one of “ours.” In the age of the jet-setting virus, how much wiser would it be to make proactive investments that ensure adequate health care and infrastructure for all. A good start might be to adequately fund efforts like the U.N.’s Special Program for Research and Training in Tropical Diseases, recognizing its lifesaving contributions to responding to and reducing threats from the world’s neglected diseases.