CHOLERA was eradicated in Cuba more than half a century ago. But on July 3rd the government announced that the disease had returned, infecting 53 people and killing three in the south-eastern province of Granma. Since then unconfirmed reports have said that up to 15 may have died, and that the outbreak has spread to Havana, at the opposite end of the island.

The most likely source is Haiti, which since 2010 has suffered an epidemic that has killed more than 7,000 people, plus 363 in the Dominican Republic, its neighbour. Only 50 miles (80km) of sea separate Haiti from Cuba, which has sent hundreds of doctors to help the Haitians control the outbreak (and who may inadvertently have brought the illness back). Tests are expected to establish within days whether the Cuban cases match the Haitian strain.

So far Cuba’s celebrated health-care system seems to be coping. “The response is generally excellent in containing outbreaks of disease,” says a European diplomat in Havana. Health workers have distributed chlorine drops and rehydration salts in Granma province. State-controlled media have reminded people to boil water, keep food refrigerated and wash their hands frequently. Nevertheless, the communist state’s habitual lack of openness has generated rumours.

Until recently, Cubans were justifiably proud of their health-care system. Life-expectancy matches that of Americans, who are eight times richer. Infant mortality ties with Canada’s as the lowest in the Americas. Measles jabs have been near-universal for more than 20 years, putting Cuba ahead of many rich countries.

But Cuba’s crumbling economy has put this system under stress. Though the state still trains armies of doctors, a third of these are deployed overseas in “soft-power” missions. Pharmacies are generally ill-stocked. In many hospitals patients must provide their own sheets, food and dressings. Neglect of infrastructure means that almost 10% of the population lacks access to clean drinking water. The American embargo against the island does not help: equipment for radiology, mammograms and cancer therapy is hard to replace, says Julia Sweig of the Council on Foreign Relations, an American think-tank.

Raúl Castro, the president, who this month visited China and Vietnam, is trying to revive the economy by cautiously transferring chunks of it into private hands. The next step, reported this week, will be to let transport and other service workers form co-operatives, currently restricted to farming. If the health service is to thrive again, this sort of economic surgery will need to speed up.