LA GUAIRA, Venezuela (AP) — Aid groups warned 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 overwhelmed by the injured and deteriorating conditions in the disaster zone causing infectious diseases to spread.

WATCH: Venezuela rescue efforts grow desperate as death toll rises and aftershock rattles country

The scores of international and domestic teams across Venezuela remain focused on the search for survivors, with the government death toll surpassing 1,700 and new bodies still being hauled out from the rubble.

But a humanitarian crisis is already unfolding among the living. 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.

Venezuelan officials say that more than 15,800 people have been affected by the earthquakes — a figure that reflects the official number of displaced people, U.N. refugee agency spokesperson Carlotta Wolf said on Tuesday. Suddenly homeless Venezuelans are sleeping in cars, parks and elsewhere without adequate emergency shelter available.