Aid groups warned on Tuesday that Venezuela’s fragile healthcare system is being pushed to its limits nearly a week after two powerful earthquakes, with damaged and understaffed hospitals getting overwhelmed by the injured and infectious diseases flaring in the disaster zone.

Meanwhile, the number of official rescues has dropped dramatically in the last three days, the government said, from 5,380 people saved in the first two days after the quakes to just four people found alive on Monday by authorities. The prime window for finding earthquake survivors is typically 48 to 72 hours, but it is possible to survive longer depending on factors such as temperature and access to water or food. The sole survivor rescued by Tuesday afternoon was a toddler who had been trapped for six days under a collapsed building, said Jorge Rodríguez, the president of the National Assembly.

Those numbers do not include the many rescues carried out across the country by volunteer groups that, frustrated with the government’s sluggish response, scrambled to save their trapped loved ones days before the arrival of expert international teams. The government puts the death toll at more than 1,900. Experts say that is a significant undercount as more bodies are hauled from the rubble every day and morgues struggle to handle the influx. Among the living, a humanitarian crisis is unfolding. United Nations agencies expressed concern about the health effects of thousands of displaced people sleeping for days in the open or in crowded, unsanitary shelters.